Formulations for three-dimensional printing on fabric

Abstract

An additive formulation for use in combination with a modeling material formulation in three-dimensional printing of an object on a fabric, is disclosed herein. The additive formulation features, when hardened, Tg higher than 50 °C, or that ranges from 50 to 90, or from 60 to 80, °C, and presents a rigid additive formulation. The additive formulation is made of a combination of mono-functional and multi-functional curable materials as detailed in the instant specification. Also provided are methods of three-dimensional printing an object on a fabric, of preparing a fabric for three-dimensional printing of an object thereon and of forming an adhesive structure on a fabric, which utilize the rigid additive formulation.

Description

[0001] FORMULATIONS FOR THREE-DIMENSIONAL PRINTING ON FABRIC

[0002] RELATED APPLICATION / S

[0003] This application claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 63 / 682,653 filed on August 13, 2024, the contents of which are incorporated herein by reference in their entirety.

[0004] FIELD AND BACKGROUND OF THE INVENTION

[0005] The present invention, in some embodiments thereof, relates to three-dimensional printing and, more particularly, but not exclusively, to formulations usable in three-dimensional printing on fabrics and to methods utilizing same. More specifically, the present invention, in some embodiments thereof, relates to formulations that provide, when hardened, a material usable as an adhesive material or as a priming material (or primer) to improve the adhesion of 3D printed elements on fabrics, and optionally, as a coating material and / or a modeling material, as well as to methods utilizing same.

[0006] Additive manufacturing (AM) is a technology enabling fabrication of shaped structures directly from computer data via additive formation steps. The basic operation of any AM system consists of slicing a three-dimensional computer model into thin cross sections, translating the result into two-dimensional position data and feeding the data to control equipment which fabricates a three-dimensional structure in a layerwise manner.

[0007] Additive manufacturing entails many different approaches to the method of fabrication, including three-dimensional (3D) printing such as 3D inkjet printing, electron beam melting, stereolithography, selective laser sintering, laminated object manufacturing, fused deposition modeling and others.

[0008] Some 3D printing processes, for example, 3D inkjet printing, are being performed by a layer-by-layer inkjet deposition of building materials. Thus, a building material is dispensed from a dispensing head having a set of nozzles to deposit layers on a receiving medium. Depending on the building material, the layers may then be cured or solidified using a suitable device, optionally after being leveled by a leveling device.

[0009] Various three-dimensional printing techniques exist and are disclosed in, e.g., U.S. Patent Nos. 6,259,979, 6,569,373, 6,658,314, 6,850,334, 6,863,859, 7,183,335, 7,209,797, 7,225,045, 7,300,619, 7,500,846, 9,031,680 and 9,227,365, U.S. Patent Application having Publication No. 2006 / 0054039, WO 2016 / 009426, and WO 2022 / 024114 all by the present Assignee, and being hereby incorporated by reference in their entirety. A printing system utilized in additive manufacturing may include a receiving medium and one or more printing heads. The receiving medium can be, for example, a fabrication tray that may include a horizontal surface to carry the material dispensed from the printing head. The printing head may be, for example, an ink jet head having a plurality of dispensing nozzles arranged in an array of one or more rows along the longitudinal axis of the printing head. The printing head may be located such that its longitudinal axis is substantially parallel to the indexing direction, he printing system may further include a controller, such as a microprocessor to control the printing process, including the movement of the printing head according to a pre-defined scanning plan (e.g., a CAD configuration converted to a Stereo Lithography (STL) format and programmed into the controller). The printing head may include a plurality of jetting nozzles. The jetting nozzles dispense material onto the receiving medium to create the layers representing cross sections of a 3D object.

[0010] In addition to the printing head, there may be a source of curing energy, for curing the dispensed building material. The curing energy is typically radiation, for example, UV radiation.

[0011] Additionally, the printing system may include a leveling device for leveling and / or establishing the height of each layer after deposition and at least partial solidification, prior to the deposition of a subsequent layer.

[0012] The building materials may include modeling materials and support materials, which form the object and the temporary support constructions supporting the object as it is being built, respectively.

[0013] The modeling material (which may include one or more material(s)) is deposited (as a modeling material formulation) to produce the desired object / s and the support material (which may include one or more material(s)) is used (as a support material formulation), with or without modeling material elements, to provide support structures for specific areas of the object during building and assure adequate vertical placement of subsequent object layers, e.g., in cases where objects include overhanging features or shapes such as curved geometries, negative angles, voids, and so on.

[0014] Both the modeling and support materials, when deposited as modeling and support material formulations, respectively, are preferably liquid at the working temperature at which they are dispensed (as a respective formulation), and subsequently harden, typically upon exposure to curing energy (e.g., UV curing), to form the required layer shape, made of the hardened (cured) modeling and support materials, respectively. After printing completion, support structures are removed to reveal the final shape of the fabricated 3D object. In order to be compatible with most of the commercially-available print heads utilized in a 3D inkjet printing system, the uncured building materials (modeling and / or support material formulations) should feature the following characteristics: a relatively low viscosity (e.g., Brookfield Viscosity of up to 500 centipoises, 100 centipoises, 50 centipoises, or up to 35 centipoises, for instance from 8 to 25 centipoises) at the working (e.g., jetting) temperature; Surface tension of from about 20 or from about 25 to about 55 Dyne / cm, for instance from about 25 to about 40 Dyne / cm; and a Newtonian liquid behavior and high reactivity to a selected curing condition, to enable fast solidification of the jetted layer upon exposure to a curing condition, of no more than 1 minute, for instance no more than 20 seconds.

[0015] In a 3D inkjet printing process such as PolyJet™ (Stratasys® Ltd., Israel), the uncured building material is selectively jetted from one or more printing heads and deposited onto a substrate (e.g. a fabric) or a fabrication tray in consecutive layers according to a pre-determined configuration as defined by a software file.

[0016] WO 2022 / 024114 describes a system for three-dimensional printing, which comprises an array of nozzles for dispensing uncured building materials, a work tray, a jig for affixing a fabric to the work tray, and a computerized controller for operating the array of nozzles to dispense an uncured building material on the affixed fabric. An imaging system may be positioned to image a fabric placed on the work tray, and image data received from the imaging system may be processed to identify patterns on the fabric, wherein the nozzles dispense the building material at locations selected relative to the identified features.

[0017] WO 2023 / 209711 describes a system for three-dimensional printing, which comprises an array of nozzles for dispensing uncured building materials, a work tray, a jig for affixing a fabric to the work tray, and a computerized controller for operating the array of nozzles to dispense an uncured building material on the affixed fabric, as well as methods for 3D printing on fabrics, including methods for testing the adherence level of a 3D printed material to a fabric.

[0018] WO 2024 / 142067 describes a method of forming an object on a fabric by three-dimensional printing, which comprises printing on the fabric an adhesion structure having a stack of layers in a configured pattern corresponding to a shape of a bottommost surface of the object, and printing the object onto the stack by dispensing and curing a building formulation in layers along the direction in configured patterns corresponding to shapes of slices of the object.

[0019] WO 2024 / 142068 describes curable formulations usable in printing three-dimensional objects on a substrate such as a fabric, which comprise a combination of mono-functional and multi-functional materials that provide a suitable adhesive material or structure and / or a suitable coating to the printed objects. WO 2024 / 142069 describes modeling material formulations usable for printing three- dimensional objects on a substrate such as a fabric, which comprise a combination of monofunctional and multi-functional materials that provide a flexible hardened material.

[0020] SUMMARY OF THE INVENTION

[0021] According to an aspect of some embodiments of the present invention there is provided an additive formulation for use in combination with a modeling material formulation in three- dimensional printing of an object on a fabric, the additive formulation comprising: at least one mono-functional curable material featuring, when hardened, Tg higher than 50 °C (Component A); at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C); at least one multi-functional epoxy-type curable material featuring viscosity lower than 10,000 or lower than 5,000, mPa- sec (centipoises) at 25 °C (Component DI and / or Component D2); and at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G).

[0022] According to some embodiments of any of the embodiments described herein, the additive formulation is characterized by at least one of: Viscosity in a range of from 15 to 20, or from 15.5 to 18.5, mPa- sec (centipoises); Surface tension is a range of from 24 to 29, or from 26 to 28, Dyne / cm; and Adhesion level to a fabric of at least 20 N / cm.

[0023] According to some embodiments of any of the embodiments described herein, the additive formulation is characterized, when hardened, by Tg higher than 50 °C, or that ranges from 50 to 90, or from 60 to 80, °C.

[0024] According to some embodiments of any of the embodiments described herein, the additive formulation is characterized, when hardened, by at least one of: Tensile Modulus in a range of from 2,000 to 3,000 MPa; Tensile Strength in a range of from 50 to 70 MPa; Elongation at break in a range of from 5 to 15 %; Flexural Modulus in a range of from 2000 to 3000 MPa; Flexural Stress in a range of from 70 to 120 MPa; and HDT at 0.45 MPa in a range of from 40 to 80 °C.

[0025] According to some embodiments of any of the embodiments described herein, the additive formulation is an adhesive (priming) formulation, which provides, when hardened, an adhesive structure (e.g., rigid) on the fabric. According to some embodiments of any of the embodiments described herein, each of the mono-functional and multi-functional curable materials is a UV-curable material.

[0026] According to some embodiments of any of the embodiments described herein, each of the mono-functional and multi-functional curable materials is a (meth) acrylate material.

[0027] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises a photoinitiator.

[0028] According to some embodiments of any of the embodiments described herein, the photoinitiator is a bis(acyl) phenyl oxide (BAPO)-type photoinitiator.

[0029] According to some embodiments of any of the embodiments described herein, an amount of the photoinitiator is from 1 to 5, or from 1 to 3, or from 1 to 2, % by weight of the total weight of the formulation.

[0030] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg higher than 50 °C (Component A) comprises a hydrophilic mono-functional curable (e.g., (meth)acrylate) material featuring the Tg (Component Al).

[0031] According to some embodiments of any of the embodiments described herein, an amount of the at least one mono-functional curable material featuring Tg higher than 50 °C (Component A) ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation.

[0032] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C) comprises at least one mono-functional aliphatic urethane (meth) acrylate featuring the Tg (Component Cl).

[0033] According to some embodiments of any of the embodiments described herein, an amount of the at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C) ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation.

[0034] According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy-type curable material (Component DI and / or D2) comprises at least one multi-functional (e.g., di-functional) epoxy (meth)acrylate featuring the viscosity.

[0035] According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy-type curable material (Component DI and / or D2) features, when hardened, Tg lower than 100 °C (e.g., from 20 to 100 or from 20 to 80 °C). According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy-type curable material featuring the indicated viscosity at 25 °C (Component DI and / or D2) comprises at least one di-functional epoxy (meth) acrylate.

[0036] According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy-type curable material featuring the indicated viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy-type curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2).

[0037] According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy curable material featuring the viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI).

[0038] According to some embodiments of any of the embodiments described herein, the at least one multi-functional epoxy-type curable material featuring the indicated viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI) and at least one multi-functional epoxy-type curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2).

[0039] According to some embodiments of any of the embodiments described herein, a weight ratio of the at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI) and at least one multi-functional epoxytype curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2) ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2.

[0040] According to some embodiments of any of the embodiments described herein, a total amount of the at least one multi-functional epoxy-type curable material featuring the viscosity at 25 °C (Component DI and / or D2) ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation.

[0041] According to some embodiments of any of the embodiments described herein, the at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G), features, when hardened, Tg of from 100 to 200, or from 150 to 200, °C.

[0042] According to some embodiments of any of the embodiments described herein, the at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) is a hydrophobic curable material featuring the Tg. According to some embodiments of any of the embodiments described herein, the at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) is a (e.g., hydrophobic) di-functional (meth)acrylate.

[0043] According to some embodiments of any of the embodiments described herein, an amount of the at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation.

[0044] According to some embodiments of any of the embodiments described herein, the additive formulation comprises: at least one hydrophilic mono-functional (meth)acrylate featuring Tg higher than 50 °C (Component Al); at least one mono-functional aliphatic urethane (meth)acrylate featuring Tg lower than 20, or lower than 0 °C (Component Cl); at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI); at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2); and at least one hydrophobic multi-functional (e.g., di-functional) (meth) acrylate featuring, when hardened, Tg of from 100 to 200, or from 150 to 200, °C (Component G).

[0045] According to some embodiments of any of the embodiments described herein, an amount of Component Al ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation; and / or an amount of Component Cl ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation; and / or a total amount of Component DI and the Component D2 ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation; and / or a weight ratio of Component DI and Component D2 ranges from 1:1 to 1:5, or from 1: 1 to 1:3, or from 1:1 to 1:2; and / or an amount of Component G ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation.

[0046] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises at least one of a polymerization inhibitor, a surface active agent, a dispersant, and a pigment and / or dye. According to some embodiments of any of the embodiments described herein, the additive formulation further comprises a surface active agent, wherein the surface active agent comprises curable groups (e.g., UV-curable groups such as (meth)acrylate groups).

[0047] According to some embodiments of any of the embodiments described herein, an amount of the surface active agent is from 0.05 to 0.5 % by weight of the total weight of the formulation.

[0048] According to an aspect of some embodiments of the present invention there is provided a method of three-dimensional printing an object on a fabric, the method comprising dispensing a plurality of layers in a configured pattern corresponding to the shape the object, thereby forming the object, wherein the formation of each layer of at least a few of the layers comprises dispensing at least one building formulation, and exposing the dispensed formulation to a curing condition to thereby form a cured modeling material, thereby printing the object, the method further comprising: prior to dispensing the at least one building material formulation, dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of a bottommost surface of the object or a portion thereof, wherein for each layer of the stack the dispensing is of an additive formulation as described herein in any of the respective embodiments and any combination thereof with regard to a rigid material or a rigid adhesive formulation, and exposing at least one of the layers, or the stack of layers, to a curing condition, to thereby form a hardened adhesive material (an adhesive structure).

[0049] According to an aspect of some embodiments of the present invention there is provided a method of forming an adhesive structure on a fabric, the method comprising dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of the adhesive structure, wherein for at least a few layers, or for each layer, of the stack the dispensing is of an additive formulation as described herein in any of the respective embodiments and any combination thereof with regard to a rigid material or a rigid adhesive formulation, and exposing each of the layers, or the stack of layers, to a curing condition, to thereby form the adhesive structure.

[0050] According to an aspect of some embodiments of the present invention there is provided a method of preparing a fabric for three-dimensional printing of an object thereon, the method comprising forming an adhesive structure on the fabric in a configured pattern corresponding to a shape of a bottommost surface of the object.

[0051] According to some embodiments of any of the embodiments described herein, forming the adhesive structure comprises dispensing on the fabric a stack of layers in the configured pattern, wherein for at least a few layers, or for each layer, of the stack, the dispensing is of an additive formulation as described herein in any of the respective embodiments and any combination thereof with regard to a rigid material or a rigid adhesive formulation, and exposing at least one of the layers, or the stack of layers, to a curing condition, to thereby form a hardened adhesive material (an adhesive structure).

[0052] According to some embodiments of any of the embodiments described herein, for at least a few or for each layer of the stack, the dispensing is of an additional curable formulation, the additional formulation being an additional additive formulation and / or of a building (e.g., modeling) material formulation.

[0053] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0054] Implementation of the method and / or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and / or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.

[0055] For example, hardware for performing selected tasks according to embodiments of the invention could be implemented as a chip or a circuit. As software, selected tasks according to embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of method and / or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and / or data and / or a non-volatile storage, for example, a magnetic hard-disk and / or removable media, for storing instructions and / or data. Optionally, a network connection is provided as well. A display and / or a user input device such as a keyboard or mouse are optionally provided as well.

[0056] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0057] Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

[0058] In the drawings:

[0059] FIGs. 1A-D are schematic illustrations of an additive manufacturing system according to some embodiments of the invention;

[0060] FIGs. 2A-2C are schematic illustrations of printing heads according to some embodiments of the present invention;

[0061] FIGs. 3 A and 3B are schematic illustrations demonstrating coordinate transformations according to some embodiments of the present invention;

[0062] FIGs. 4A and 4B are schematic illustrations of a jig suitable for some embodiments of the present invention.

[0063] FIG. 5 is a schematic illustration of a configuration in which a fabric is placed on a ramp structure, according to some embodiments of the present invention.

[0064] FIG. 6 is a flowchart diagram describing a method suitable for forming a three-dimensional object on a fabric by three-dimensional printing, by forming an adhesion structure, according to some embodiments of the present invention.

[0065] FIGs. 7A-D are schematic illustrations of irradiating protocols according to some embodiments of the present invention.

[0066] FIGs. 8A-B present photographs of a test object (FIG. 8 A) and an exemplary device (FIG. 8B) used for measuring the peel strength (adhesion level) of a hardened rigid material obtained using an adhesive formulation, according to some of the present embodiments, in the test object.

[0067] FIG. 9 presents photographs (x60) of exemplary fabrics onto which objects were printed using an exemplary adhesive formulation according to the present embodiments (Formulation XXVII), and the corresponding adhesion level (peel strength) of the obtained hardened adhesive material measured for each of these fabrics.

[0068] FIGs. 10A-B present comparative plots showing the peel strength (adhesion) provided by an exemplary adhesive formulation according to the present embodiments (Formulation XXVII) printed on different fabrics as indicated along with an exemplary flexible modeling formulation as described in Example 5, upon subjecting the printed fabrics to 10 consecutive washing and drying cycles at the indicated conditions.

[0069] FIG. 11 presents a schematic illustration of an exemplary pattern used for forming an adhesive structure made of exemplary adhesive and model formulations according to some of the present embodiments. DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0070] The present invention, in some embodiments thereof, relates to three-dimensional printing and, more particularly, but not exclusively, to formulations usable in three-dimensional printing on fabrics and to methods utilizing same. More specifically, the present invention, in some embodiments thereof, relates to formulations that provide, when hardened, a material usable as an adhesive material or as a priming material (or primer) to improve the adhesion of 3D printed elements on fabrics, and optionally, as a coating material and / or a modeling material, as well as to methods utilizing same.

[0071] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0072] Embodiments of the present invention relate to the manufacturing of three-dimensional objects in a layer-wise manner by forming a plurality of layers in a configured pattern corresponding to the shape of the objects, as described herein.

[0073] The final three-dimensional object is made of a modeling material or a combination of modeling materials or a combination of modeling material / s and support material / s or modification thereof (e.g., following curing). All these operations are well-known to those skilled in the art of solid freeform fabrication.

[0074] According to an aspect of some embodiments of the present invention there is provided a method of additive manufacturing of a three-dimensional object on a fabric, and in some embodiments, the object is made of a flexible material, as described herein.

[0075] Embodiments of the present invention relate to the manufacture of three-dimensional objects based on computer object data in a layerwise manner by forming a plurality of layers in a configured pattern corresponding to the shape of the objects. The computer object data can be in any known format, including, without limitation, a Standard Tessellation Language (STL) or a StereoLithography Contour (SLC) format, an OBJ File format (OBJ), a 3D Manufacturing Format (3MF), Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Exchange Format (DXF), Polygon File Format (PLY) or any other format suitable for Computer-Aided Design (CAD).

[0076] Each layer is formed by an additive manufacturing apparatus which scans a two- dimensional surface and patterns it. While scanning, the apparatus visits a plurality of target locations on the two-dimensional layer or surface, and decides, for each target location or a group of target locations, whether or not the target location or group of target locations is to be occupied by building material, and which type of building material is to be delivered thereto. The decision is made according to a computer image of the surface.

[0077] The method is generally effected or performed by sequentially forming a plurality of layers in a configured pattern corresponding to the shape of the object, such that formation of each of at least a few of said layers, or of each of said layers, comprises dispensing a building material (uncured) which comprises one or more modeling material formulation(s), and exposing the dispensed modeling material to curing energy to thereby form a cured modeling material, as described in further detail hereinafter.

[0078] In some exemplary embodiments of the invention an object is manufactured by dispensing a building material (uncured) that comprises two or more different modeling material formulations, each modeling material formulation from a different nozzle array of the inkjet printing apparatus. The modeling material formulations are optionally and preferably deposited in layers during the same pass of the printing heads. The modeling material formulations and / or combination of formulations within the layer are selected according to the desired properties of the object, and as further described in detail hereinbelow.

[0079] The phrase “digital materials”, as used herein and in the art, describes a combination of two or more (e.g., model, modeling, additive) materials on a microscopic scale or voxel level such that the printed zones of a specific material are at the level of few voxels, or at a level of a voxel block. Such digital materials may exhibit new properties that are affected by the selection of types of (e.g., model, modeling, additive) materials and / or the ratio and relative spatial distribution of two or more (e.g., model, modeling, additive) materials.

[0080] In exemplary digital materials, the model (modeling) material of each voxel or voxel block, obtained upon curing, is independent of the model (modeling) material of a neighboring voxel or voxel block, obtained upon curing, such that each voxel or voxel block may result in a different model (modeling) material and the new properties of the whole part are a result of a spatial combination, on the voxel level, of several different model (modeling) materials.

[0081] In the context of a digital material, the interlacing can be either among single voxels, each containing a different building (e.g., model, modeling) material, or among blocks of voxels wherein a block of voxels is defined as a continues region that is occupied by n voxels all containing the same building (e.g., model, modeling) material, and wherein the border of this region is define as a collection of voxels that are adjacent to at least one voxel that contains a building (e.g., model, modeling) material other than the building (e.g., model, modeling) material contained in the voxels of the collection. In preferred embodiments, n is less than 1000, or less than 500, or less than 100, or less than 50, or less than 10.

[0082] According to embodiments of the present invention, the method further utilizes one or more additive formulations as described herein, and is further effected by dispensing these additive formulations before and / or after the formation of the three-dimensional object on the fabric. According to embodiments of the present invention, the additive formulations include an adhesive or priming formulation, which forms an adhesive structure on the fabric, and is dispensed before the formation of the object, and / or a coating formulation, which forms a coating on the object or a part or portion thereof, and is dispensed during or after the formation of the object.

[0083] Embodiments of the present invention relate to such additive formulations that are usable in additive manufacturing of a three-dimensional object on a fabric.

[0084] The term "object" as used herein refers to a whole object or a part thereof.

[0085] An object according to some of the present embodiments is such that at least a part or a portion thereof is made of a flexible material, and is also referred to herein as “an object made of a flexible material”. The object may be such that several parts or portions thereof are made of a flexible material, or such that is entirely made of a flexible material. The flexible material can be the same or different in the different parts or portions, and, for each part, portion or the entire object, which is made of a flexible material, the flexible material can be the same or different within the portion, part or object. When different flexible materials are used, they can differ in their chemical composition and / or mechanical properties and / or visual properties (e.g., color, transparency, etc.), as is further explained hereinafter.

[0086] Herein throughout, the phrases “building material formulation”, “uncured building material”, “uncured building material formulation”, “building material” and other variations therefore, collectively describe the materials that are dispensed to sequentially form the layers, as described herein. This phrase encompasses uncured materials dispensed so as to form the object, namely, one or more uncured modeling material formulation(s), and uncured materials dispensed so as to form the support, namely uncured support material formulations.

[0087] Herein throughout, the phrase “cured modeling material” or “hardened modeling material” describes the part of the building material that forms the object, as defined herein, upon exposing the dispensed building material to curing, and, optionally, if a support material has been dispensed, also upon removal of the cured support material, as described herein. The cured modeling material can be a single cured material or a mixture of two or more cured materials, depending on the modeling material formulations used in the method, as described herein. The phrase “cured modeling material” or “cured modeling material formulation” can be regarded as a cured building material wherein the building material consists only of a modeling material formulation (and not of a support material formulation). That is, this phrase refers to the portion of the building material, which is used to provide the final object.

[0088] Herein throughout, the phrase “modeling material formulation”, which is also referred to herein interchangeably as “modeling formulation”, “model formulation” “model material formulation” or simply as “formulation”, describes a part or all of the building material which is dispensed so as to form the object, as described herein. The modeling material formulation is an uncured modeling formulation (unless specifically indicated otherwise), which, upon exposure to curing energy, forms the object or a part thereof.

[0089] In some embodiments of the present invention, a modeling material formulation is formulated for use in three-dimensional inkjet printing and is able to form a three-dimensional object on its own, without having to be mixed or combined with any other substance.

[0090] An uncured building material can comprise one or more modeling formulations, and can be dispensed such that different parts of the object are made, upon curing, of different cured modeling formulations or different combinations thereof, and hence are made of different cured modeling materials or different mixtures of cured modeling materials.

[0091] The formulations forming the building material (modeling material formulations and support material formulations) comprise one or more curable materials, which, when exposed to a curing condition (e.g., a curing energy, for example, irradiation), form hardened (cured) material.

[0092] The formulations forming the building material (modeling material formulations and support material formulations) are also referred to herein as curable formulations (e.g., a curable modeling material formulation or a curable support material formulation).

[0093] Herein throughout, a “curable material” is a compound (typically a monomeric or oligomeric compound, yet optionally a polymeric material) which, when exposed to a curing condition (e.g., curing energy), as described herein, solidifies or hardens to form a cured material. Curable materials are typically polymerizable materials, which undergo polymerization and / or cross-linking when exposed to a suitable energy source.

[0094] A curable material, according to the present embodiments, also encompasses materials which harden or solidify (cure) without being exposed to a curing energy, but rather to another curing condition (for example, upon exposure to a chemical reagent or simply upon exposure to the environment).

[0095] The terms “curable” and “solidifiable” as used herein are interchangeable. The polymerization can be, for example, free-radical polymerization, cationic polymerization or anionic polymerization, and each can be induced when exposed to curing energy such as, for example, radiation, heat, etc., as described herein.

[0096] In some of any of the embodiments described herein, a curable material is a photopolymerizable material, which polymerizes and / or undergoes cross-linking upon exposure to radiation, as described herein, and in some embodiments the curable material is a UV-curable material, which polymerizes and / or undergoes cross-linking upon exposure to UV radiation, as described herein.

[0097] In some embodiments, a curable material as described herein is a photopolymerizable material that polymerizes via photo-induced free-radical polymerization. Alternatively, the curable material is a photopolymerizable material that polymerizes via photo-induced cationic polymerization.

[0098] In some of any of the embodiments described herein, a curable material can be a monomer, an oligomer or a short-chain polymer, each being polymerizable and / or cross -linkable as described herein.

[0099] In some of any of the embodiments described herein, when a curable material is exposed to curing energy (e.g., irradiation), it hardens (cured) by any one, or combination, of chain elongation and cross-linking.

[0100] In some of any of the embodiments described herein, a curable material is a monomer or a mixture of monomers which can form a polymeric material upon a polymerization reaction, when exposed to curing energy at which the polymerization reaction occurs. Such curable materials are also referred to herein as monomeric curable materials.

[0101] In some of any of the embodiments described herein, a curable material is an oligomer or a mixture of oligomers which can form a polymeric material upon a polymerization reaction, when exposed to curing energy at which the polymerization reaction occurs. Such curable materials are also referred to herein as oligomeric curable materials.

[0102] In some of any of the embodiments described herein, a curable material, whether monomeric or oligomeric, can be a mono-functional curable material or a multi-functional curable material.

[0103] Herein, a mono-functional curable material comprises one functional group that can undergo polymerization when exposed to curing energy (e.g., irradiation).

[0104] A multi-functional curable material comprises two or more, e.g., 2, 3, 4 or more, functional groups that can undergo polymerization when exposed to curing energy. Multi-functional curable materials can be, for example, di-functional, tri-functional or tetra-functional curable materials, which comprise 2, 3 or 4 groups that can undergo polymerization, respectively (also referred to herein as featuring a functionality of 2, 3, or 4, etc.). The two or more functional groups in a multifunctional curable material are typically linked to one another by a linking moiety, as defined herein. When the linking moiety is an oligomeric or polymeric moiety, the multi-functional group is an oligomeric or polymeric multi-functional curable material. Multi-functional curable materials can undergo polymerization when subjected to curing energy and / or act as cross -linkers.

[0105] System:

[0106] A representative and non-limiting example of a system 110 suitable for AM of an object 112 according to some embodiments of the present invention is illustrated in FIG. 1A. System 110 comprises an additive manufacturing apparatus 114 having a dispensing unit 16 which comprises a plurality of printing heads. Each head preferably comprises one or more arrays of nozzles 122, typically mounted on an orifice plate 121, as illustrated in FIGs. 2A-C described below, through which a liquid building material 124 is dispensed.

[0107] Preferably, but not obligatorily, apparatus 114 is a three-dimensional printing apparatus, in which case the printing heads are printing heads, and the uncured building material is dispensed via inkjet technology. This need not necessarily be the case, since, for some applications, it may not be necessary for the additive manufacturing apparatus to employ three-dimensional printing techniques. Representative examples of additive manufacturing apparatus contemplated according to various exemplary embodiments of the present invention include, without limitation, fused deposition modeling apparatus and fused material deposition apparatus.

[0108] Each printing head is optionally and preferably fed via one or more building material reservoirs which may optionally include a temperature control unit (e.g., a temperature sensor and / or a heating device), and a material level sensor. To dispense the uncured building material, a voltage signal is applied to the printing heads to selectively deposit droplets of uncured material via the printing head nozzles, for example, as in piezoelectric inkjet printing technology. Another example includes thermal inkjet printing heads. In these types of heads, there are heater elements in thermal contact with the uncured building material, for heating the building material to form gas bubbles therein, upon activation of the heater elements by a voltage signal. The gas bubbles generate pressures in the uncured building material, causing droplets of the uncured building material to be ejected through the nozzles. Piezoelectric and thermal printing heads are known to those skilled in the art of solid freeform fabrication. For any type of inkjet printing heads, the dispensing rate of the head depends on the number of nozzles, the type of nozzles and the applied voltage signal rate (frequency). In some embodiments, an array of nozzles that dispense a modeling material formulation and an array of nozzles that dispense a support material formulation are both located in the same printing head. In some embodiments, an array of nozzles that dispense a modeling material formulation and an array of nozzles that dispense a support material formulation are located in separate printing heads.

[0109] Preferably, but not obligatorily, the overall number of dispensing nozzles or nozzle arrays is selected such that half of the dispensing nozzles are designated to dispense support material and half of the dispensing nozzles are designated to dispense modeling material, i.e. the number of nozzles jetting modeling materials is the same as the number of nozzles jetting support material. In the representative example of FIG. 1 A, four printing heads 16a, 16b, 16c and 16d are illustrated. Each of heads 16a, 16b, 16c and 16d has a nozzle array. In this Example, heads 16a and 16b can be designated for modeling material / s and heads 16c and 16d can be designated for support material. Thus, head 16a can dispense one modeling material formulation, head 16b can dispense another modeling material formulation and heads 16c and 16d can both dispense support material formulation. In an alternative embodiment, heads 16c and 16d, for example, may be combined in a single head having two nozzle arrays for depositing a support material formulation. In a further alternative embodiment, any one or more of the printing heads may have more than one nozzle arrays for depositing more than one material formulation, e.g. two nozzle arrays for depositing two different modeling materials or a modeling material and a support material, each formulation via a different array or number of nozzles.

[0110] Yet it is to be understood that it is not intended to limit the scope of the present invention and that the number of modeling material printing heads (modeling heads) and the number of support material printing heads (support heads) may differ. Generally, the number of arrays of nozzles that dispense modeling material formulation, the number of arrays of nozzles that dispense support material formulation, and the number of nozzles in each respective array are selected such as to provide a predetermined ratio, a, between the maximal dispensing rate of the support material formulation and the maximal dispensing rate of modeling material formulation. The value of the predetermined ratio, a, is preferably selected to ensure that in each formed layer, the height of modeling material equals the height of support material. Typical values for a are from about 0.6 to about 1.5.

[0111] For example, for a = 1, the overall dispensing rate of support material formulation is generally the same as the overall dispensing rate of the modeling material formulation when all the arrays of nozzles operate. Apparatus 114 can comprise, for example, M modeling heads each having m arrays of p nozzles, and S support heads each having s arrays of q nozzles such that Mxmxp = Sxsxq. Each of the Mxm modeling arrays and Sxs support arrays can be manufactured as a separate physical unit, which can be assembled and disassembled from the group of arrays. In this embodiment, each such array optionally and preferably comprises a temperature control unit and a material level sensor of its own, and receives an individually controlled voltage for its operation.

[0112] Apparatus 114 can further comprise a solidifying device 18 which can include any device configured to emit light, heat or the like that may cause the deposited material or formulation to harden. For example, solidifying device 18 can comprise one or more radiation sources, which can be, for example, an ultraviolet or visible or infrared lamp, or other sources of electromagnetic radiation, or electron beam source, depending on the modeling material being used. In some embodiments of the present invention, solidifying device 18 serves for curing or solidifying the modeling material formulation. Preferably, as illustrated in FIG. 1A, there are two solidifying devices 18, at both sides of the dispensing heads 16, so that during operation of both devices 18 one provides radiation to locations immediately before the formulation is dispensed to these locations, and one provides radiation to locations immediately after the material is dispensed to these locations. Devices 18 are preferably configured to operate independently, both from the standpoint of timing and from the standpoint of radiation intensity. Yet, by controlling their independent operations, a synchronized radiation protocol can be achieved, as further explained hereinunder.

[0113] In addition to solidifying device 18, apparatus 114 optionally and preferably comprises an additional radiation source 328 for solvent evaporation. Radiation source 328 optionally and preferably generates infrared radiation. In various exemplary embodiments of the invention solidifying device 18 comprises a radiation source generating ultraviolet radiation, and radiation source 328 generates infrared radiation.

[0114] In some embodiments of the present invention apparatus 114 comprises cooling system 134 such as one or more fans or the like.

[0115] The printing head(s) and radiation source are preferably mounted in a frame or block 128 which is preferably operative to reciprocally move over a tray 360, which serves as the working surface. In some embodiments of the present invention the radiation sources are mounted in the block such that they follow in the wake of the printing heads to at least partially cure or solidify the materials just dispensed by the printing heads. Tray 360 is positioned horizontally. According to the common conventions an X-Y-Z Cartesian coordinate system is selected such that the X-Y plane is parallel to tray 360. Tray 360 is preferably configured to move vertically (along the Z direction), typically downward. In various exemplary embodiments of the invention, apparatus 114 further comprises one or more leveling devices 32, e.g. a roller 326. Leveling device 326 serves to straighten, level and / or establish a thickness of the newly formed layer prior to the formation of the successive layer thereon. Leveling device 326 preferably comprises a waste collection device 136 for collecting the excess material generated during leveling. Waste collection device 136 may comprise any mechanism that delivers the material to a waste tank or waste cartridge.

[0116] In the schematic illustrations of FIG. 1A, the edge(s) of tray 360 are provided with straight corners. However, this need not necessarily be the case, since, for some applications, particularly when tray 360 is in contact with a fabric on which the object is printed, it may be desired for the edge(s) of the top surface of tray 360 to be formed as a fillet and / or a chamfer.

[0117] In use, the printing heads of unit 16 move in a scanning direction, which is referred to herein as the X direction, and selectively dispense uncured building material in a predetermined configuration in the course of their passage over tray 360. The uncured building material typically comprises one or more types of a support material formulation and one or more types of a modeling material formulation. The passage of the printing heads of unit 16 is followed by the curing of the modeling material formulation(s) by radiation source 126. In the reverse passage of the heads, back to their starting point for the layer just deposited, an additional dispensing of uncured building material may be carried out, according to predetermined configuration. In the forward and / or reverse passages of the printing heads, the layer thus formed may be straightened by leveling device 326, which preferably follows the path of the printing heads in their forward and / or reverse movement. Once the printing heads return to their starting point along the X direction, they may move to another position along an indexing direction, referred to herein as the Y direction, and continue to build the same layer by reciprocal movement along the X direction. Alternately, the printing heads may move in the Y direction between forward and reverse movements or after more than one forward-reverse movement. The series of scans performed by the printing heads to complete a single layer is referred to herein as a single scan cycle.

[0118] Once the layer is completed, tray 360 is lowered in the Z direction to a predetermined Z level, according to the desired thickness of the layer subsequently to be printed. The procedure is repeated to form three-dimensional object 112 in a layerwise manner.

[0119] In another embodiment, tray 360 may be displaced in the Z direction between forward and reverse passages of the printing head of unit 16, within the layer. Such Z displacement is carried out in order to cause contact of the leveling device with the surface in one direction and prevent contact in the other direction. System 110 optionally and preferably comprises a supply system 330 which comprises the building material containers or cartridges and supplies a plurality of formulations to fabrication apparatus 114.

[0120] A controller 20 controls fabrication apparatus 114 and optionally and preferably also supply system 330. Controller 20 typically includes an electronic circuit configured to perform the controlling operations. Controller 20 preferably communicates with a data processor 154 which transmits digital data pertaining to fabrication instructions based on computer object data, e.g., a CAD configuration represented on a computer readable medium in a form of a Standard Tessellation Language (STL) format or the like. Typically, controller 20 controls the voltage applied to each printing head or each nozzle array and the temperature of the uncured building material in the respective printing head or respective nozzle array.

[0121] Once the manufacturing data is loaded to controller 20 it can operate without user intervention. In some embodiments, controller 20 receives additional input from the operator, e.g., using data processor 154 or using a user interface 116 communicating with controller 20. User interface 116 can be of any type known in the art, such as, but not limited to, a keyboard, a touch screen and the like. For example, controller 20 can receive, as additional input, one or more building material types and / or attributes, such as, but not limited to, color, characteristic distortion and / or transition temperature, viscosity, electrical property, magnetic property. Other attributes and groups of attributes are also contemplated.

[0122] Another representative and non-limiting example of a system 10 suitable for AM of an object according to some embodiments of the present invention is illustrated in FIGs. 1B-D. FIGs. 1B-D illustrate a top view (FIG. IB), a side view (FIG. 1C) and an isometric view (FIG. ID) of system 10.

[0123] In the present embodiments, system 10 comprises a tray 12 and a plurality of inkjet printing heads 16, each having one or more arrays of nozzles with respective one or more pluralities of separated nozzles. The material used for the three-dimensional printing is supplied to heads 16 by a building material supply system 42. Tray 12 can have a shape of a disk or it can be annular. Nonround shapes are also contemplated, provided they can be rotated about a vertical axis. In the schematic illustrations of FIG. 1C, the edge(s) of tray 12 are provided with straight corners. However, as in the case of tray 360 above, for some applications, particularly when tray 12 is in contact with a fabric on which the object is printed, it may be desired for the edge(s) of the top surface of tray 12 to be formed as a fillet and / or a chamfer.

[0124] Tray 12 and heads 16 are optionally and preferably mounted such as to allow a relative rotary motion between tray 12 and heads 16. This can be achieved by (i) configuring tray 12 to rotate about a vertical axis 14 relative to heads 16, (ii) configuring heads 16 to rotate about vertical axis 14 relative to tray 12, or (iii) configuring both tray 12 and heads 16 to rotate about vertical axis 14 but at different rotation velocities (e.g., rotation at opposite direction). While some embodiments of system 10 are described below with a particular emphasis to configuration (i) wherein the tray is a rotary tray that is configured to rotate about vertical axis 14 relative to heads 16, it is to be understood that the present application contemplates also configurations (ii) and (iii) for system 10. Any one of the embodiments of system 10 described herein can be adjusted to be applicable to any of configurations (ii) and (iii), and one of ordinary skills in the art, provided with the details described herein, would know how to make such adjustment.

[0125] In the following description, a direction parallel to tray 12 and pointing outwardly from axis 14 is referred to as the radial direction r, a direction parallel to tray 12 and perpendicular to the radial direction r is referred to herein as the azimuthal direction <p, and a direction perpendicular to tray 12 is referred to herein is the vertical direction z-

[0126] The radial direction r in system 10 enacts the indexing direction y in system 110, and the azimuthal direction cp enacts the scanning direction x in system 110. Therefore, the radial direction is interchangeably referred to herein as the indexing direction, and the azimuthal direction is interchangeably referred to herein as the scanning direction.

[0127] The term “radial position,” as used herein, refers to a position on or above tray 12 at a specific distance from axis 14. When the term is used in connection to a printing head, the term refers to a position of the head which is at specific distance from axis 14. When the term is used in connection to a point on tray 12, the term corresponds to any point that belongs to a locus of points that is a circle whose radius is the specific distance from axis 14 and whose center is at axis 14.

[0128] The term “azimuthal position,” as used herein, refers to a position on or above tray 12 at a specific azimuthal angle relative to a predetermined reference point. Thus, radial position refers to any point that belongs to a locus of points that is a straight line forming the specific azimuthal angle relative to the reference point.

[0129] The term “vertical position,” as used herein, refers to a position over a plane that intersect the vertical axis 14 at a specific point.

[0130] Tray 12 serves as a building platform for three-dimensional printing. The working area on which one or objects are printed is typically, but not necessarily, smaller than the total area of tray 12. In some embodiments of the present invention the working area is annular. The working area is shown at 26. In some embodiments of the present invention tray 12 rotates continuously in the same direction throughout the formation of object, and in some embodiments of the present invention tray reverses the direction of rotation at least once (e.g., in an oscillatory manner) during the formation of the object. Tray 12 is optionally and preferably removable. Removing tray 12 can be for maintenance of system 10, or, if desired, for replacing the tray before printing a new object. In some embodiments of the present invention system 10 is provided with one or more different replacement trays (e.g., a kit of replacement trays), wherein two or more trays are designated for different types of objects (e.g., different weights) different operation modes (e.g., different rotation speeds), etc. The replacement of tray 12 can be manual or automatic, as desired. When automatic replacement is employed, system 10 comprises a tray replacement device 36 configured for removing tray 12 from its position below heads 16 and replacing it by a replacement tray (not shown). In the representative illustration of FIG. IB tray replacement device 36 is illustrated as a drive 38 with a movable arm 40 configured to pull tray 12, but other types of tray replacement devices are also contemplated.

[0131] Exemplified embodiments for the printing head 16 are illustrated in FIGs. 2A-2C. These embodiments can be employed for any of the AM systems described above, including, without limitation, system 110 and system 10.

[0132] FIGs. 2A-B illustrate a printing head 16 with one (FIG. 2A) and two (FIG. 2B) nozzle arrays 22. The nozzles in the array are preferably aligned linearly, along a straight line. In embodiments in which a particular printing head has two or more linear nozzle arrays, the nozzle arrays are optionally and preferably can be parallel to each other. When a printing head has two or more arrays of nozzles (e.g., FIG. 2B) all arrays of the head can be fed with the same building (modeling or support) formulation, or at least two arrays of the same head can be fed with different building (modeling and / or support) formulations.

[0133] When a system similar to system 110 is employed, all printing heads 16 are optionally and preferably oriented along the indexing direction with their positions along the scanning direction being offset to one another.

[0134] When a system similar to system 10 is employed, all printing heads 16 are optionally and preferably oriented radially (parallel to the radial direction) with their azimuthal positions being offset to one another. Thus, in these embodiments, the nozzle arrays of different printing heads are not parallel to each other but are rather at an angle to each other, which angle being approximately equal to the azimuthal offset between the respective heads. For example, one head can be oriented radially and positioned at azimuthal position <pi, and another head can be oriented radially and positioned at azimuthal position 92. In this example, the azimuthal offset between the two heads is 91-92, and the angle between the linear nozzle arrays of the two heads is also 91-92. In some embodiments, two or more printing heads can be assembled to a block of printing heads, in which case the printing heads of the block are typically parallel to each other. A block including several inkjet printing heads 16a, 16b, 16c is illustrated in FIG. 2C.

[0135] In some embodiments, system 10 comprises a stabilizing structure 30 positioned below heads 16 such that tray 12 is between stabilizing structure 30 and heads 16. Stabilizing structure 30 may serve for preventing or reducing vibrations of tray 12 that may occur while inkjet printing heads 16 operate. In configurations in which printing heads 16 rotate about axis 14, stabilizing structure 30 preferably also rotates such that stabilizing structure 30 is always directly below heads 16 (with tray 12 between heads 16 and tray 12).

[0136] Tray 12 and / or printing heads 16 is optionally and preferably configured to move along the vertical direction z, parallel to vertical axis 14 so as to vary the vertical distance between tray 12 and printing heads 16. In configurations in which the vertical distance is varied by moving tray 12 along the vertical direction, stabilizing structure 30 preferably also moves vertically together with tray 12. In configurations in which the vertical distance is varied by heads 16 along the vertical direction, while maintaining the vertical position of tray 12 fixed, stabilizing structure 30 is also maintained at a fixed vertical position.

[0137] The vertical motion can be established by a vertical drive 28. Once a layer is completed, the vertical distance between tray 12 and heads 16 can be increased (e.g., tray 12 is lowered relative to heads 16) by a predetermined vertical step, according to the desired thickness of the layer subsequently to be printed. The procedure is repeated to form a three-dimensional object in a layerwise manner.

[0138] The operation of inkjet printing heads 16 and optionally and preferably also of one or more other components of system 10, e.g., the motion of tray 12, are controlled by a controller 20. The controller can have an electronic circuit and a non-volatile memory medium readable by the circuit, wherein the memory medium stores program instructions which, when read by the circuit, cause the circuit to perform control operations as further detailed below.

[0139] Controller 20 can also communicate with a host computer 24 which transmits digital data pertaining to fabrication instructions based on computer object data, e.g., in a form of a Standard Tessellation Language (STL) or a StereoLithography Contour (SLC) format, Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Exchange Format (DXF), Polygon File Format (PLY) or any other format suitable for Computer-Aided Design (CAD). The object data formats are typically structured according to a Cartesian system of coordinates. In these cases, computer 24 preferably executes a procedure for transforming the coordinates of each slice in the computer object data from a Cartesian system of coordinates into a polar system of coordinates. Computer 24 optionally and preferably transmits the fabrication instructions in terms of the transformed system of coordinates. Alternatively, computer 24 can transmit the fabrication instructions in terms of the original system of coordinates as provided by the computer object data, in which case the transformation of coordinates is executed by the circuit of controller 20.

[0140] The transformation of coordinates allows three-dimensional printing over a rotating tray. In non-rotary systems with a stationary tray with the printing heads typically reciprocally move above the stationary tray along straight lines. In such systems, the printing resolution is the same at any point over the tray, provided the dispensing rates of the heads are uniform. In system 10, unlike non-rotary systems, not all the nozzles of the head points cover the same distance over tray 12 during at the same time. The transformation of coordinates is optionally and preferably executed so as to ensure equal amounts of excess material at different radial positions. Representative examples of coordinate transformations according to some embodiments of the present invention are provided in FIGs. 3A-B, showing three slices of an object (each slice corresponds to fabrication instructions of a different layer of the objects), where FIG. 3A illustrates a slice in a Cartesian system of coordinates and FIG. 3B illustrates the same slice following an application of a transformation of coordinates procedure to the respective slice.

[0141] Typically, controller 20 controls the voltage applied to the respective component of the system 10 based on the fabrication instructions and based on the stored program instructions as described below.

[0142] Generally, controller 20 controls printing heads 16 to dispense, during the rotation of tray 12, droplets of building material in layers, such as to print a three-dimensional object on tray 12.

[0143] System 10 optionally and preferably comprises one or more solidifying devices 18, which can include, for example, one or more radiation sources, such as, but not limited to, an ultraviolet or visible or infrared lamp, or other sources of electromagnetic radiation, or electron beam source, depending on the modeling material being used. Radiation source can include any type of radiation emitting device, including, without limitation, light emitting diode (LED), digital light processing (DLP) system, resistive lamp and the like. Radiation source 18 serves for curing or solidifying the modeling material. In various exemplary embodiments of the invention the operation of solidifying device 18 is controlled by controller 20 which may activate and deactivate solidifying device 18 and may optionally also control the amount of radiation generated by solidifying device 18.

[0144] In some embodiments of the invention, system 10 further comprises one or more leveling devices 32 which can be manufactured as a roller or a blade. Leveling device 32 serves to straighten the newly formed layer prior to the formation of the successive layer thereon. In some embodiments, leveling device 32 has the shape of a conical roller positioned such that its symmetry axis 34 is tilted relative to the surface of tray 12 and its surface is parallel to the surface of the tray. This embodiment is illustrated in the side view of system 10 (FIG. 1C).

[0145] The conical roller can have the shape of a cone or a conical frustum.

[0146] The opening angle of the conical roller is preferably selected such that there is a constant ratio between the radius of the cone at any location along its axis 34 and the distance between that location and axis 14. This embodiment allows roller 32 to efficiently level the layers, since while the roller rotates, any point p on the surface of the roller has a linear velocity which is proportional (e.g., the same) to the linear velocity of the tray at a point vertically beneath point p. In some embodiments, the roller has a shape of a conical frustum having a height h, a radius Ri at its closest distance from axis 14, and a radius R2 at its farthest distance from axis 14, wherein the parameters h, R\ and R satisfy the relation R IR2=(R-h)lh and wherein R is the farthest distance of the roller from axis 14 (for example, R can be the radius of tray 12).

[0147] The operation of leveling device 32 is optionally and preferably controlled by controller 20 which may activate and deactivate leveling device 32 and may optionally also control its position along a vertical direction (parallel to axis 14) and / or a radial direction (parallel to tray 12 and pointing toward or away from axis 14.

[0148] In some embodiments of the present invention printing heads 16 are configured to reciprocally move relative to tray along the radial direction r. These embodiments are useful when the lengths of the nozzle arrays 22 of heads 16 are shorter than the width along the radial direction of the working area 26 on tray 12. The motion of heads 16 along the radial direction is optionally and preferably controlled by controller 20.

[0149] Some embodiments contemplate the fabrication of an object by dispensing different materials from different arrays of nozzles (belonging to the same or different printing head). These embodiments provide, inter alia, the ability to select materials from a given number of materials and define desired combinations of the selected materials and their properties. According to the present embodiments, the spatial locations of the deposition of each material with the layer is defined, either to effect occupation of different three-dimensional spatial locations by different materials, or to effect occupation of substantially the same three-dimensional location or adjacent three-dimensional locations by two or more different materials so as to allow post deposition spatial combination of the materials within the layer, thereby to form a composite material at the respective location or locations.

[0150] Any post deposition combination or mix of model (modeling) material formulations is contemplated. For example, once a certain formulation is dispensed, the hardened material may preserve its original properties. However, when it is dispensed simultaneously with another modeling material formulation or other dispensed materials / formulations which are dispensed at the same or nearby locations, a composite material having a different property or properties compared to the material formed from a certain formulation per se may be formed.

[0151] In some embodiments of the present invention the system dispenses digital material for at least one of the layers, as described herein.

[0152] Further details on the principles and operations of an AM system suitable for the present embodiments are found in U.S. Published Application No. 20100191360, the contents of which are hereby incorporated by reference.

[0153] In some embodiments of the present invention system 10 and / or system 110 are configured for printing one or more objects on a fabric.

[0154] As used herein “fabric” encompasses any article of manufacture that is made at least partially of a natural or man-made fibrous material, including, for example, woven, non-woven, knitted, or mesh textile materials. Examples of fabrics include, without limitation, cotton, polyester, linen, Lycra, nylon, spandex / elastane (including blends), nonwoven polypropylene (PP), glass fiber fabric, and thermoplastic polyurethane (TPU), silk, conductive fabrics (e.g., silver-coated textiles), aramid fibers (e.g., Kevlar), polyurethane-coated fabrics, and any other fabric present or used to form articles such as clothes, shoes, toys, fabric articles, carpets, cloth hats, cloth bags, socks, towels, linen, draperies, etc.

[0155] As used herein, “woven” means a structure produced when at least two sets of strands are interlaced, e.g., at right angles to each other, according to a predetermined pattern of interlacing, and such that at least one set is parallel to the axis along the lengthwise direction of the fabric, in accordance with ASTM D 123-03.

[0156] As used herein, the term “non-woven” means a textile structure produced by bonding or interlocking of fibers, or both, accomplished by mechanical, chemical, thermal, or solvent means and combinations in accordance with ASTM D 123-03.

[0157] Preferably, but not necessarily, when the printing system (e.g., system 10 or 110) is employed for printing an object on a fabric, leveling device 32 is not used or is used only after the object reaches a predetermined height above the fabric.

[0158] Preferably, but not necessarily, when the printing system (e.g., system 10 or 110) is employed for printing an object on a fabric, the height of the printed objects is below 10 cm, more preferably below 9 cm, more preferably below 8 cm, more preferably below 8 cm, more preferably below 7 cm, more preferably below 6 cm, more preferably below 5 cm, more preferably below 4 cm, more preferably below 3 cm, more preferably below 2 cm, more preferably below 1 cm. In some embodiments of the present invention the work tray of the system (e.g., tray 12 or 360) has reflectivity of at least 50 % or at least 60 % or at least 70 % or at least 80 % or more to radiation emitted by the radiation source of solidifying device 18. The advantage of making the work tray reflective or partially reflective is that the reflected radiation arriving to the fabric from below can solidify building material that is below the fabric and can also penetrate the pores of the fabric and solidify droplets of building material within these pores, thereby improving the adherence of the printed object to the fabric.

[0159] The present embodiments also contemplate providing the work tray with one or more fluid channels 52. A fluid delivery system 54 can generate a flow of fluid within fluid channel 52. The fluid is optionally and preferably can be at a controlled temperature, thereby controlling the temperature of the work tray. When fluid delivery system 54 generates a flow of fluid that is at a temperature that is less than the temperature of the dispensed building material, the fluid absorbs heat from the building material. Fluid delivery system 54 can also generate a flow of fluid that is at an elevated temperature relative to the fabric, facilitating straightening wrinkles in the fabric before dispensing the building materials on the fabric. The present inventors also contemplate combination of these embodiments, wherein the fluid is at an elevated temperature before dispensing the building materials and at a reduced temperature during the fabrication of the object. The fluid can be in a gaseous or liquid phase (e.g., air, helium, water, oil or the like). Preferably, fluid delivery system 54 is controlled by controller 20.

[0160] In some embodiments of the present invention system 10 and / or 110 comprise a jig 402 configured for affixing a fabric 420 to a predetermined location on the work tray of the system (e.g., tray 12 or 360), and also at a predetermined orientation relative to the nozzle arrays (e.g., arrays 122) of the system. In some embodiments of the present invention jig 402 is also configured for stretching fabric 420.

[0161] Jig 402 is illustrated in greater detail in FIGs. 4A-B. FIGs. 4A and 4B illustrate an embodiment in which jig 402 comprises a frame 403 and one or more magnetic or metallic elements 405, wherein elements 405 are attached, preferably permanently, to tray 360 / 12 or adjacent thereto, e.g., onto a static platform 361 surrounding tray 360 / 12, and wherein at least one of tray 360 / 12 and elements 405 comprises a permanent magnet to ensure mutual magnetic attraction between elements 405 and frame 403. Frame 403 can be made magnetic or metallic in its entirety, or it can include metallic or magnetic elements on its periphery, at lateral locations that match the locations of elements 405. FIG. 4A illustrates jig 402 in its opened state, before fabric 420 is placed on the work tray 360 / 12, and FIG. 4B illustrates jig 402 in its closed state wherein frame 403 is magnetically attached to elements 405 (not shown in FIG. 4B), affixing and optionally and preferably stretching fabric 420 onto work tray 360 / 12. Jig 402 can also comprise a pair of frames 403 magnetically attachable to each other, in which case the fabric 420 is stretched between the frames of jig 402 before it is placed on work tray 360 / 12. In these embodiments, elements 405 are not necessary.

[0162] FIG. 5 is a schematic illustration of a configuration in which fabric 420 is placed on a ramp structure 450 which includes a planar ramp 452 and one or more spacer beams 454 keeping ramp 452 spaced apart vertically from the work tray 12 / 360. Ramp structure 450 can be placed on tray 12 / 360, or connected to the tray 12 / 360 by connectors (not shown), such as, but not limited to, snap connectors. When ramp structure 450 is connected to the tray, the connectors are preferably outside the printing area of the AM system, so as not to interfere with the printing process when the AM system is operated without ramp 450. Fabric 420 can be affixed using any of the techniques described above except that the fabric is affixed to ramp structure 450 rather than to tray 12 / 360.

[0163] The advantage of using ramp structure 450 is that it allows printing a three-dimensional object on a fabric that is larger than the work tray. In use, fabric 420 is affixed to the upper surface of ramp 452. When the size of fabric 420 is larger than the size of ramp structure, fabric 420 is folded over the edge of ramp structure 450, so that a horizontal portion 420a of fabric 420 is supported by the upper surface of ramp 452 and a hanging portion 420b of fabric 420 is folded into a space below ramp 452 but above work tray 12 / 360, as illustrated in FIG. 5. Preferably, fabric 420 is affixed to ramp structure 450 before placing on work tray 12 / 360 or connecting it thereto, but embodiments in which fabric 420 is affixed to ramp 452, while ramp structure 450 is on work tray 12 / 360, are also contemplated.

[0164] Once fabric 420 is affixed to work tray 12 / 360 (FIGs. 4A and 4B) or ramp 452 (FIG. 5), the computerized controller 20 (FIGs. 1A and IB) operates the array(s) of nozzles 122 (FIGs. 2A- C) to dispense building material(s) in a configured pattern corresponding to a shape of an object on the affixed fabric 420. In embodiments in which ramp structure 450 is employed the computerized controller 20 controls the array(s) of nozzles 122 to terminate any dispensing when the nozzles are above the gap between ramp structure 450 and platform 361, thereby ensuring that the droplets of building material(s) land only on the horizontal portion 402a of fabric 420.

[0165] With reference to FIGs. 1A-C, system 10 and 110 optionally and preferably comprises a position tracking system 50. In some embodiments of the present invention position tracking system 50 is configured for determining a position of jig 402 relative to work tray 12 or 360, once jig 402 is placed on the tray. Position tracking system 50 can include, for example, an optical scanner, an imaging device, a magnetic sensor, and / or a radiofrequency sensor. Computerized controller 20 receives position tracking signals from system 50 and executes a registration procedure based on the position tracking signals and operates nozzle array 122 responsively to the registration. The advantage of this embodiment is that it does not require accurate positioning of jig 402 on the tray, since the registration procedure performed by controller 20 ensures that the nozzles are activated to dispense the building materials at the appropriate locations on fabric 420.

[0166] Position tracking system 50 can determine the position of jig 402 in more than one way. In some embodiments of the present invention, system 50 captures an image of the tray or a portion thereof (e.g., when system 50 comprises a pixelated imager or an optical scanner) and executes an image processing procedure to identify the location of jig 402 relative to the tray. In some embodiments of the present invention position tracking system 50 can determine the position of jig 402 using marks 414, which can be formed or attached, for example, to the frame 406 of jig 402, or, as illustrated in FIG. 4A on static platform 361. The marks 414 are identifiable by position tracking system 50 and are used by system 50 for determining the position of jig 402. For example, when system 50 comprises an optical scanner or an imager, marks 414 can be a printed pattern, such as, but not limited to, a barcode, or a source of optical signal, e.g., a light emitting diode emitting radiation that does not solidify the building materials dispensed by the nozzle arrays. When system 50 comprises a magnetic or radiofrequency sensor, marks can comprise a source of radiofrequency or magnetic field, such as, but not limited to, a miniature coil or the like.

[0167] The present disclosure also contemplates embodiments in which position tracking system 50 is used to identify patterns (e.g., printed patterns, weaving pattern, knitted pattern) on fabric 420 itself. In these embodiments, it is not necessary for tracking system 50 to be used for determining the position of the jig 402 (although such determination is also contemplated in some embodiments) since controller 20 can execute the registration procedure based on the identified patterns on fabric 420.

[0168] The fabrication process of three-dimensional objects on fabric 420 may optionally and preferably include use of one or more liquid formulations other than an uncured building material for three-dimensional printing. The liquid formulations can be curable or non-curable. The liquid formulations are also referred to herein interchangeably as “liquid additives” or as “additive formulations” or as “liquid additive formulations”. Liquid additive formulations can be deposited on the fabric by the dispensing heads of system 10 or 110. When the additive formulation is a priming (e.g., adhesive) liquid formulation, such a process may be defined as “digital priming”. Also contemplated are embodiments in which the liquid formulations are deposited by additive dispensing system 340 (see FIGs. 1A and IB), which is in fluid communication with a container 342 containing the liquid formulation (shown only in FIG. 1A), and which can be controlled by controller 20. In some embodiments of the present invention, one or more additive formulation(s) is / are applied by directing an aerosol or mist of the liquid additive to the fabric. In these embodiments, system 340 is in the form of an aerosol dispenser or a sprinkler for generating the aerosol or mist of the liquid additive and directing it to the fabric. In some embodiments of the present invention, one or more liquid additives is applied by depositing droplets of the additive at discrete addressable locations on the fabric. In these embodiments, one or more of the printing heads 16 can be configured to dispense the respective additive formulation, and one or more of the containers or cartridges of supply system 330 can contain the respective additive formulation. When there are two or more additive formulations (e.g., formulations that are otherwise non- reactive but react with each other in situ after deposition), the depositing at discrete addressable locations on the fabric can be done in an interlaced manner, preferably laterally, to form interfaces between adjacent drops of different additive formulations.

[0169] Additive dispensing system 340 can be mounted on the same printing block with heads 16, as illustrated in FIG. 1A, and therefore move horizontally together with heads 16. Alternatively, system 340 can be mounted separately from heads 16 (see, e.g., FIG. IB), in which case heads 16 and system 340 can be configured to move independently. In some embodiments, building tray 12 / 360 or a section thereof moves under a static additive dispensing system 340 (e.g. a row of sprinklers) and / or a static printing block 128 on which heads 16 are mounted. In some other embodiments, tray 360 is configured to move in the Z direction, heads 16 are mounted in printing block 128 which is configured to perform horizontal scans of the surface of tray 360 in a first direction (e.g. X axis), and additive dispensing system 340 is configured to perform horizontal scans of the surface of tray 360 in a second direction (e.g. Y axis). In some embodiments, both printing block 128 and additive dispensing system 340 are configured to perform horizontal scans of the surface of tray 360 in the same direction (e.g. X axis).

[0170] Types of liquid additive formulations that are contemplated according to some embodiments of the present invention include, but are not limited to, a priming formulation (e.g., a stiffening formulation, an adhesive formulation, a pore size modifying formulation, etc.), a finishing or coating formulation (e.g., a radiation protective formulation, a glossy finish formulation, a matte finish formulation, etc.), and the like. Other types of additive formulations that can be used according to some embodiments of the present invention include temporary protection formulations, water repellent formulations, waterproof formulations, hydrophobic formulations, and the like.

[0171] When the additive formulation is a priming formulation or an adhesive formulation, it is applied prior to the dispensing of the building material. Thus, for example, an adhesive formulation can be applied to the fabric and then a building material formulation(s) (e.g., modeling material formulation(s) and optionally support material formulation(s)) can be dispensed wherein the adhesive formulation ensures adherence of the building material formulation and / or the hardened building material to the fabric.

[0172] Another example is the application of a pore size modifying solution that increases the sizes of the pores of the fabric. A building material formulation (e.g., modeling material formulation(s) and optionally support material formulation(s)) can then be dispensed to form a penetration element (e.g., element 506) within the increased pores. An additional example is the application of a stiffening substance so as to stabilize the fabric prior to the dispensing.

[0173] When the additive formulation is a finishing or a coating formulation, it is applied after the dispensing of the building material formulation(s) (e.g., modeling material formulation(s) and optionally support material formulation(s)). For example, a glossy or matte finish formulation can be applied on the dispensed building material formulation(s) formulation(s) (e.g., modeling material formulation(s) and optionally support material formulation(s)) and / or the hardened building material(s) to impart the hardened materials with a desired appearance. Similarly, a paint such as a metallic paint (e.g. chrome, gold) can be applied in the form of a finishing formulation on at least part of the object that has been printed with the building material. Also contemplated are finishing formulations that serve for protecting the fabric or printed object, for example, against discoloration, radiation, abrasion, chemical damages, water absorption, and the like. Representative examples of such protective formulations, include, without limitation, UV resistant material (such as the UV resistant material commercially available from Krylon®), polyurethane (such as the polyurethane solution available from Rust-Oleum).

[0174] Any of the aforementioned additive formulations can optionally and preferably comprise a non-reactive (e.g., non-curable) formulation capable of being activated in situ, namely while being spread on the fabric. In these embodiments, the formulation is applied to the fabric and activated thereafter. In exemplary embodiments, the formulation is a curable formulation that undergoes polymerization of monomers and / or oligomers, or cross-linking of polymeric chains, or modification of optical properties of the formulation, upon being exposed to a curing condition, as described herein (e.g., irradiation, heat).

[0175] Also contemplated are formulations that are activated by chemical reaction. Such reaction can occur between the formulation and one or more of the building materials, and / or between two or more applied formulations. For example, in some embodiments of the present invention one or more building material formulation(s) (e.g., modeling material formulation(s) and optionally support material formulation(s)) are dispensed onto the fabric and are allowed to at least partially penetrate into the pores of the fibers while being in their liquid phase (before hardening upon exposure to a curing condition). Thereafter, a formulation that reacts with the dispensed building material formulation(s) is applied. The chemical reaction between the building material formulation(s) (e.g., between one or more curable materials therein) and the applied formulation modifies at least one property of the hardened building material(s) (e.g., mechanical and / or optical property). In some embodiments, the formulation induces polymerization of one or more curable material(s) in the dispensed building formulation.

[0176] In embodiments in which two or more formulations react with one another, they are preferably deposited separately so as to induce reaction therebetween on the fabric. Depending on the product of such a reaction, the formulations can be deposited before the dispensing of the building material formulation(s), after the dispensing of the building material formulation(s), or contemporaneously or intermittently with the dispensing of the building material formulation(s).

[0177] For example, the formulations can be deposited before the dispensing of the building material formulation(s), when the reaction product forms an adhesive allowing adherence of the building material(s), and / or when the reaction product modifies the pore size (e.g., a reaction product that locally shrinks the fibers of the fabric, thereby increasing the inter-fiber pore size), and / or when the reaction product that forms a mask on regions of the fabric which are desired to be protected from being contacted with building materials. The formulations can be deposited after the dispensing of the building material formulation(s), when the reaction product modifies the appearance of the hardened building material(s) (e.g., increases or reduces glossiness, modifies color), or to cover the hardened building material(s) with a (typically transparent) cover, e.g., a protective cover. The formulations can be deposited contemporaneously or intermittently with the dispensing of the building material formulation(s), when it is desired to interlace the reaction product vertically or laterally with the hardened building material(s), e.g., to reinforce the building materials, improve the flexibility of the final object, etc.

[0178] A representative example of an additive formulation suitable for use as a priming (e.g., adhesive) and / or coating formulation according to some exemplary embodiments of the invention, which features, when hardened, Tg higher than 50 °C, and is also referred to herein as a rigid material formulation, or a rigid adhesive formulation, is described in greater detail hereinafter.

[0179] Another representative example of an additive formulation suitable for use as a priming (e.g., adhesive) and / or coating formulation according to some exemplary embodiments of the invention, which can be used in combination with a priming (e.g., adhesive) and / or coating formulation according to any of the present embodiments, and which features, when hardened, Tg lower than 50 °C, and is also referred to herein as a flexible material formulation, or a flexible adhesive is described in greater detail in Example 4 in the Examples section that follows. These two additive formulations can be combined and used as digital materials as described herein, for example, for forming an adhesive structure and / or a coating structure. Alternatively, one of these formulations can be used as a priming (e.g., adhesive) formulation according to any of the respective embodiments and one of these formulations can be used as a coating formulation according to any of the respective embodiments. According to some of any of the embodiments described herein, a rigid material formulation according to the present embodiments is used as an adhesive formulation as described herein, either alone or combined with an exemplary flexible material (adhesive) formulation as described in Example 4 herein. According to some of any of the embodiments described herein, a rigid material formulation according to the present embodiments is used as a coating formulation as described herein, either alone or combined with an exemplary flexible material formulation as described in Example 4 herein. According to some of any of the embodiments described herein, a rigid material formulation according to the present embodiments is used as an adhesive formulation as described herein, either alone or combined with an exemplary modeling material formulation as described in Example 5 herein.

[0180] Method:

[0181] The methods of the present embodiments can be executed by the computerized controller (e.g., controller 20) of system 10 or 110.

[0182] It is to be understood that, unless otherwise defined, the operations described hereinbelow can be executed either contemporaneously or sequentially in many combinations or orders of execution. Specifically, the ordering of the flowchart diagrams is not to be considered as limiting. For example, two or more operations, appearing in the following description or in the flowchart diagrams in a particular order, can be executed in a different order (e.g., a reverse order) or substantially contemporaneously. Additionally, several operations described below are optional and may not be executed.

[0183] The methods of the present embodiments can be used as a printing protocol for improving adhesion of three-dimensional printed objects to the fabric and / or for improving the appearance and / or mechanical properties of the printed objects.

[0184] In some embodiments, the method is for forming an adhesion structure or adhesive material in the fabric, to thereby prepare the fabric for 3D printing of the object thereof. The adhesion structure is formed by sequential dispensing of an additive formulation that is suitable for serving as a priming or adhesive formulation in layers, as described herein in any of the respective embodiments. Preferably, but not necessarily, the entire adhesion structure is made of a single formulation, which is an additive formulation as described herein. Typically, once the adhesion structure is formed on the fabric as described below, a three- dimensional object made of one or more modeling materials is printed onto the adhesion structure.

[0185] According to an aspect of some embodiments of the present invention, there is provided a method of forming an adhesive structure on a fabric via digital priming (e.g., selective deposition of one or more priming formulations onto the fabric). The method is generally effected by dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of the adhesive structure, wherein for at least a few layers, or for each layer, of this stack, the dispensing is of an additive (e.g., priming / adhesive) formulation as described herein in any of the respective embodiments. The method further comprises exposing at least one of the layers, or the stack of layers, to a curing condition, as described herein, to thereby form the adhesive structure.

[0186] According to an aspect of some embodiments of the present invention, there is provided a method of preparing a fabric for three-dimensional printing of an object thereon. The method is generally effected by forming an adhesive structure on the fabric in a configured pattern corresponding to a shape of a bottommost surface of the object or a part thereof, whereby the adhesive structures is formed by a method as described herein in any of the respective embodiments and any combination thereof.

[0187] According to an aspect of some embodiments of the present invention, there is provided a method of forming a coating on a three-dimension object printed on a fabric, or on a part of the object. The method is generally effected by dispensing on the printed object a stack of layers in a configured pattern corresponding to a shape of a outermost surface of the object or a part thereof onto which the coating is desirable, wherein for each layer of this stack the dispensing is of an additive (e.g., coating) formulation as described herein in any of the respective embodiments and any combination thereof. The method further comprises exposing at least one of the layers, or the stack of layers, to a curing condition, to thereby form a hardened coating material on the printed object or the part thereof.

[0188] According to an aspect of some embodiments of the present invention, there is provided a method of three-dimensional printing an object on a fabric, the method comprising dispensing a plurality of layers in a configured pattern correspond to the shape the object, thereby forming the object, wherein the formation of each layer of at least a few of the layers comprises dispensing one or more building (e.g., modeling) material formulation, and exposing the dispensed formulation to a curing condition to thereby form a cured building (e.g., modeling) material, thereby printing the object. According to some of these embodiments, the building material formulation(s) comprise, or consist of, one or more of a modeling material formulation as described in Example 5 in the Examples section that follows.

[0189] According to these embodiments, the method further comprises, prior to dispensing the one or more building (e.g., modeling) material formulation(s), forming an adhesive structure on the fabric, or preparing the fabric by forming an adhesive structure, as described herein in any of the respective embodiments; and / or subsequent to dispensing the one or more building (e.g., modeling) material formulation and exposing it to the curing condition, forming a coating on the printed object or a part thereof, as described herein in any of the respective embodiments,

[0190] According to some of these embodiments, the method further comprises, prior to dispensing the one or more building (e.g., modeling) material formulation(s), dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of a bottommost surface of the object, or a part thereof, wherein for each layer of the stack the dispensing is of an additive (e.g., priming / adhesive) formulation as described herein in any of the respective embodiments, and exposing at least one of the layers, or the stack of layers, to a curing condition, to thereby form a hardened adhesive material (an adhesive structure), as described herein in any of the respective embodiments.

[0191] The methods as described herein can be used to fabricate on the fabric any type of object or 3D printed element, using any formulation suitable for three-dimensional printing. Representative examples of formulations suitable for the present embodiments include, without limitation, the formulations marketed under the trade names Vero™ family, e.g., VeroVivid™, VeroClear™, VeroUltra™ VeroEco™Flex, and VeroEco™Rigid and Agilus family, e.g., Agilus30™, Agilus™White, Agilus™Clear, Agilus™Black, Agilus™Cyan, Agilus™Magenta, Agilus™Yellow, all marketed by Stratasys® Ltd., Israel. In some embodiments of the present invention at least one of the formulations that is dispensed for fabricating the object(s) of the fabric provides a flexible material. A representative example of such a formulation is described in Example 5 in the Examples section that follow. In some embodiments of the present invention, at least one of the formulations that is dispensed for fabricating the object(s) of the fabric provides a rigid material. A representative example of such a formulation is as described herein in any of the respective embodiments and any combination therefore for a rigid material formulation. In some embodiments of the present invention, at least one of the formulations that is dispensed for fabricating the object(s) of the fabric provides a rigid material and can be a rigid material formulation as described herein in any of the respective embodiments and at least another one of the formulations that is dispensed for fabricating the object(s) of the fabric provides a flexible material and can be any of the formulations as described herein, including, for example, a flexible material formulation as described in Example 5 in the Examples section that follow. In some embodiments of the present invention, when two or more formulations are dispensed for fabricating the object on the fabric, the two or more formulations are used in a “digital material” mode as described herein.

[0192] According to some embodiments, these methods are performed in accordance with the embodiment described herein for FIG. 6.

[0193] Referring to FIG. 6, the method begins at 840 and optionally and preferably continues to 601 at which computer object data are received. The computer object data can be in any of the aforementioned formats, and describe at least the bottommost surface of an object to be fabricated on top of the adhesion structure. Typically, however, the computer object data describe the entire shape of the object.

[0194] The method continues to 841 at which a priming (adhesive) formulation of the present embodiments is dispensed to form a layer of a priming (adhesive) formulation, which layer later becomes a layer of the adhesion structure. The dispensing is on the fabric or on a previously dispensed layer, when such a layer was already formed by the method. In some embodiments, the formulation is dispensed in a selective manner, for instance, according to the computer object data of the bottommost surface of the object or a part thereof to be fabricated on top of the adhesive structure. Thus, the formulation is optionally and preferably dispensed at lateral coordinates which are expected to be occupied by the object, once printed, and is not dispensed at other locations. In some embodiments, the adhesive formulation is an adhesive formulation as described herein. In some embodiments, the adhesive formulation is a flexible adhesive formulation, as described, for example, in Example 4. In some embodiments, the dispensing is of a DM combination of a rigid adhesive formulation as described herein and a flexible adhesive or modeling formulation as described herein. The dispensing is on the fabric or on a previously dispensed layer, when such a layer was already formed by the method. The formulation is dispensed in a selective manner (i.e. digital priming) according to the computer object data of the bottommost surface of the object or a part thereof to be fabricated on top of the adhesive structure. Thus, the formulation is dispensed at lateral coordinates which are expected to be occupied by the object, once printed, and is not dispensed at other locations.

[0195] Optionally, but not necessarily, the method continues to step 842, at which the layer of the dispensed priming (adhesive) formulation (or a part of the layer) is exposed to a curing condition (e.g., is irradiated) When irradiation, the formulation is irradiated by curing radiation having a radiation intensity IA, to form a hardened (e.g., cured, solidified) adhesive material that composes a layer of the adhesive structure. The wavelength of the curing radiation depends on the type of formulation that is used. For example, when the formulation is UV-curable, the radiation can be UV radiation. In some embodiments, a value for the intensity IA is from about 5 W / cm2to about 10 W / cm2.

[0196] For any layer of the adhesive structure, operation 842 can be executed according to a protocol in which a pattern of curing radiation is created on the layer wherein the pattern has a shape of a single stripe and is advanced along the scanning direction (x or cp). A representative example of an irradiating protocol suitable for operation 842 is illustrated in FIGs. 7A and 7B, showing a layer 610 of the priming (adhesive) formulation on fabric 420 and a pattern 612 of curing radiation in the form of a single straight stripe propagating along the direction x when fabric 420 is on tray 360 (FIG. 7A) or and along the direction cp when fabric 420 is on tray 12 (FIG. 7B).

[0197] The radiation pattern is created by the devices that emit the radiation (e.g.. devices 18 of system 10 or 110), and the irradiating protocol illustrated in FIGs. 7A and 7B can be employed by judicious control over these devices. For example, when the system is configured to perform reciprocal relative motion between the dispensing head and the tray along a straight line (e.g.. system 110) operation 842 can be executed by activating only the solidification (curing) device that follows the printing head and deactivating the solidification (curing) device that is followed by the printing head (e.g.. with reference to FIG. ID, when the head 16 moves to the left the device 18 at the right-hand- side of head 16 is activated and the device 18 at the left-hand-side of head 16 is deactivated and vice versa). This ensures execution of the protocol shown in FIG. 7A. When the system is configured to perform rotary relative motion between the dispensing head and the tray (e.g., system 10), operation 842 can be executed by activating only the solidification device that is in front of the printing head with respect to the rotation direction, and deactivating the solidification device that is behind the printing head with respect to the rotation direction. This ensures execution of the protocol shown in FIG. 7B. The control over the solidification devices is typically by means of the controller of the three-dimensional printing system (e.g., controller 20 of system 10 or 110).

[0198] Alternatively, for any layer of the adhesive structure, operation 842 can be executed according to a protocol in which a pattern of curing radiation is created on the layer wherein the pattern has a shape of two stripes and is advanced along the scanning direction (x or cp). A representative example of an irradiation protocol suitable for such embodiments of operation 842 is illustrated in FIGs. 7C and 7D, showing layer 614 of the object 112 on fabric 420 and a pattern 616 of curing radiation in the form of two straight stripes propagating along the direction x when fabric 420 is on tray 360 (FIG. 7C) or and along the direction cp when fabric 420 is on tray 12 (FIG. 7D). Such a pattern of curing radiation can be created by activating both devices, each at the same power to provide Intensity IA. Specifically, when the system is configured to perform reciprocal relative motion along a straight line (e.g., system 110) operation 842 can be executed by activating both the solidification (curing) device that follows the printing head and the solidification (curing) device that is followed by the printing head, and when the system is configured to perform rotary relative motion (e.g., system 10), operation 843 can be executed by activating both the solidification (curing) device that is in front of the printing head with respect to the rotation direction, and the solidification (curing) device that is behind the printing head with respect to the rotation direction. The control over the solidification (curing) devices is typically by means of the controller of the three-dimensional printing system (e.g., controller 20 of system 10 or 110).

[0199] In some embodiments, operation 842 is executed using the irradiation protocol as described in FIGs. 7C and 7D. In some embodiments, some of the layers of operation 842 are printed according to the irradiation protocol described in FIGs. 7C and 7D and some of the layers according to the protocol described in FIGs. 7A and 7B.

[0200] From 842 the method optionally loops back to 841 for the formation of the subsequent layer of the adhesive structure. The looping is repeated a predetermined number of times. Preferably, the looping is repeated until the number of layers in the adhesive structure is Ni, where Ni is from about 1 to about 50 layers, or from about 5 to about 40 layers, or from about 5 to 20 layers, e.g., 10 layers.

[0201] In some embodiments, all the layers of the dispensed priming (adhesive) formulation are exposed to a curing condition, while in some other embodiments, at least one layer (e.g., a first layer) of the dispensed priming (adhesive) formulation is not exposed to curing conditions.

[0202] Once the loop is completed, a stack of layers is formed, and the method optionally and preferably continues to 843 at which the three-dimensional object is printed in layers on the topmost layer of the stack, based on the computer object data. The object is preferably printed using one or more modeling material formulations, such as, but not limited to, one of more of the aforementioned modeling material formulations. The object is printed by dispensing one or more modeling formulations in layers in configured patterns corresponding to shapes of slices of the object, and by irradiating the modeling formulation(s) of each layer by the curing radiation having a radiation intensity IB, to form a hardened object. The wavelength of the curing radiation depends on the type of formulation that is used. For example, when the formulation is UV-curable, the radiation can be UV radiation. In some embodiments, a value for the intensity IB is from about 1 W / cm2to about 5 W / cm2.

[0203] In some embodiments, operation 843 is executed using the irradiation protocol as described in FIGs. 7C and 7D. In some embodiments, operation 843 is executed using the irradiation protocol as described in FIGs. 7 A and 7B.

[0204] In some embodiments, some of the layers of operation 843 are printed according to the irradiation protocol described in FIGs. 7C and 7D and some of the layers according to the protocol described in FIGs. 7A and 7B.

[0205] Optionally, but not necessarily, the method continues to 844 at which a formulation suitable for use as a coating formulation as described herein in any of the respective embodiments is dispensed. In some embodiments, the coating formulation is also dispensed to at least partially surround one or more of the layers formed at 843. Such a surrounding or partially surrounding coating can be formed substantially simultaneously with the formation of the respective layer of the object, by dispensing the modeling formulation(s) and coating formulation using different nozzle arrays of the dispensing heads 16. Alternatively, the surrounding or partially surrounding coating can be formed for the respective layer after the layer of modeling formulation(s) is dispensed. The advantage of forming a surrounding or partially surrounding coating is that it provides coating also at the sides of the object. For example, a coating that surrounds the printing object from all sides can be provided by dispensing the coating formulation to completely surround each of the layers formed at 843.

[0206] The method continues to 845 at which the coating formulation is exposed to a curing condition (e.g., is irradiated). When the coating is dispensed to surround or partially surround the layers of the building (e.g., modeling) material formulation, the exposure at to 845 is optionally and preferably executed substantially simultaneously with the exposure of the building (e.g., modeling) material formulation.

[0207] From 845 the method optionally loops back to 844 for the formation of the subsequent layer of the coating structure. The looping is repeated a predetermined number of times. Preferably, the looping is repeated until the number of layers in the coating structure is N2, where N2 is from about 1 to about 20 layers, or from about 1 to about 10 layers, or from about 1 to 5 layers, e.g., 2 layers.

[0208] In some embodiments, operation 845 is executed using the irradiation protocol as described in FIGs. 7C and 7D.

[0209] In some embodiments, operation 845 is executed using the irradiation protocol as described in FIGs. 7A and 7B.

[0210] In some embodiments, some of the layers of operation 845 are printed according to the irradiation protocol described in FIGs. 7C and 7D and some of the layers according to the protocol described in FIGs. 7A and 7B. In some embodiments operation 845 is executed using a radiation intensity Ic, which can be the same or different from IA and / or IB.

[0211] A coating on the upper surface of the object is optionally and preferably formed by dispensing the formulation in layers over the object, and irradiating the formulation of each layer by the curing radiation. The thickness of the hardened (e.g., cured) coating is preferably from about 0.01 mm to about 0.5 mm, e.g., about 0.05 mm or about 0.1 mm.

[0212] In some embodiments of the present invention the object is a testing object that is printed in order to test the adherence level that the adhesive structure provides. In these embodiments, the method executes an operation in which the adherence level of the object to the fabric is tested. FIG. 8A presents a photograph of an exemplary testing object and FIG. 8B presents a photograph of an exemplary device for executing the testing procedure.

[0213] According to some embodiments, the method comprises one or both of operations 841 and 842 and of operations 844 and 845.

[0214] Optionally, but not necessarily, the method proceeds to 846 at which the topmost layer of the object or the coating (if applied) is scanned by the curing radiation at intensity ID. In some embodiments, the number of scans is between 1 to 10 or 1 to 5, e.g. 2, and no formulation is dispensed during the execution of 846. In some embodiments, a value for the intensity ID is from about 2 W / cm2to about 5 W / cm2.

[0215] The irradiating protocol employed by the controller at 846 is optionally and preferably different from the irradiating protocol employed in 843. Specifically, 846 is executed according to a protocol in which a pattern of curing radiation is created on the layer wherein the pattern has a shape of two stripes and is advanced along the scanning direction (x or <p). A representative example of an irradiation protocol suitable for operation 843 is illustrated in FIGs. 7C and 7D, showing layer 614 of the object 112 on fabric 420 and a pattern 616 of curing radiation in the form of two straight stripes propagating along the direction x when fabric 420 is on tray 360 (FIG. 7C) or and along the direction cp when fabric 420 is on tray 12 (FIG. 7D). Such a pattern of curing radiation can be created by activating both devices, each at the same power that is used during operation 843. Specifically, when the system is configured to perform reciprocal relative motion along a straight line (e.g., system 110) operation 846 can be executed by activating both the solidification (curing) device that follows the printing head and the solidification (curing) device that is followed by the printing head, and when the system is configured to perform rotary relative motion (e.g., system 10), operation 846 can be executed by activating both the solidification (curing) device that is in front of the printing head with respect to the rotation direction, and the solidification (curing) device that is behind the printing head with respect to the rotation direction. The control over the solidification (curing) devices is typically by means of the controller of the three-dimensional printing system (e.g., controller 20 of system 10 or 110).

[0216] Alternatively, operation 846 can be implemented by doubling or otherwise increasing (e.g., multiplying by 1.2-2) the power of one of the solidification (curing) devices while deactivating the other device, in which case the radiation pattern is as shown in FIGs. 7 A and 7B except that its intensity is doubled or otherwise increased.

[0217] The method ends at 847.

[0218] According to some of any of the embodiments described herein, executing the method described below with reference to FIG. 6 provides an adequate adherence between the object and any fabric.

[0219] The absorbance level of the fabric can be determined before printing using any procedure known in the art. For example, a drop of the dispensed formulation can be applied to the fabric, and the absorbance level can be determined based on the contact angle between the drop and the fabric, wherein higher contact angles correspond to a fabric that is more hydrophobic hence less absorbent. Alternatively, or additionally, the fabric can be immersed in liquid (e.g., water) and the amount of time at which the fabric absorbs the liquid can be correlated to the absorbance level of the fabric.

[0220] In some embodiments of the present invention the method is executed for fabricating an object such as, but not limited to, a lenticular, a prismatic object, an object that is reflective to visible light, an object that is transparent to visible light but reflective to non-visible light, a fluorescent object, and a waveguide. In some embodiments, the fabricated object is capable of changing an optical, mechanical, and / or geometrical property in response to an environmental change, such as, but not limited to, a change in temperature, a change in humidity, a change in electromagnetic content of the environment, and the like. For example, the object can be made of an optically sensitive material that changes its color in response to a change in light condition or temperature.

[0221] In some embodiments of the present invention the method is executed for fabricating an object which comprises an agent such as, but not limited to, a pharmaceutical agent and / or a cosmetic agent. For example, the agent can be adsorbed on the surface of the object (e.g., by applying the agent to the building material as an additive) or the object can be in a form of a capsule containing the agent. Representative examples of pharmaceutical agents that can be incorporated in the object include, without limitation, anti-bacterial agents and anti-viral agents.

[0222] In some embodiments of the present invention, the method is executed for fabricating an object which comprises a heating element capable of releasing heat or a cooling element capable of absorbing heat. In some embodiments the method is executed for fabricating an object which comprises a circuit, and in some embodiments the method is executed for fabricating an object which comprises a cavity for receiving a foreign object, such as, but not limited to, an electric circuit, or a magnetic element, or a light emitting element, or a chip, or a capsule containing a pharmaceutical or cosmetic agent.

[0223] Additive formulations:

[0224] According to an aspect of some embodiments of the present invention, there is provided an additive formulation for use in combination with a modeling material formulation in three- dimensional printing of an object on a fabric.

[0225] According to some embodiments of any of the embodiments described herein, the additive formulation is characterized by one or more of a viscosity in a range of from about 15 to about 25, or from about 15 to about 20, or from about 15.5 to about 18.5, centipoises or mPa- second, at the working (e.g., jetting) temperature; a surface tension in a range of from about 20 to about 40, or from about 24 to about 30, or from about 26 to about 29, or from about 26 to about 28 Dyne / cm; and an adhesion level (e.g., of a hardened material formed therefrom) to a respective fabric of at least 20 N / cm.

[0226] According to some embodiments of any of the embodiments described herein, the additive formulation is characterized by Tg of a hardened material formed therefrom which is higher than 50 °C, and is also referred to herein as a rigid additive formulation or a rigid adhesive formulation.

[0227] According to some embodiments of any of the embodiments described herein, the rigid additive formulation is characterized by Tg of a hardened material formed therefrom that ranges from about 50 to about 90, or from about 50 to about 80, or from about 60 to 80, °C, including any intermediate values and subranges therebetween.

[0228] According to some embodiments of any of the embodiments described herein, the rigid additive formulation is characterized by water absorption of a hardened material formed therefrom that is lower than 25 %, or lower than 20 %, preferably lower than 15 %, or lower than 10 %, for example, in a range of from 0.1 to 20, or from 0.1 to 15, or from 0.1 to 10, or from 1 to 10, or from 2 to 10, or from 5 to 10, or from 2 to 8, or from 2 to 5, %, including any intermediate values and subranges therebetween.

[0229] Herein throughout and in the art, the phrase “water absorption”, which is used herein and in the art interchangeably as “water absorbance”, whereby both these phrases are abbreviated herein as WA, describes an amount of water that a hardened material is capable of absorbing, relative to its weight, when immersed in water at room temperature, for 24 hours. Water absorption of a sample can be determined as described herein in the Examples section that follows. According to some embodiments of any of the embodiments described herein, the rigid additive formulation is characterized by least one or more, or each, of the following properties of a hardened material formed therefrom (e.g., upon exposure to a curing condition as described herein): Tensile Modulus in a range of from 2,000 to 3,000 MPa, including any intermediate values and subranges therebetween; Tensile Strength in a range of from 50 to 70 MPa, including any intermediate values and subranges therebetween; Elongation at break in a range of from 5 to 15 %, including any intermediate values and subranges therebetween; Flexural Modulus in a range of from 2000 to 3000 MPa, including any intermediate values and subranges therebetween; Flexural Stress is a range of from 70 to 120 MPa, including any intermediate values and subranges therebetween; and HDT at 0.45 MPa in a range of from 40 to 80 °C, including any intermediate values and subranges therebetween.

[0230] According to some embodiments of any of the embodiments described herein, the rigid additive formulation is an adhesive (priming) formulation (e.g., a rigid adhesive formulation), which provides, when hardened, an adhesive material or structure (e.g., a rigid adhesive material or structure) on the fabric.

[0231] Optionally, the additive formulation is a coating or finishing formulation, which provides, when hardened, a coating of the object or a part thereof.

[0232] Further optionally, the rigid additive formulation is used as a modeling material formulation, for example, as a modeling material formulation usable for printing a 3D object on a fabric, as described herein in any of the respective embodiments. The additive formulation can be used as a modeling material formulation in cases where a rigid object or a rigid part thereof is desired. In some embodiments, the additive formulation is used in combination with a modeling material formulation, for example, any of the modeling material formulations as described herein, for example, as described in Example 5 in the Examples section hereinbelow, for example, in a digital material (DM) mode as described herein.

[0233] According to some embodiments of any of the embodiments described herein, the rigid additive formulation is both an adhesive (priming) formulation, which provides, when hardened, an adhesive material or structure on the fabric, and a coating or finishing formulation, which provides, when hardened, a coating of the object or a part thereof.

[0234] According to some embodiments of any of the embodiments described herein, the additive formulation is both an adhesive (priming) formulation, which provides, when hardened, an adhesive material or structure on the fabric, and a modeling material formulation used in combination with a modeling material formulation, for example, any of the modeling material formulations as described herein, which provides, when hardened, an object or a part thereof. The rigid additive formulation according to the present embodiments is also referred to herein interchangeably as a rigid adhesive formulation, as a rigid material formulation, or simply as an adhesive or additive formulation, yet, it is to be noted that it can also be used in accordance with any of the embodiments described herein.

[0235] According to some embodiments of any of the embodiments described herein, the rigid additive formulation (rigid material formulation; rigid adhesive formulation) comprises a combination of one or more mono-functional curable material(s) and one or more multi-functional curable material(s).

[0236] According to the present embodiments, the additive formulation comprises: at least one mono-functional curable material featuring, when hardened, Tg higher than 50 °C, which is also referred to herein as Component A; at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C, which is also referred to herein as Component C; at least one multi-functional epoxy-type curable material featuring viscosity lower than 10,000 or lower than 5,000, mPa- sec (centipoises) at 25 °C, which is also referred to herein as Component DI and / or Component D2; and at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C, which is also referred to herein as Component G.

[0237] According to some embodiments of any of the embodiments described herein, a total amount of the mono-functional curable materials in the formulation ranges from about 40 to about 60, or from about 45 to about 55, % by weight of the total weight of the formulation.

[0238] According to some embodiments of any of the embodiments described herein, a total amount of the multi-functional curable materials in the formulation ranges from about 40 to about 60, or from about 45 to about 55, % by weight of the total weight of the formulation.

[0239] According to some embodiments of any of the embodiments described herein, the additive formulation is such that can interact with the fibrous structure of a fabric, for example, by being interlaced or entangled within the fibrous structure, and hence should feature, for example, a viscosity as defined herein.

[0240] As discussed and demonstrated in the Examples section that follows, the present inventors have uncovered that an adhesion level of a hardened material made of an adhesive formulation as described herein is in linear correlation with the Tg of the formulation and that the Tg, in turn, is in inverse correlation to the water absorbance of the formulation. The curable materials included in the formulation are therefore selected so as to provide a relatively low water absorption as described herein, a viscosity as described herein, and Tg as described herein.

[0241] Fabrics typically include a plurality of exposed surface groups, which are typically hydroxy groups or other polar groups, but can also be or include hydrophobic and / or aromatic groups. Groups that are capable of interacting with such surface functional groups typically include groups that are capable of forming transient formation of bond(s), e.g., hydrogen bonds, hydrophobic interactions, aromatic interactions, and like transient bonds, with such functional groups. For example, when the fabric’s surface functional groups are hydrophobic, the groups that are capable of interacting with these functional groups can be an alkyl, a cycloalkyl, and aryl, or a hydrocarbon, as defined herein, which are preferably all-carbon groups, and have 2, 3, 4, or more carbon atoms. When the fabric’s surface functional groups are aromatic, the groups that are capable of interacting with these functional groups can be or comprise aromatic groups such as aryls and / or heteroaryls, as defined herein, which may interact with the surface groups by aromatic interactions such as 7t-7t stacking. When the fabric’s surface functional groups are hydroxy groups or any other polar groups (e.g., carboxylate or amine groups), the groups that are capable of interacting with these functional groups are typically polar groups, that may interact electrostatically with the surface groups, for example, via hydrogen bonding.

[0242] An adhesive formulation as described herein therefore comprises curable materials that were carefully selected to balance the desired low water absorbance and the polarity desired for exhibiting interaction of the formulation with surface groups of the fabric, while featuring the desired viscosity and Tg as described herein.

[0243] According to some of any of the embodiments described herein, the mono-functional curable material Component A features Tg higher than 50 °C, or higher than 80 °C, or for example, feature Tg that ranges from about 50 to about 150, or from about 80 to about 150, or from about 50 to about 100, or from about 80 to about 120, or from about 80 to about 100, °C, including any intermediate values and subranges therebetween.

[0244] Component A as described herein can be hydrophilic or hydrophobic.

[0245] As used herein throughout, the term “hydrophilic” describes a physical property of a material or a portion of a material (e.g., a chemical group in a compound) which accounts for transient formation of bond(s) with water molecules, typically through hydrogen bonding.

[0246] Hydrophilic materials dissolve more readily in water than in oil or other hydrophobic solvents. Hydrophilic materials can be determined by, for example, as having LogP lower than 0.5, when LogP is determined in octanol and water phases, typically at room temperature. Hydrophilic materials can alternatively, or in addition, be determined as featuring a lipophilicity / hydrophilicity balance (HLB), according to the Davies method, of at least 10, or of at least 12.

[0247] As used herein throughout, the term “amphiphilic” describes a property of a material that combines both hydrophilicity, as described herein for hydrophilic materials, and hydrophobicity or lipophilicity, as defined herein for hydrophobic materials.

[0248] Amphiphilic materials typically comprise both hydrophilic groups as defined herein and hydrophobic groups, as defined herein, and are substantially soluble in both water and a water- immiscible solvent (oil).

[0249] Amphiphilic materials can be determined by, for example, as having LogP of 0.8 to 1.2, or of about 1, when LogP is determined in octanol and water phases, typically at room temperature.

[0250] Amphiphilic materials can alternatively, or in addition, be determined as featuring a lipophilicity / hydrophilicity balance (HLB), according to the Davies method, of 3 to 12, or 3 to 9.

[0251] As used herein throughout, the term “hydrophobic” describes a physical property of a material or a portion of a material (e.g., a chemical group in a compound) which does not form bond(s) with water molecules.

[0252] Hydrophobic materials dissolve more readily in oil than in water or other hydrophilic solvents. Hydrophobic materials can be determined by, for example, as having LogP higher than 1, when LogP is determined in octanol and water phases, typically at room temperature.

[0253] Hydrophobic materials can alternatively, or in addition, be determined as featuring a lipophilicity / hydrophilicity balance (HLB), according to the Davies method, lower than 3.

[0254] A hydrophilic material or portion of a material (e.g., a chemical group in a compound) is one that is typically charge-polarized and capable of forming hydrogen bonding.

[0255] Amphiphilic materials typically comprise one or more hydrophilic groups (e.g., a charge- polarized group), in addition to hydrophobic groups.

[0256] A hydrophobic material or portion of a material (e.g., a chemical group in a compound) is one that is typically non-polarized and incapable of forming hydrogen bonding.

[0257] Hydrophilic materials or groups, and amphiphilic materials, typically include one or more electron-donating heteroatoms which form strong hydrogen bonds with water molecules. Such heteroatoms include, but are not limited to, oxygen and nitrogen. Preferably, a ratio of the number of carbon atoms to a number of heteroatoms in a hydrophilic materials or groups is 10:1 or lower, and can be, for example, 8:1, more preferably 7:1, 6:1, 5:1 or 4:1, or lower. It is to be noted that hydrophilicity and amphiphilicity of materials and groups may result also from a ratio between hydrophobic and hydrophilic moieties in the material or chemical group, and does not depend solely on the above-indicated ratio.

[0258] A hydrophilic or amphiphilic material can have one or more hydrophilic groups or moieties. Hydrophilic groups are typically polar groups, comprising one or more electron-donating heteroatoms such as oxygen and nitrogen.

[0259] Exemplary hydrophilic groups include, but are not limited to, an electron-donating heteroatom, a carboxylate, a thiocarboxylate, oxo (=0), a linear amide, hydroxy, a (Cl-4)alkoxy, an (Cl-4)alcohol, a heteroalicyclic (e.g., having a ratio of carbon atoms to heteroatoms as defined herein), a cyclic carboxylate such as lactone, a cyclic amide such as lactam, a carbamate, a thiocarbamate, a cyanurate, an isocyanurate, a thiocyanurate, urea, thiourea, an alkylene glycol (e.g., ethylene glycol or propylene glycol), and a hydrophilic polymeric or oligomeric moiety, as these terms are defined hereinunder, and any combinations thereof (e.g., a hydrophilic group that comprises two or more of the indicated hydrophilic groups).

[0260] In some embodiments, the hydrophilic group is, or comprises, an electron donating heteroatom, a carboxylate, a heteroalicyclic, an alkylene glycol and / or a hydrophilic oligomeric moiety.

[0261] An amphiphilic moiety or group typically comprises one or more hydrophilic groups as described herein and one or more hydrophobic groups, or, can a heteroatom-containing group or moiety in which the ratio of number of carbon atoms to the number of heteroatoms accounts for amphiphilicity.

[0262] Hydrophobic groups include, for example, all-carbon groups such as alkyl, alkenyl, alkynyl, aryl, cycloalkyl, and the like.

[0263] According to some of any of the embodiments described herein, Component A comprises one or more mono-functional (meth)acrylate materials.

[0264] Monomeric mono-functional (meth) acrylate materials according to the present embodiments can be collectively represented by Formula A:

[0265] Formula A wherein Ri is a carboxylate, -C(=O)-O-Ra, R2 is hydrogen (for acrylate) or methyl (methacrylate), and Ra is an aliphatic, alicyclic or aromatic moiety, which can be hydrophilic or hydrophobic, as described herein.

[0266] When the material is an alicyclic monomeric mono-functional (meth) acrylate material(s), Ra can be, for example, an alicyclic moiety such as, but not limited to, isobornyl or any other substituted or unsubstituted cycloalkyl as described herein, or a heteroalicyclic moiety as described herein such as morpholine, tetrahydrofuran, oxalidine, or any other substituted or unsubstituted heteroalicyclic as described herein, wherein the substituent(s), if present for a cycloalkyl or for a heteroalicyclic, do not comprise an aryl or heteroaryl, as defined herein. Exemplary alicyclic monomeric mono-functional acrylate include, but are not limited to isobornylacrylate (IBOA), acryloyl morpholine (ACMO), and a material marketed under the tradename SR-218.

[0267] When the material is an aliphatic monomeric mono-functional (meth)acrylate material(s), Ra can be, for example, a substituted or unsubstituted alkyl or alkylene, or any other short hydrocarbon as defined herein, wherein the substituent(s), if present do not comprise an aryl or heteroaryl, as defined herein.

[0268] When the material is an aromatic monomeric mono-functional (meth)acrylate material(s), Ra can be, or comprise, for example, an aryl or a heteroaryl, as defined herein, for example a substituted or unsubstituted phenyl, a substituted or unsubstituted naphthalenyl, etc., wherein when substituted, there can be 1, 2, 3 or more substituents each being the same or different, or an alkyl or cycloalkyl substituted by one or more substituted or unsubstituted aryl(s) or substituted or unsubstituted heteroaryl(s), as described herein, for example, substituted or unsubstituted benzyl. Exemplary aromatic monomeric mono-functional (meth)acrylates include, for example, a material marketed as CN131B.

[0269] According to some embodiments of any of the embodiments described herein, Component A is a mono-functional (meth)acrylate, for example, acrylate.

[0270] According to some embodiments of any of the embodiments described herein, Component A is or comprises a hydrophilic mono-functional curable material, for example, a hydrophilic mono-functional (meth)acrylate, for example, acrylate, which is also referred to herein as Component Al.

[0271] A hydrophilic mono-functional (meth)acrylate according to some of the present embodiments has Formula I as described herein, wherein Ra is a hydrophilic moiety or group as described herein.

[0272] Any hydrophilic mono-functional (meth)acrylates or other hydrophilic mono-functional curable materials featuring Tg as indicated for Component A or Al are contemplated. According to some of any of the embodiments described herein, Component A comprises or consists of Component Al.

[0273] According to some embodiments of any of the embodiments described herein, Component Al is a hydrophilic mono-functional curable material, featuring Tg that ranges from about 50 to about 150, or from about 80 to about 150, or from about 50 to about 100, or from about 80 to about 120, or from about 80 to about 100, °C, including any intermediate values and subranges therebetween.

[0274] According to some embodiments of any of the embodiments described herein, Component Al is a hydrophilic mono-functional (meth)acrylate, preferably a hydrophilic mono-functional acrylate, featuring Tg that ranges from about 50 to about 150, or from about 80 to about 150, or from about 50 to about 100, or from about 80 to about 120, or from about 80 to about 100, °C, including any intermediate values and subranges therebetween. An exemplary material usable as Component Al is ACMO, although other materials are also contemplated.

[0275] Optionally, the formulation further comprises one or more other mono-functional curable material(s), featuring Tg as indicated for Component A. In exemplary embodiments, the formulation may further comprise one or more hydrophobic mono-functional curable material(s) featuring Tg higher than 50 °C as described herein, which are collectively referred to herein as Component A2. In exemplary embodiments, the formulation may further comprise one or more hydrophobic mono-functional (meth)acrylate material(s) featuring Tg higher than 50 °C as described herein as Component A2. Exemplary such materials (Component A2) can be represented by Formula I above, in which Ra is a hydrophobic moiety as described herein. In exemplary embodiments, Ra is an aliphatic or alicyclic hydrophobic moiety. Exemplary such materials include isobornylacrylate (IBOA) and isobornyl methacrylate (IBOMA).

[0276] Whenever the formulation further comprises Component A2, an amount of Component A2 is no more than 10 %, or no more than 5 %, or no more than 1 %, of the total weight of the formulation.

[0277] Whenever the formulation further comprises Component A2, an amount of Component A2 is no more than 10 %, or no more than 5 %, or no more than 1 %, of the total weight of Component A in the formulation.

[0278] According to some embodiments of any of the embodiments described herein, the formulation is devoid of Component A2.

[0279] According to some embodiments of any of the embodiments described herein, Component A as described herein consists of Component Al as described herein in any of the respective embodiments and any combination thereof. According to some embodiments of any of the embodiments described herein, a total amount of the at least one mono-functional curable material featuring Tg higher than 50 °C (Component A or Al) as described herein is no more than 50 %, preferably no more than 45 %, more preferably no more than 40 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween. According to some of any of the embodiments described herein, a total amount of the at least one hydrophilic mono-functional curable material featuring Tg higher than 50 °C (Component Al) is no more than 40 %, by weight, of the total weight of the formulation. Without being bound by any particular theory, it is assumed that higher amounts of Component Al may adversely affect (increase) the water absorption of the hardened material and thereby affect its adhesion performance. According to some of any of the embodiments described herein, a total amount of the at least one hydrophilic mono-functional curable material featuring Tg higher than 50 °C (Component Al) ranges from 15 to 40, or from 20 to 40, or from 30 to 40, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0280] A rigid material formulation as described herein further comprises at least one additional mono-functional curable material, which features, when hardened, a lower Tg, more specifically, Tg lower than 20, or lower than 0 °C, which is also referred to herein as Component C.

[0281] According to some embodiments of any of the embodiments described herein, the monofunctional curable material Component C features, when hardened, Tg lower than 0 °C, for example, of from 0 to about -50, or from 0 to about -40, or from 0 to about -20, °C, including any intermediate values and subranges therebetween.

[0282] Mono-functional curable materials that feature such a low Tg typically include a flexible, typically long (e.g., of at least 4 carbon atoms in length) moiety or group, which can be an aliphatic moiety, an ethoxylated moiety or an aliphatic urethane moiety.

[0283] A mono-functional curable materials that features when hardened, Tg lower than 0 °C, and include an aliphatic moiety is also referred to herein as Component C3.

[0284] A mono-functional curable materials that features when hardened, Tg lower than 0 °C, and include an ethoxylated moiety is also referred to herein as Component C2.

[0285] A mono-functional curable materials that features when hardened, Tg lower than 0 °C, and include a urethane (e.g., aliphatic urethane) moiety is also referred to herein as Component Cl.

[0286] According to some embodiments of any of the embodiments described herein, the monofunctional curable material Component C is or comprises one or more mono-functional (meth)acrylate material(s) that features, when hardened, Tg lower than 0 °C, for example, of from 0 to about -50, or from 0 to about -40, or from 0 to about -20, °C, including any intermediate values and subranges therebetween.

[0287] According to some embodiments of any of the embodiments described herein, the monofunctional (meth)acrylate material(s) that features, when hardened, Tg lower than 0 °C (Component C) can include one or more of mono-functional aliphatic (meth)acrylate material(s) (Component C3), mono-functional ethoxylated (meth) acrylate material(s) (Component C2), and monofunctional (e.g., aliphatic) urethane (meth) acrylate material(s) (Component Cl).

[0288] Exemplary mono-functional aliphatic (meth) acrylate material(s) that feature when hardened, Tg lower than 0 °C (Component C3), as described herein, include, for example, materials of Formula I in which Ra is an alkyl, typically unsubstituted alkyl, of at least 4, preferably at least 6, or at least 8 or at least 10, carbon atoms in length. Representative examples are materials marketed under the tradenames SR-504D, SR-257C, SR-285, SR-395, SR-335, and Miramer Ml 30, although other materials are also contemplated.

[0289] Exemplary mono-functional ethoxylated (meth) acrylate material(s) that feature when hardened, Tg lower than 0 °C (Component C2), as described herein, include, for example, materials of Formula I in which Ra is a moiety, for example, a hydrocarbon, that comprises 2, 3, 4 or more ethoxylated groups as these are defined herein. Representative examples are materials marketed under the tradenames SR-489 and SR-256.

[0290] Exemplary mono-functional urethane (meth)acrylate material(s) that feature when hardened, Tg lower than 0 °C (Component Cl), as described herein, include, for example, aliphatic, alicyclic and aromatic urethane acrylates. Preferably, Component C is an aliphatic urethane acrylate which comprises at least 4 carbon atoms in its chain (e.g., as Ra in Formula I).

[0291] According to some embodiments of any of the embodiments described herein, the at least one mono-functional urethane (meth) acrylate material Component Cl is a catalyst-free material (e.g., tin-free material).

[0292] Exemplary mono-functional urethane (meth)acrylates featuring the indicated Tg and which are usable as Component Cl include, for example, those marketed under the tradename Genomer, for example, Genomer 1122, including a tin-free material Genomer referred to herein as Genomer 1122TF.

[0293] According to some embodiments of any of the embodiments described herein, Component C comprises two or more of Components Cl, C2 and C3, and in some of these embodiments, at least 50 %, or at least 60 %, or at least 70 %, or at least 80 %, or at least 90 %, by weight, of the total weight of Component C in the formulation is Component C 1. According to some embodiments of any of the embodiments described herein, Component C consists of Component Cl as described herein in any of the respective embodiments.

[0294] According to some embodiments of any of the embodiments described herein, Component C 1 is an aliphatic urethane (meth)acrylate that features, when hardened, low Tg as described herein.

[0295] According to some embodiments of any of the embodiments described herein, Component Cl is an aliphatic urethane acrylate that features, when hardened, low Tg as described herein.

[0296] According to some embodiments of any of the embodiments described herein, a total amount of the at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C) ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0297] According to some embodiments of any of the embodiments described herein, a total amount of the at least one mono-functional (e.g., aliphatic) urethane (meth)acrylate featuring Tg lower than 20, or lower than 0 °C (Component Cl) ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0298] The mono-functional curable materials included in the additive formulation of the present embodiments may further include additional mono-functional curable materials, which feature, when hardened, an intermediate Tg of from 20 to 50 °C, also referred to herein collectively as Component B .

[0299] According to some embodiments of any of the embodiments described herein, a monofunctional curable material Component B comprises one or more mono-functional (meth)acrylate materials that feature, when hardened, such Tg. Such mono-functional (meth)acrylates can be hydrophobic, having Formula I above in which Ra is a hydrophobic moiety, for example, one or more alicyclic moiety / moieties such as cyclohexanol or cyclodecanol, which are referred to herein as Component B l. Representative examples of materials usable as Component B 1 include, without limitation, those marketed under the tradenames SR-420 and SR-789, although any other materials are contemplated. Such mono-functional (meth)acrylates can be hydrophilic, preferably epoxytype, (meth)acrylates, as defined herein, for example, having Formula la described below, which are referred to herein as Component B2, and include, for example, a hydrophilic mono-functional epoxy (meth) acrylate material that features a hydroxy group, such as 2-Hydroxy-3-phenoxypropyl acrylate, which is marketed under the tradename DA- 141. Such mono-functional (meth)acrylates can be polyester (meth)acrylates, as defined herein, which are referred to herein as Component B3, and include, as a representative non-limiting example, the compound marketed under the tradename Genomer 1751. According to some embodiments of any of the embodiments described herein, when one or more of materials defined as Component B is / are included in the additive formulation, a total amount of these materials is no more than 20 %, or no more than 10 %, or no more than 5 %, of the total weight of the formulation.

[0300] According to some embodiments of any of the embodiments described herein, when one or more of materials defined as Component B is / are included in the additive formulation, a total amount of these materials is no more than 20 %, or no more than 10 %, or no more than 5 %, of the total weight of the mono-functional curable materials in the formulation.

[0301] According to some embodiments of any of the embodiments described herein, the monofunctional curable materials in the formulation comprise or consist of Components A and C, as described herein in any of the respective embodiments and any combination thereof.

[0302] According to some embodiments of any of the embodiments described herein, the monofunctional curable materials in the formulation comprise or consist of Components Al and C, as described herein in any of the respective embodiments and any combination thereof.

[0303] According to some embodiments of any of the embodiments described herein, the monofunctional curable materials in the formulation comprise or consist of Components A and C3, as described herein in any of the respective embodiments and any combination thereof.

[0304] According to some embodiments of any of the embodiments described herein, the monofunctional curable materials in the formulation comprise or consist of Components Al and C3, as described herein in any of the respective embodiments and any combination thereof.

[0305] According to some embodiments of any of the embodiments described herein, the rigid additive formulation comprises one or more multi-functional (e.g., di- or tri-functional) epoxy-type curable materials, which are referred to herein as Component D, such as multi-functional epoxytype (meth) acrylate materials.

[0306] According to some embodiments of any of the embodiments described herein, the one or more multi-functional (e.g., di- or tri-functional) epoxy-type curable materials, such as multifunctional epoxy-type (meth)acrylate materials, are such that feature, when hardened, Tg lower than 100 °C, for example, of from 0 to 100, or from 20 to 100, or from 40 to 100, or from 0 to 80, or from 20 to 80, or from 40 to 80, °C, including any intermediate values and subranges therebetween.

[0307] According to some embodiments of any of the embodiments described herein, the one or more multi-functional epoxy-type curable materials Component D each independently features a viscosity at room temperature (e.g., of from 15 to 30, or from 15 to 25, or from 20 to 25 °C) or at 25 °C, which is lower than 10,000 or lower than 5,000 centipoises or mPa- sec. In some embodiments, Component D features a viscosity that ranges from 100 to 10,000 or from 100 to 8,000 or from 100 to 6,000, or from 100 to 5,000, or from 500 to 5,000, or from 1,000 to 5,000, or from 500 to 2,000, or from 500 to 1,500, centipoises or mPa- sec, at 25 °C, including any intermediate values and subranges therebetween.

[0308] According to some embodiments of any of the embodiments described herein, the one or more multi-functional epoxy-type curable materials Component D is each independently a multifunctional epoxy-type (meth)acrylate, for example, a multi-functional epoxy-type acrylate or a difunctional epoxy-type methacrylate. According to some of these embodiments, the one or more multi-functional epoxy-type (meth)acrylates each independently features a viscosity at room temperature or at 25 °C, which is lower than 10,000 or lower than 5,000 centipoises or mPa- sec.

[0309] According to some embodiments of any of the embodiments described herein, Component D comprises one or more multi-functional epoxy-type curable material as described herein, for example, one or more di-functional epoxy-type (meth)acrylates, each independently featuring a viscosity at room temperature or at 25 °C, which is lower than 10,000 or lower than 5,000 centipoises or mPa- sec and each independently featuring, when hardened, Tg lower than 100 °C, for example, of from 0 to 100, or from 20 to 100, or from 40 to 100, or from 0 to 80, or from 20 to 80, or from 40 to 80, °C, including any intermediate values and subranges therebetween.

[0310] According to some embodiments of any of the embodiments described herein, Component D comprises at least one multi-functional epoxy-type curable material featuring a viscosity as indicated at 25 °C, and a viscosity at 70 °C (e.g., a jetting temperature) which is lower than 100 mPa- sec (centipoises), and which is referred to herein as Component D2.

[0311] According to some embodiments of any of the embodiments described herein, Component D2 features a viscosity that ranges from 100 to 5,000, or from 500 to 5,000, or from 100 to 2,000, or from 500 to 2,000, or from 500 to 1,500, centipoises or mPa- sec, at 25 °C, including any intermediate values and subranges therebetween.

[0312] According to some embodiments of any of the embodiments described herein, Component D2 features a viscosity that ranges from 10 to 100, or from 20 to 100, or from 40 to 100, or from 40 to 80, or from 50 to 80, centipoises or mPa- sec, at 70 °C, including any intermediate values and subranges therebetween.

[0313] According to some embodiments of any of the embodiments described herein, Component D2 features a viscosity that ranges from 100 to 5,000, or from 500 to 5,000, or from 100 to 2,000, or from 500 to 2,000, or from 500 to 1,500, centipoises or mPa- sec, at 25 °C, including any intermediate values and subranges therebetween, and a viscosity that ranges from 10 to 100, or from 20 to 100, or from 40 to 100, or from 40 to 80, or from 50 to 80, centipoises or mPa- sec, at 70 °C, including any intermediate values and subranges therebetween. According to some of these embodiments, Component D2 is a di-functional epoxy-type (meth) acrylate. According to some of these embodiments, Component D2 features, when hardened, Tg lower than 100 °C, as described herein in any of the respective embodiments.

[0314] According to some embodiments of any of the embodiments described herein, Component D consists of Component D2.

[0315] An exemplary Component D2 is marketed under the tradename Genomer 2235.

[0316] According to some embodiments of any of the embodiments described herein, Component D comprises at least one multi-functional epoxy-type curable material featuring a viscosity as indicated at 25 °C, and a viscosity at 70 °C (e.g., a jetting temperature) which is higher than 1,000 mPa- sec (centipoises), and which is referred to herein as Component DI.

[0317] According to some embodiments of any of the embodiments described herein, Component DI features a viscosity that ranges from 1,000 to 10,000, or from 2,000 to 10,000, or from 5,000 to 10,000, centipoises or mPa- sec, at 25 °C, including any intermediate values and subranges therebetween.

[0318] According to some embodiments of any of the embodiments described herein, Component DI features a viscosity that is lower than 10,000, or lower than 8,000, or lower than 5,000, or lower than 2,000, centipoises or mPa- sec, at 70 °C.

[0319] According to some embodiments of any of the embodiments described herein, Component DI features a viscosity that ranges from 1,000 to 5,000, or from 1,000 to 3,000, or from 1,000 to 2,000, or from 1,000 to 1,500, or from 1,200 to 2,000, centipoises or mPa- sec, at 70 °C, including any intermediate values and subranges therebetween.

[0320] According to some embodiments of any of the embodiments described herein, Component DI features a viscosity that ranges from 1,000 to 10,000, or from 2,000 to 10,000, or from 5,000 to 10,000,, centipoises or mPa- sec, at 25 °C, including any intermediate values and subranges therebetween, and a viscosity that ranges from 10,000 to 5,000, or from 1,000 to 3,000, or from 1,000 to 2,000, or from 1,000 to 1,500, or from 1,200 to 2,000, centipoises or mPa- sec, at 70 °C, including any intermediate values and subranges therebetween. According to some of these embodiments, Component DI is a di-functional epoxy-type (meth) acrylate. According to some of these embodiments, Component DI features, when hardened, Tg lower than 100 °C, as described herein in any of the respective embodiments.

[0321] An exemplary Component DI is marketed under the tradename Genomer 2281. According to some embodiments of any of the embodiments described herein, an amount of Component DI is no more than 25 % or no more than 20 %, or no more than 15 %, by weight, of the total weight of the formulation, and can range for example, from 5 to 25, or from 5 to 20, or from 5 to 15, or from 10 to 20, or from 10 to 15, or from 5 to 10, % by weight of the total weight of the formulation.

[0322] According to some embodiments of any of the embodiments described herein, an amount of Component D2 ranges for example, from 5 to 40, or from 10 to 40, or from 10 to 30, or from 15 to 30, or from 15 to 25, or from 20 to 30, % by weight of the total weight of the formulation.

[0323] According to some embodiments of any of the embodiments described herein, Component D comprises both Component DI and Component D2, each as described herein in any of the respective embodiments and any combination thereof.

[0324] According to some of these embodiments, a weight ratio of Component DI and Component D2 ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2, including any intermediate value and subranges therebetween.

[0325] According to some embodiments of any of the embodiments described herein, a total amount of Component D, or of Component DI and Component D2, ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0326] According to some embodiments of any of the embodiments described herein, the formulation comprises Component DI in an amount that is no more than 25 % or no more than 20 %, or no more than 15 %, by weight, of the total weight of the formulation, and can range for example, from 5 to 25, or from 5 to 20, or from 5 to 15, or from 10 to 20, or from 10 to 15, or from 5 to 10, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0327] According to some embodiments of any of the embodiments described herein, the formulation comprises Component D2 in an amount that ranges for example, from 5 to 40, or from 10 to 40, or from 10 to 30, or from 15 to 30, or from 15 to 25, or from 20 to 30, % by weight of the total weight of the formulation.

[0328] According to some embodiments of any of the embodiments described herein, Component D comprises a mixture of Component DI and D2, and can include additional epoxy-type curable materials, including such that feature, when hardened, Tg lower than 100 °C, as described herein. Exemplary such compounds are referred to herein as Component D3 and Component D4. According to some of these embodiments, if one or both of Components D3 and D4 are included in the formulation, an amount of each of these components is independently no more than 10 %, or no more than 5 %, or no more than 2 %, by weight, of the total weight of the formulation. In some embodiments, the formulation is devoid of Components described herein as Component D3 and Component D4.

[0329] According to some embodiments of any of the embodiments described herein, the formulation comprises additional multi-functional curable materials, for example, such that feature other chemical compositions and / or other Tg values and / or other viscosities. Exemplary such materials are described herein as Component F, including Component Fl and Component F2, and Component E, including Component El, E2 and E3, as these are defined in Table 1 in the Examples section that follows. Exemplary such additional multi-functional curable materials are those marketed under the tradenames SR-9003; SR-344, Genomer 3497, Genomer 3364, Genomer 5275, Genomer 3486, Genomer 4312 and catalyst-free Genomer 4312TF. Whenever such multifunctional curable materials are included in the formulation, an amount of each is independently no more than 10 %, or no more than 5 %, or no more than 2 %, of the total weight of the formulation.

[0330] According to some embodiments of any of the embodiments described herein, the formulation further comprises a multi-functional (e.g., di-functional and / or tri-functional) (meth)acrylate that feature, when hardened, Tg higher than 100, or higher than 150, °C, and which is also referred to herein as Component G. Without being bound by any particular theory, it is assumed that the inclusion of Component G may be required so as to reduce the water absorbance of the formulation when hardened, since otherwise most of the other components (e.g., at least Component Al, DI and D2) feature polar or hydrophilic group that increase the water absorbance.

[0331] According to some embodiments of any of the embodiments described herein, Component G features, when hardened, Tg of from 100 to 300 °C, or from 150 to 250, or from 150 to 200 °C.

[0332] According to some embodiments of any of the embodiments described herein, Component G is such that features, when hardened, Tg of from 100 to 200, or from 150 to 200, °C.

[0333] According to some embodiments of any of the embodiments described herein, Component G is such that features a viscosity lower than 1,000, or lower than 500, or lower than 300, or lower than 200 cps at 25 °C, for example, a viscosity of from 100 to 1,000, or from 100 to 500, or from 100 to 300, or from 100 to 200, cps at 25 °C, and is referred to herein as Component Gl.

[0334] According to some of any of the embodiments described herein, Component G or Component Gl is a hydrophobic multi-functional material, for example, a hydrophobic difunctional or tri-functional (meth) acrylate which features a viscosity as described herein and Tg, when hardened, as described herein.

[0335] In multi-functional materials, typically, each of the curable (e.g., (meth) acrylate) groups) are linked to one another through a linking moiety. The linking moiety can be a branching unit, such as, for example, a linear (in case of a di-functional material) or branched alkyl, cycloalkyl, aryl (e.g., bisphenol A), etc. (in case of di-, tri- and higher functional materials).

[0336] The multi-functional (e.g., di-functional) curable material Component G can be, for example, an aromatic or non-aromatic (e.g., alicyclic or aliphatic), multi-functional (e.g., di- functional) (meth)acrylate, which comprises at least one aromatic moiety or non-aromatic moiety (e.g., alicyclic or aliphatic) linking moiety that connects between the curable groups (e.g., (meth)acrylate groups).

[0337] According to some embodiments of any of the embodiments described herein, the multifunctional (e.g., di-functional) curable material Component G or G1 is a non-aromatic (e.g., alicyclic or aliphatic, multi-functional (e.g., di-functional) (meth) acrylate), which comprises an alicyclic and / or aliphatic moiety that connects between the curable groups (e.g., (meth)acrylate groups).

[0338] In some of these embodiments, the linking moiety in Component G1 is or comprises an all-carbon alicyclic moiety, optionally a polyalicyclic moiety which comprises 2, 3 or more rings. In some embodiments, the alicyclic moiety is of at least 6, at least 7, at least 8, at least 9 or at least 10, carbon atoms.

[0339] In some embodiments, the linking moiety comprises a polyalicyclic moiety as described herein, in which the two or more rings are fused to one another.

[0340] An exemplary such multi-functional curable material Component G1 is tricyclododecane dimethanol diacrylate (e.g., SR833S, marketed by Sartomer).

[0341] Component G may alternatively or in addition comprise a multi-functional (e.g., di- or trifunctional) (meth) acrylate featuring Tg higher than 200 °C and solid consistency at 25 °C, that is, a viscosity higher than 20,000 cps at 25 °C), which is referred to herein as Component G2. In some embodiments, Component G2 is a tri-functional (meth)acrylate, for example, a tri-functional (meth)acrylate that features cyanurate or isocyanurate moiety or moieties that connect the curable acrylic groups, such as, but not limited to, a material marketed under the tradename SR-368.

[0342] According to some embodiments of any of the embodiments described herein, Component G consists of Component G1 as described herein in any of the respective embodiments. According to some embodiments, Component G comprises a mixture of Components G1 and G2, as described herein. According to some of these embodiments, an amount of Component G2 is no more than 20 %, or no more than 10 %, or no more than 5 %, of the total amount of Component G.

[0343] According to some embodiments of any of the embodiments described herein, a total amount of Component G ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation. According to some embodiments of any of the embodiments described herein, an amount of Component G1 ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation.

[0344] According to some embodiments of any of the embodiments described herein, each of the mono-functional and multi-functional curable materials is a UV-curable material.

[0345] According to some embodiments of any of the embodiments described herein, each of the mono-functional and multi-functional curable materials is a (meth) acrylate material.

[0346] According to some embodiments of any of the embodiments described herein, each of the mono-functional and multi-functional curable materials is an acrylate material.

[0347] According to some embodiments of any of the embodiments described herein, each of the multi-functional curable materials is a multi-functional (e.g., di-functional) acrylate or a multifunctional (e.g., di-functional) epoxy-type acrylate.

[0348] According to some embodiments of any of the embodiments described herein, each of the mono-functional curable materials is a mono-functional acrylate or a mono-functional urethane acrylate.

[0349] In exemplary embodiments, a rigid additive (e.g., adhesive) formulation as described herein comprises: at least one hydrophilic mono-functional (meth)acrylate featuring Tg higher than 50, or higher than 80, °C (Component Al, as described herein in any of the respective embodiments); at least one mono-functional (e.g., aliphatic) urethane (meth) acrylate featuring Tg lower than 20, or lower than 0 °C (Component Cl, as described herein in any of the respective embodiments); at least one multi-functional (e.g., di-functional) epoxy-type (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI, as described herein in any of the respective embodiments); at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2, as described herein in any of the respective embodiments); and at least one hydrophobic multi-functional (e.g., di-functional) (meth) acrylate featuring, when hardened, Tg of from 100 to 200, or from 150 to 200, °C (Component Gl, as described herein in any of the respective embodiments). According to some embodiments of these exemplary embodiments, an amount of the Component Al ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation, .

[0350] According to some of these exemplary embodiments, an amount of the Component Cl ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0351] According to some of these exemplary embodiments, a total amount of the Component DI and the Component D2 ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0352] According to some of these exemplary embodiments, a weight ratio of the Component DI and the Component D2 ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2, including any intermediate values and subranges therebetween.

[0353] According to some of these exemplary embodiments, a total amount of the Component DI and the Component D2 ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween, and a weight ratio of the Component DI and the Component D2 ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2, including any intermediate values and subranges therebetween.

[0354] According to some of these exemplary embodiments, an amount of the Component G1 ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0355] According to some of these exemplary embodiments, an amount of the Component Al ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; an amount of the Component Cl ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; a total amount of the Component DI and the Component D2 ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; a weight ratio of the Component DI and the Component D2 ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2, including any intermediate values and subranges therebetween; and an amount of the Component G1 ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0356] According to some embodiments of any of the embodiments described herein, the additive formulation is a biocompatible formulation, in which all the components, or at least components that are included in an amount higher than 0.1 %, or higher than 0.5 %, or higher than 1 %, are biocompatible.

[0357] According to some embodiments of any of the embodiments described herein, each of the curable materials in the formulation is a biocompatible material.

[0358] According to some embodiments of any of the embodiments described herein, each of the curable materials in the formulation is devoid of materials that are not considered biocompatible, for example, is devoid of metallic catalysts (e.g., is catalyst-free), or any other materials that may be present along with the curable material in a residual amount as a result of the synthetic process used for preparing these curable materials.

[0359] According to some embodiments of any of the embodiments described herein, at least one, or all, of the curable materials in the formulation are photocurable materials (e.g. UV-curable materials such as acrylic materials), and the additive formulation further comprises at least one photoinitiator (Component J).

[0360] According to some embodiments of any of the embodiments described herein, an amount of the photoinitiator ranges from 1 to 3, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0361] According to some embodiments of any of the embodiments described herein, the photoinitiator(s) comprises, or consists essentially of, a phosphine oxide-type (e.g., mono- acrylated (MAPO) or bis-acrylated phosphine oxide-type (BAPO) photoinitiator.

[0362] Exemplary monoacyl and bisacyl phosphine oxides include, but are not limited to, 2,4,6- trimethylbenzoyldiphenyl phosphine oxide, bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide, dibenzoylphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenyl phosphine oxide, tris(2,4- dimethylbenzoyl) phosphine oxide, tris(2-methoxybenzoyl)phosphine oxide, 2,6- dimethoxybenzoyldiphenyl phosphine oxide, 2,6-dichlorobenzoyldiphenyl phosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenyl phosphine oxide, benzoyl-bis(2,6-dimethylphenyl) phosphonate, and 2,4,6-trimethylbenzoylethoxyphenyl phosphine oxide. Commercially available phosphine oxide photoinitiators capable of free-radical initiation when irradiated at wavelength ranges of greater than about 380 nm to about 450 nm include 2,4,6-trimethylbenzoyldiphenyl phosphine oxide (TPO), bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide (marketed as IRGACURE® 819), bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl) phosphine oxide (marketed as CGI 403), a 25:75 mixture, by weight, of bis(2,6-dimethoxybenzoyl)-2,4,4- trimethylpentyl phosphine oxide and 2-hydroxy-2-methyl-l-phenylpropan-l-one (marketed as IRGACURE® 1700), a 1:1 mixture, by weight, of bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide and 2-hydroxy-2-methyl-l -phenylpropane- 1 -one (marketed as DAROCUR® 4265), and ethyl 2,4,6-trimethylbenzylphenyl phosphinate (LUCIRIN LR8893X).

[0363] According to some embodiments of any of the embodiments described herein, the photoinitiator(s) comprises, or consists essentially of, a bis-acrylated phosphine oxide-type (BAPO) photoinitiator.

[0364] In an exemplary embodiments, the photoinitiator is or comprises bis(2,4,6- trimethylbenzoyl)phenyl phosphine oxide (marketed as IRGACURE® 819).

[0365] In an exemplary embodiments, the photoinitiator is devoid of a mono-acrylated (MAPO) phosphine oxide-type photoinitiator, and is some embodiments, it is devoid of 2,4,6- trimethylbenzoyldiphenyl phosphine oxide (marketed as TPO).

[0366] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises additional, non-curable components, such as, for example, inhibitors, surfactants, dispersants, colorants (coloring agents), stabilizers, and the like. Commonly used surfactants, dispersants, colorants and stabilizers are contemplated. Exemplary concentrations of each component, if present, range from about 0.01 to about 1, or from about 0.01 to about 0.5, or from about 0.01 to about 0.1, weight percent, of the total weight of the formulation containing same, including any intermediate values and subranges therebetween. Exemplary components are described hereinafter.

[0367] In some embodiments of any of the embodiments described herein, the formulation comprises a curing inhibitor, that is, an agent that inhibits or reduces an amount of the curing in the absence of a curing condition, which is also referred to herein as Component I. In some embodiments, the inhibitor is a free radical polymerization inhibitor. In some embodiments, an amount of an inhibitor (e.g., Component I, e.g., a free radical inhibitor) ranges from 0.01 to 2, or from 0.01 to 1, or from 0.05 to 0. 5, or from 0.1 to 0.2, weight percent, including any intermediate values and subranges therebetween, depending on the type of inhibitor used. Commonly used inhibitors, such as radical inhibitors, are contemplated.

[0368] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises an inhibitor (Component I), as described herein, for example, a phenol-type inhibitor or any other inhibitor that is commonly used in medical devices or applications and / in food products.

[0369] According to some embodiments of any of the embodiments described herein, an amount of the inhibitor ranges from 0.05 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween. In exemplary embodiments, a free radical inhibitor such as are those of the Genorad™ family (e.g., Genorad 20).

[0370] In exemplary embodiments, such a free radical inhibitor is used in an amount of from 0.1 to 3, or from 0.1 to 2, or from 0.1 to 1, or from 0.1 to 0.5, weight percent, including any intermediate values and subranges therebetween.

[0371] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises one or more dispersant or surfactant (Component H).

[0372] According to some embodiments of any of the embodiments described herein, an amount of the dispersant ranges from 0.01 to 1, or from 0.1 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0373] Exemplary dispersants and surfactants are those marketed as BYK surface additives.

[0374] According to some of these embodiments, the dispersant is such that features curable groups, preferably (meth)acrylic groups.

[0375] According to some embodiments of any of the embodiments described herein, the dispersant is a multi-functional (e.g., di-functional) aliphatic silicon (meth) acrylate.

[0376] According to some embodiments of any of the embodiments described herein, the dispersant is a di-functional aliphatic silicon (meth)acrylate.

[0377] According to some embodiments of any of the embodiments described herein, the dispersant is a multi-functional (e.g., di-functional) aliphatic silicon acrylate.

[0378] According to some embodiments of any of the embodiments described herein, the dispersant is a di-functional aliphatic silicon acrylate.

[0379] According to some embodiments of any of the embodiments described herein, the dispersant has an average MW of at least 1,000, or at least 2,000, or at least 3,000 grams / mol, and is considered as an oligomeric material.

[0380] According to some embodiments of any of the embodiments described herein, the dispersant is a multi-functional (e.g., di-functional) aliphatic silicon (meth)acrylate, having an average MW of at least 1,000 grams / mol as described herein.

[0381] According to some embodiments of any of the embodiments described herein, the dispersant is a di-functional aliphatic silicon (meth)acrylate, having an average MW of at least 1,000 grams / mol as described herein.

[0382] According to some embodiments of any of the embodiments described herein, the dispersant is a multi-functional (e.g., di-functional) aliphatic silicon acrylate, having an average MW of at least 1,000 grams / mol as described herein. According to some embodiments of any of the embodiments described herein, the dispersant is a di-functional aliphatic silicon acrylate, having an average MW of at least 1,000 grams / mol as described herein.

[0383] According to some embodiments of any of the embodiments described herein, the dispersant features, when hardened, low Tg, preferably lower than 0, or lower than -20, or lower than -50, °C.

[0384] According to some embodiments of any of the embodiments described herein, an amount of the dispersant ranges from 0.1 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0385] According to some embodiments of any of the embodiments described herein, the additive formulation is a clear (e.g., transparent), colorless formulation, which is devoid of a coloring agent or pigment.

[0386] According to some embodiments of any of the embodiments described herein, the additive formulation further comprises one or more coloring agent(s) or pigments (Component P).

[0387] The coloring agent can be a pigment or a dye and is preferably a pigment.

[0388] The pigments can be organic and / or inorganic and / or metallic pigments, and in some embodiments the pigments are nanoscale pigments, which include nanoparticles.

[0389] Exemplary inorganic pigments include nanoparticles of titanium oxide, and / or of zinc oxide and / or of silica. Exemplary organic pigments include nano- sized carbon black.

[0390] In some embodiments, combinations of white and color pigments are used to prepare colored cured materials.

[0391] According to some embodiments of any of the embodiments described herein, the coloring agent comprises a mixture of a pigment and at least one (meth)acrylic material, such that the pigment is introduced to the formulation within this mixture.

[0392] According to some embodiments of any of the embodiments described herein, the pigment is a white pigment and the formulation provides a white hardened material.

[0393] According to some embodiments of any of the embodiments described herein, the coloring agent comprises a mixture of a white pigment and one or more curable materials such as (meth)acrylic materials, such that the pigment is introduced to the formulation within this mixture.

[0394] According to some of these embodiments, an amount of the white pigment in the mixture ranges from 20 to 50 % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween. According to some of these embodiments, an amount of the coloring agent, which is a mixture of a white pigment and at least one (meth)acrylic material ranges from 1 to 5 % by weight of the total weight of the formulation.

[0395] According to some embodiments of any of the embodiments described herein, the pigment is a cyan pigment and the formulation provides a cyan hardened material.

[0396] According to some embodiments of any of the embodiments described herein, the coloring agent comprises a mixture of a cyan pigment and one or more curable materials such as (meth)acrylic materials, such that the cyan pigment is introduced to the formulation within this mixture.

[0397] According to some of these embodiments, an amount of the cyan pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0398] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a cyan pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0399] According to some embodiments of any of the embodiments described herein, the pigment is a yellow pigment and the formulation provides a yellow hardened material.

[0400] According to some embodiments of any of the embodiments described herein, the coloring agent comprises a mixture of a yellow pigment and one or more curable materials such as (meth)acrylic materials, such that the yellow pigment is introduced to the formulation within this mixture.

[0401] According to some of these embodiments, an amount of the yellow pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0402] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a yellow pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation.

[0403] According to some embodiments of any of the embodiments described herein, the pigment is a magenta pigment and the formulation provides a magenta hardened material.

[0404] According to some embodiments of any of the embodiments described herein, the coloring agent comprises a mixture of a magenta pigment and one or more curable materials such as (meth)acrylic materials, such that the magenta pigment is introduced to the formulation within this mixture. According to some of these embodiments, an amount of the magenta pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0405] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a magenta pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0406] According to some embodiments of any of the embodiments described herein, the formulation comprises one or more of a white, magenta, cyan, and yellow coloring agents, and in some of these embodiments, each pigment is introduced to the formulation in a mixture with curable materials as described herein.

[0407] According to some embodiments of any of the embodiments described herein, the coloring agent further comprises a pigment dispersant (Component Dp). Preferred pigment dispersants are such that has a plurality of groups that feature an affinity to the pigment.

[0408] According to some embodiments of any of the embodiments described herein, the additive formulation comprises Components H, I, and J, as described herein in any of the respective embodiments. An exemplary such a formulation is a clear colorless formulation, that is devoid of a coloring agent.

[0409] According to some embodiments of any of the embodiments described herein, the additive formulation comprises Components H, I, J and P and optionally Dp, as described herein in any of the respective embodiments. An exemplary such a formulation is a white formulation that comprises a white pigment as described herein.

[0410] According to some embodiments of any of the embodiments described herein, the additive formulation comprises, in addition to the curable materials as described herein in any of the respective embodiments, Components H, I, J, P and optionally Dp, as described herein in any of the respective embodiments.

[0411] Kits:

[0412] In some embodiments of any of the embodiments described herein there is provided a kit comprising one or more rigid additive formulations as described herein in any of the respective embodiments and any combination thereof.

[0413] In some embodiments of any of the embodiments described herein there is provided a kit comprising two or more rigid additive formulations as described herein in any of the respective embodiments and any combination thereof. In some of these embodiments, each formulation is packaged individually in the kit. In some embodiments of any of the embodiments described herein there is provided a kit comprising two or more additive formulations as described herein in any of the respective embodiments and any combination thereof, at least one of these formulations is a rigid additive formulation as described herein in any of the respective embodiments. In some embodiments, the other additive formulation is a flexible additive formulation, for example, as described in Example 4 in the Examples section that follows.

[0414] In exemplary embodiments, the kit comprises a combination of two or more formulations (e.g., two or more additive formulations, for example, two or more rigid additive formulations) that differ from one another by the presence and / or type of the coloring agent or pigment.

[0415] In exemplary embodiments, the kit comprises a combination of two or more rigid additive formulations that differ from one another by the presence and / or type of the coloring agent or pigment, and two or more flexible additive formulations, that differ from one another by the presence and / or type of the coloring agent or pigment.

[0416] In exemplary embodiments, the kit comprises a combination of two or more additive formulations, at least one additive formulation being usable as an adhesive formulation and at least one additive formulation being usable as a coating formulation, as described herein.

[0417] A kit as described herein is usable for additive manufacturing of a three-dimensional object on a fabric, as containing one or more additive formulation(s).

[0418] In some embodiments of any of the embodiments described herein, the kit further comprises one or more modeling material formulation(s), which can be any of the aforementioned modeling material formulations. In exemplary embodiments, the kit further comprises a formulation as described in Example 5 in the Examples section that follows, to be used as a modeling material formulation, as described herein. In some of these embodiments, each formulation is packaged individually in the kit.

[0419] In exemplary embodiments, the formulations are packaged within the kit in a suitable packaging material, preferably, an impermeable material (e.g., water- and gas-impermeable material), and further preferably an opaque material. In some embodiments, the kit further comprises instructions to use the formulations in an additive manufacturing process, preferably a 3D inkjet printing process as described herein. The kit may further comprise instructions to use the formulations in the process in accordance with the method as described herein.

[0420] Objects and Articles-of-manufacturing:

[0421] According to some embodiments of the present invention, there is provided a three- dimensional object obtained by an additive manufacturing process as described herein, using at least one rigid additive formulation as described herein in any of the respective embodiments and any combination thereof.

[0422] According to some embodiments, the object is formed on a substrate, for example, a fabric as described herein.

[0423] According to some embodiments of the present invention, there is provided an article-of- manufacturing, which comprises a substrate and a three-dimensional object as described herein applied on at least a portion of a surface of the substrate.

[0424] In some of these embodiments, the substrate is a fabric as described herein, and the article- of-manufacturing can be any article that comprises a fabric or is made of fabric, for example, a garment, or any of the other fabric-containing articles such as described herein.

[0425] As used herein the term “about” refers to ± 10 % or ± 5 %.

[0426] The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to".

[0427] The term “consisting of’ means “including and limited to”.

[0428] The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0429] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0430] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0431] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging / ranges between” a first indicate number and a second indicate number and “ranging / ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0432] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

[0433] Herein throughout, whenever the phrase “weight percent”, or “% by weight” or “% wt ”, is indicated in the context of embodiments of a formulation (e.g., a modeling formulation), it is meant weight percent of the total weight of the respective uncured formulation.

[0434] Herein throughout, an acrylic material is used to collectively describe material featuring one or more acrylate, methacrylate, acrylamide and / or methacrylamide group(s).

[0435] Similarly, an acrylic group is used to collectively describe curable groups which are acrylate, methacrylate, acrylamide and / or methacrylamide group(s), preferably acrylate or methacrylate groups (referred to herein also as (meth)acrylate groups).

[0436] Herein throughout, the term “(meth) acrylic” encompasses acrylic and methacrylic materials.

[0437] Herein throughout, the phrase “linking moiety” or “linking group” describes a group that connects two or more moieties or groups in a compound. A linking moiety is typically derived from a bi- or tri-functional compound, and can be regarded as a bi- or tri-radical moiety, which is connected to two or three other moieties, via two or three atoms thereof, respectively.

[0438] Exemplary linking moieties include a hydrocarbon moiety or chain, optionally interrupted by one or more heteroatoms, as defined herein, and / or any of the chemical groups listed below, when defined as linking groups.

[0439] When a chemical group is referred to herein as “end group” it is to be interpreted as a substituent, which is connected to another group via one atom thereof.

[0440] Herein throughout, the term “hydrocarbon” collectively describes a chemical group composed mainly of carbon and hydrogen atoms. A hydrocarbon can be comprised of alkyl, alkene, alkyne, aryl, and / or cycloalkyl, each can be substituted or unsubstituted, and can be interrupted by one or more heteroatoms. The number of carbon atoms can range from 2 to 30, and is preferably lower, e.g., from 1 to 10, or from 1 to 6, or from 1 to 4. A hydrocarbon can be a linking group or an end group. Bisphenol A is an example of a hydrocarbon comprised of 2 aryl groups and one alkyl group. Dimethylenecyclohexane is an example of a hydrocarbon comprised of 2 alkyl groups and one cycloalkyl group.

[0441] As used herein, the term “amine” describes both a -NR’R” group and a -NR'- group, wherein R’ and R" are each independently hydrogen, alkyl, cycloalkyl, aryl, as these terms are defined hereinbelow.

[0442] The amine group can therefore be a primary amine, where both R’ and R” are hydrogen, a secondary amine, where R’ is hydrogen and R” is alkyl, cycloalkyl or aryl, or a tertiary amine, where each of R’ and R” is independently alkyl, cycloalkyl or aryl.

[0443] Alternatively, R' and R" can each independently be hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, carbonyl, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.

[0444] The term “amine” is used herein to describe a -NR'R" group in cases where the amine is an end group, as defined hereinunder, and is used herein to describe a -NR'- group in cases where the amine is a linking group or is or part of a linking moiety.

[0445] The term "alkyl" describes a saturated aliphatic hydrocarbon including straight chain and branched chain groups. Preferably, the alkyl group has 1 to 30, or 1 to 20 carbon atoms. Whenever a numerical range; e.g., " 1-20", is stated herein, it implies that the group, in this case the alkyl group, may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. The alkyl group may be substituted or unsubstituted. Substituted alkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.

[0446] The alkyl group can be an end group, as this phrase is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, which connects two or more moieties via at least two carbons in its chain. When the alkyl is a linking group, it is also referred to herein as “alkylene” or “alkylene chain”.

[0447] Alkene and Alkyne, as used herein, are an alkyl, as defined herein, which contains one or more double bond or triple bond, respectively. The term "cycloalkyl" describes an all-carbon monocyclic ring or fused rings (z.e., rings which share an adjacent pair of carbon atoms) group where one or more of the rings does not have a completely conjugated pi-electron system. Examples include, without limitation, cyclohexane, adamantine, norbomyl, isobomyl, and the like. The cycloalkyl group may be substituted or unsubstituted. Substituted cycloalkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C- carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The cycloalkyl group can be an end group, as this phrase is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof.

[0448] The term "heteroalicyclic" describes a monocyclic or fused ring group having in the ring(s) one or more atoms such as nitrogen, oxygen and sulfur. The rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi-electron system. Representative examples are piperidine, piperazine, tetrahydrofurane, tetrahydropyrane, morpholino, oxalidine, and the like.

[0449] The heteroalicyclic may be substituted or unsubstituted. Substituted heteroalicyclic may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, O-carbamate, N-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The heteroalicyclic group can be an end group, as this phrase is defined hereinabove, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof.

[0450] The term "aryl" describes an all-carbon monocyclic or fused-ring polycyclic (z.e., rings which share adjacent pairs of carbon atoms) groups having a completely conjugated pi-electron system. The aryl group may be substituted or unsubstituted. Substituted aryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The aryl group can be an end group, as this term is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this term is defined hereinabove, connecting two or more moieties at two or more positions thereof.

[0451] The term "heteroaryl" describes a monocyclic or fused ring (z.e., rings which share an adjacent pair of atoms) group having in the ring(s) one or more atoms, such as, for example, nitrogen, oxygen and sulfur and, in addition, having a completely conjugated pi-electron system. Examples, without limitation, of heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline and purine. The heteroaryl group may be substituted or unsubstituted. Substituted heteroaryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, hetero alicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, O-carbamate, N-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The heteroaryl group can be an end group, as this phrase is defined hereinabove, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof. Representative examples are pyridine, pyrrole, oxazole, indole, purine and the like.

[0452] The term "halide" and “halo” describes fluorine, chlorine, bromine or iodine.

[0453] The term “haloalkyl” describes an alkyl group as defined above, further substituted by one or more halide.

[0454] The term “sulfate” describes a -O-S(=O)2-OR’ end group, as this term is defined hereinabove, or an -O-S(=O)2-O- linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove.

[0455] The term “thiosulfate” describes a -O-S(=S)(=O)-OR’ end group or a -O-S(=S)(=O)-O- linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove.

[0456] The term “sulfite” describes an -O-S(=O)-O-R’ end group or a -O-S(=O)-O- group linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove.

[0457] The term “thiosulfite” describes a -O-S(=S)-O-R’ end group or an -O-S(=S)-O- group linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove.

[0458] The term “sulfinate” describes a -S(=O)-OR’ end group or an -S(=O)-O- group linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove. The term “sulfoxide” or “sulfinyl” describes a -S(=O)R’ end group or an -S(=O)- linking group, as these phrases are defined hereinabove, where R’ is as defined hereinabove.

[0459] The term "sulfonate” describes a -S(=O)2-R’ end group or an -S(=O)2- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0460] The term “S-sulfonamide” describes a -S(=O)2-NR’R” end group or a -S(=O)2-NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0461] The term "N- sulfonamide" describes an R’S(=O)2-NR”- end group or a -S(=O)2-NR’- linking group, as these phrases are defined hereinabove, where R’ and R’ ’ are as defined herein.

[0462] The term “disulfide” refers to a -S-SR’ end group or a -S-S- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0463] The term “phosphonate” describes a -P(=O)(OR’)(OR”) end group or a -P(=O)(OR’)(O)- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0464] The term “thiophosphonate” describes a -P(=S)(OR’)(OR”) end group or a -P(=S)(OR’)(O)- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0465] The term “phosphinyl” describes a -PR'R" end group or a -PR’- linking group, as these phrases are defined hereinabove, with R’ and R" as defined hereinabove.

[0466] The term “phosphine oxide” describes a -P(=O)(R’)(R”) end group or a -P(=O)(R’)- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0467] The term “phosphine sulfide” describes a -P(=S)(R’)(R”) end group or a -P(=S)(R’)- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0468] The term “phosphite” describes an -O-PR'(=O)(OR") end group or an -O-PH(=O)(O)- linking group, as these phrases are defined hereinabove, with R’ and R" as defined herein.

[0469] The term "carbonyl" or "carbonate" as used herein, describes a -C(=O)-R’ end group or a -C(=O)- linking group, as these phrases are defined hereinabove, with R’ as defined herein.

[0470] The term "thiocarbonyl" as used herein, describes a -C(=S)-R’ end group or a -C(=S)- linking group, as these phrases are defined hereinabove, with R’ as defined herein.

[0471] The term “oxo” as used herein, describes a (=0) group, wherein an oxygen atom is linked by a double bond to the atom (e.g., carbon atom) at the indicated position.

[0472] The term “thiooxo” as used herein, describes a (=S) group, wherein a sulfur atom is linked by a double bond to the atom (e.g., carbon atom) at the indicated position. The term “oxime” describes a =N-OH end group or a =N-O- linking group, as these phrases are defined hereinabove.

[0473] The term “hydroxyl” describes a -OH group.

[0474] The term "alkoxy" describes both an -O-alkyl and an -O-cycloalkyl group, as defined herein. The term alkoxide describes -R’O“ group, with R’ as defined herein.

[0475] The term "aryloxy" describes both an -O-aryl and an -O-heteroaryl group, as defined herein.

[0476] The term "thiohydroxy" or “thiol” describes a -SH group. The term “thiolate” describes a -S’ group.

[0477] The term "thioalkoxy" describes both a -S-alkyl group, and a -S-cycloalkyl group, as defined herein.

[0478] The term "thioaryloxy" describes both a -S-aryl and a -S-heteroaryl group, as defined herein.

[0479] The “hydroxyalkyl” is also referred to herein as “alcohol”, and describes an alkyl, as defined herein, substituted by a hydroxy group.

[0480] The term "cyano" describes a -C=N group.

[0481] The term “isocyanate” describes an -N=C=O group.

[0482] The term “isothiocyanate” describes an -N=C=S group.

[0483] The term "nitro" describes an -NO2 group.

[0484] The term “acyl halide” describes a -(C=O)R"" group wherein R"" is halide, as defined hereinabove.

[0485] The term "azo" or “diazo” describes an -N=NR’ end group or an -N=N- linking group, as these phrases are defined hereinabove, with R’ as defined hereinabove.

[0486] The term "peroxo" describes an -O-OR’ end group or an -O-O- linking group, as these phrases are defined hereinabove, with R’ as defined hereinabove.

[0487] The term “carboxylate” as used herein encompasses C-carboxylate and O-carboxylate.

[0488] The term “C-carboxylate” describes a -C(=0)-0R’ end group or a -C(=O)-O- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0489] The term “O-carboxylate” describes a -0C(=0)R’ end group or a -OC(=O)- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0490] A carboxylate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-carboxylate, and this group is also referred to as lactone. Alternatively, R’ and O are linked together to form a ring in O-carboxylate. Cyclic carboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group. The term “thiocarboxylate” as used herein encompasses C-thiocarboxylate and O- thiocarboxylate.

[0491] The term “C-thiocarboxylate” describes a -C(=S)-OR’ end group or a -C(=S)-O- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0492] The term “O-thiocarboxylate” describes a -OC(=S)R’ end group or a -OC(=S)- linking group, as these phrases are defined hereinabove, where R’ is as defined herein.

[0493] A thiocarboxylate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-thiocarboxylate, and this group is also referred to as thiolactone. Alternatively, R’ and O are linked together to form a ring in O-thiocarboxylate. Cyclic thiocarboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0494] The term “carbamate” as used herein encompasses N-carbamate and O-carbamate.

[0495] The term “N-carbamate” describes an R”OC(=O)-NR’- end group or a -OC(=O)-NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0496] The term “O-carbamate” describes an -OC(=O)-NR’R” end group or an -OC(=O)- NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0497] A carbamate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in O-carbamate. Alternatively, R’ and O are linked together to form a ring in N-carbamate. Cyclic carbamates can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0498] The term “carbamate” as used herein encompasses N-carbamate and O-carbamate..

[0499] The term “thiocarbamate” as used herein encompasses N-thiocarbamate and O- thiocarbamate.

[0500] The term “O-thiocarbamate” describes a -OC(=S)-NR’R” end group or a -OC(=S)-NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0501] The term “N-thiocarbamate” describes an R”OC(=S)NR’- end group or a -OC(=S)NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0502] Thiocarbamates can be linear or cyclic, as described herein for carbamates.

[0503] The term “dithiocarbamate” as used herein encompasses S -dithiocarbamate and N- dithiocarbamate.

[0504] The term “S -dithiocarbamate” describes a -SC(=S)-NR’R” end group or a -SC(=S)NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein. The term “N-dithiocarbamate” describes an R”SC(=S)NR’- end group or a -SC(=S)NR’- linking group, as these phrases are defined hereinabove, with R’ and R” as defined herein.

[0505] The term "urea", which is also referred to herein as “ureido”, describes a -NR’C(=O)- NR”R’ ’ ’ end group or a -NR’C(=O)-NR”- linking group, as these phrases are defined hereinabove, where R’ and R” are as defined herein and R'" is as defined herein for R' and R".

[0506] The term “thiourea”, which is also referred to herein as “thioureido”, describes a -NR’- C(=S)-NR”R”’ end group or a -NR’-C(=S)-NR”- linking group, with R’, R” and R’” as defined herein.

[0507] The term “amide” as used herein encompasses C-amide and N-amide.

[0508] The term “C-amide” describes a -C(=O)-NR’R” end group or a -C(=O)-NR’- linking group, as these phrases are defined hereinabove, where R’ and R” are as defined herein.

[0509] The term “N-amide” describes a R’C(=O)-NR”- end group or a R’C(=O)-N- linking group, as these phrases are defined hereinabove, where R’ and R” are as defined herein.

[0510] An amide can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-amide, and this group is also referred to as lactam. Cyclic amides can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0511] The term “guanyl” describes a R’R”NC(=N)- end group or a -R’NC(=N)- linking group, as these phrases are defined hereinabove, where R’ and R” are as defined herein.

[0512] The term “guanidine” describes a -R’NC(=N)-NR”R”’ end group or a - R’NC(=N)- NR”- linking group, as these phrases are defined hereinabove, where R’, R" and R'" are as defined herein.

[0513] The term “hydrazine” describes a -NR’-NR”R’” end group or a -NR’ -NR”- linking group, as these phrases are defined hereinabove, with R’, R”, and R'" as defined herein.

[0514] As used herein, the term “hydrazide” describes a -C(=O)-NR’-NR”R”’ end group or a - C(=O)-NR’-NR”- linking group, as these phrases are defined hereinabove, where R’, R” and R’” are as defined herein.

[0515] As used herein, the term “thiohydrazide” describes a -C(=S)-NR’-NR”R”’ end group or a -C(=S)-NR’-NR”- linking group, as these phrases are defined hereinabove, where R’, R” and R’” are as defined herein.

[0516] OR OR

[0517] The term “cyanurate” describes an g p linking group, with R’ and R’ ’ as defined herein. The term “isocyanurate” describes linking group, with R’ and R’ ’ as defined herein.

[0518] The term “thiocyanurate” describes linking group, with R’ and R’ ’ as defined herein.

[0519] As used herein, the term “alkylene glycol” describes a -O-[(CR’R”)Z-O]y-R”’ end group or a -O-[(CR’R”)Z-O]y- linking group, with R’, R” and R’” being as defined herein, and with z being an integer of from 1 to 10, preferably, from 2 to 6, more preferably 2 or 3, and y being an integer of 1 or more. Preferably R’ and R” are both hydrogen. When z is 2 and y is 1, this group is ethylene glycol. When z is 3 and y is 1, this group is propylene glycol. When y is 2-4, the alkylene glycol is referred to herein as oligo(alkylene glycol).

[0520] Herein, an “ethoxylated” material describes an acrylic or methacrylic compound which comprises one or more alkylene glycol groups, or, preferably, one or more alkylene glycol chains, as defined herein. Ethoxylated (meth)acrylate materials can be mono-functional, or, preferably, multi-functional, namely, di-functional, tri-functional, tetra-functional, etc.

[0521] In multi-functional materials, typically, each of the (meth)acrylate groups are linked to an alkylene glycol group or chain, and the alkylene glycol groups or chains are linked to one another through a branching unit, such as, for example, a branched alkyl, cycloalkyl, aryl (e.g., Bisphenol A), etc.

[0522] In some embodiments, the ethoxylated material comprises at least one, or at least two ethoxylated group(s), that is, at least one or at least two alkylene glycol moieties or groups. Some or all of the alkylene glycol groups can be linked to one another to form an alkylene glycol chain. For example, an ethoxylated material that comprises 30 ethoxylated groups can comprise a chain of 30 alkylene glycol groups linked to one another, two chains, each, for example, of 15 alkylene glycol moieties linked to one another, the two chains linked to one another via a branching moiety, or three chains, each, for example, of 10 alkylene glycol groups linked to one another, the three chains linked to one another via a branching moiety. Shorter and longer chains are also contemplated. The ethoxylated material can comprise one, two or more alkylene glycol chains, of any length.

[0523] The term “branching unit” as used herein describes a multi-radical, preferably aliphatic or alicyclic group. By “multi-radical” it is meant that the unit has two or more attachment points such that it links between two or more atoms and / or groups or moieties.

[0524] In some embodiments, the branching unit is derived from a chemical moiety that has two, three or more functional groups. In some embodiments, the branching unit is a branched alkyl or a cycloalkyl (alicyclic) or an aryl (e.g., phenyl) as defined herein.

[0525] Herein throughout, the phrase “epoxy-type” with respect to a curable material describes a material featuring a curable group (e.g., a (meth) acrylate group as defined herein) and one or more groups derived from epoxide, for example, a -O-CH2-CH2-CH(OH)- group. Epoxy types materials can be monomeric, oligomeric or polymeric curable materials. In some embodiments, epoxy-type curable materials polymerize and / or crosslink by radical polymerization, as described herein. In some embodiments, the epoxy-type curable material is an epoxy (meth) acrylate. In some embodiments, the epoxy-type curable material is an epoxy acrylate.

[0526] Herein throughout, the term “polyether” describes a polymeric moiety that features a plurality of -O- groups, for example, a plurality of -R’-O-R”- groups in its backbone chain, with R’ and R” as described herein. A poly(alkylene glycol) is an exemplary polyether. An ethoxylated material as defined herein is also an exemplary polyether.

[0527] Herein throughout, the term “polyamine” describes a polymeric moiety that features a plurality of -NH- groups in its backbone change, for example, a plurality of -R’-NH-R”- groups, with R’ and R” as described herein and / or a plurality of amine pendant groups.

[0528] Herein throughout, the term “polyester” describes a polymeric moiety that features a plurality of -O-C(=O)- groups, for example, a plurality of -R’-O-C(=O)-R”- groups in its backbone chain, with R’ and R” as described herein and / or a plurality of pendant carboxylate groups.

[0529] As used herein, the phrase “impact resistance”, which is also referred to interchangeably, herein and in the art, as “impact strength” or simply as “impact”, describes the resistance of a material to fracture by a mechanical impact, and is expressed in terms of the amount of energy absorbed by the material before complete fracture. Impact resistance can be measured using, for example, the ASTM D256-06 standard Izod impact testing (also known as “Izod notched impact”, or as “Izod impact”), and / or as described hereinunder, and is expressed as J / m.

[0530] As used herein, HDT refers to a temperature at which the respective formulation or combination of formulations deforms under a predetermined load at some certain temperature. Suitable test procedures for determining the HDT of a formulation or combination of formulations are the ASTM D-648 series, particularly the ASTM D-648-06 and ASTM D-648-07 methods. In various exemplary embodiments of the invention the core and shell of the structure differ in their HDT as measured by the ASTM D-648-06 method as well as their HDT as measured by the ASTM D-648-07 method. In some embodiments of the present invention the core and shell of the structure differ in their HDT as measured by any method of the ASTM D-648 series. In the majority of the examples herein, HDT at a pressure of 0.45 MPa was used.

[0531] Herein, "Tg" of a material refers to glass transition temperature defined as the location of the local maximum of the E" curve, where E" is the loss modulus of the material as a function of the temperature.

[0532] Broadly speaking, as the temperature is raised within a range of temperatures containing the Tg temperature, the state of a material, particularly a polymeric material, gradually changes from a glassy state into a rubbery state.

[0533] Herein, "Tg range" is a temperature range at which the E" value is at least half its value (e.g., can be up to its value) at the Tg temperature as defined above.

[0534] Without wishing to be bound to any particular theory, it is assumed that the state of a polymeric material gradually changes from the glassy state into the rubbery within the Tg range as defined above. The lowest temperature of the Tg range is referred to herein as Tg(low) and the highest temperature of the Tg range is referred to herein as Tg(high).

[0535] Herein throughout, whenever a Tg value is indicated for a curable material or formulation, it relates to the hardened material obtained from this curable material per se, for example, for a homopolymer formed of the curable material, or to the hardened material formed of the formulation, respectively.

[0536] Herein throughout, whenever a curable material is defined by a property of a hardened material obtained therefrom, it is to be understood that this property is for a hardened material obtained from this curable material per se, for example, for a homopolymer formed of the curable material.

[0537] By “Tensile strength” it is meant the maximum stress that a material can withstand while being stretched or pulled before breaking. Tensile strength may be determined, for example, according to ASTM D-638-03.

[0538] By “Tensile modulus” it is meant the stiffness of a material, defined as the relationship between stress (force per unit area) and strain (proportional deformation) in a material in the linear elasticity regime of a uniaxial deformation. Tensile modulus may be determined, for example, according to ASTM D-638-04. By “flexural strength” or “flexural stress” it is meant the stress in a material just before it yields in a flexure test. Flexural strength may be determined, for example, according to ASTM D- 790-03, unless otherwise indicated.

[0539] By “flexural modulus” or “flexural Y modulus” it is meant the ratio of stress to strain in flexural deformation, which is determined from the slope of a stress-strain curve produced by a flexural test such as the ASTM D790. Flexural modulus may be determined, for example, according to ASTM D-790-04, unless otherwise indicated.

[0540] According to some embodiments, flexural strength and flexural modulus are determined in accordance to ISO 20795-1(8.5).

[0541] Herein throughout, unless otherwise indicated, viscosity values are provided for a viscosity of a material or a formulation when measured at 25 °C on a Brookfield’s viscometer. Measured values are provided in centipoise units, which correspond to mPa / second units.

[0542] By “transparent curable formulation” it is meant a curable formulation, as defined herein, which provides, when hardened, a transparent material. Such a formulation is also referred to herein as “clear” formulation, and encompasses formulations that are devoid of pigments, as described herein.

[0543] The term “transparent” describes a property of a hardened material that reflects the transmittance of light therethrough. A transparent material is typically characterized as capable of transmitting at least 70 % of a light that passes therethrough, or by transmittance of at least 70 %. Transmittance of a material can be determined using methods well known in the art.

[0544] A transparent curable formulation as described herein can be transparent also before it is hardened.

[0545] A transparent curable formulation as described herein can be characterized as colorless and / or by color properties as determined by the L*a*b* scale, as described hereinafter for a hardened material.

[0546] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0547] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples. EXAMPLES

[0548] Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non-limiting fashion.

[0549] EXPERIMENTAL METHODS

[0550] Formulations were printed using a 3D-inkjet system as described in FIG. 1A or FIGs. 1B- D, equipped with a LED source of curing energy as described herein.

[0551] Adhesive formulations were printed along with a modeling material formulation in accordance with the method depicted in FIG. 6. Adhesive structures featuring a thickness of 0.1- 1 mm were printed directly on a fabric substrate.

[0552] Unless otherwise indicated, the adhesive formulations were printed in accordance with the method described in FIG. 6, while printing 10 layers of the adhesive formulation (Ni=10) and curing the same with two UV lamps at an irradiation intensity of about 3 W / cm2each (e.g., as in FIGs. 7C and 7D) subsequently printing 10 layers of the modeling material formulation and curing the same with two UV lamps at irradiation intensity of about 3 W / cm2each (e.g., as in FIGs. 7C and 7D), subsequently printing the following modeling material formulation layers and curing the same with one UV lamp at irradiation intensity of about 1.5 W / cm2(e.g., as in FIGs. 7A and 7B), and applying two scans with two UV lamps at an irradiation intensity of about 1.5 W / cm2each (e.g., as in FIGs. 7C and 7D).

[0553] Unless otherwise indicated, in all of the operations described herein, printing was performed using, as a modeling material formulation, an exemplary white (e.g., flexible) formulation such as described in WO 2024 / 142069 and in Example 5 hereinbelow.

[0554] Printability was determined by inspecting formulation’s compatibility with a 3D-inkjet system (e.g., as described in FIG. 1A or FIGs. 1B-D; and / or a system equipped with a LED source of curing energy), in terms of viscosity, reactivity, jettability, etc.

[0555] Curling and deformation were visually inspected.

[0556] Formulations were prepared by mixing all components at room temperature unless otherwise indicated. Powder components such as photoinitiators were dissolved at 85 °C for 30 minutes.

[0557] Viscosity was measured using a Brookfield viscometer, at the indicated temperature, and is presented in centipoise units (cps), which correspond to mPa- second.

[0558] Surface tension was measured using a Kruss K6 Force Tensiometer, and is presented in Dyne / cm units. Adhesion (peel strength) was measured in accordance with ASTM D751 - Standard Methods for Coated Fabrics and is expressed as the maximal force (N / cm) required for detachment. An exemplary testing sample and testing device for measuring adhesion is presented in FIGs. 8 A and 8B.

[0559] Jettability was evaluated, for example, by recording the jetting pattern using a fast camera and analytical weight, and / or by using, for example, a jetting station which tests jetting parameters relevant to the printing process.

[0560] Tg values as presented herein are calculated values based on the Molecular Weights of the monomers, the respective Tg of each monomer and its amount in the formulation.

[0561] Water Absorption was measured in accordance with ASTM D-570, using a 60 x 60 x 1 mm 3D-printed test specimen, as follows:

[0562] Water absorption type specimens were printed in XY orientation, in a glossy mode; cleaned to fully remove the support material (if used) and / or with a cloth wetted with ethanol. The water absorption test is preferably performed at least 24 hours after printing, but no later than 5 days after printing. During this time period, the printed specimens are kept at standard lab conditions 20-25 °C-.

[0563] The printed specimens are dried in an oven for 24 hours at 50 ± 3 °C, cooled in a desiccator for 1 hour, and immediately weighed on an analytical balance to the nearest 0.0001 gram (write 5 digits after decimal point). The thus conditioned specimens are fully immersed in a container filled with distilled water and maintained at temperature of 23 ± 1 °C. Following 24 ± 0.5 hours in water, the specimens are removed from the container, surface water are wiped off and the specimens are re-weighed on the analytical balance. Optionally, the specimens are subjected to re-conditioning in an oven for 24 hours at 50 ± 3 °C, followed by cooling in a desiccator for 1 hour and are then weighed.

[0564] The change in the specimen weight following immersion in water is calculated as % by weight of the specimen original weight (after printing, cleaning and drying and before being immersed in water and after drying).

[0565] Tear Resistance (TR) was determined in accordance with ASTM D 624 and is expressed by N / m units.

[0566] Shore A hardness was determined using a Shore A durometer, in accordance to ASTM-

[0567] 2240.

[0568] Other properties were determined as described herein. EXAMPLE 1

[0569] Design

[0570] WO 2024 / 142068 describes curable formulations that provide a suitable adhesive material or structure and / or a suitable coating to 3D objects printed on fabrics. The formulations taught therein were designed so as to include curable materials that feature functional groups that may interact with functional groups of common fabrics, preferably polar protic functional groups that may interact (e.g., via hydrogen bond formation) with hydroxy groups that are typically present on fabric’s surfaces, and as characterized by Tg lower than 50 °C.

[0571] The present inventors have now turned to design additional curable formulations that can be efficiently used as additive formulations, for forming an adhesive material.

[0572] More specifically, the present inventors have turned to design formulations that can serve as curable adhesive additive formulations, which are dispensed from the printing heads and form a configured pattern of an adhesive material that promotes adhesion of the modeling material formed of subsequently dispensed modeling material formulation(s). Such curable formulations can also serve as coating formulations which are dispensed from the printing heads subsequent to the formation of a model object by dispensing modeling material formulation(s), and form a configured pattern of a coating material that improves properties of the printed object such as tear resistance and durability (in terms, of e.g., maintaining color of the object, withstanding washing, etc.).

[0573] The newly designed curable formulations were aimed at providing a relatively rigid hardened adhesive material (priming material; primer), featuring Tg higher than 50 °C, and / or as providing a suitable adhesion, of at least 20 N / cm and even of at least 30 N / cm, for a wide variety of fabric substrates.

[0574] The present inventors have realized that a desirable performance further includes jettability (e.g., viscosity of 15-30, or 15-25, or 15-20 centipoises at the jetting temperature, e.g., 70 °C; and surface tension of 20-40, preferably 20-30, or 24-30 at the jetting temperature, e.g., 70 °C). In addition, the formulations were designed as suitable for use in a system as described in FIG. 1A or as described in FIGs. 1B-D, each comprising LED irradiation source (e.g., at a 395 nm wavelength).

[0575] Further in addition, the formulations were designed as biocompatible, for example, as compliant with Restricted Substance Lists (RSL) used for the manufacturing process and the final products in the textile and apparel industry; as durable when exposed to repeating washing cycles (e.g., at least 10 washing cycles); and as stable during storage, e.g., for a period of at least 6 months or at least one year. Further in addition, the formulations were designed so as to featuring mechanical properties (when determined as described herein) that are suitable for printing on fabrics, for example, as depicted in the following: Tensile Modulus: 2,000-3,000 MPa

[0576] Tensile Strength: 50-70 MPa

[0577] Elongation at break: 5-15 %

[0578] Flexural Modulus: 2000-3000 MPa Flexural Stress: 70-120 MPa

[0579] HDT at 0.45 MPa: 40-80 °C

[0580] Tg: 60-80 °C.

[0581] While aiming at providing a rigid adhesive material, the present inventors have opted to devise formulations that comprise a mono-functional curable material that feaures, when hardened, Tg higher than 80 °C, in various combinations with multi-functional curable materials and / or other mono-functional curable materials, so as to identify formulations that exhibit a desirable performance.

[0582] Table 1 below presents the tested materials.

[0583] Table 1

[0584] (Table 1; Cont.)

[0585] EXAMPLE 2

[0586] A preliminary set of formulations that are based on a hydrophilic mono-functional (meth)acrylate (Component Al) and a mono-functional aliphatic urethane (meth)acrylate featuring Tg lower than 0 °C (Component Cl), with different combinations of Components DI and DI as multi-functional curable materials was first tested.

[0587] Table 2A below presents the chemical composition of exemplary tested formulations. Components Hl, H2 and I are typically included in an amount lower than 0.5 % by weight of the total weight of the formulation.

[0588] Table 2A

[0589] Viscosity of the tested formulations and Tg and maximal adhesion strength of the dispensed material upon hardening were measured as described hereinabove, and the obtained data is presented in Table 2B below. The formulations were dispensed on different fabrics, as indicated.

[0590] Table 2B

[0591] As can be seen in Tables 2A and 2B, adhesion to cotton fabrics was less than desired. As can further be seen, Formulation III, which included a lower amount of Component Al and a higher amount of Component B3, exhibited inferior performance. As this formulation exhibits a lower Tg compared to the other formulations, it has been assumed that there is a linear correlation between the Tg and the adhesion, such that higher Tg provides a higher adhesion performance.

[0592] Formulation I was characterized by Water Absorbance of 22.26 %. In order to improve bonding to fabrics such as cotton, which feature hydroxy surface groups, another set of curable formulations, in which an ethoxylated mono-functional (meth)acrylate Component C3 and / or an ethoxylated multi-functional (meth)acrylate Component E were included instead of Component Cl, while reducing the amount of Component Al, was prepared and tested.

[0593] Table 3 A below presents the chemical composition of exemplary curable formulations and Table 3B below presents the viscosity of the tested formulations and the maximal adhesion strength of the dispensed material upon hardening. The formulations were dispensed on a Brown cotton fabric. Table 3A

[0594] Table 3B

[0595] As can be seen, the implemented modifications did not improve the adhesion performance, suggesting that the interaction of the formulation with the fabric is more of a physical nature rather than via chemical interactions. In a following set of curable formulations, Component Cl was used in an amount of 20-30 % by weight, the amount of Component Al was maintained at about 20-35 % by weight, and Component D2 was used in combination with Component D3, E2, E3, Fl, F2 and / or F3.

[0596] Table 4A below presents the chemical composition of exemplary such curable formulations and Table 4B below presents the viscosity of the tested formulations and the maximal adhesion strength of the dispensed material upon hardening. The formulations were dispensed on a Brown cotton fabric.

[0597] Table 4A Table 4B As can be seen in Tables 4A and 4B, the assayed manipulations did not result in improved adhesion performance and resulted in slight increase in the formulations’ viscosity.

[0598] The present inventors have therefore turned to test the effect of water absorption of the hardened material on its adhesion performance, and to this end have prepared and tested an additional set of formulations, in which hydrophilic Component Al was replaced by hydrophobic Component A2 or Component B 1.

[0599] Table 5 A below presents the chemical composition of exemplary such curable formulations and Table 5B below presents the viscosity of the tested formulations and the Tg, water absorption and maximal adhesion strength of the dispensed material upon hardening. The formulations were dispensed on a Brown cotton fabric and / or Burlington Black fabric.

[0600] Table 5A

[0601] Table 5B

[0602] As can be deduced from the data shown in Table 5B, using Component A2 instead of Component A2 reduced substantially the water absorption, but did not improve sufficiently the adhesion performance. Further, a correlation between the Tg and the adhesion performance was further established. An inverse correlation between water absorption and adhesion performance can also be seen, such that the lower the water absorption, the better the adhesion performance.

[0603] With these understandings in mind, the present inventors have turned to devise formulation that are based on Components Al and Component Cl, as in the first set of formulations presented in Table 2A hereinabove, while introducing to the formulation Component G. In some of the assayed formulations, Component C 1 and / or Component Al was / were replaced by Component B2, to test the effect of polarity and / or lower Tg.

[0604] Table 6A below presents the chemical composition of exemplary such curable formulations and Table 6B below presents the viscosity of the tested formulations and the Tg, water absorption and maximal adhesion strength of the dispensed material upon hardening. The formulations were dispensed on several fabric types, as indicated.

[0605] Table 6A

[0606] Table 6B As can be seen, this set of formulations provided the desirable adhesion performance with various fabrics.

[0607] Formulation XXVII was tested also with additional fabrics, and desirable adhesion performance of more than 20 N / cm and even more than 30 N / cm was observed with the following fabrics (data not shown): black satin, black thick, grey cotton, brown cotton, grey viscose, blue Lycra, pink Lycra, Jeans, grey silky, orange Lycra, beige Lycra, grey satin, Papier beige, white denim, dark blue Jeans, dark grey Jeans, beige synthetic, light blue Jeans, colored patterned wool, medium blur Jeans and plain black. Overall, this formulation provided desirable performance with more than 60 % of the tested fabrics.

[0608] The data presented herein indicate that for achieving the best performance, a combination of a hydrophilic mono-functional (meth)acrylate which features high Tg (e.g., Tg higher than 50, or higher than 80 °C) (Component Al) and an aliphatic urethane (meth) acrylate which features low Tg (e.g., Tg lower than 50, or lower than 10 °C) (Component Cl) as mono-functional materials, should be used, wherein an amount of Component Al should be no more than 40 (e.g., from 15 to 40, or from 20 to 40, or from 30 to 40 %), % by weight, of the total weight of the formulation, and the total amount of mono -functional materials should be no more than 50-55 % by weight. Multifunctional components in the formulation should comprise epoxy-type (meth)acrylates which feature a viscosity at 25 °C lower than 10,000 or lower than 5,000, cps (Component DI and / or D2), and a di-functional (meth)acrylate that features high Tg (Component G) and preferably relatively low viscosity at 25 °C (Component Gl) in an amount of 5-30, or 10-30, or 10-20, % by weight of the total weight of the formulation. An amount of the epoxy-containing multi-functional materials (Component DI and / or D2) and the ratio thereof can be manipulated so to as achieve a desired viscosity and / or Tg. Exemplary suitable ratios of Component Dl:Component D2 can range from 1:1 to 1:5, preferably from 1:1 to 1:3, or from 1:1 to 1:2, including any intermediate values and subranges therebetween.

[0609] EXAMPLE 3 Optimization and Characterization

[0610] Table 7 below presents the mechanical and physical properties of the exemplary adhesive formulation XXVII, demonstrating that it meets the requirements as set forth hereinabove (see, Example 1).

[0611] Table 7 The performance of the exemplary adhesive formulation XXVII was tested on different fabrics, made of different materials and / or featuring different colors and using different printing systems and / or printing conditions and / or post-printing treatments (e.g., washing).

[0612] FIG. 9 presents images of exemplary tested fabrics and the corresponding adhesion level measured as described herein while using Formulation XXVII, showing that desirable adhesion performance can be obtained for fabrics of different porosities, patterns and colors.

[0613] FIGs. 10A-B present the peel strength (adhesion) provided by Formulation XXVII printed on different fabrics as indicated along with an exemplary flexible modeling formulation as described in Example 5, upon subjecting the printed fabrics to 10 consecutive washing and drying cycles at the indicated conditions. As can be seen, no substantial change was observed following 10 washing and drying cycles, demonstrating the washing durability of the printed adhesive formulation.

[0614] In a search for printing protocols that may further improve the adhesion level of the designed adhesive formulations, the effect of manipulating the printing protocol was tested. For some tested fabrics, it was found that omitting the irradiation of the first adhesion layer, results in improved adhesion level. The adhesive formulations were printed in accordance with the method described in FIG. 6 and under the Material and Methods section hereinabove, while printing one layer (e.g., the first layer) of the adhesive formulation without operating the curing device(s), followed by while printing 10 layers of the adhesive formulation (Ni=10) and curing the same with two UV lamps at irradiation intensity of about 3 W / cm2each, followed by printing 10 layers of the modeling material formulation and curing the same with two UV lamps at irradiation intensity of about 3 W / cm2each, followed by printing the following modeling material formulation layers and curing the same with one UV lamp at irradiation intensity of about 1.5 W / cm2, and applying two final scans with two UV lamps at irradiation intensity of about 1.5 W / cm2each.

[0615] Table 8 below presents exemplary data obtained for the adhesion level of bar-shaped objects printed on various fabrics using formulation XXVII, according to the protocol described hereinabove (under the Material and Methods section), referred to as Protocol I and according to the modified protocol described in this Example, referred to as Protocol II. Table 8

[0616] The durability of the adhesive formulation when applied to different fabrics was further determined under conditions that reflect accelerated ageing, namely, when maintained at 60 °C and 10 % humidity. Under these conditions, each day corresponds to about 10 days at ambient conditions (room temperature and ambient humidity), thus reflecting accelerated ageing.

[0617] Four model bars were printing for these tests for each tested fabric: 2 bars were tested immediately after printing, and 2 bars were tested after two weeks at the accelerated ageing conditions. Formulation XXVII was used as the adhesive formulation. Printing was performed according to the protocol described in FIG. 6, while using curing protocol II as described hereinabove.

[0618] Table 9 below presents exemplary data obtained for the adhesion level of the objects to various fabrics immediately after printing and after two weeks under accelerated ageing conditions, while printing adhesive structures at the indicated thickness. As can be seen, a sufficient adhesion level is maintained after a period that corresponds to several months. Similar data was observed after a period that corresponds to 2 years (not shown).

[0619] Table 9

[0620] The present inventors have further conceived employing an adhesive formulation as described herein in combination with an additional curable formulation, for forming on the fabric an adhesive structure which is a digital material, as described herein.

[0621] The present inventors have practiced such a methodology while employing an adhesive formulation as described herein (for example, formulation XXVII) in combination with an exemplary flexible modeling material such as described in Example 5 herein, according to a pattern as depicted in FIG. 11.

[0622] EXAMPLE 4

[0623] Flexible additive (adhesive and / or Coating) Formulation (featuring lower Tg)

[0624] This Example describes an exemplary curable additive formulation which can be used in combination with a modeling material formulation as described herein, and / or in combination with a rigid additive formulation as described herein in any of the respective embodiments and any combination thereof, and which is suitable for use, both as a priming formulation providing upon curing a priming material that forms the adhesion structure, and as a coating formulation providing upon curing a coating material forming a solidified coating, optionally in combination with the rigid additive formulation described herein.

[0625] The exemplary additive formulations can serve as curable adhesive additive formulation, which is dispensed from the printing heads and form a configured pattern of an adhesive material that promotes adhesion of the modeling material formed of subsequently dispensed modeling material formulation(s), and which can further serve as a coating formulation, which is dispensed from the printing heads subsequent to the formation of a model object by dispensing modeling material formulation(s), and form a configured pattern of a coating material that improves properties of the printed object such as tear resistance and durability (in terms, of e.g., maintaining color of the object, withstanding washing, etc.).

[0626] This exemplary additive formulation features Tg lower than 80, preferably lower than 50, °C, and is also referred to herein as a flexible additive formulation or as a flexible adhesive formulation or as a flexible coating formulation.

[0627] The exemplary additive formulation includes curable materials that feature functional groups that may interact with surface functional groups of common fabrics, preferably polar functional groups that may interact (e.g., via hydrogen bond formation) with hydroxy groups that are typically present on fabric’s surfaces, and which are further characterized by Tg lower than 100, or lower than 80, or lower than 50, °C, so as to provide a hardened material which exhibits flexibility that is suitable for application onto fabrics. The additive formulation exhibits a desirable performance, that is, sufficient adhesion level to fabrics, of at least 20 N / cm and / or the provision of a sufficient tear resistance to the coated object, of at least 10,000 N / m and should further include jettability (e.g., viscosity of 15-30, preferably 15-25 or 15-20 centipoises (mPa- second) at the jetting temperature, e.g., 70 °C; surface tension of 20-40, preferably 20-30, more preferably of 26- 30 at the jetting temperature).

[0628] In addition, the additive formulation was designed as suitable for use in a system as described in FIG. 1A or in FIGs. 1B-D, and which comprises LED irradiation source (e.g., at a 395 nm wavelength), and preferably as biocompatible.

[0629] According to some embodiments of any of the embodiments described in this Example, the additive formulation is characterized by one or more of a viscosity in a range of 15 to 30, or 15 to 25, or 15 to 20 centipoises; a surface tension is a range of from 20 to 40, preferably from 20 to 30, more preferably 26 to 30, or 26 to 28 Dyne / cm; and an adhesion level to a respective fabric of at least 20 N / cm.

[0630] According to some embodiments of any of the embodiments described in this Example, the additive formulation is an adhesive (priming) formulation, which provides, when hardened, a flexible adhesive material or structure on the fabric.

[0631] According to some embodiments of any of the embodiments described in this Example, the additive formulation is a coating or finishing formulation, which provides, when hardened, a flexible coating of the object or a part thereof.

[0632] According to some embodiments of any of the embodiments described in this Example, the additive formulation is both an adhesive (priming) formulation, which provides, when hardened, a flexible adhesive material or structure on the fabric, and a flexible coating or finishing formulation, which provides, when hardened, a coating of the object or a part thereof. According to some embodiments of any of the embodiments described in this Example, the flexible additive formulation comprises a combination of one or more mono-functional curable material(s) and one or more multi-functional curable material(s).

[0633] According to some embodiments of any of the embodiments described in this Example, the one or more mono-functional curable materials comprise at least one mono-functional curable material featuring at least one polar group that is capable of interacting with surface functional groups in the fabric and Tg lower than 50 °C.

[0634] According to some of these embodiments, an amount of this at least one mono-functional curable material featuring at least one polar group that is capable of interacting with surface functional groups in the fabric and Tg lower than 50 °C from 85 to 90 % by weight of the total weight of the formulation.

[0635] According to some embodiments of any of the embodiments described in this Example, the one or more multi-functional curable materials comprise at least one multi-functional curable material featuring Tg lower than 50 °C.

[0636] According to some of these embodiments, an amount of the at least one multi-functional curable material featuring Tg lower than 50 °C is from 10 to 15 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0637] According to some embodiments of any of the embodiments described in this Example, the additive formulation comprises at least one mono-functional curable material featuring at least one group that is capable of interacting with surface functional groups in the fabric and Tg lower than 50 °C, in an amount of from 85 to 90 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; and at least one multi-functional curable material featuring Tg lower than 50 °C, in an amount of from 10 to 15 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0638] According to some embodiments of any of the embodiments described in this Example, the at least one mono-functional curable material features at least one polar group that is capable of interacting with surface functional groups in the fabric, as described herein. Such a material is also referred to herein as “Component A**”.

[0639] Herein throughout, the phrase “polar group” describes a charge-polarized group, which is capable of exhibiting transient charge polarization.

[0640] Exemplary polar groups typically include one or more electron-donating heteroatoms which form strong hydrogen bonds with surface polar groups. Such heteroatoms include, but are not limited to, oxygen and nitrogen. Exemplary polar groups include, but are not limited to, an electron-donating heteroatom (e.g., oxygen or nitrogen), a carboxylate, a thiocarboxylate, oxo (=0), a linear amide, hydroxy, a (Cl-4)alkoxy, an (Cl-4)alcohol, a hetero alicyclic (e.g., having a ratio of carbon atoms to heteroatoms as defined herein), a cyclic carboxylate such as lactone, a cyclic amide such as lactam, a carbamate, a thiocarbamate, a cyanurate, an isocyanurate, a thiocyanurate, urea, thiourea, an alkylene glycol (e.g., ethylene glycol or propylene glycol).

[0641] In exemplary embodiments, the mono-functional curable material comprises one or more of a hydroxy group and an electron-donating heteroatom.

[0642] According to some embodiments, the one or more mono-functional curable material(s) are collectively represented by Formula I**:

[0643] Y-L-X

[0644] Formula I** wherein:

[0645] Y is a terminal group, optionally and preferably selected from an alkyl, including linear and branched, substituted or unsubstituted alkyl, an aryl, a heteroaryl, a cycloalkyl, a heteroalicyclic, hydroxy, alkoxy, aryloxy, and amine;

[0646] X is a polymerizable group, optionally and preferably a (meth)acrylate group (-0-C(=0)- CRI=CR2R3, wherein Ri is hydrogen for acrylate and methyl for methacrylate and R2and R3 are typically each hydrogen); and

[0647] E is a hydrocarbon linking moiety of 2 to 10, preferably being of 2 to 8, or 2 to 6, carbon atoms in length, substituted by at least one polar groups (e.g., hydroxy groups) and optionally interrupted by one or more heteroatoms (e.g., heteroatoms that can form hydrogen bonds with hydroxy groups such as oxygen or nitrogen).

[0648] In exemplary embodiments, the at least one mono-functional curable material is a monofunctional (meth)acrylate, such that X is a (meth)acrylate group and the mono-functional curable material is represented by Formula la**:

[0649] Formula la** wherein Ri is hydrogen (for acrylate) or alkyl (e.g., methyl, for methacrylate).

[0650] In exemplary embodiments, Ri is hydrogen.

[0651] In some embodiments, Y is a group that comprises an electron-donating heteroatom, such as a heteroalicyclic, hydroxy, alkoxy, aryloxy, and amine, and in exemplary embodiments, Y is alkoxy or aryloxy (e.g., phenoxy).

[0652] In some embodiments, L is a hydrocarbon of 2 to 6 carbon atoms, or of 2 to 4, carbon atoms, substituted by one or more hydroxy group(s).

[0653] An exemplary mono-functional acrylate material, Component A, is shown in the Examples section that follows.

[0654] According to some embodiments of any of the embodiments described in this Example, the additive formulation comprises one or more multi-functional curable material featuring Tg lower than 50 °C.

[0655] According to some embodiments of any of the embodiments described in this Example, the at least one multi-functional curable material comprises a di-functional curable material featuring the indicated Tg.

[0656] According to some embodiments of any of the embodiments described in this Example, the at least one multi-functional curable material comprises a multi-functional (e.g., di-functional) aliphatic or non-aromatic (e.g., aliphatic or alicyclic) meth(acrylate) featuring the indicated Tg.

[0657] According to some embodiments of any of the embodiments described in this Example, the at least one multi-functional curable material comprises a multi-functional (e.g., di-functional) aliphatic or non-aromatic (e.g., aliphatic or alicyclic) urethane meth(acrylate) featuring the indicated Tg.

[0658] According to some embodiments of any of the embodiments described in this Example, the one or more multi-functional curable material(s) feature Tg of from -20 to 50, or from -20 to 40, or from -20 to 30, or from -20 to 20, or from -10 to 40, or from -10 to 30, or from -10 to 20, or from 0 to 50, or from 0 to 40, or from 0 to 30, °C, including any intermediate values and subranges therebetween.

[0659] An exemplary multi-functional curable material include materials of a family marketed under the tradename Miramer, for example, Miramer PU2100NT.

[0660] According to some embodiments of any of the embodiments described in this Example, the additive formulation is a biocompatible formulation, in which all the components, or at least components that are included in an amount higher than 0.1 %, or higher than 0.5 %, or higher than 1 %, are biocompatible. According to some embodiments of any of the embodiments described in this Example, each of the curable materials in the formulation is a biocompatible material.

[0661] According to some embodiments of any of the embodiments described in this Example, each of the curable materials in the formulation is devoid of materials that are not considered biocompatible, for example, are devoid of metallic catalysts (e.g., is catalyst-free), or any other materials that may be present along with the curable material in a residual amount as a result of the synthetic process used for preparing these curable materials.

[0662] According to some embodiments of any of the embodiments described in this Example, each of the multi-functional curable materials is a multi-functional (e.g., di-functional) acrylate or a multi-functional (e.g., di-functional) urethane acrylate.

[0663] According to some embodiments of any of the embodiments described in this Example, each of the mono-functional curable materials is a mono-functional acrylate.

[0664] According to some embodiments of any of the embodiments described in this Example, at least one, or all, of the curable materials in the formulation are photocurable materials (e.g. UV- curable materials such as acrylic materials), and the additive formulation further comprises at least one photoinitiator (Component J), as described herein in any of the respective embodiments of the formulation of the present invention.

[0665] According to some embodiments of any of the embodiments described in this Example, an amount of the photoinitiator ranges from 1 to 3, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0666] According to some embodiments of any of the embodiments described in this Example, the photoinitiator(s) comprises, or consists essentially of, a phosphine oxide-type (e.g., mono- acrylated (MAPO) or bis-acrylated phosphine oxide-type (BAPO) photoinitiator.

[0667] According to some embodiments of any of the embodiments described in this Example, the photoinitiator(s) comprises, or consists essentially of, a bis-acrylated phosphine oxide-type (BAPO) photoinitiator.

[0668] In an exemplary embodiments, the photoinitiator is or comprises bis(2,4,6- trimethylbenzoyl)phenyl phosphine oxide (marketed as IRGACURE® 819).

[0669] In an exemplary embodiments, the photoinitiator is devoid of a mono-acrylated (MAPO) phosphine oxide-type photoinitiator, and is some embodiments, it is devoid of 2,4,6- trimethylbenzoyldiphenyl phosphine oxide (marketed as TPO).

[0670] According to some embodiments of any of the embodiments described in this Example, the additive formulation further comprises additional, non-curable components, such as, for example, inhibitors, surfactants, dispersants, colorants (coloring agents), stabilizers, and the like, as described herein for the rigid additive formulation. Commonly used surfactants, dispersants, colorants and stabilizers are contemplated. Exemplary concentrations of each component, if present, range from about 0.01 to about 1, or from about 0.01 to about 0.5, or from about 0.01 to about 0.1, weight percent, of the total weight of the formulation containing same, including any intermediate values and subranges therebetween. Exemplary components are described hereinafter.

[0671] According to some embodiments of any of the embodiments described in this Example, the formulation comprises a curing inhibitor, that is, an agent that inhibits or reduces an amount of the curing in the absence of a curing condition, which is also referred to herein as Component I, as described herein in any of the respective embodiments for the rigid additive formulation. In some embodiments, the inhibitor is a free radical polymerization inhibitor. In some embodiments, an amount of an inhibitor (e.g., Component I, e.g., a free radical inhibitor) ranges from 0.01 to 2, or from 0.01 to 1, or from 0.05 to 0. 5, or from 0.1 to 0.2, weight percent, including any intermediate values and subranges therebetween, depending on the type of inhibitor used. Commonly used inhibitors, such as radical inhibitors, are contemplated.

[0672] According to some embodiments of any of the embodiments described in this Example, the additive formulation further comprises an inhibitor (Component I), as described herein in any of the respective embodiments for the rigid additive formulation, for example, a phenol-type inhibitor or any other inhibitor that is commonly used in medical devices or applications and / in food products.

[0673] According to some embodiments of any of the embodiments described in this Example, an amount of the inhibitor ranges from 0.05 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0674] In exemplary embodiments, a free radical inhibitor such as are those of the Genorad™ family (e.g., Genorad 20).

[0675] In exemplary embodiments, such a free radical inhibitor is used in an amount of from 0.1 to 3, or from 0.1 to 2, or from 0.1 to 1, or from 0.1 to 0.5, weight percent, including any intermediate values and subranges therebetween.

[0676] According to some embodiments of any of the embodiments described in this Example, the additive formulation further comprises one or more dispersant or surfactant (Component H), as described herein in any of the respective embodiments for the rigid additive formulation.

[0677] According to some embodiments of any of the embodiments described in this Example, an amount of the dispersant ranges from 0.01 to 1, or from 0.1 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween. According to some embodiments of any of the embodiments described in this Example, an amount of the dispersant ranges from 0.1 to 0.5, % by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0678] According to some embodiments of any of the embodiments described in this Example, the additive formulation is a clear (e.g., transparent), colorless formulation, which is devoid of a coloring agent or pigment.

[0679] According to some embodiments of any of the embodiments described in this Example, the additive formulation further comprises one or more coloring agent(s) or pigments (Component P), as described herein in any of the respective embodiments for the rigid additive formulation.

[0680] According to some embodiments of any of the embodiments described in this Example, the pigment is a white pigment and the formulation provides a white hardened material.

[0681] According to some embodiments of any of the embodiments described in this Example, the coloring agent comprises a mixture of a white pigment and one or more curable materials such as (meth)acrylic materials, such that the pigment is introduced to the formulation within this mixture.

[0682] According to some of these embodiments, an amount of the white pigment in the mixture ranges from 20 to 50 % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0683] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a white pigment and at least one (meth)acrylic material ranges from 1 to 5 % by weight of the total weight of the formulation.

[0684] According to some embodiments of any of the embodiments described in this Example, the pigment is a cyan pigment and the formulation provides a cyan hardened material.

[0685] According to some embodiments of any of the embodiments described in this Example, the coloring agent comprises a mixture of a cyan pigment and one or more curable materials such as (meth)acrylic materials, such that the cyan pigment is introduced to the formulation within this mixture.

[0686] According to some of these embodiments, an amount of the cyan pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0687] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a cyan pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween. According to some embodiments of any of the embodiments described in this Example, the pigment is a yellow pigment and the formulation provides a yellow hardened material.

[0688] According to some embodiments of any of the embodiments described in this Example, the coloring agent comprises a mixture of a yellow pigment and one or more curable materials such as (meth)acrylic materials, such that the yellow pigment is introduced to the formulation within this mixture.

[0689] According to some of these embodiments, an amount of the yellow pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0690] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a yellow pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation.

[0691] According to some embodiments of any of the embodiments described in this Example, the pigment is a magenta pigment and the formulation provides a magenta hardened material.

[0692] According to some embodiments of any of the embodiments described in this Example, the coloring agent comprises a mixture of a magenta pigment and one or more curable materials such as (meth)acrylic materials, such that the magenta pigment is introduced to the formulation within this mixture.

[0693] According to some embodiments of any of the embodiments described in this Example, an amount of the magenta pigment in the mixture ranges from 0.01 to 1, or from 0.05 to 0.5, or from 0.1 to 0.2, % by weight of the total weight of the mixture, including any intermediate values and subranges therebetween.

[0694] According to some of these embodiments, an amount of the coloring agent, which is a mixture of a magenta pigment and at least one (meth)acrylic material ranges from 0.1 to 1 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0695] According to some embodiments of any of the embodiments described in this Example, the formulation comprises one or more of a white, magenta, cyan, and yellow coloring agents, and in some of these embodiments, each pigment is introduced to the formulation in a mixture with curable materials as described herein.

[0696] According to some embodiments of any of the embodiments described in this Example, the coloring agent further comprises a pigment dispersant (Component Dp), for example, as described herein in any of the respective embodiments of the rigid additive formulation. Preferred pigment dispersants are such that has a plurality of groups that feature an affinity to the pigment. According to some embodiments of any of the embodiments described in this Example, the additive formulation comprises Components H, I, and J, as described herein in any of the respective embodiments (e.g., for a rigid additive formulation). An exemplary such a formulation is a clear colorless formulation, that is devoid of a coloring agent.

[0697] According to some embodiments of any of the embodiments described in this Example, the additive formulation comprises Components H, I, J and P and optionally Dp, as described herein in any of the respective embodiments (e.g., for a rigid additive formulation). An exemplary such a formulation is a white formulation that comprises a white pigment as described herein.

[0698] According to some embodiments of any of the embodiments described in this Example, the additive formulation comprises Components H, I, J, P and optionally Dp, as described herein in any of the respective embodiments (e.g., for a rigid additive formulation).

[0699] EXAMPLE 5

[0700] Exemplary flexible modeling material formulation

[0701] An exemplary modeling material formulation is such that exhibits desirable Shore A hardness values (e.g., 70-100) and printability, and preferably provides biocompatible hardened materials that can be suitable for 3D printing on fabrics such as garment fabrics.

[0702] The exemplary modeling material formulation includes materials that are devoid of elements that may adversely affect the biocompatibility of the hardened material.

[0703] The exemplary formulation is suitable for use in a system as described in FIGs. 1B-D, which comprises LED irradiation source (e.g., at a 395 nm wavelength).

[0704] The exemplary modeling material formulation is also referred to herein as “modeling formulation” or “flexible formulation” or “flexible modeling material formulation” or “modeling material formulation that provides, when hardened, a flexible material”, and other diversions thereof.

[0705] The modeling material formulation comprises a combination of curable materials, as defined herein, and is therefore a curable formulation, which, upon exposure to a curing condition, as defined herein, is hardened or solidifies.

[0706] The modeling material formulation of the present embodiments has been designed as suitable for forming, by additive manufacturing (e.g., 3D inkjet printing) of three-dimensional objects on fabrics, and provides, when hardened, a flexible material.

[0707] According to some embodiments of any of the embodiments described herein, the modeling material formulation is such that the hardened material formed therefrom is characterized by mechanical properties that correspond to a flexible material and / or meet the requirements of materials that are printed in a fabric. Such properties include, for example, suitable Shore A hardness (e.g., between 80 and 100 or between 80 and 90), and / or high Tear resistance (e.g., higher than 10,000, or higher than 12,000, or higher than 15,000 N / m, for example, from 10,000 to 25,000 N / m).

[0708] According to some embodiments, the modeling material formulation is such that provides, when hardened, one or more of:

[0709] Tg, as defined herein, lower than 50 °C, e.g., of from 0 to 50 °C, or from 0 to 45, or from 0 to 40, or from 0 to 30, or from 10 to 40, or from 20 to 40, or from 10 to 30, or from 10 to 30, °C, including any intermediate values and subranges therebetween;

[0710] Shore A hardness, when determined as defined herein, of at least 80, for example, of from 80 to 120, or from 80 to 100, preferably of from 80 to 90; and

[0711] Tear resistance of at least 10,000, or of at least 12,000, or of at least 15,000 N / m, for example, from 10,000 to 25,000 N / m, or from 12,000 to 25,000 N / m, or from 15,000 to 25,000 N / m, including any intermediate values and subranges therebetween.

[0712] According to some embodiments of any of the embodiments described herein, the modeling material formulation is a biocompatible formulation, in which all the components, or at least components that are included in an amount higher than 0.1 %, or higher than 0.5 %, or higher than 1 %, are biocompatible.

[0713] According to some embodiments of any of the embodiments described herein, each of the curable materials in the formulation is a biocompatible material.

[0714] According to some embodiments of any of the embodiments described herein, each of the curable materials in the formulation is devoid of materials that are not considered biocompatible, for example, are devoid of metallic catalysts (e.g., is catalyst-free), or any other materials that may be present along with the curable material in a residual amount as a result of the synthetic process used for preparing these curable materials.

[0715] The modeling material formulation of some of the present embodiments comprises a combination of mono-functional and multi-functional materials that feature low Tg, e.g., lower than 150, or lower than 100, °C.

[0716] According to some embodiments of any of the embodiments of the present invention, a total amount of the mono-functional and multi-functional materials that feature low Tg as described herein, is at least 60, or at least 65, or at least 70, or at least 75, or at least 80, or at least 85, or even at least 90, %, by weight, of the total weight of the formulation, from example, in a total amount of from 60 to 95, or from 60 to 90, or from 70 to 90, or from 70 to 95, or from 80 to 95, or from 80 to 90, or from 60 to 85, or from 60 to 80, or from 70 to 85, or from 70 to 80, % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0717] According to some embodiments of any of the embodiments described herein, the modeling material formulation comprises: at least one mono-functional curable material featuring Tg lower than 150 °C, in a total amount of from 40 to 60 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; at least one multi-functional curable material featuring Tg higher than 100, or higher than 150, °C, in an amount of from 4 to 10 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween; and at least one multi-functional curable material featuring Tg lower than 150, or lower than 100, °C, in a total amount of 25-35 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0718] Mono-functional curable materials:

[0719] According to some embodiments of any of the embodiments described herein, the modeling material formulation comprises one or more mono-functional curable materials, each featuring Tg lower than 150 °C.

[0720] According to some embodiments of any of the embodiments described herein, the modeling material formulation comprises two or more mono-functional materials.

[0721] According to some of these embodiments, one or more of the mono-functional curable materials comprise(s) at least a first mono-functional curable material which features Tg of from 50 to 150 °C, which is also referred to herein as Component Al*, and one or more other monofunctional curable material(s) comprise(s) at least a second mono-functional curable material which features Tg lower than 50, or lower than 20, °C, which is also referred to herein as Component A2* and / or B*.

[0722] According to some embodiments of any of the embodiments described herein, the modeling material formulation comprises one (or more) of a first mono-functional curable material which features Tg of from 50 to 150 °C (Component Al*); and two or more of a second monofunctional curable material which features Tg lower than 50, or lower than 20, °C (Components A2* and B*).

[0723] According to some embodiments of any of the embodiments described herein, each of the one or more mono-functional curable materials as described herein, is a mono-functional (meth)acrylate. According to some embodiments of any of the embodiments described herein, each of the mono-functional materials has an average molecular weight lower than 1,000 grams / mol or lower than 500 grams / mol.

[0724] According to some embodiments of any of the embodiments described herein, the one or more mono-functional curable materials comprise one or more of a first mono -functional (meth)acrylate, which features Tg of from 50 to 150, °C, including any intermediate values and subranges therebetween, which is also referred to herein as Component Al*; and one or more of a second mono-functional (meth)acrylate, which features Tg lower than 50, or lower than 20, °C, which is also referred to herein as Component A2*.

[0725] According to some embodiments, the first mono-functional curable material as described herein, e.g., the first mono-functional (meth)acrylate, or Component Al*, is a hydrophobic material, as described herein.

[0726] According to some embodiments, the second mono-functional curable material as described herein, e.g., the second mono-functional (meth)acrylate, or Component A2*, is a hydrophilic and / or amphiphilic material, as described herein.

[0727] In some embodiments, the hydrophilic group is, or comprises, an electron donating heteroatom, a carboxylate, a heteroalicyclic, an alkylene glycol and / or a hydrophilic oligomeric moiety.

[0728] An amphiphilic moiety or group typically comprises one or more hydrophilic groups as described herein and one or more hydrophobic groups, or, can a heteroatom-containing group or moiety in which the ratio of number of carbon atoms to the number of heteroatoms accounts for amphiphilicity.

[0729] Hydrophobic groups include, for example, all-carbon groups such as alkyl, alkenyl, alkynyl, aryl, cycloalkyl, and the like.

[0730] Monomeric mono-functional (meth) acrylate materials according to the present embodiments can be collectively represented by Formula A:

[0731] Formula A wherein Ri is a carboxylate, -C(=O)-O-Ra, R2 is hydrogen (for acrylate) or methyl (methacrylate), and Ra is an aliphatic, alicyclic or aromatic moiety, which can be hydrophilic or hydrophobic, as described herein.

[0732] When the material is an alicyclic monomeric mono-functional (meth) acrylate material(s), Ra can be, for example, an alicyclic moiety such as, but not limited to, isobornyl or any other substituted or unsubstituted cycloalkyl as described herein, or a heteroalicyclic moiety as described herein such as morpholine, tetrahydrofuran, oxalidine, or any other substituted or unsubstituted heteroalicyclic as described herein, wherein the substituent(s), if present for a cycloalkyl or for a heteroalicyclic, do not comprise an aryl or heteroaryl, as defined herein. Exemplary alicyclic monomeric mono-functional acrylate include, but are not limited to isobornylacrylate (IBOA), acryloyl morpholine (ACMO), and a material marketed under the tradename SR-218.

[0733] When the material is an aliphatic monomeric mono-functional (meth)acrylate material(s), Ra can be, for example, a substituted or unsubstituted alkyl or alkylene, or any other short hydrocarbon as defined herein, wherein the substituent(s), if present do not comprise an aryl or heteroaryl, as defined herein.

[0734] When the material is an aromatic monomeric mono-functional (meth)acrylate material(s), Ra can be, or comprise, for example, an aryl or a heteroaryl, as defined herein, for example a substituted or unsubstituted phenyl, a substituted or unsubstituted naphthalenyl, etc., wherein when substituted, there can be 1, 2, 3 or more substituents each being the same or different, or an alkyl or cycloalkyl substituted by one or more substituted or unsubstituted aryl(s) or substituted or unsubstituted heteroaryl(s), as described herein, for example, substituted or unsubstituted benzyl. Exemplary aromatic monomeric mono-functional (meth)acrylates include, for example, a material marketed as CN131B.

[0735] Additional exemplary monomeric mono-functional (meth)acrylates featuring Tg as indicated for Component A2*, or the second mono-functional (meth)acrylate, and which are optionally hydrophilic or amphiphilic, include, without limitation, those marketed under the tradenames SR-256, SR-217, SR-285, SR-336, SR-420 and SR-238.

[0736] According to some embodiments of any of the embodiments described herein, Component Al* is a mono-functional (meth)acrylate, for example, acrylate, having an alicyclic moiety.

[0737] According to some embodiments of any of the embodiments described herein, Component A2* is a mono-functional (meth)acrylate, for example, acrylate, having an aromatic moiety (e.g., phenoxy).

[0738] According to some embodiments of any of the embodiments described herein, one or more or all of the mono-functional (meth) acrylate materials, e.g., Components Al* and A2*, and optionally also Component B*, is such that the MW of the compound is no more than 1,000 grams / mol, or no more than 500 grams / mol.

[0739] According to some embodiments of any of the embodiments described herein, a total amount of mono-functional acrylate or methacrylates, e.g., Components Al* and A2* as described herein, in the formulation, ranges from 20 to 40, or from 25 to 35, %, by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0740] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material in the formulation comprises at least two types of monofunctional curable materials, which differ from one another by the chemical composition, that is, one type includes one or more materials having Formula A as described herein, that is, this type includes acrylates and / or methacrylates, which are collectively referred to herein as Component A*, and another type includes one or more materials that are urethane acrylates, which are collectively referred to herein as Component B*.

[0741] According to some of these embodiments, the at least one mono-functional curable material featuring Tg lower than 150 °C comprises at least one mono-functional (meth) acrylate material featuring Tg lower than 150 °C (e.g., Component A*, which can comprise Components Al* and A2*, or a first and a second mono-functional curable materials, as described herein) and at least one mono-functional urethane (meth) acrylate material featuring Tg lower than 150 °C (e.g., Component B*), as described herein.

[0742] According to some of these embodiments, the one or more mono-functional (meth)acrylate materials, Component A*, comprise one mono-functional (meth)acrylate, preferably acrylate, that features Tg of from 50 to 150 °C, or from 50 to 100 °C, as described herein, and is referred to herein also as Component Al*, or as a first mono-functional curable material or a first monofunctional (meth)acrylate, and one or more mono-functional (meth)acrylate, preferably acrylate, that features Tg lower than 50 or lower than 20, °C, as described herein, and is referred to herein also as Component A2*, or as a second mono-functional curable material or a second monofunctional (meth)acrylate.

[0743] According to some of these embodiments, a total amount of mono-functional (meth)acrylate materials, Component A*, e.g., of Component Al* and Component A2*, or the first and second mono-functional materials, ranges from 20 to 40, or from 25 to 35, %, by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0744] According to some embodiments of any of these embodiments, an amount of the second mono-functional curable material (e.g., mono-functional (meth)acrylate), which features Tg lower than 50, or lower than 20, °C, (e.g., Component A2*) ranges from 5 to 10 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0745] According to some embodiments of any of these embodiments, an amount of the first mono-functional curable material (e.g., mono-functional (meth)acrylate), which features Tg of from 50 to 150, or from 50 to 100, °C, (e.g., Component Al*) ranges from 20 to 30, or from 20 to 25, %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0746] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material in the formulation comprises at least two types of monofunctional curable materials, which differ from one another by the Tg thereof, that is, one type includes one or more materials each featuring Tg of from 50 to 150 °C, or from 50 to 100 °C, including any intermediate values and subranges therebetween, and another type includes one or more materials each featuring Tg lower than 50, or lower than 20, °C, e.g., in a range of from -50 to 50, or from -20 to 50, or from -50 to 20, or from -20 to 20, °C, including any intermediate values and subranges therebetween.

[0747] According to some of these embodiments, each of the mono -functional curable materials is a (meth) acrylate material, including acrylate, methacrylate and urethane acrylate materials.

[0748] According to some of these embodiments, a total amount of the one or more monofunctional curable materials featuring Tg of from 50 to 150 °C, or from 50 to 100 °C, ranges from 20 to 30, or from 20 to 25, %, by weight of the total weight formulation, including any intermediate values and subranges therebetween.

[0749] According to some of these embodiments, a total amount of the one or more monofunctional curable materials featuring Tg lower than 50, or lower than 20, °C, ranges from 20 to 40, %, or from 25 to 35, %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0750] According to some of these embodiments, the one or more mono-functional curable materials featuring Tg lower than 50, or lower than 20, °C, comprise two or more such monofunctional curable materials; one or more is / are mono-functional acrylate or methacrylate, which features the indicated Tg (e.g., Component A2*) and one or more is / are mono-functional urethane acrylate or urethane methacrylate, which features the indicated Tg (e.g., Component B*).

[0751] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C as described herein, comprises one or more, or two or more Component A* and one or more Component B*. According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C as described herein, comprises at least a first mono-functional (meth) acrylate material which features Tg of from 50 to 150 °C, as described herein (e.g., Component Al*) and a second mono-functional (meth)acrylate material which features Tg lower than 50, or lower than 20, °C (e.g., Component A2*), and one or more mono -functional urethane (meth) acrylate material that features Tg lower than 150 °C as described herein (e.g., Component B*).

[0752] According to some embodiments of any of the embodiments described herein, the at least one mono-functional urethane (meth)acrylate material (e.g., Component B*) features Tg lower than 20, or lower than 10, or lower than 0, °C.

[0753] According to some embodiments of any of the embodiments described herein, the at least one mono-functional urethane (meth)acrylate material (e.g., Component B*) is an aliphatic urethane (meth) acrylate.

[0754] According to some embodiments of any of the embodiments described herein, the at least one mono-functional urethane (meth)acrylate material (e.g., Component B*) is an aliphatic urethane (meth) acrylate that features Tg lower than 20, or lower than 10, or lower than 0, °C.

[0755] According to some embodiments of any of the embodiments described herein, the at least one mono-functional urethane (meth) acrylate material (e.g., Component B*) is a catalyst-free material (e.g., tin-free material).

[0756] Exemplary mono-functional urethane (meth)acrylates featuring the indicated Tg and which are usable as Component B*, for example, include those marketed under the tradename Genomer, for example, Genomer 1122, which is also marketed as a tin-free material. Any other monofunctional aliphatic urethane (meth)acrylates are contemplated.

[0757] According to some embodiments of any of the embodiments described herein, an amount of the at least one mono-functional urethane (meth)acrylate material as described herein in any of the respective embodiments ranges from 20 to 30 % by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0758] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C is in a total amount of from 40 to 60 % by weight, including any intermediate values and subranges therebetween, and comprises: a first mono-functional (meth)acrylate material (optionally hydrophobic and / or alicyclic) which features Tg of from 50 to 150 °C, as described herein in any of the respective embodiments (e.g., Component Al*); a second mono-functional (meth) acrylate material (optionally hydrophilic or amphiphilic and / or aromatic) which features Tg lower than 50, or lower than 20, °C, as described herein in any of the respective embodiments (e.g., Component A2*); and at least one (preferably catalyst-free) mono-functional (preferably aliphatic) urethane (meth)acrylate material features Tg lower than 20, or lower than 10, or lower than 0, °C, as described herein in any of the respective embodiments (e.g., Component B*).

[0759] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C comprises a first monofunctional (meth)acrylate material (optionally hydrophobic and / or alicyclic) which features Tg of from 50 to 150 °C, as described herein in any of the respective embodiments (e.g., Component Al*), in an amount of from 10 to 30 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0760] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C comprises a second monofunctional (meth) acrylate material (optionally hydrophilic or amphiphilic and / or aromatic) which features Tg lower than 50, or lower than 20, °C, as described herein in any of the respective embodiments (e.g., Component A2*), in an amount of from 5 to 10 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0761] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C comprises at least one (preferably catalyst-free) mono-functional (preferably aliphatic) urethane (meth)acrylate material features Tg lower than 20, or lower than 10, or lower than 0, °C, as described herein in any of the respective embodiments (e.g., Component B*), in an amount of from 10 to 30 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0762] According to some embodiments of any of the embodiments described herein, the at least one mono-functional curable material featuring Tg lower than 150 °C is in a total amount of from 40 to 60 % by weight, including any intermediate values and subranges therebetween, and comprises: a first mono-functional (meth)acrylate material (optionally hydrophobic and / or alicyclic) which features Tg of from 50 to 150 °C, as described herein in any of the respective embodiments (e.g., Component Al*), in an amount of from 10 to 30 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween; a second mono-functional (meth) acrylate material (optionally hydrophilic or amphiphilic and / or aromatic) which features Tg lower than 50, or lower than 20, °C, as described herein in any of the respective embodiments (e.g., Component A2*), in an amount of from 5 to 10 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween; and at least one (preferably catalyst-free) mono-functional (preferably aliphatic) urethane (meth)acrylate material features Tg lower than 20, or lower than 10, or lower than 0, °C, as described herein in any of the respective embodiments (e.g., Component B*), in an amount of from 10 to 30 %, by weight, of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0763] According to some embodiments of any of the embodiments described herein, the modeling material formulation further comprises two or more multi-functional curable materials.

[0764] According to some embodiments of any of the embodiments described herein, a total amount of all of the multi-functional curable materials is at least 15 %, or ranges from 15 to 25 %, by weight of the total weight of the formulation, including any intermediate values and subranges therebetween.

[0765] The two or more multi-functional curable materials comprise one or more multi-functional curable material(s) featuring higher Tg, e.g., Tg higher than 100 °C, or higher than 150 °C, which includes, for example, a Component C* as described herein, and one or more multi-functional curable material(s) featuring lower Tg, e.g., Tg lower than 150, or lower than 100, °C, which includes, for example, a Component D* as described herein.

[0766] According to some embodiments of any of the embodiments described herein, the at least one multi-functional curable material featuring Tg higher than 100 °C, or higher than 150 °C, comprises a di-functional curable material.

[0767] According to some embodiments of any of the embodiments described herein, the at least one multi-functional curable material featuring Tg higher than 100 °C, or higher than 150 °C, comprises at least one multi-functional (e.g., di-functional) (meth)acrylate (Component C*).

[0768] According to some embodiments of any of the embodiments described herein, an average molecular weight of the at least one multi-functional curable material featuring Tg higher than 100 °C, or higher than 150 °C, is lower than 500 grams / mol, and is e.g., in a range of from 200 to 500, or 200 to 400, grams / mol, including any intermediate values and subranges therebetween. In multifunctional materials, typically, each of the curable (e.g., (meth) acrylate) groups are linked to one another through a linking moiety. The linking moiety can be a branching unit, such as, for example, a linear (in case of a di-functional material) or branched alkyl, cycloalkyl, aryl (e.g., bisphenol A), etc. (in case of di-, tri- and higher functional materials).

[0769] The multi-functional (e.g., di-functional) curable material featuring the higher Tg (e.g., Component C*), can be, for example, an aromatic or non-aromatic (e.g., alicyclic or aliphatic), multi-functional (e.g., di-functional) (meth)acrylate, which comprises at least one aromatic moiety or non-aromatic moiety (e.g., alicyclic or aliphatic) linking moiety that connects between the curable groups (e.g., (meth) acrylate groups).

[0770] According to some embodiments of any of the embodiments described herein, the multifunctional (e.g., di-functional) curable material featuring the higher Tg (e.g., Component C*), is a non-aromatic (e.g., alicyclic or aliphatic, multi-functional (e.g., di-functional) (meth)acrylate, which comprises an alicyclic and / or aliphatic moiety that connects between the curable groups (e.g., (meth) acrylate groups).

[0771] In some of these embodiments, the linking moiety is or comprises an all-carbon alicyclic moiety, optionally a polyalicyclic moiety which comprises 2, 3 or more rings. In some embodiments, the alicyclic moiety is of at least 6, at least 7, at least 8, at least 9 or at least 10, carbon atoms.

[0772] In some embodiments, the linking moiety comprises a polyalicyclic moiety as described herein, in which the two or more rings are fused to one another.

[0773] An exemplary such multi-functional curable material (e.g., Component C*) is tricyclododecane dimethanol diacrylate (e.g., SR833S and / or SR 368, marketed by Sartomer).

[0774] According to some embodiments of any of the embodiments described herein, the one or more multi-functional curable material(s) featuring Tg higher than 100 °C, or higher than 150 °C (e.g., Component C*), provide(s), when hardened, a transparent material.

[0775] According to some embodiments of any of the embodiments described herein, the formulation comprises one or more multi-functional (e.g., di-functional) (meth)acrylate(s) featuring Tg higher than 100 °C, or higher than 150 °C, for example Tg of from 100 to 200, or from 150 to 200, or from 160 to 200, °C, including any intermediate values and subranges therebetween.

[0776] According to some embodiments of any of the embodiments described herein, the formulation comprises one or more multi-functional (e.g., di-functional) (meth)acrylate(s) featuring Tg higher than 100 °C, or higher than 150 °C (e.g., Component C*), for example Tg of from 100 to 200, or from 150 to 200, or from 160 to 200, °C, including any intermediate values and subranges therebetween, and having a molecular weight lower than 500 grams / mol, as described herein. In some of these embodiments, the multi-functional (e.g., di-functional) curable material is a non-aromatic material, having a non-aromatic linking moiety between the curable groups, and in some embodiments, the linking moiety is an aliphatic or alicyclic moiety. In some of any of these embodiments, the curable material provides, when hardened, a transparent material.

[0777] According to some embodiments of any of the embodiments described herein, the formulation comprises one or more multi-functional (e.g., di-functional) (meth)acrylate(s) featuring Tg higher than 100 °C, or higher than 150 °C (e.g., Component C*), for example Tg of from 100 to 200, or from 150 to 200, or from 160 to 200, °C, including any intermediate values and subranges therebetween, and which provide, when hardened, a transparent material. In some of these embodiments, the multi-functional (e.g., di-functional) curable material is a non-aromatic material, having a non-aromatic linking moiety between the curable groups, and in some embodiments, the linking moiety is an aliphatic or alicyclic moiety.

[0778] According to some embodiments of any of the embodiments described herein, other one or more multi-functional curable material(s) are included in the formulation, each featuring a lower Tg, namely, Tg lower than 150, preferably lower than 100, °C. Exemplary such materials are also collectively referred to herein as Component D*.

[0779] According to some embodiments of any of the embodiments described herein, one or more or each of the at least one multi-functional curable material(s) featuring Tg lower than 150, or lower than 100, °C, is a di-functional curable material featuring Tg lower than 150, or lower than 100, °C.

[0780] According to some embodiments of any of the embodiments described herein, one or more or each of the at least one multi-functional curabl...

Claims

WHAT IS CLAIMED IS:

1. An additive formulation for use in combination with a modeling material formulation in three-dimensional printing of an object on a fabric, the additive formulation comprising: at least one mono-functional curable material featuring, when hardened, Tg higher than 50 °C (Component A); at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C); at least one multi-functional epoxy-type curable material featuring viscosity lower than 10,000 or lower than 5,000, mPa- sec (centipoises) at 25 °C (Component DI and / or Component D2); and at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G).

2. The additive formulation of claim 1, being characterized, when hardened, by Tg higher than 50 °C, or that ranges from 50 to 90, or from 60 to 80, °C.

3. The additive formulation of claim 1 or 2, being characterized by at least one of:Tensile Modulus in a range of from 2,000 to 3,000 MPa;Tensile Strength in a range of from 50 to 70 MPa;Elongation at break in a range of from 5 to 15 %;Flexural Modulus in a range of from 2000 to 3000 MPa;Flexural Stress is a range of from 70 to 120 MPa; andHDT at 0.45 MPa in a range of from 40 to 80 °C.

4. The additive formulation of any one of claims 1 to 3, being an adhesive (priming) formulation, which provides, when hardened, an adhesive structure on the fabric.

5. The additive formulation of any one of claims 1 to 4, wherein each of said monofunctional and multi-functional curable materials is a UV-curable material.

6. The additive formulation of any one of claims 1 to 5, wherein each of said monofunctional and multi-functional curable materials is a (meth)acrylate material.

7. The additive formulation of claim 5 or 6, further comprising a photoinitiator.

8. The additive formulation of claim 7, wherein said photoinitiator is a bis(acyl) phenyl oxide (BAPO)-type photoinitiator.

9. The additive formulation of claim 7 or 8, wherein an amount of said photoinitiator is from 1 to 5, or from 1 to 3, or from 1 to 2, % by weight of the total weight of the formulation.

10. The additive formulation of any one of claims 1 to 9, wherein said at least one monofunctional curable material featuring Tg higher than 50 °C (Component A) comprises a hydrophilic mono -functional curable material featuring said Tg (Component Al).

11. The additive formulation of any one of claims 1 to 10, wherein a total amount of said at least one mono-functional curable material featuring Tg higher than 50 °C (Component A) ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation.

12. The additive formulation of any one of claims 1 to 10, wherein said at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C) comprises at least one mono-functional aliphatic urethane (meth)acrylate featuring said Tg (Component Cl).

13. The additive formulation of any one of claims 1 to 12, wherein a total amount of said at least one mono-functional curable material featuring Tg lower than 20, or lower than 0 °C (Component C) ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation.

14. The additive formulation of any one of claims 1 to 13, wherein said at least one multi-functional epoxy-type curable material (Component DI and / or D2) comprises at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring said viscosity.

15. The additive formulation of any one of claims 1 to 14, wherein said at least one multi-functional epoxy-type curable material (Component DI and / or D2) features, when hardened, Tg lower than 100 °C.

16. The additive formulation of any one of claims 1 to 15, wherein said at least one multi-functional epoxy-type curable material featuring said viscosity at 25 °C (Component DI and / or D2) comprises at least one di-functional epoxy (meth) acrylate.

17. The additive formulation of any one of claims 1 to 16, wherein said at least one multi-functional epoxy-type acrylate curable material featuring said viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy acrylate curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2).

18. The additive formulation of any one of claims 1 to 17, wherein said at least one multi-functional epoxy-type curable material featuring said viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI).

19. The additive formulation of any one of claims 1 to 18, wherein said at least one multi-functional epoxy-type curable material featuring said viscosity at 25 °C (Component DI and / or D2) comprises at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI) and at least one multifunctional epoxy-type curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2).

20. The additive formulation of claim 19, wherein a weight ratio of said at least one multi-functional epoxy-type curable material featuring a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI) and at least one multi-functional epoxy curable material featuring a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2) ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2.

21. The additive formulation of any one of claims 1 to 20, wherein a total amount of said at least one multi-functional epoxy-type curable material featuring said viscosity at 25 °C (Component DI and / or D2) ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation.

22. The additive formulation of any one of claims 1 to 21, wherein said at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G), features, when hardened, Tg of from 100 to 200, or from 150 to 200, °C.

23. The additive formulation of any one of claims 1 to 22, wherein said at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) is a hydrophobic curable material featuring said Tg.

24. The additive formulation of any one of claims 1 to 23, wherein said at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) is a (e.g., hydrophobic) di-functional (meth)acrylate.

25. The additive formulation of any one of claims 1 to 24, wherein a total amount of said at least one multi-functional curable material featuring, when hardened, Tg higher than 100 or higher than 150 °C (Component G) ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation.

26. The additive formulation of any one of claims 1 to 25, comprising: at least one hydrophilic mono-functional (meth)acrylate featuring Tg higher than 50 °C (Component Al); at least one mono-functional aliphatic urethane (meth)acrylate featuring Tg lower than 20, or lower than 0 °C (Component Cl); at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity higher than 1,000 mPa- sec (centipoises) at 70 °C (Component DI); at least one multi-functional (e.g., di-functional) epoxy (meth) acrylate featuring a viscosity lower than 10,000 or lower than 5,000 mPa- sec (centipoises) at 25 °C and a viscosity lower than 100 mPa- sec (centipoises) at 70 °C (Component D2); andat least one hydrophobic multi-functional (e.g., di-functional) (meth) acrylate featuring, when hardened, Tg of from 100 to 200, or from 150 to 200, °C (Component G).

27. The additive formulation of claim 26, wherein: an amount of said Component Al ranges from 15 to 40, or from 20 to 40, or from 30 to 40 % by weight of the total weight of the formulation; and / or an amount of said Component Cl ranges from 5 to 20, or from 5 to 15, or from 5 to 10, % by weight of the total weight of the formulation; and / or a total amount of said Component DI and said Component D2 ranges from 20 to 50, or from 30 to 50, or from 30 to 40, % by weight of the total weight of the formulation; and / or a weight ratio of said Component DI and said Component D2 ranges from 1:1 to 1:5, or from 1:1 to 1:3, or from 1:1 to 1:2; and / or an amount of said Component G ranges from 5 to 30, or from 10 to 30, or from 10 to 20, % by weight of the total weight of the formulation.

28. The additive formulation of any one of claims 1 to 27, further comprising at least one of a polymerization inhibitor, a surface active agent, a dispersant, and a pigment and / or dye.

29. The additive formulation of any one of claims 1 to 28, further comprising a surface active agent, wherein said surface active agent comprises curable groups.

30. The additive formulation of claim 29, wherein an amount of said surface active agent is from 0.05 to 0.5 % by weight of the total weight of the formulation.

31. A method of three-dimensional printing an object on a fabric, the method comprising dispensing a plurality of layers in a configured pattern corresponding to the shape the object, thereby forming the object, wherein the formation of each layer of at least a few of said layers comprises dispensing at least one building formulation, and exposing the dispensed formulation to a curing condition to thereby form a cured modeling material, thereby printing the object, the method further comprising: prior to dispensing said at least one building material formulation, dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of a bottommost surface of the object or a portion thereof, wherein for each layer of said stack said dispensing is of an additiveformulation according to any one of claims 1 to 30, and exposing at least one of said layers, or said stack of layers, to a curing condition, to thereby form a hardened adhesive material.

32. A method of forming an adhesive structure on a fabric, the method comprising dispensing on the fabric a stack of layers in a configured pattern corresponding to a shape of the adhesive structure, wherein for at least a few layers, or for each layer, of said stack said dispensing is of an additive formulation according to any one of claims 1 to 30, and exposing each of said layers, or said stack of layers, to a curing condition, to thereby form the adhesive structure.

33. A method of preparing a fabric for three-dimensional printing of an object thereon, the method comprising forming an adhesive structure on the fabric in a configured pattern corresponding to a shape of a bottommost surface of the object, said forming the adhesive structure comprises dispensing on the fabric a stack of layers in said configured pattern, wherein for at least a few layers, or for each layer, of said stack, said dispensing is of an additive formulation according to any one of claims 1 to 30, and exposing at least one of said layers, or said stack of layers, to a curing condition, to thereby form a hardened adhesive material.

34. The method of any one of claims 31 to 33, wherein for at least a few or for each layer of said stack, said dispensing is of an additional curable formulation, said additional formulation being an additional additive formulation and / or of a modeling material formulation.

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