Method and system for three-dimensional printing on fabric

Abstract

A three-dimensional printing system includes a nozzle array for dispensing a build material, a work tray (12 / 360), and a fixture (402) configured to apply a fabric (420) to the work tray. A computerized controller operates at least the nozzle array to dispense the build material onto the applied fabric in a structured pattern corresponding to the shape of the object.

Description

[Technical Field]

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 056,759, filed July 27, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] The present invention, in some embodiments thereof, relates to three-dimensional printing, and more particularly, but not exclusively, to methods and systems for three-dimensional printing on fabrics. [Background technology]

[0003] Additive manufacturing (AM) is a technology that allows shaped structures to be produced directly from computer data through additive forming steps. The basic operation of any AM system consists of slicing a three-dimensional computer model into thin cross-sectional sections, converting the results into two-dimensional positional data, and feeding that data to a controller that builds the three-dimensional structure layer by layer.

[0004] Additive manufacturing involves many different approaches to fabrication, such as three-dimensional (3D) printing, such as 3D inkjet printing, electron beam melting, stereolithography, selective laser sintering, thin film deposition modeling, and fused deposition modeling.

[0005] Some 3D printing processes, such as 3D inkjet printing, operate by inkjet deposition of a build material layer by layer. Thus, a build material is ejected from an ejection head having a set of nozzles and deposited in layers onto a support structure. Depending on the build material, the layers can then be cured or solidified using appropriate equipment.

[0006] Various three-dimensional printing techniques exist and are disclosed, for example, in commonly assigned 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, 9,227,365, U.S. Published Patent Application No. 20060054039, and International Publication No. WO2016 / 009426, all of which are incorporated by reference herein in their entireties.

[0007] U.S. Patent No. 8,993,061 discloses a method for direct 3D printing on footwear. A 3D pattern for printing is designed. The footwear is placed substantially flat on the tray of a 3D printing system, and 3D material is printed directly onto the footwear fabric using the designed pattern. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 6,259,979 [Patent Document 2] U.S. Patent No. 6,569,373 [Patent Document 3] U.S. Patent No. 6,658,314 [Patent Document 4] U.S. Patent No. 6,850,334 [Patent Document 5] U.S. Patent No. 6,863,859 [Patent Document 6] U.S. Patent No. 7,183,335 [Patent Document 7] U.S. Patent No. 7,209,797 [Patent Document 8] U.S. Patent No. 7,225,045 [Patent Document 9] U.S. Patent No. 7,300,619 [Patent Document 10] U.S. Patent No. 7,500,846 [Patent Document 11] U.S. Patent No. 9,031,680 [Patent Document 12] U.S. Patent No. 9,227,365 [Patent Document 13] U.S. Published Patent Application No. 20060054039 [Patent Document 14] International Publication No. WO2016 / 009426 [Patent Document 15] U.S. Patent No. 8,993,061 Summary of the Invention

[0009] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing system comprising: a nozzle array for dispensing a build material, a work tray, a fixture configured to apply a fabric to the work tray, and a computerized controller configured to manipulate at least the nozzle array to dispense the build material onto the applied fabric in a configured pattern corresponding to a shape of an object.

[0010] According to some embodiments of the present invention, the tool is configured to stretch the fabric.

[0011] According to some embodiments of the present invention, the system further includes a robotic mechanism connected to the fixture and configured to place the fixture on the tray.

[0012] According to some embodiments of the present invention, the robot mechanism is configured to reverse the orientation of the fixture relative to a horizontal plane.

[0013] According to some embodiments of the present invention, the computerized controller is configured to operate at least the nozzle array to dispense the build material onto the tray, and to operate the robotic mechanism to position a jig on the tray after dispensing the build material onto the tray and before dispensing the build material onto the affixed fabric.

[0014] According to some embodiments of the invention, the system includes a position tracking system configured to determine the position of the fixture relative to the work tray, and the computerized controller is configured to perform an alignment procedure based on the position and to operate the nozzle array in response to the alignment.

[0015] According to some embodiments of the present invention, the fixture comprises marks, which are identifiable by a position tracking system to determine the position.

[0016] According to some embodiments of the present invention, the system includes a radiation source, and the work tray has a reflectivity of at least 50% to radiation emitted from the radiation source.

[0017] According to some embodiments of the present invention, the work tray comprises a fluid flow path, and the system comprises a fluid delivery system that generates a fluid flow within the fluid flow path.

[0018] According to an aspect of some embodiments of the present invention, there is provided a three dimensional printing system comprising: a nozzle array for dispensing a build material, a radiation source for emitting radiation for solidifying the dispensed build material, a work tray characterized by at least 50% reflectivity to the radiation, and a computerized controller configured to operate at least the nozzle array to dispense the build material onto a fabric in a configured pattern corresponding to a shape of an object.

[0019] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing system comprising: a nozzle array for dispensing a build material, a work tray having a fluid flow path, a fluid delivery system for generating a fluid flow in the fluid flow path, and a computerized controller configured to operate at least the nozzle array to dispense the build material onto a fabric in a configured pattern corresponding to a shape of an object.

[0020] According to some embodiments of the present invention, the system includes an additive dispensing system in fluid communication with a container containing an additive other than a build material for three-dimensional printing to dispense the additive onto the fabric.

[0021] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing system comprising: a nozzle array for dispensing a build material, a work tray, a computerized controller configured to operate at least the nozzle array to dispense the build material onto a fabric in a configured pattern corresponding to a shape of an object, and an additive dispensing system in fluid communication with a reservoir containing an additive other than the build material for three dimensional printing to dispense the additive onto the fabric.

[0022] According to some embodiments of the present invention, the computerized controller is configured to operate the additive delivery system.

[0023] According to some embodiments of the present invention, the array and additive dispensing system are mounted on the same print block.

[0024] According to some embodiments of the present invention, the array and the additive dispensing system are configured to move independently along a horizontal direction.

[0025] According to some embodiments of the present invention, the array and the additive dispensing system are configured to move independently along the vertical direction.

[0026] According to an aspect of some embodiments of the present invention, there is provided a system for three dimensional printing on fabric, the system including a print chamber having a nozzle array and a work tray therein for dispensing build material, a computerized controller configured to operate at least the nozzle array to dispense the build material onto the fabric in a configured pattern corresponding to a shape of an object, and a fabric unwinder configured to unroll a roll of fabric and feed the unrolled fabric into the print chamber.

[0027] According to some embodiments of the present invention, the system comprises a cutting device for cutting the unfolded fabric into portions.

[0028] According to some embodiments of the present invention, the system includes a fabric take-up device for taking up the fabric after dispensing.

[0029] According to some embodiments of the present invention, a fabric take-up device receives fabric from a fabric unwinder through a print chamber, thereby providing a continuous roll of fabric printed with a three-dimensional object.

[0030] According to an aspect of some embodiments of the present invention there is provided a system for three dimensional printing comprising: a nozzle array for dispensing build material, a work tray, an imaging system arranged to image a fabric disposed on the work tray, and a computerized controller for receiving image data from the imaging system, processing the image data to identify a pattern on the fabric, and operating at least the nozzle array to dispense build material at locations selected relative to the identified feature on the fabric in a configured pattern corresponding to a shape of an object.

[0031] According to some embodiments of the present invention, the imaging system comprises a pixelated image sensor.

[0032] According to some embodiments of the present invention, the imaging system comprises a scanner.

[0033] According to some embodiments of the present invention, the work tray is in operative association with a radiation source configured to emit radiation upward to solidify the dispensed build material from below.

[0034] According to some embodiments of the present invention, the system includes a stationary platform surrounding a work tray, and the fixture includes a frame configured to apply the fabric to the platform at a periphery of the work tray.

[0035] According to some embodiments of the invention, at least one of the platform and the frame comprises protruding elements or roughened surfaces. According to some embodiments of the invention, both the platform and the frame comprise complementary protruding elements or roughened surfaces.

[0036] According to some embodiments of the present invention, the edges of the top surface of the tray are filleted and / or chamfered.

[0037] According to some embodiments of the present invention, the system comprises a ramp structure mountable or positionable on the work tray to define an upper space above the work tray, the upper surface of the ramp structure configured to support a horizontal portion of the fabric, the space configured to receive a hanging portion of said fabric, and a computerized controller configured to control the nozzle array to dispense build material only onto the upper surface.

[0038] According to some embodiments of the present invention, the computerized controller is configured to adjust the vertical position of the work tray to compensate for the height of the lamp structure above the work tray.

[0039] According to an aspect of some embodiments of the present invention there is provided a system for three dimensional printing that includes applying a curable material to a fabric and operating a nozzle array to dispense the build material onto the fabric in a configured pattern corresponding to a shape of an object.

[0040] According to some embodiments of the present invention, applying the curable substance includes applying the curable substance to the same side of the fabric onto which the build material is dispensed.

[0041] According to some embodiments of the present invention, applying the curable substance includes applying the curable substance to an opposite side of the fabric from which the build material is dispensed.

[0042] According to some embodiments of the present invention, applying the curable material comprises placing a sheet containing the curable material on the fabric and heating the sheet.

[0043] According to some embodiments of the present invention, applying the curable material comprises placing a sheet containing the curable material under the fabric and heating the sheet.

[0044] According to some embodiments of the present invention, operating the nozzle array includes operating a three dimensional printing system including a nozzle array and a work tray, and applying the curable material includes placing a sheet including the curable material on the tray, placing a fabric on the sheet, and heating the tray.

[0045] According to some embodiments of the present invention, the hardenable substance is an oily substance.

[0046] According to some embodiments of the present invention, the curable material comprises a wax.

[0047] According to an aspect of some embodiments of the present invention there is provided a system for three dimensional printing comprising operating a first nozzle array to dispense a first build material onto a fabric to form a bonded area on the fabric, and operating a second nozzle array to dispense a second build material onto the bonded area in a configuration pattern corresponding to a shape of an object.

[0048] According to some embodiments of the present invention, the fabric is on a work tray, and the method includes obtaining alignment data regarding the position of the fabric relative to the work tray, and aligning the dispensing position of the build material based on the alignment data.

[0049] According to some embodiments of the present invention, the second build material comprises a generally water-clear build material.

[0050] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing system comprising: dispensing at least one build material onto a receiving surface to form fastening elements thereon; disposing a fabric over the fastening elements; dispensing the at least one build material onto the fabric to form piercing elements through the fabric and connected to the fastening elements; and dispensing the at least one build material onto the piercing elements in a configuration pattern corresponding to an object shape.

[0051] According to an aspect of some embodiments of the present invention there is provided a system for three dimensional printing comprising dispensing at least one build material onto a receiving surface in a configured pattern corresponding to a shape of an object, disposing a fabric over the object, dispensing at least one build material onto the fabric to form piercing elements through the fabric to connect to the object, and dispensing at least one build material onto the piercing elements to form another object.

[0052] According to some embodiments of the present invention, the other object is a fixing element.

[0053] According to some embodiments of the present invention, the other object is a decorative object.

[0054] According to some embodiments of the present invention, at least one of the object and the further object is a thermal protection object.

[0055] According to some embodiments of the present invention, the method includes dispensing at least one build material onto a work tray to form a sacrificial structure, the receiving surface being said sacrificial structure.

[0056] According to some embodiments of the present invention, dispensing at least one build material to form the piercing elements includes dispensing a generally clear and colorless build material.

[0057] According to some embodiments of the present invention, the method includes dispensing at least one build material to form a piercing element, penetrating the fabric while the piercing element is in a liquid state, and then irradiating the build material with solidifying irradiation.

[0058] According to some embodiments of the present invention, the method includes dispensing at least one build material to form a sacrificial layer on exposed portions of the fabric, and non-selectively irradiating all of the dispensed build material with solidification radiation.

[0059] According to some embodiments of the present invention, the method includes obtaining alignment data relating to a position of the fabric relative to the work tray, and aligning a dispensing position of the build material based on the alignment data.

[0060] According to an aspect of some embodiments of the present invention there is provided a method of fabricating a garment, the method including dispensing a build material onto a first piece of textile to form a female snap connector, dispensing a build material onto a second piece of textile to form a male snap connector, and connecting the female snap connector to the male snap connector, thereby fabricating a garment.

[0061] According to an aspect of some embodiments of the present invention there is provided a method of fabricating a garment comprising dispensing a build material onto an element of fabric to form a female snap connector and a male snap connector laterally offset from the female snap connector, folding the element of fabric to align the connectors, and connecting the female snap connector to the male snap connector, thereby fabricating the garment.

[0062] According to some embodiments of the present invention, the method includes applying at least one additive other than the three dimensional printing build material to the textile prior to dispensing the build material and / or after dispensing the build material.

[0063] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing method comprising: operating a nozzle array to dispense a build material onto a fabric in a configuration pattern corresponding to a shape of an object; and applying at least one additive other than the build material for three dimensional printing onto the fabric prior to dispensing the build material and / or after dispensing the build material.

[0064] According to some embodiments of the present invention, the at least one additive comprises a primer liquid selected from the group consisting of an adhesive solution and a pore size adjusting liquid, and the application of the primer liquid occurs before the dispensing.

[0065] According to some embodiments of the present invention, the at least one additive comprises a radiation protection solution and a finish selected from the group consisting of a glossy finish and a matte finish, and application of the finish occurs after the dispensing.

[0066] According to some embodiments of the present invention, the at least one additive comprises a masking solution, and application of the masking solution is performed before dispensing and selectively to locations not occupied by the object.

[0067] According to some embodiments of the present invention, the at least one additive is an in-situ activatable non-active formulation, and the method comprises applying the formulation to the fabric and then activating the formulation.

[0068] According to some embodiments of the present invention, activation is by irradiation.

[0069] According to some embodiments of the present invention, activation is by heating.

[0070] According to some embodiments of the present invention, activation is by chemical reaction between the additive and one or more build materials.

[0071] According to some embodiments of the present invention, applying the additive comprises applying an aerosol of the additive to the fabric.

[0072] According to some embodiments of the present invention, applying the additive comprises depositing droplets of the additive at discrete addressable locations on the fabric.

[0073] According to some embodiments of the present invention, there are at least two additives, and applying the additives comprises depositing interleaved droplets of the additives at discrete addressable locations on the fabric.

[0074] According to some embodiments of the present invention, there is a first additive and a second additive, the first additive and the second additive chemically react with each other upon contact, and applying the additives includes separately depositing the additives on the fabric to subsequently induce a reaction between them.

[0075] According to an aspect of some embodiments of the present invention, there is provided a three dimensional printing method including receiving, via a user interface, data related to properties of a fabric, receiving data related to properties of an object to be printed on the fabric, accessing a computer readable medium storing a library having a plurality of entries, each entry having a fabric property library, an object property library, and a set of printing parameters, searching the library for an entry that best suits the received properties, and operating a three dimensional printing system according to the set of printing parameters of the entry to form the object on the fabric.

[0076] According to some embodiments of the invention, the characteristic of the fabric comprises at least one characteristic selected from the group consisting of: type of fabric, pore size of the fabric, and weave pattern of the fabric.

[0077] According to some embodiments of the present invention, the property of the object comprises at least one property selected from the group consisting of thickness of the object, shape of the object, and stiffness of the object.

[0078] According to some embodiments of the present invention, the set of printing parameters includes at least one of: (i) an application order of the primer liquid; (ii) a build material; (iii) an ejection order of the build material; and (iv) an application order of the finishing liquid.

[0079] According to some embodiments of the present invention, the method includes receiving a scan of an individual's body or an external body part thereof and selecting at least one characteristic of the object based on the scan.

[0080] According to some embodiments of the present invention, the object is selected from the group consisting of a lens or prismatic object, an object that reflects visible light, an object that is transparent to visible light but reflects non-visible light, a fluorescent object, and a waveguide.

[0081] According to some embodiments of the present invention, the object is capable of changing optical, mechanical and / or geometric properties in response to environmental changes.

[0082] According to some embodiments of the present invention, the environmental change comprises at least one change selected from the group consisting of a temperature change, a humidity change, and a change in the electromagnetic content of the environment.

[0083] According to some embodiments of the present invention, the substance comprises a drug.

[0084] According to some embodiments of the invention, the agent is selected from the group consisting of an antibacterial agent and an antiviral agent.

[0085] According to some embodiments of the present invention, the object comprises a cosmetic product.

[0086] According to some embodiments of the present invention, the object comprises a heating element.

[0087] According to some embodiments of the present invention, the object comprises a cooling element.

[0088] According to some embodiments of the present invention, the object comprises a circuit.

[0089] According to some embodiments of the present invention, the object includes a cavity for receiving the foreign object.

[0090] According to some embodiments of the present invention, the object comprises a female or male portion of a snap connector.

[0091] According to some embodiments of the present invention, the method includes folding the fabric onto a ramp structure and mounting or placing the ramp structure on a work tray such that the horizontal portions of the fabric are supported on the upper surface of the ramp structure and the hanging portions of the fabric are folded below the upper surface and into the space above the work tray, with dispensing only onto the upper surface.

[0092] According to some embodiments of the present invention, the method includes adjusting the vertical position of the work tray to compensate for the elevation of the upper surface of the ramp structure above the work tray.

[0093] According to an aspect of some embodiments of the present invention there is provided a three dimensional printing system comprising: a work tray in operative communication with a nozzle array that dispenses a build material, a radiation source configured to emit radiation upward to solidify the dispensed build material from below, and a computerized controller configured to operate at least the nozzle array to dispense the build material in a configured pattern corresponding to a shape of an object, and to operate the radiation source after dispense.

[0094] According to some embodiments of the present invention, the computerized controller is configured to spatially select and manipulate the radiation source.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, the present specification, including definitions, will control. Furthermore, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0096] Implementation of the method and / or apparatus of the invention embodiments may involve performing or completing selected tasks manually, automatically, or a combination thereof. Furthermore, depending on the actual instrumentation and installation of the method and / or apparatus embodiments of the invention, some selected tasks may be performed by hardware, or by software or firmware using an operating system, and / or a combination thereof.

[0097] For example, hardware for performing selected tasks according to embodiments of the present invention may be implemented as a chip or circuit. With respect to software, selected tasks according to embodiments of the present invention may be implemented as a plurality of software instructions executed by a computer using any suitable operating system. In exemplary embodiments of the present invention, one or more tasks according to exemplary embodiments of the methods and / or apparatus described herein are performed by a data processor, such as a computing platform, executing a plurality of instructions. Optionally, the data processor includes volatile memory for storing instructions and / or data, and / or non-volatile storage, such as a magnetic hard disk and / or removable media, for storing instructions and / or data. Optionally, a network connection is also provided. A display and / or user input device, such as a keyboard or mouse, are also optionally provided.

[0098] Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. Referring now specifically to the drawings in detail, it is emphasized 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 together with the drawings will make apparent to those skilled in the art how embodiments of the invention may be carried out. [Brief explanation of the drawings]

[0099] [Figure 1A] FIG. 1 is a schematic diagram of an additive manufacturing system according to some embodiments of the present invention. [Figure 1B]FIG. 1 is a schematic diagram of an additive manufacturing system according to some embodiments of the present invention. [Figure 1C] FIG. 1 is a schematic diagram of an additive manufacturing system according to some embodiments of the present invention. [Figure 1D] FIG. 1 is a schematic diagram of an additive manufacturing system according to some embodiments of the present invention. [Figure 1E] FIG. 1 is a schematic diagram of a work tray for an additive manufacturing system, the work tray including or associated with a radiation source, in an embodiment of the present invention. [Figure 1F] FIG. 1 is a schematic diagram of a work tray for an additive manufacturing system, the work tray including or associated with a radiation source, in an embodiment of the present invention. [Figure 1G] FIG. 1 is a schematic diagram of a work tray for an additive manufacturing system, the work tray including or associated with a radiation source, in an embodiment of the present invention. [Figure 2A] FIG. 1 is a schematic diagram of a print head according to some embodiments of the present invention. [Figure 2B] FIG. 1 is a schematic diagram of a print head according to some embodiments of the present invention. [Figure 2C] FIG. 1 is a schematic diagram of a print head according to some embodiments of the present invention. [Figure 3A] FIG. 1 is a schematic diagram illustrating coordinate transformation according to some embodiments of the present invention. [Figure 3B] FIG. 1 is a schematic diagram illustrating coordinate transformation according to some embodiments of the present invention. [Figure 4A] FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 4B] FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 4C] FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 4D] FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 4E] FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 4F]FIG. 1 is a schematic diagram of a fixture suitable for some embodiments of the present invention. [Figure 5A] FIG. 1 is a schematic diagram of a robotic mechanism connected to a three dimensional printing print chamber or system housing, according to some embodiments of the present invention. [Figure 5B] FIG. 1 is a schematic diagram of a robotic mechanism connected to a three dimensional printing print chamber or system housing, according to some embodiments of the present invention. [Figure 5C] FIG. 1 is a schematic diagram of a tool store being accessed by a robotic mechanism, according to some embodiments of the present invention. [Figure 6A] 1 is a schematic diagram of an operational sequence suitable for a two-sided printing method for adhering an object to a fabric, according to some embodiments of the present invention. [Figure 6B] 1 is a schematic diagram of an operational sequence suitable for a two-sided printing method for adhering an object to a fabric, according to some embodiments of the present invention. [Figure 6C] 1 is a schematic diagram of an operational sequence suitable for a two-sided printing method for adhering an object to a fabric, according to some embodiments of the present invention. [Figure 6D] 1 is a schematic diagram of an operational sequence suitable for a two-sided printing method for adhering an object to a fabric, according to some embodiments of the present invention. [Figure 6E] 1 is a schematic diagram of an operational sequence suitable for a two-sided printing method for adhering an object to a fabric, according to some embodiments of the present invention. [Figure 7] 1 is a schematic diagram of an object printed upside down using double-sided printing and adhered to fabric, according to some embodiments of the present invention. [Figure 8A] 1 is a schematic diagram of a printed object adhered to a fabric without double-sided printing, according to some embodiments of the present invention. FIG. [Figure 8B] 1 is a schematic diagram of a printed object adhered to a fabric without double-sided printing, according to some embodiments of the present invention. FIG. [Figure 9] FIG. 1 is a schematic diagram of a system suitable for unfolding a roll of fabric and printing on the unfolded fabric, according to some embodiments of the present invention. [Figure 10]FIG. 1 is a flow diagram of a method suitable for printing three-dimensional objects on fabric, according to some embodiments of the present invention. [Figure 11A] 1 is a schematic diagram of a method suitable for fabricating a garment from two or more textile elements, according to some embodiments of the present invention. [Figure 11B] 1 is a schematic diagram of a method suitable for fabricating a garment from two or more textile elements, according to some embodiments of the present invention. [Figure 11C] 1 is a schematic diagram of a method suitable for fabricating a garment from two or more textile elements, according to some embodiments of the present invention. [Figure 12A] 1 is a schematic diagram of a method suitable for producing folded garments according to some embodiments of the present invention. [Figure 12B] 1 is a schematic diagram of a method suitable for producing folded garments according to some embodiments of the present invention. [Figure 13] FIG. 1 is a flow diagram of a method suitable for printing three-dimensional objects on fabric in an embodiment of the invention where the system determines the printing protocol. [Figure 14] FIG. 1 is a schematic diagram of a library of characteristics and printing parameters according to some embodiments of the present invention. [Figure 15A] 1A-1C are schematic diagrams of configurations in which fabric is placed on a lamp structure, according to some embodiments of the present invention. [Figure 15B] 1A-1C are schematic diagrams of configurations in which fabric is placed on a lamp structure, according to some embodiments of the present invention. [Figure 15C] 1A-1C are schematic diagrams of configurations in which fabric is placed on a lamp structure, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0100] The present invention, in some embodiments thereof, relates to three-dimensional printing, and more particularly, but not exclusively, to methods and systems for printing objects onto fabrics.

[0101] Before describing at least one embodiment of the present 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 components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The invention is capable of other embodiments and of being practiced or carried out in various ways.

[0102] The present method and system fabricates a three-dimensional object layer-by-layer by forming multiple layers in a construction pattern that corresponds to the shape of the object based on computer object data, which may be in any known format, including but not limited to Standard Tessellation Language (STL) or Stereolithography Contour (SLC) format, OBJ file format (OBJ), 3D Manufacturing Format (3MF), Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Interchange Format (DXF), Polygon File Format (PLY), or any other format suitable for computer-aided design (CAD).

[0103] As used herein, the term "object" refers to the entire object or a portion thereof.

[0104] Each layer is formed by an additive manufacturing device that scans a two-dimensional surface to pattern it. During scanning, the device visits multiple target locations on the two-dimensional layer or surface and, for each target location or group of target locations, determines whether and what type of build material should be delivered to that target location or group of target locations. The decision is made according to a computer image of the surface.

[0105] In preferred embodiments of the present invention, AM comprises three-dimensional printing, more preferably three-dimensional inkjet printing. In these embodiments, build material is ejected from a printhead having one or more nozzle arrays to deposit the build material in layers onto a receiving surface. The AM device thus ejects build material at target locations to be covered, leaving other target locations empty. The device typically includes multiple nozzle arrays, each configurable to eject a different build material. This is typically achieved by providing a printhead with multiple fluid channels that are isolated from one another and not in fluid communication with one another. Each channel receives a different build material through a separate inlet, which is then delivered to a separate nozzle array.

[0106] Thus, different target locations can be occupied by different build materials. Build material types are broadly divided into two categories: build materials and support materials. Typically, build materials are solvent-free (e.g., free of water or any organic solvents) and / or dispensed at temperatures above 40°C, 50°C, or 60°C. Support materials function as a support matrix or structure to support an object or portion of an object during the fabrication process and / or for other purposes, such as providing a hollow or porous object. Support structures can also include additional build material elements, e.g., to provide additional support strength.

[0107] Build materials are generally compounds formulated for use in additive manufacturing that are capable of forming three-dimensional objects by themselves, i.e., without the need for mixing or combining with any other substances.

[0108] The final three-dimensional object may be made from the build material, or a combination of build materials, or a build material and a support material, or variations thereof (e.g., after hardening), all of which are well known to those skilled in the art of solid freeform molding.

[0109] In some exemplary embodiments of the invention, an object is fabricated by dispensing two or more different build materials, each material dispensed through a different nozzle array (on the same or different print head) of the AM device. In some embodiments, two or more such nozzle arrays dispensing different build materials are all located on the same print head of the AM device. In some embodiments, the nozzle arrays dispensing different build materials are located on separate print heads. For example, a first nozzle array dispensing a first build material is located on a first print head, and a second nozzle array dispensing a second build material is located on a second print head.

[0110] In some embodiments, both the nozzle arrays that eject the build material and the nozzle arrays that eject the support material are located on the same print head, while in some embodiments, the nozzle arrays that eject the build material and the nozzle arrays that eject the support material are located on separate print heads.

[0111] A representative, non-limiting example of a system 110 suitable for AM of an object 112, according to some embodiments of the present invention, is shown in Figure 1A. The system 110 includes an additive manufacturing device 114 having a dispensing unit 16 with multiple print heads. Each head preferably includes one or more nozzle arrays 122, typically mounted in an orifice plate 121 as shown in Figures 2A-2C, described below, through which a liquid build material 124 is dispensed.

[0112] Preferably, but not necessarily, device 114 is a three-dimensional printing device, in which case the print head is a print head and the build material is dispensed via inkjet technology. This need not be the case, as some applications may not require the additive manufacturing device to use three-dimensional printing technology. Representative examples of additive manufacturing devices contemplated by various exemplary embodiments of the present invention include, but are not limited to, fused deposition modeling devices and fused material deposition models.

[0113] Each print head is optionally and preferably fed via one or more build 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 eject the build material, a voltage signal is applied to the print head, selectively depositing droplets of material through the print head nozzles, as in, for example, piezoelectric inkjet printing technology. Another example is a thermal inkjet print head. In this type of head, a heater element is in thermal contact with the build material, and a voltage signal activates the heater element to heat the build material and form a gas bubble therein. The gas bubble generates pressure within the build material, causing droplets of the build material to be ejected through the nozzles. Piezoelectric and thermal print heads are known to those skilled in the art of solid free-form molding. For any type of inkjet print head, the ejection speed of the head depends on the number of nozzles, the type of nozzle, and the applied voltage signal rate (frequency).

[0114] Preferably, but not necessarily, the total number of ejection nozzles or nozzle arrays is selected so that half of the ejection nozzles are for ejecting support material and half are for ejecting build material. That is, the number of nozzles ejecting build material is the same as the number of nozzles ejecting support material. In the representative example shown in FIG. 1A , four print heads 16 a, 16 b, 16 c, and 16 d are shown. Each head 16 a, 16 b, 16 c, and 16 d has a nozzle array. In this example, heads 16 a and 16 b may be for the build material, and heads 16 c and 16 d may be for the support material. In this way, head 16 a may eject one build material, head 16 b may eject another build material, and heads 16 c and 16 d may both eject support material. In alternative embodiments, heads 16 c and 16 d may be combined into a single head with two nozzle arrays, for example, for depositing support material. In further alternative embodiments, any one or more print heads may have two or more nozzle arrays for depositing two or more materials, such as two nozzle arrays for two different build materials, or one build material and one support material, with each formulation being deposited through a different array or different number of nozzles.

[0115] However, it should be understood that this is not intended to limit the scope of the invention, and that the number of print heads (build heads) for the build material and the number of print heads (support heads) for the support material may vary. Generally, the number of nozzle arrays discharging the build material, the number of nozzle arrays discharging the support material, and the number of nozzles in each array are selected to provide a predetermined ratio a between the maximum discharging velocity of the support material and the maximum discharging velocity of the build material. The value of the predetermined ratio a is preferably selected so that the height of the build material and the height of the support material are equal in each layer formed. Typical values ​​of a are from about 0.6 to about 1.5.

[0116] As used throughout this specification, the term "about" refers to ±10%.

[0117] For example, when a=1, the total dispensing rate of the support material is approximately equal to the total dispensing rate of the build material when all nozzles in the nozzle array are operational.

[0118] For example, apparatus 114 may include M build heads, each with m p nozzle arrays, and S support heads, each with s q nozzle arrays, where M×m×p=S×s×q. Each of the M×m build arrays and S×s support arrays may be fabricated as a separate physical unit, capable of being assembled and disassembled from a group of multiple arrays. In this embodiment, each such array optionally and preferably includes its own temperature control unit and material level sensor, and receives an individually controlled voltage for its operation.

[0119] Apparatus 114 further includes solidification device 18, which may include any device configured to emit light, heat, or the like that may solidify the deposited material. For example, solidification device 18 may include one or more radiation sources, which may be, for example, ultraviolet, visible, or infrared lamps, or other electromagnetic radiation sources, or electron beam sources, depending on the build material used. In some embodiments of the present invention, solidification device 18 functions to harden or solidify the build material.

[0120] In addition to the coagulation device 18, the device 114 optionally and preferably includes an additional radiation source 328 for evaporating the solvent. The radiation source 328 optionally and preferably generates infrared light. In some embodiments of the invention, the coagulation device 18 includes a radiation source that generates ultraviolet light, and the radiation source 328 generates infrared light.

[0121] In some embodiments of the present invention, the device 114 includes a cooling device 134, such as one or more fans.

[0122] The print head(s) and radiation source(s) are preferably mounted on a frame or block 128, which preferably reciprocates over a tray 360, which acts as a work surface. In some embodiments of the invention, the radiation source is mounted on the block and is adapted to follow the trajectory of the dispensing heads to at least partially cure or solidify the material just dispensed by the print heads. The tray 360 is positioned horizontally. According to common practice, an XYZ Cartesian coordinate system is selected such that the XY plane is parallel to the tray 360. The tray 360 is preferably configured to move vertically (along the Z direction), typically downward. In various exemplary embodiments of the invention, the apparatus 114 further includes one or more leveling devices 32, e.g., rollers 326. The leveling devices 326 act to straighten, flatten, and / or establish the thickness of a newly formed layer before a subsequent layer is formed thereon. The leveling devices 326 preferably include a waste collection device 136 for collecting excess material generated during flattening. The waste collector 136 may include any mechanism that delivers materials to a waste tank or waste cartridge.

[0123] In the schematic diagram of Figure 1A, the edges of the tray 360 are formed with straight corners, however this is not required and in some applications it may be desirable for the corners of the top surface of the tray 360 to be formed with fillets and / or chamfers (see chamfer 411 in Figures 4E and 4F), particularly when the tray 360 is in contact with the fabric on which the object is to be printed.

[0124] In use, the print heads of the units 16 move in a scanning direction, referred to herein as the X direction, selectively dispensing build material in a predetermined configuration as they pass over the tray 360. The build material typically includes one or more support materials and one or more build materials. The print heads' passage is followed by curing of the build material by the radiation source 126. Additional build material may be dispensed in a predetermined configuration during the head's reverse movement back to the starting point of the deposited layer. The layer thus formed can be leveled by a leveling device 326 during the print head's forward or reverse movement, preferably along the path of the print head during the forward and / or reverse movement. Once the print heads return to their starting points along the X direction, they can be moved to another position along an indexing direction, referred to herein as the Y direction, and continue building the same layer by reciprocating along the X direction. Alternatively, the print heads may move in the Y direction between forward and reverse movements, or after two or more forward-reverse movements. The series of scans performed by the printhead to complete a single layer is referred to herein as a single scan cycle.

[0125] Once that layer is complete, the tray 360 is lowered in the Z direction to a predetermined Z level depending on the desired thickness of the next printed layer. This procedure is repeated to build the three-dimensional object 112 layer by layer.

[0126] In another embodiment, the tray 360 may be displaced in the Z direction within the layer between the forward and reverse passes of the print head of the unit 16. Such Z displacement is performed to bring the leveling device into contact with the surface in one direction and out of contact in the opposite direction.

[0127] System 110 optionally and preferably includes a supply system 330 that includes containers or cartridges of build material and supplies a plurality of build materials to fabrication device 114 .

[0128] The controller 20 controls the fabrication apparatus 114 and, optionally and preferably, the supply system 330. The controller 20 typically includes electronic circuitry configured to perform control operations. The controller 20 preferably communicates with a data processor 154, which transmits digital data relating to fabrication instructions based on computer object data, such as a CAD configuration represented on a computer-readable medium in a format such as Standard Tessellation Language (STL) format. Typically, the controller 20 controls the voltage applied to each print head or each nozzle array and the temperature of the build material at each print head or each nozzle array.

[0129] Once the production data is loaded into the controller 20, the controller can operate without user intervention. In some embodiments, the controller 20 receives additional input from an operator, for example, using the data processor 154 or using a user interface 116 in communication with the controller 20. The user interface 116 may be of any type known in the art, such as, for example, but not limited to, a keyboard, a touch screen, etc. For example, the controller 20 may receive as additional input one or more build material types and / or attributes, such as, for example, but not limited to, color, characteristic distortion and / or transition temperature, viscosity, electrical properties, magnetic properties, etc. Other attributes and groups of attributes are also contemplated.

[0130] Another representative, non-limiting example of a system 10 suitable for AM of an object according to some embodiments of the present invention is shown in Figures 1B-1D, which show a top view (Figure 1B), a side view (Figure 1C), and an isometric view (Figure 1D) of the system 10.

[0131] In this embodiment, the system 10 includes a tray 12 and a plurality of inkjet print heads 16, each having one or more nozzle arrays with one or more separated nozzles. Material used for three-dimensional printing is supplied to the heads 16 by a build material supply system 42. The tray 12 may be disk-shaped or annular. Non-circular shapes are also contemplated, provided they are rotatable about a vertical axis. In the schematic diagram of FIG. 1C, the edges of the tray 12 are shown with straight corners. However, in some applications, such as the tray 360 described above, it may be desirable for the corners on the top surface of the tray 12 to be formed as fillets and / or chamfers, particularly when the tray 12 abuts a fabric on which an object is to be printed.

[0132] The tray 12 and head 16 are optionally and preferably mounted to allow relative rotational movement between the tray 12 and head 16. This can be achieved by (i) a configuration in which the tray 12 rotates relative to the head 16 about a vertical axis 14; (ii) a configuration in which the head 16 rotates relative to the tray 12 about a vertical axis 14; or (iii) a configuration in which both the tray 12 and the head 16 rotate about a vertical axis 14, but at different rotational speeds (e.g., in opposite directions). Below, several embodiments of the system 10 are described with particular emphasis on configuration (i), in which the tray is a rotating tray configured to rotate relative to the head 16 about a vertical axis 14, but it should be understood that the present application also contemplates configurations (ii) and (iii) for the system 10. Any of the embodiments of the system 10 described herein can be adapted to apply to either configuration (ii) or configuration (iii), and one of ordinary skill in the art would know how to make such adjustments given the details provided herein.

[0133] In the following description, the direction parallel to the tray 12 and outward from the axis 14 will be referred to as the radial direction r, the direction parallel to the tray 12 and perpendicular to the radial direction r will be referred to herein as the azimuthal direction φ, and the direction perpendicular to the tray 12 will be referred to herein as the vertical direction z.

[0134] The radial direction r of system 110 defines an index direction y of system 110, and the azimuthal direction φ defines a scan direction x of system 110. Thus, the radial direction is referred to herein interchangeably as the index direction, and the azimuthal direction is referred to herein interchangeably as the scan direction.

[0135] As used herein, the term "radial position" refers to a position on or above tray 12 that is a particular distance from axis 14. When the term is used in reference to a print head, the term refers to a position of the head that is a particular distance from axis 14. When the term is used in reference to a point on tray 12, the term corresponds to any point belonging to a locus of points that is a circle whose radius is a particular distance from axis 14 and whose center is at axis 14.

[0136] As used herein, the term "azimuthal position" refers to a position on or above tray 12 that is at a particular azimuthal angle relative to a given reference point. A radial position, therefore, refers to any point belonging to a linear locus of points that is at a particular azimuthal angle relative to a reference point.

[0137] As used herein, the term "vertical position" refers to a position on a plane that intersects the vertical axis 14 at a particular point.

[0138] Tray 12 serves as a build platform for three-dimensional printing. The work area, on which one or more objects are printed, is typically, but not necessarily, smaller than the total area of ​​tray 12. In some embodiments of the present invention, the work area is annular. The work area is indicated by the reference numeral 26. In some embodiments of the present invention, tray 12 rotates continuously in the same direction during the formation of an object; in some embodiments of the present invention, the tray reverses its direction of rotation (e.g., oscillates) at least once during the formation of an object. Tray 12 is optionally and preferably removable. Removal of tray 12 can be performed for maintenance of system 10 or, if desired, to replace 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), where two or more trays are designated for different types of objects (e.g., different weights), different modes of operation (e.g., different rotational speeds), etc. Tray 12 replacement can be manual or automatic, as desired. When automatic exchange is used, system 10 includes a tray exchanger 36 configured to remove tray 12 from its position under head 16 and replace it with a replacement tray (not shown). In the representative view of Figure 1B, tray exchanger 36 is shown as a drive unit 38 having a movable arm 40 configured to pull tray 12, although other types of tray exchangers are contemplated.

[0139] 2A-2C show exemplary embodiments of print head 16. These embodiments may be used in any of the AM systems described above, including but not limited to system 110 and system 10.

[0140] 2A-2B show print heads 16 having one (FIG. 2A) and two (FIG. 2B) nozzle arrays 22. The nozzles in the arrays are preferably arranged linearly along a straight line. In embodiments where a particular print head has two or more linear nozzle arrays, the nozzle arrays may optionally and preferably be parallel to one another. When a print head has two or more nozzle arrays (e.g., FIG. 2B), all arrays on that head may be supplied with the same build material, or at least two arrays on the same head may be supplied with different build materials.

[0141] When a system similar to system 110 is used, all print heads 16 are optionally and preferably oriented along an index direction and their positions along the scan direction are offset from one another.

[0142] When a system similar to system 10 is used, all print heads 16 are optionally and preferably oriented radially (parallel to the radial direction) and are azimuthal offset from one another. Thus, in these embodiments, the nozzle arrays of different print heads are not parallel to one another, but rather are at an angle to one another, the angle being approximately equal to the azimuthal offset between the respective heads. For example, one head can be oriented radially and positioned at an azimuthal position φ1, and another head can be oriented radially and positioned at an azimuthal position φ2. In this example, the azimuthal offset between the two heads is φ1-φ2, and the angle between the linear nozzle arrays of the two heads is also φ1-φ2.

[0143] In some embodiments, two or more printheads can be combined into a printhead block, where the printheads in the block are generally parallel to one another. A block containing multiple inkjet printheads 16a, 16b, and 16c is shown in Figure 2C.

[0144] In some embodiments, system 10 includes a stabilizing structure 30 positioned below head 16, with tray 12 between stabilizing structure 30 and head 16. Stabilizing structure 30 can function to prevent or reduce vibrations of tray 12 that may occur when inkjet print head 16 is operated. In configurations in which print head 16 rotates about axis 14, stabilizing structure 30 also preferably rotates so that stabilizing structure 30 is always directly below head 16 (with tray 12 between head 16 and tray 12).

[0145] Tray 12 and / or print head 16 are optionally and preferably configured to move parallel to vertical axis 14 along vertical direction z to enable the vertical distance between tray 12 and print head 16 to be changed. In configurations in which the vertical distance is changed by moving tray 12 along the vertical direction, stabilizing structure 30 also preferably moves vertically with tray 12. In configurations in which the vertical position of tray 12 remains fixed and the vertical distance along the vertical direction is changed by head 16, stabilizing structure 30 is also held in a fixed vertical position.

[0146] Vertical movement can be achieved by vertical drive 28. Once a layer is completed, the vertical distance between tray 12 and head 16 can be increased (e.g., tray 12 can be lowered relative to head 16) by a predetermined vertical distance depending on the desired thickness of the next layer to be printed. This procedure is repeated to build the three-dimensional object layer by layer.

[0147] The operation of inkjet print head 16, and optionally and preferably, the operation of one or more other components of system 10, such as movement of tray 12, is controlled by a controller 20. The controller may include electronic circuitry and a non-volatile storage medium readable by the circuitry that stores program instructions that, when read by the circuitry, cause the circuitry to perform control operations as described in further detail below.

[0148] The controller 20 can also communicate with a host computer 24, which transmits digital data related to fabrication instructions based on the computer object data. The digital data may be, for example, Standard Tessellation Language (STL) or 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 format is typically organized according to a Cartesian coordinate system. In such cases, the computer 24 preferably performs a procedure for converting the coordinates of each slice in the computer object data from the Cartesian coordinate system to a polar coordinate system. The computer 24 optionally and preferably transmits the fabrication instructions in the transformed coordinate system. Alternatively, the computer 24 can transmit the fabrication instructions in the original coordinate system provided by the computer object data. In that case, the coordinate conversion is performed by circuitry in the controller 20.

[0149] Coordinate transformation enables three-dimensional printing on a rotating tray. In non-rotating systems with a fixed tray, the print head typically moves back and forth along a straight line above the fixed tray. In such systems, if the head's ejection velocity is uniform, the print resolution is the same at any point on the tray. Unlike non-rotating systems, in system 10, not all nozzles of the head point the same distance above tray 12 in the same amount of time. Coordinate transformation is optionally and preferably performed to ensure equal amounts of excess material at different radial locations. A representative example of coordinate transformation according to some embodiments of the present invention is shown in Figures 3A-3B, which represent three slices of an object (each slice corresponding to a fabrication command for a different layer of the object), where Figure 3A shows the slice in a Cartesian coordinate system and Figure 3B shows the same slice after applying the coordinate transformation procedure to each slice.

[0150] Generally, controller 20 controls the voltages applied to each component of system 10 based on manufacturing instructions and based on stored program instructions described below.

[0151] Generally, controller 20 controls print head 16 to eject droplets of build material in layers to print a three-dimensional object onto tray 12 while tray 12 rotates.

[0152] System 10 optionally and preferably includes one or more solidification devices 18, which may include, for example, one or more radiation sources, such as, but not limited to, ultraviolet, visible, or infrared lamps, or other electromagnetic radiation sources, or electron beam sources, depending on the build material being used. Radiation sources may include any type of radiation-emitting device, including, but not limited to, light-emitting diodes (LEDs), digital light processing (DLP) systems, resistive heat lamps, etc. Radiation source 18 serves to harden or solidify the build material. In various exemplary embodiments of the invention, operation of radiation source 18 is controlled by controller 20, which activates and deactivates radiation source 18 and optionally controls the amount of radiation generated by radiation source 18.

[0153] In some embodiments of the present invention, system 10 further comprises one or more leveling devices 32, which may be manufactured as rollers or blades. Leveling devices 32 serve to straighten a newly formed layer before forming the next layer thereon. In some embodiments, leveling devices 32 have the shape of a conical roller, positioned so that its axis of symmetry 34 is inclined relative to the surface of tray 12 and its surface is parallel to the surface of the tray. This embodiment is shown in a side view of system 10 (FIG. 1C).

[0154] The conical roller may be in the shape of a cone or a truncated cone.

[0155] The opening angle of the conical roller is preferably selected so that the ratio between the radius of the cone at any point along its axis 34 and the distance between that point and axis 14 is constant. This embodiment allows roller 32 to efficiently level the layer because, as the roller rotates, any point p on the roller surface has a linear velocity proportional to (e.g., the same as) the linear velocity of the tray at a point directly vertically below point p. In some embodiments, the roller has a frustoconical shape with height h, radius R1 at a point closest to axis 14, and radius R2 at a point farthest from axis 14, where parameters h, R1, and R2 satisfy the relationship R1 / R2=(Rh) / h, and R is the farthest distance of the roller from axis 14 (e.g., R can be the radius of tray 12).

[0156] The operation of leveling device 32 is optionally and preferably controlled by controller 20. The controller may start and stop leveling device 32 and optionally also control its position along the vertical direction (parallel to axis 14) and / or radial direction (parallel to tray 12, toward or away from axis 14).

[0157] In some embodiments of the invention, print head 16 is configured to move reciprocally relative to the tray along a radial direction r. These embodiments are useful when the length of nozzle array 22 of head 16 is less than the radial width of working area 26 on tray 12. Movement of head 16 in the radial direction is optionally and preferably controlled by controller 20.

[0158] 1E-1G are schematic diagrams of a work tray 12 / 360 according to an embodiment of the present invention. Here, the work tray includes or is associated with a radiation source 19 that emits radiation 17 that irradiates the build material from below. Depending on the build material being used, the radiation source 19 can emit any type of radiation 17, including, but not limited to, electromagnetic radiation (e.g., ultraviolet, visible light, infrared, etc.), electron beam radiation, etc. The radiation 17 emitted by the radiation source 19 serves to solidify the build material from below. The radiation source 19 can include any device capable of emitting radiation 17, such as, but not limited to, one or more LEDs, a digital light projector (DLP), a laser device, an electron beam source, etc. The radiation source 19 can be controlled by a controller 20, which can activate, deactivate, and optionally control the amount and / or cross-sectional area of ​​the radiation 17.

[0159] In the schematic diagram of FIG. 1E, the radiation source 19 is located below the work tray 12 / 360, in which case the work tray 12 / 360 is preferably transparent to the radiation 17 emitted by the source 19. In the schematic diagram of FIG. 1F, the radiation source 19 is embedded within the tray 12 / 360, in which case the portion of the work tray above the source 19 is transparent to the radiation 17. In the schematic diagram of FIG. 1G, the radiation source 19 is attached to the side of the tray 12 / 360, in which case the radiation 17 is coupled into the tray 12 / 360 and guided within the tray 12 / 360 before exiting upward. The radiation 17 is guided by the material of the work tray 12 / 360 (e.g., by total internal reflection) and exits upward by a redirecting element 21 (e.g., a mirror or diffraction grating). The radiation 17 may be guided by one or more waveguides (not shown) embedded in the work tray 12 / 360.

[0160] In some embodiments, the radiation source 19 is activated by the controller 20 only when the bottom layer(s) of build material are dispensed (e.g., the first 1, 2, 3, 4, or 5 layers) and is then deactivated. Alternatively, the build material dispensed to form the bottom layer may be transparent to the radiation 17, allowing the radiation 17 to penetrate the bottom layer and solidify the layers above. In some embodiments, it is contemplated that the build material for the bottom layer may be selected to absorb the radiation 17, thereby shielding the layers above from the radiation 17.

[0161] In some embodiments, the radiation source 19 is activated in a spatially selective manner so that certain areas on the tray emit radiation and other areas do not. For example, the radiation source 19 is activated in a spatially selective manner so that only the areas on the work tray where the build material is being dispensed are irradiated. Spatially selective irradiation can be achieved, for example, by providing the radiation source 19 with an LED array and selectively activating individual LEDs.

[0162] In some embodiments, it is contemplated that an object may be fabricated by ejecting different materials from different nozzle arrays (belonging to the same or different printheads). These embodiments provide, among other things, the ability to select materials from a predetermined number of materials and define a desired combination of the selected materials and their properties. According to this embodiment, the spatial locations at which each material is deposited in a layer are defined either by having different materials occupy different three-dimensional spatial locations, or by placing two or more different materials at substantially the same three-dimensional location or adjacent three-dimensional locations and spatially intermixing the materials within the layer after deposition, thereby forming a composite material at each location or locations.

[0163] Any combination or mixing of build materials after deposition is contemplated. For example, after a particular material is dispensed, it may maintain its original properties. However, if it is dispensed simultaneously with another build material or other dispensed materials, at the same or nearby locations, a composite material may be formed that has one or more properties different from the dispensed materials.

[0164] In some embodiments of the present invention, the system dispenses digital material for at least one of the layers.

[0165] As used herein and in the art, the term "digital material" refers to the combination of two or more materials at the pixel or voxel level, such that pixels or voxels of different materials intersect with one another in a region. Such digital materials can exhibit novel properties that are influenced by the choice of material type and / or the ratio and relative spatial distribution of two or more materials.

[0166] As used herein, a "voxel" of a layer refers to a physical three-dimensional elemental volume within the layer and corresponds to a single pixel in a bitmap describing the layer. The dimensions of a voxel are approximately equal to the dimensions of the area formed by the build material after it has been dispensed, flattened, and solidified at the location corresponding to the individual pixel.

[0167] This embodiment thus allows for the deposition of a wide range of material combinations and enables the creation of objects where different parts may be composed of multiple different material combinations, depending on the properties required to characterize each part of the object.

[0168] Further details of the principles and operation of an AM system suitable for this embodiment are provided in U.S. Published Patent Application No. 20100191360, the contents of which are incorporated herein by reference.

[0169] In some embodiments of the present invention, system 10 and / or system 110 are configured to print one or more objects onto fabric.

[0170] As used herein, "fabric" includes any manufactured article made at least in part from natural or man-made fiber materials. Examples of types of fabric include, but are not limited to, clothing, shoes, toys, cloth products, carpets, cloth hats, cloth bags, socks, towels, curtains, etc.

[0171] This embodiment contemplates printing on woven or nonwoven fabric.

[0172] As used herein, the term "woven fabric" refers to a structure in accordance with ASTM D123-03 in which at least two sets of twisted yarns are interlaced, e.g., perpendicular to each other, according to a predetermined interlacing pattern, with at least one set parallel to an axis along the length of the fabric.

[0173] As used herein, the term "nonwoven" means a woven structure made by bonding or entangling fibers, or both, by mechanical, chemical, thermal, or solvent means, or combinations thereof, in accordance with ASTM D123-03.

[0174] Preferably, but not necessarily, when a printing system (e.g., system 10 or system 110) is used to print objects on fabric, leveling device 32 is not used. In these embodiments, each layer of build material dispensed onto the fabric is solidified (e.g., cured) after dispense without leveling the layer.

[0175] Preferably, but not necessarily, when a printing system (e.g., system 10 or system 110) is used to print objects onto fabric, the height of the printed object is less than 10 cm, more preferably less than 9 cm, more preferably less than 8 cm, more preferably less than 8 cm, more preferably less than 7 cm, more preferably less than 6 cm, more preferably less than 5 cm, more preferably less than 4 cm, more preferably less than 3 cm, more preferably less than 2 cm, more preferably less than 1 cm.

[0176] In some embodiments of the invention, the working tray of the system (e.g., tray 12 or tray 360) has a reflectivity of at least 50%, or at least 60%, or at least 70%, or at least 80%, or more, to the radiation emitted by the radiation source of solidification device 18. An advantage of making the working tray reflective or partially reflective is that reflected radiation reaching the fabric from below can solidify the build material below the fabric and can also penetrate the pores of the fabric and solidify droplets of build material within those pores, thereby improving adhesion of the printed object to the fabric.

[0177] This embodiment also contemplates providing one or more fluid flow paths 52 in the work tray. A fluid delivery system 54 can generate a fluid flow within the fluid flow paths 52. The fluid can optionally and preferably be temperature controlled, thereby controlling the temperature of the work tray. When the fluid delivery system 54 generates a fluid flow that is at a temperature lower than that of the dispensed build material, the fluid absorbs heat from the build material. The fluid delivery system 54 can also generate a fluid flow that is at a temperature higher than that of the fabric, facilitating smoothing of the fabric before dispensing the build material onto the fabric. The inventors also contemplate combinations of these embodiments, in which the fluid is at a high temperature before dispensing the build material and at a reduced temperature during fabrication of the object. The fluid can be in a gas or liquid phase (e.g., air, helium, water, oil, etc.). Preferably, the fluid delivery system 54 is controlled by the controller 20.

[0178] In some embodiments of the present invention, system 10 and / or system 110 includes a fixture 402 configured to apply fabric 420 to a predetermined location on a work tray of the system (e.g., tray 12 or tray 360) and in a predetermined orientation relative to a nozzle array of the system (e.g., array 122). In some embodiments of the present invention, fixture 402 is also configured to stretch fabric 420.

[0179] The fixture 402 is shown in detail in Figures 4A-4F. Figures 4A and 4B show an embodiment of the fixture 402 comprising a frame 403 and one or more magnetic or metallic elements 405. The elements 405 are preferably permanently attached to or adjacent to the tray 360 / 12, e.g., on a stationary platform 361 surrounding the tray 360 / 12. At least one of the tray 360 / 12 and the elements 405 includes permanent magnets to ensure mutual magnetic attraction between the elements 405 and the frame 403. The frame 403 may be entirely made of magnetic or metallic material, or may include metallic or magnetic elements (not shown in Figures 4E and 4F) around its periphery, laterally positioned to coincide with the location of the elements 405. 4A shows the jig 402 in an open state before the fabric 420 is placed on the work tray 360 / 12, and FIG. 4B shows the jig 402 in a closed state, with a frame 403 magnetically attached to an element 405 (not shown in FIG. 4B) to affix and optionally and preferably stretch the fabric 420 onto the work tray 360 / 12. The jig 402 may also be made of a pair of frames 403 that are magnetically attachable to each other. In that case, the fabric 420 is stretched between the jig frames before being placed on the work tray 360 / 12. In these embodiments, the element 405 is not required.

[0180] 4E and 4F show side views of jig 402. In the illustrated embodiment, frame 403 includes magnetic or metallic elements 407 attached to it in a lateral position that corresponds to the position of elements 405 around its periphery. Elements 407 and 405 may be flat, as shown in FIG. 4E, or may have protruding elements 409 or roughened surfaces, as shown in FIG. 4F. The protruding elements or roughened surfaces may be on metallic or magnetic elements attached to frame 403, platform 361, or both frame 403 and platform 361. If frame 403 is entirely metallic or magnetic and has no other metallic or magnetic elements 407 attached thereto, protruding elements 409 or roughened surfaces may be formed on frame 403 in a lateral position that corresponds to the position of elements 405.

[0181] 4C and 4D show an embodiment in which the fixture 402 includes a rotatable frame 406 and a flat fabric holder 408. Here, the frame 406 is sized and shaped so that when the frame 406 rotates to engage the surface of the fabric holder 408, the frame 406 surrounds the fabric holder 408 and captures the fabric 420 between the frame 406 and the fabric holder 408. The fabric holder 408 may be in the form of a continuous surface or a frame. If the fabric holder 408 is a continuous surface, once the fabric 420 is placed on the fabric holder 408 and, optionally and preferably, stretched, the fabric 420 is accessible from only one side (typically the top side). If the fabric holder 408 is in the form of a frame, once the fabric 420 is placed on the fabric holder 408 and, optionally and preferably, stretched over the holder, the fabric 420 is accessible from both sides. FIG. 4C shows the fixture 402 in an open position ready to receive the fabric 420, and FIG. 4D shows the fixture 402 in a closed position with the fabric 420 attached to the tray 12 / 360.

[0182] An advantage of having a fixture with a flat fabric holder 408 is that the fixture 402 can receive the fabric 420 either while the fixture 402 is placed in the work tray 12 / 360 (as shown in Figures 4C and 4D) or before the fixture 402 is placed in the work tray 12 / 360 (as shown in Figures 5A-5C, which will be described later).

[0183] 15A-15C are schematic diagrams of a configuration in which fabric 420 is disposed on a ramp structure 450 that includes a flat ramp 452 and one or more spacer beams 454 that hold the ramp 452 vertically spaced apart from the work tray 12 / 360. The ramp structure 450 may be disposed above the tray 12 / 360 or may be connected to the tray 12 / 360 by a connector (not shown), such as, but not limited to, a snap connector. If the ramp structure 450 is connected to the tray, the connector is preferably outside the printing area of ​​the AM system so as not to interfere with the printing process when the AM system is operating without the ramp 450. Fabric 420 can be attached using any of the techniques previously described, except that the fabric is attached to the ramp structure 450 rather than the tray 12 / 360.

[0184] An advantage of using the ramp structure 450 is that it allows three-dimensional objects to be printed on fabric that is larger than the work tray. In use, the fabric 420 is affixed to the top surface of the ramp 452. If the dimensions of the fabric 420 are larger than the dimensions of the ramp structure, the fabric 420 is folded over the edge of the ramp structure 450 so that a horizontal portion 420a of the fabric 420 is supported on the top surface of the ramp 452 and a hanging portion 420b of the fabric 420 is folded below the ramp 452 into the space above the work tray 12 / 360, as shown in FIG. 15A . Preferably, the fabric 420 is affixed to the ramp structure 450 before being placed on or connected to the work tray 12 / 360. However, embodiments are also contemplated in which the fabric 420 is affixed to the ramp 452 while the ramp structure 450 is over the work tray 12 / 360.

[0185] Once the fabric 420 is applied to the work tray 12 / 360 (FIGS. 4A-4F) or the lamp 452 (FIGS. 15A-15C), the computerized controller 20 (FIGS. 1A and 1B) operates the nozzle array 122 (FIGS. 2A-2C) to dispense build material onto the applied fabric 420 in a configuration pattern corresponding to the object shape. In embodiments where a lamp structure 450 is used, the computerized controller 20 controls the nozzle array 122 to terminate all dispensing when the nozzle is over the gap between the lamp structure 450 and the platform 361, thereby ensuring that build droplets land only on the horizontal portions 402a of the fabric 420.

[0186] When the ramp structure 450 is used, it can be seen that the vertical position of the ramp 452 in the Z-axis direction is higher than the position of the work tray 12 / 360. In this case, the computerized controller 20 adjusts the vertical position of the work tray 12 / 360 to compensate for the height of the ramp structure 452 above the work tray 12 / 360. This adjustment process is illustrated in FIGS. 15A-15C. The initial vertical position of the work tray 12 / 360 is preferably selected so that the upper surface of the ramp 452 is at the vertical position that the work tray 12 / 360 would be in if the ramp structure were not being used. For example, as shown in FIG. 15C, the initial vertical position of the work tray 12 / 360 can be selected so that the upper surface of the ramp 452 is at the same vertical position as the upper surface of the platform 361. After the initial vertical position is adjusted, the printing process continues layer by layer as described further herein. Thereafter, upon completion of that layer, the work tray 12 / 360 is lowered in the Z-direction according to the desired thickness of the subsequent layer.

[0187] In some embodiments of the invention, system 10 / 110 includes a robotic mechanism 410 (e.g., a multi-axis robotic arm, a gantry robot, etc.) connected to fixture 402 and configured to position fixture 402 on tray 360 or tray 12. For example, robotic mechanism 410 can be connected at its distal end to fixture 402 and at its proximal end to a print chamber or housing of printing system 10 or printing system 110. Figures 5A and 5B show a print chamber or housing 412 of system 110 (Figure 5A) and system 10 (Figure 5B) connected to the proximal end of robotic mechanism 410.

[0188] Preferably, the computerized controller 20 also controls the robotic mechanism 410. The controller 20 controls the robotic mechanism 410 to introduce the jig 402 into the print chamber or housing 412 and position it on the tray 12 or tray 360 before dispensing the build material onto the fabric 420. The jig can then optionally and preferably be removed from the print chamber or housing 412 after forming an object or portion thereof based on a preprogrammed three-dimensional printing protocol. Suitable three-dimensional printing protocols are described below. An advantage of using a computerized controller to control the robotic mechanism 410 is that the jig 402 can be precisely positioned on the work tray 12 or work tray 360 at a predetermined location and in a predetermined orientation relative to the nozzle array 122.

[0189] The robotic mechanism 10 can grasp the fixture 402 by any grasping technique known in the art, such as, but not limited to, grasping jaws, suction, magnetic attachment, and the like.

[0190] In some embodiments of the present invention, the robotic mechanism 410 is controlled by the controller 20 to access a jig storage, grab and remove a jig from the storage, and place the removed jig on a work tray. These embodiments are generally depicted in FIG. 5C , which shows a storage of multiple jigs 402 accessible by the robotic mechanism 410. While not intended to be limiting, the representation in FIG. 5C shows that the storage 430 is in the form of a static shelf, although other types of static or movable storage (e.g., rotatable wheels, conveyors, etc.) are also contemplated. Preferably, one or more jigs 402, and more preferably, each of the jigs 402 in the storage 430, holds and optionally and preferably stretches a fabric portion 420. In these embodiments, when the robotic mechanism 410 grabs one of the jigs 402 from the storage 430, it retrieves the respective jig while the fabric portion is still held therein and places the jig, along with the stretched fabric, on a work tray (not shown; see FIGS. 5A and 5B ).

[0191] In some embodiments of the invention, the robotic mechanism 410 is optionally and preferably configured to flip the orientation of the jig 402 relative to a horizontal plane (e.g., the plane engaged by tray 12 or tray 360) in response to a signal received from the controller 20. These embodiments are particularly useful when the fabric holder 408 is in the form of a frame, as they allow a series of printing operations to print objects on both sides of the fabric 420. For example, the fabric can be stretched over the jig 402, and an object can be printed on one side of the fabric. The jig 402 can then be flipped while the fabric is still stretched thereon, and an object can be printed on the other side of the fabric.

[0192] This embodiment also contemplates printing on both sides of the fabric without inverting the jig 402. In these embodiments, the nozzle array 122, and optionally also the solidification device 18, are typically operated by the controller 20 to form an object on a tray or some other receiving surface placed on the tray. A robotic mechanism 410 then introduces the jig 402, holding and optionally and preferably stretching the fabric, into the print chamber or print housing 412 and onto the previously formed object so that one side of the fabric contacts the object. The nozzle array 122, and optionally also the solidification device 18, are then operated again to form another object on the other side of the fabric.

[0193] When double-sided printing is used in any of the above embodiments, the objects printed on different sides of the fabric can have different properties and functions. For example, if the fabric is intended to be part of a garment, objects having desired aesthetic properties or that give the garment a desired appearance (e.g., lenticular, prismatic, or hidden or fluorescent objects, or objects with selective optical reflectivity, or waveguides, etc.) are printed on the outer surface of the fabric, and objects having the desired function (e.g., pharmaceuticals, or cosmetics, or objects with heat generating or cooling elements, etc.) are printed on the inner surface of the fabric.

[0194] Duplex printing is also useful for securely fixing the printed object to the fabric. This will now be described with reference to FIGS. 6A-6E, which are schematic diagrams of an operational sequence suitable for duplex printing, according to some embodiments of the present invention. The method optionally and preferably prints a base structure 502 onto a receiving surface, such as, but not limited to, work tray 12 or work tray 360, using array 122 (FIG. 6A). The base 502 optionally and preferably serves to facilitate removal of the printed object from the print tray and may therefore help prevent deformation due to manual or mechanical damage. The base 502 can also improve the accuracy of the object in the Z direction (height) and / or the XY direction. The base 502 forms a sacrificial layer and, therefore, is made of a support material. Preferably, the support compound is soluble in a liquid, such as water. In various exemplary embodiments of the present invention, the base 502 is made of a combination of a support material and a build material.

[0195] The method also prints anchoring elements 504 onto the receiving surface (FIG. 6B). If a base structure 502 is formed, the anchoring elements 504 are preferably printed onto the base structure 502. Alternatively, the anchoring elements 504 can be printed on other receiving surfaces, such as, but not limited to, the work tray 12 or 360. Unlike the base structure 502, the anchoring elements 504 are preferably not a sacrificial layer and are therefore at least partially made of a build material, optionally and preferably an insoluble build material. Preferably, the build material used to form the anchoring elements 504 is generally transparent to visible light (e.g., has a visible light transmittance of at least 50%, e.g., from about 50% to about 99%, or from about 55% to about 95%).

[0196] The lateral dimensions of the fixing element 504 are preferably about the same as the lateral dimensions of the object to be printed, although the present embodiment also contemplates fixing elements 504 that are larger or smaller than the object in at least one lateral dimension (index direction and / or scan direction). An advantage of printing fixing elements 504 that have lateral dimensions that are about the same as or smaller than the lateral dimensions of the object to be printed is that such a configuration conserves the amount of material used, making it economical in terms of the total weight of the final product and efficient in terms of printing time.

[0197] Following printing of the fastening elements 504, a fabric 420 is placed over the fastening elements 504, as shown in FIG. 6C. FIG. 6C is a close-up of a portion of the fabric 420, showing the pores 422 between the fibers forming the fabric and the protruding fluff fibers 424. The fabric 420 can be placed over the fastening elements 504 in a stretched state over a jig 402 (not shown in FIGS. 6A-6D). An advantage of using the jig 402 is that the stretching widens the pores 422, creating a stronger bond between the printed object and the fabric. The placement of the fabric 420 over the fastening elements 504 can be accomplished by activating a robotic mechanism 410. The method then dispenses a build material onto the fabric 420, penetrating the pores 422 in the fabric 420 and forming one or more piercing elements 506 that connect to the fastening elements 504 underneath the fabric 420 (FIG. 6C). The piercing elements 506 are preferably made at least in part of a build material. Preferably, the construction material used to form the fastening element 504 is generally transparent to visible light.

[0198] The penetration of element 506 through pores 422 is optionally and preferably ensured by carefully controlling the length of time Δt between the time the build material forming element 506 is dispensed and the time solidification device 18 solidifies it. Specifically, the length of time Δt is selected to be long enough to ensure that element 506 contacts element 504 while the build material forming element 506 is still in a liquid state.

[0199] Control of length Δt can be accomplished in several ways. In some embodiments of the present invention, solidification device 18 is stopped for a delay time selected to provide Δt as the length of time between when elements 506 are dispensed and when they are solidified. For example, when system 110 is used, block 128 can be stationary, e.g., at a position outside tray 360, and when system 10 is used, solidification device 18 can be stopped while tray 10 continues to rotate.

[0200] Additional control of the length of time Δt can be achieved by providing a solidification device on either side of head 16 and activating the solidification device based on the direction of relative motion between the head and tray. Specifically, a large value of Δt can be achieved by activating a solidification device that reaches element 506 before the head (so that the return stroke is completed before element 506 is irradiated), and a small value of Δt can be achieved by activating a solidification device that reaches element 506 after the head (so that the return stroke is incomplete before element 506 is irradiated).

[0201] In some embodiments of the invention, the speed of relative motion between the tray and solidification device 18 is selected so that the length of time between when elements 506 are dispensed and when they are solidified is Δt. This can be done throughout the entire print job, but more preferably only during the formation of elements 506. For example, the method can slow the speed of relative motion just before or just after the dispense of build material that forms elements 506, and then increase the speed after elements 506 are solidified.

[0202] Once the elements 506 are dispensed and solidified, the method dispenses build material onto the fabric 420 and the piercing elements 506 in a structured pattern that corresponds to the shape of the pre-designed object 112 (FIG. 6E).

[0203] It should be understood that the printing sequence shown in Figures 6A-6E can be varied and still provide an object on one side of the fabric, a fastening element on the other side of the fabric, and one or more piercing elements that penetrate pores in the fabric and connect the object to the fastening element. One skilled in the art will know, given the details provided herein, how to adjust the described printing sequence to suit their needs.

[0204] A representative example of such a modification is shown in FIG. 7. In this embodiment, selected operations shown in FIGS. 6A-6E are reversed. The object 112 is printed upside down on a tray, or more preferably, on a base structure 502. The fabric 420 is then placed on the printed object 112, preferably while stretched on the jig 402. Placement of the fabric 420 on the object 112 can be achieved by activating a robotic mechanism 410. Piercing elements 506 are printed on the fabric 420 and penetrate through pores 422 to connect to the object 112. Then, fastening elements 504 are printed on the fabric 420 and connected to the piercing elements 506. FIG. 7 also shows a support structure 510, preferably made at least in part from a support material, which serves to support the suspended portion or thin walls of the object 112 during the fabrication process known in three-dimensional printing technology. Although support structure 510 is only shown in FIG. 7, it should be understood that the use of support structure 510 during the fabrication of object 112 is contemplated even when object 112 is not printed upside down (e.g., the operational sequence of FIGS. 6A-6E), and that support structures such as structure 510 may be printed at any stage in the fabrication of object 112.

[0205] An advantage of the embodiment shown in Figure 7 is that it can be used to fabricate most of the height of an object on the tray before placing the fabric, allowing for the fabrication of relatively tall objects (e.g., greater than 10cm, or greater than 12cm, or greater than 14cm, or greater than 16cm, or greater than 18cm, or greater than 20cm thick).

[0206] This embodiment also contemplates the use of piercing elements 506 to bond a printed object to the fabric 420 without performing double-sided printing. These embodiments are shown in FIGS. 8A and 8B. FIG. 8A illustrates an embodiment in which the piercing elements 506 penetrate deeply into the pores 422 but do not reach the other side of the fabric 420 (e.g., about 50-80% of the pore depth), while FIG. 8B illustrates an embodiment in which the piercing elements 506 penetrate only slightly into the pores 422 (e.g., less than 50%, e.g., 10-40% of the pore depth). The inventors have found that such bonding is sufficient, especially for fabrics having a high density of protruding fluffy fibers 424, because the fluffy fibers tend to adhere to the build material of the object 112, thereby further strengthening the bond between the object 112 and the fabric 420.

[0207] 1A-1C, systems 10 and 110 optionally and preferably include a position tracking system 50. In some embodiments of the present invention, position tracking system 50 is configured to determine the position of fixture 402 relative to work tray 12 or work tray 360 when fixture 402 is placed in the tray. Position tracking system 50 may include, for example, an optical scanner, an imaging device, a magnetic sensor, and / or a radio frequency sensor. A computerized controller 20 receives position tracking signals from system 50, performs an alignment procedure based on the position tracking signals, and activates nozzle array 122 accordingly. An advantage of this embodiment is that precise positioning of fixture 402 in the tray is not required, as the alignment procedure performed by controller 20 ensures that nozzles dispense build material onto the appropriate locations on fabric 420.

[0208] The position tracking system 50 can determine the position of the fixture 402 in several ways. In some embodiments of the invention, the system 50 captures an image of the tray or a portion thereof (e.g., if the system 50 includes a pixelated imager or optical scanner) and performs an image processing procedure to determine the position of the fixture 402 relative to the tray. In some embodiments of the invention, the position tracking system 50 can determine the position of the fixture 402 using marks 414, which can be formed or attached, for example, to the frame 406 of the fixture 402, or to a fabric holder 408 as shown in FIGS. 4A, 4C, and 4D, or to a work tray, or to a stationary platform 361 as shown in FIG. 4A. The marks 414 are identifiable by the position tracking system 50 and used by the system 50 to determine the position of the fixture 402. For example, if the system 50 includes an optical scanner or imager, the marks 414 can be a printed pattern, such as, but not limited to, a barcode, or an optical signal source, such as a light emitting diode that emits radiation that does not cure the build material dispensed by the nozzle array. If the system 50 includes a magnetic or radio frequency sensor, the mark may include a source of radio frequency or magnetic field, such as, but not limited to, a miniature coil.

[0209] The present disclosure also contemplates embodiments in which the position tracking system 50 is used to identify a pattern (e.g., a printed pattern, a woven pattern, a knit pattern) on the fabric 420 itself. In these embodiments, the controller 20 can perform an alignment procedure based on the identified pattern on the fabric 420, without the need to use the tracking system 50 to determine the position of the fixture 402 (although such determination is contemplated in some embodiments).

[0210] The process of fabricating a three-dimensional object on fabric 420 optionally and preferably includes the use of one or more liquid additives other than the build material for three-dimensional printing. Such liquid additives may include, but are not limited to, priming fluids (e.g., curing fluids, adhesive fluids, pore size adjustment fluids, etc.), finishing fluids (e.g., radiation protection fluids, glossy finish fluids, matte finish fluids, etc.), masking fluids, etc. Other types of additives that may be used according to some embodiments of the present invention include temporary protection fluids, water-repellent fluids, waterproofing fluids, hydrophobic fluids, etc.

[0211] If the additive is a primer, it is applied before dispensing the build material. Thus, for example, an adhesive liquid can be applied to the fabric before dispensing the build material, ensuring that the adhesive adheres the build material to the fabric. Another example is the application of a pore size adjusting liquid that increases the pore size of the fabric. Build material can then be dispensed to form piercing elements (e.g., element 506) within the enlarged pores. A further example is the application of a hardening substance to stabilize the fabric before dispensing.

[0212] If the additive is a finish, it is applied after the build material is dispensed. For example, a glossy or matte finish can be applied to the dispensed build material to give the dispensed material a desired appearance. Similarly, paints such as metallic paints (e.g., chrome, gold) can be applied in the form of a finish to at least a portion of an object printed with the build material. Finishes that serve to protect the fabric or printed object against, for example, discoloration, radiation, abrasion, chemical damage, moisture absorption, etc. are also contemplated. Representative examples of such protective liquids include, but are not limited to, UV-resistant materials (such as those commercially available from Krylon®) and polyurethanes (such as polyurethane solutions manufactured by Rust-Oleum).

[0213] If the additive is a masking fluid, it is preferably applied before the build material is dispensed. The masking fluid serves to prevent selected areas of the fabric from contacting the dispensed build material. Thus, it is selectively applied to locations not to be occupied by the object to be printed. Preferably, the masking fluid is removable, e.g., washable. For example, the masking fluid may include the solution disclosed in U.S. Pat. No. 5,308,647, the contents of which are incorporated herein by reference. The masking fluid may also be applied after printing, if possible, rather than before finishing (if applied), to protect other locations of the object or fabric from the finishing fluid (if applied).

[0214] It is also envisaged to use the layer of support material as a protective covering in places not occupied by the object to be printed.

[0215] Any of the additives described above may optionally and preferably comprise a non-active formulation that can be activated in situ, i.e., while spread on the fabric. In these embodiments, the formulation is applied to the fabric and then activated. Activation can, for example, induce polymerization of monomers and / or oligomers, cross-linking of polymer chains, or modification of the optical properties of the formulation. The present embodiments contemplate many types of non-active formulations that can be activated in situ. In some embodiments of the present invention, activation is by radiation, such as ultraviolet or infrared optical radiation. In some embodiments, activation is by heat.

[0216] Also contemplated are formulations that are activated by a chemical reaction. Such a reaction can occur between the formulation and one or more build materials and / or between two or more applied formulations. For example, in some embodiments of the present invention, one or more build materials are dispensed onto a fabric and allowed to at least partially penetrate into the pores of the fabric while in a liquid phase. A formulation that reacts with the build material is then applied. The chemical reaction between the build material and the applied formulation alters at least one property (e.g., mechanical property and / or optical property) of the build material. In some embodiments, the formulation induces polymerization of the dispensed build material.

[0217] In embodiments where two or more formulations react with each other, they are preferably dispensed separately to induce their reaction on the fabric. Depending on the product of such reaction, the formulations can be dispensed before the dispense of the build material, after the dispense of the build material, or simultaneously with or intermittently with the dispense of the build material.

[0218] For example, if the reaction product forms an adhesive that allows build materials to adhere, and / or If the reaction product alters pore size (e.g., a reaction product that locally shrinks fibers in a fabric, thereby increasing the pore size between the fibers) and / or forms a mask in areas of the fabric where it is desired to prevent build material contact, the formulation can be dispensed before the dispense of the build material. If the reaction product alters the appearance of the build material (e.g., increases or decreases gloss, modifies color) or encases the build material with a (usually transparent) cover, e.g., a protective cover, the formulation can be deposited after the dispense of the build material. If it is desired to interweave the reaction product perpendicularly or transversely to the build material, e.g., to strengthen the build material, increase flexibility of the final object, etc., the formulation can be deposited simultaneously with or intermittently with the dispense of the build material.

[0219] The additives can be applied in more than one way. Typically, an additive delivery system 340 is used (FIGS. 1A and 1B). The additive delivery system 340 is typically in fluid communication with a container 342 (shown only in FIG. 1A) containing the additive. The additive delivery system 340 can be controllable by the controller 20. In some embodiments of the invention, one or more additives are applied by dispensing an aerosol or mist of the additive onto the fabric. In these embodiments, the system 340 is in the form of an aerosol dispenser or sprinkler that generates an aerosol or mist of the additive and dispenses it onto the fabric. In some embodiments of the invention, one or more additives are applied by depositing droplets of the additive at discrete, addressable locations on the fabric. In these embodiments, one or more print heads 16 can be configured to operate as the system 340 to dispense the individual additives, and one or more containers or cartridges of the supply system 330 can act as the container 342. When there are two or more additives (e.g., multiple formulations that are normally non-reactive but react with each other in situ after deposition), deposition at discrete addressable locations on the fabric can be preferably performed laterally interlaced to form interfaces between adjacent droplets of different additives.

[0220] The additive dispensing system 340 can be mounted on the same print block as the head 16, as shown in FIG. 1A, and thus can move horizontally with the head 16. Alternatively, the system 340 can be mounted separately from the head 16 (see, e.g., FIG. 1B), in which case the head 16 and system 340 can be configured to move independently. In some embodiments, the build tray 12 / 360, or a portion thereof, moves beneath the stationary additive dispensing system 340 (e.g., a sprinkler array) and / or the stationary print block 128 to which the head 16 is mounted. In some other embodiments, the tray 360 is configured to move in the Z direction, the head 16 is mounted to a print block 128 configured to horizontally scan the surface of the tray 360 in a first direction (e.g., the X-axis), and the additive dispensing system 340 is configured to horizontally scan the surface of the tray 360 in a second direction (e.g., the Y-axis). In some embodiments, both the print block 128 and the additive dispensing system 340 are configured to horizontally scan the surface of the tray 360 in the same direction (e.g., the X-axis).

[0221] The present disclosure also contemplates the use of non-liquid additives. For example, the applied additive may be in a solid phase. In these embodiments, the additive may be transferred from the substrate to the fabric by contacting the fabric with a substrate bearing the additive and applying pressure, radiation, and / or heat to the substrate. The substrate is typically, but not necessarily, in the form of a film containing or coated with the additive. For example, if the additive includes a curable substance, such as, but not limited to, an oily substance such as a wax, a sheet containing the curable substance may be placed on the fabric and the curable substance may be transferred to the fabric by heating and / or pressing the sheet against the fabric.

[0222] The solid phase additive can be applied to the side of the fabric from which the building material is dispensed and / or to the side of the fabric opposite to the side from which the building material is dispensed. Application of the solid phase additive to the fabric is typically performed before dispensing, although embodiments are contemplated in which the solid phase additive is applied after the object is formed on the fabric.

[0223] Contact between the additive-carrying substrate and the fabric can be achieved either by placing the substrate on the fabric (e.g., outside of the print chamber 412) or by placing the fabric on the substrate, for example, in tray 12 or tray 360 of the system, or in fixture 402, and then placing the fabric on the substrate. If the substrate is placed on a tray or fixture, the tray or fixture is optionally and preferably heated after the fabric is placed on the substrate to induce transfer of the solid phase additive from the substrate to the fabric.

[0224] Reference is now made to Figure 9, which is a schematic diagram of a system 520 suitable for unrolling a roll of fabric and printing on the unrolled fabric. System 520 includes a print chamber 412 having a nozzle array therein for dispensing build material, and a work tray. For example, chamber 412 may include components of system 10 and / or system 110, as described in detail above. System 520 may also include a computerized controller, such as, but not limited to, controller 20, as described in detail above. System 520 further includes a fabric unwinder 524 that unrolls fabric roll 526 and feeds fabric 420 to print chamber 412 after unrolling.

[0225] The fabric unwinder 524 may be of any type known in the art. In some embodiments of the present invention, the unwinder 524 controllably advances the fabric roll 526 and maintains a substantially constant tension on the fabric. Preferably, the unwinder 524's control of the advancement of the fabric roll 526 is responsive to changes in the diameter of the fabric roll 526 and also to the tension in the fabric. Preferably, the unwinder 524 is controlled by the controller 20 (not shown in FIG. 9 ). Typically, the unwinder 524 moves a tension roller 528 to move the fabric toward the chamber 412. The tension roller 528 is typically biased to tension the fabric. A feeder 530 receives the fabric from the tension roller 528 and feeds the fabric, preferably horizontally, into the chamber 412. In embodiments in which the jig 402 is used, the feeder 530 optionally and preferably operates in conjunction with a robotic mechanism 410 (not shown in FIG. 9 ; see FIGS. 4A-5B ). Here, feeder 530 places fabric 420 into fixture 402, and robotic mechanism 410 introduces the fixture into chamber 412 as previously described.

[0226] In some embodiments of the invention, the system 520 includes a cutting device 522 that cuts the unfolded fabric 420 into portions. For example, the cutting device 522 can cut the portions to the size of the jig 402. Preferably, the cutting device 522 is at the outlet of the feeder 530 of the unwinding device 524. In some embodiments, the system 520 includes a fabric take-up device 532 that takes up the fabric 420 after fabricating the three-dimensional object on the fabric as described herein. These embodiments are useful when it is desired to provide a continuous roll of fabric 534 having the three-dimensional object 112 printed thereon. This is achieved by continuously feeding the fabric into the printing chamber 412 without cutting it. The fabric take-up device 532 may be similar in principle and operation to the fabric unwinding device 524, except that the fabric take-up device 532 is configured to receive the unfolded fabric 420 from the chamber 412 and feed it onto the roll 534 for winding. Thus, the fabric take-up device 532 may include a fabric receiving roller 536 that receives the spread fabric 420 from the chamber 412 and a take-up tension roller 538 that applies tension to the fabric and feeds it to the roll 534 .

[0227] Reference is now made to Figure 10, which is a flow diagram of a method suitable for printing three-dimensional objects on fabric, according to various embodiments of the present invention.

[0228] Unless otherwise specified, it should be understood that the operations described below can be performed either simultaneously or sequentially in many combinations or orders of execution. In particular, the order of the flow diagrams should not be considered limiting. For example, two or more operations that appear in a particular order in the following description or flow diagrams may be performed in a different order (e.g., in the reverse order) or substantially simultaneously. Furthermore, some operations described below may be optional and not performed.

[0229] The method of the present embodiment can be performed by a computerized controller (eg, controller 20) of system 10 or system 110.

[0230] The method begins at 600 and optionally and preferably continues to 602, where computer object data is obtained, e.g., from an external source. The computer object data may include a plurality of geometric primitives (e.g., a polygonal mesh, a non-uniform rational basis spline, etc.) that define the surface of the object. In some embodiments of the invention, the geometric primitives are converted into a grid of voxels that define the shape of the object, e.g., using a slicing procedure 603 to form a plurality of slices, each consisting of a plurality of voxels that describe a layer of the 3D object. Alternatively, the method can receive the sliced ​​computer object data from an external source, e.g., a computer-readable medium. In this case, operation 603 need not be performed.

[0231] Because the grid of voxels and the plurality of geometric elements represent the same object, the term "computer object data" is used herein to refer to both the grid of voxels and the plurality of geometric elements. Thus, when the computer object data relates to a grid of voxels, each element of the computer object data is a voxel, and when the computer object data relates to geometric elements, each element of the computer object data is a geometric element, e.g., a polygon, a spline, etc.

[0232] In some embodiments of the invention, at least a portion of the computer object data is obtained from a scan (e.g., a three-dimensional image of the body) of an individual human or animal. In these embodiments, the method receives 601 a scan of an individual body, or an external body part thereof. Based on the scan, the method can select at least one characteristic of the object. For example, if the system includes a cutting device 522, the dimensions of the cut fabric portions can be selected based on the scan. Another example is the selection of a position of the object relative to the fabric to be fabricated based on the scan. For example, if a garment is to be fabricated having an object in a specific position relative to an individual's body, the scan data obtained in 601 can be used to convert body coordinates to fabric coordinates so that the object will be aligned in the desired position when the garment is worn by the person.

[0233] The method continues at 604, where the fabric is placed into the AM system. This can be done in several ways. In some embodiments, the fabric is placed into the fixture either before or after the fixture is introduced into the system (see FIGS. 4C, 4D, 5A, 5B). In some embodiments, the fabric is placed directly into the tray, and the fixture attaches the fabric to the tray (see FIGS. 4A, 4B, 4E, 4F). In some embodiments, the fabric is attached to the lamp structure either before or after the lamp structure is placed or attached to the tray (see FIGS. 15A-15C), and the vertical position of the tray is adjusted accordingly.

[0234] At 605, one or more additives are applied to the fabric, and at 606, one or more build materials are dispensed as described in more detail above. Operations 605 and 606 are repeatable and can be performed in any order. Also, one or more build materials can be dispensed onto a receiving surface before the fabric is introduced into the system to form objects on both sides of the fabric as described in more detail above, and / or to form a sacrificial base structure as described in more detail above (see FIGS. 6A-6E and 7).

[0235] At 607, the dispensed build material is solidified (eg, cured) by application of solidifying radiation.

[0236] At 608 the method ends.

[0237] Method 600 can be used to fabricate many types of objects on fabric. In some embodiments of the invention, the method is performed to fabricate an object selected from the group consisting of a lens or prismatic object, an object that reflects visible light, an object that is transparent to visible light but reflects non-visible light, a fluorescent object, and a waveguide. In some embodiments, the fabricated object is capable of changing optical, mechanical, and / or geometric properties in response to environmental changes, such as, but not limited to, temperature changes, humidity changes, or electromagnetic changes in the environment. For example, the object may be made of a photosensitive material that changes its color in response to changes in light conditions or temperature.

[0238] In some embodiments of the present invention, the methods are implemented to fabricate objects comprising agents, such as, but not limited to, pharmaceuticals and / or cosmetics. For example, the agent can be adsorbed onto the surface of the object (e.g., by applying the agent as an additive to a build material), or the object can be in the form of a capsule containing the agent. Representative examples of agents that can be incorporated into the object include, but are not limited to, antibacterial and antiviral agents.

[0239] In some embodiments of the present invention, the method provides for fabricating an object that includes a heating element capable of emitting heat or a cooling element capable of absorbing heat, in some embodiments the method provides for fabricating an object that includes a circuit, and in some embodiments the method provides for fabricating an object that includes a cavity that receives a foreign object, such as, but not limited to, an electrical circuit, a magnetic element, a light emitting element, a chip, or a capsule containing a pharmaceutical or cosmetic product.

[0240] In some embodiments of the present invention, the method provides for fabrication of female or male components of a snap connector. These embodiments are particularly useful for fabricating garments, including, but not limited to, seamless garments. In a representative example, as shown in FIGS. 11A-11C, a build material is dispensed to form a female snap connector 612 (FIG. 11A) on a first textile element 610 and a male snap connector 616 (FIG. 11B) on a second textile element 614. The female snap connector 612 is then connected to the male snap connector 616 (FIG. 11C), thereby connecting the two textile elements 610 and 614. The textile elements 610 and 614 may be parts of the same garment, such as a pocket and pants, a collar and a shirt, etc.

[0241] In another exemplary example, as shown in FIGS. 12A-12B, a build material is dispensed onto a textile element 610 to form a female snap connector 612 and a male snap connector 616 laterally offset from the female snap connector 612 (FIG. 12A). The textile element 610 is then folded to align the connectors 612 and 614, and connect the female snap connector 612 to the male snap connector 616 (FIG. 12B), thereby securing the fold. In these embodiments, the textile element 610 may be part of a garment, such as a sleeve, a sock, a seamless shirt, etc.

[0242] In embodiments in which the controller receives a scan of the body, the scan data can be used to determine the location and / or number of female and male snap connectors on the textile elements, for example, larger bodies generally have more snap connectors printed on them compared to smaller bodies.

[0243] In some embodiments of the present invention, the method is implemented to print stitching elements that connect fabrics together. For example, a first fabric element and a second fabric element are aligned next to each other on a jig, optionally in a frame, and a build material is dispensed onto and between adjacent edges of the aligned fabrics to stitch the fabrics together. Stitching elements may also be formed in the fabric to create fold lines.

[0244] The three-dimensional printing protocol for performing method 600 may be selected by an operator of the system or may be automatically selected. For example, one or more printing protocols may be presented to the operator by the system's user interface 116, and the operator may decide to run the displayed protocol, modify it according to operator requirements, or use a different protocol.

[0245] FIG. 13 is a flow diagram of a method suitable for printing three-dimensional objects on fabric in an embodiment of the invention in which the system determines the printing protocol.

[0246] The method begins at 620, optionally and preferably continuing from 602 and optionally continuing to 603 as detailed above. The method optionally and preferably extracts one or more geometric properties of the object to be printed from the computer object data, typically thickness, and optionally and preferably also shape. Alternatively, the method can receive the properties via a user interface of the system. Combinations of these options are also contemplated. For example, geometric properties can be extracted from the computer object data, and non-geometric properties such as, but not limited to, stiffness, color, etc. can be obtained via the user interface.

[0247] The method continues at 621 where the method receives data relating to fabric characteristics via a user interface of the system. Such data may include one or more of the fabric type, the average pore size of the fabric, the weave pattern of the fabric, etc.

[0248] The method continues at 622 where a computer-readable medium storing a library is accessed. A library typically includes multiple entries, each of which includes one or more libraries of fabric properties, one or more libraries of object properties, and a set of printing parameters. A representative example of a library 630 suitable for this embodiment is shown in Figure 14. There are k sets of printing parameters, where the ith (i=1, 2, ..., k) set of printing parameters corresponds to n sets of fabric properties. i value, and object properties m i Each of the k sets of printing parameters defines a printing protocol, which optionally and preferably includes a sequence of printing operations that is optimal for a particular object given one or more characteristics of the fabric. The sets of printing parameters optionally and preferably include at least one of: (i) a primer application sequence; (ii) a build material; (iii) a build material dispensing sequence; and (iv) a finish application sequence. In some embodiments of the present invention, the sets of printing parameters also include a dimensional scale factor that allows the method to scale the object's dimensions up or down by the scale factor.

[0249] Below are some examples of sets of printing parameters, which should not be considered limiting examples.

[0250] If the fabric characteristics indicate that the average size of the fabric pores is large enough to accommodate the piercing element 506 along the entire depth of the pores, the set of printing parameters includes a sequence of operations that allows double-sided printing, such as, but not limited to, the sequences of operations described above with respect to Figures 6A-6E and 7.

[0251] If the fabric characteristics indicate that the fabric contains a sufficient amount of sufficiently long protruding fluff fibers 424, and the object characteristics indicate that the object is sufficiently thin and light enough, the set of printing parameters includes an operating sequence that allows for single-sided printing, such as, but not limited to, the operating sequences described above in Figure 8A or Figure 8B.

[0252] If the characteristics of the fabric indicate that it is suitable for the application of an adhesive to adhere the object to the fabric, the set of printing parameters can include the application of adhesive to the fabric prior to the ejection of the printing material.

[0253] If the fabric characteristics indicate a particular weave pattern of the fabric, the set of printing parameters may include an operation sequence that includes alignment of the fabric based on that particular weave pattern.

[0254] If the characteristics of the object indicate that a finishing liquid is required (e.g., a finishing liquid that increases the gloss or mattes the outer surface of the object, or a finishing liquid that protects the outer surface of the object), the set of printing parameters may include applying a finishing liquid to the build material after the object is formed.

[0255] If the object's properties indicate that the object has multiple separate portions with sufficiently small gaps between adjacent separate portions, the set of printing parameters may include selectively applying a masking fluid to the fabric at the gap locations prior to dispensing of the build material. The same set of parameters may be used if the fabric's properties indicate that it may be damaged by the curing radiation, in which case the set of printing parameters may include selectively applying a masking fluid to the fabric in locations that should not be occupied by the object prior to dispensing of the build material.

[0256] If the object's properties indicate high stiffness, the set of printing parameters may include the use of a build material that is stiffer after solidification, optionally increasing the object's physical dimensions. If the object's properties indicate low stiffness, the set of printing parameters may include the use of a build material that is less stiff after solidification, optionally decreasing the object's physical dimensions. These embodiments are typically achieved by thresholding. Specifically, library 630 preferably includes entries for different numerical stiffness ranges, each defined by one or two stiffness thresholds. For each such entry, the method then compares the desired stiffness of the object obtained from the user interface with each entry's stiffness threshold and selects a set of printing parameters based, at least in part, on this comparison.

[0257] The method continues at 623, where it searches library 630 for an entry that best matches the object and fabric characteristics. For simplicity, assume that library 630 contains multiple values ​​describing the pore size of the fabric and multiple values ​​describing the thickness of the object to be produced, with one set of printing parameters for each pair of pore size value and object thickness value. In this case, the method finds an entry that has a thickness value that matches or nearly matches the object thickness and a pore size value that matches or nearly matches the pore size of the fabric. For example, the method may search the entire library to find all entries that have pore size values ​​that match or nearly match the pore size of the fabric. Then, among these entries, it may search for an entry that has a thickness value that matches or nearly matches the object thickness. The method may then select a parameter set from the entries thus found.

[0258] The method proceeds to 624 where a three-dimensional printing system, such as but not limited to system 10 or system 110, is operated to form an object on the fabric according to the set of printing parameters of the detected entry.

[0259] At 625 the method ends.

[0260] Examples of suitable three-dimensional printing protocols according to some embodiments of the present invention are described in the Examples section below.

[0261] As used herein, the term "about" refers to ±10%.

[0262] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and / or to exclude the incorporation of features of other embodiments.

[0263] The term "optionally" is used herein to mean "provided in some embodiments and not provided in other embodiments." Any particular embodiment of the present invention may include multiple "optional" features unless such features are contradictory.

[0264] The terms "comprises," "comprised," "includes," "including," "having," and their conjugations mean "including but not limited to."

[0265] The term "consisting of" means "including and limited to."

[0266] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or components, but only if the additional ingredients, steps, and / or components do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0267] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" can encompass multiple compounds, including mixtures thereof.

[0268] Throughout this application, various embodiments of the present 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 a fixed limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all possible subranges along with individual numerical values ​​within that range. For example, a description of a range such as 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as individual numerical values ​​within that range, e.g., 1, 2, 3, 4, 5, and 6. This applies regardless of the broadness of the range.

[0269] Whenever a range of numerical values ​​is given herein, it is meant to include any recited number (fractional or integer) within the stated range. The phrases "ranging between" a first specified number and a second specified number, and "ranging from" a first specified number "to" a second specified number, are used interchangeably herein and are meant to include the first specified number and the second specified number, and all fractional and integer numbers therebetween.

[0270] It is understood 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 that are for brevity described in the context of a single embodiment may also be provided separately or in any suitable subcombination, or as appropriate to any other described embodiment of the invention. Certain features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment is inoperable without those elements.

[0271] Experimental support for various embodiments and aspects of the present invention as described above and as claimed in the claims section below is provided in the following examples. Example

[0272] 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.

[0273] Example 1 Printing without a base

[0274] The fabric is placed on the tray to ensure stable positioning. For example, the fabric can be placed on a jig, and the jig can be placed on the tray. Optionally, the fabric is aligned to the tray using a positioning mark (e.g., mark 414). Optionally, one or more printing fluids are applied to the fabric. The z-height of the print block can then be adjusted to make the zero height the height of the fabric. This is particularly useful in systems that automatically add a pedestal height to the z-height. When printing without a pedestal, such automatic settings are preferably readjusted. The nozzle array is then activated to print piercing or adhesive elements on the fabric, as described in detail herein above. An object is then printed on the piercing or adhesive elements.

[0275] Example 2 Sticking due to double-sided printing

[0276] A base structure is printed onto a receiving surface or tray of the system. Then, a fastening element (e.g., 5 mm or less thick) is printed onto the base structure. Next, optionally and preferably, printing is paused and the fabric is placed on the tray, preferably, but not necessarily, using a jig to ensure stable positioning. Optionally, a registration mark (e.g., mark 414) is used to align the fabric on the tray. Optionally, one or more primer solutions are applied to the fabric. After the fastening element is placed, the z-height of the print block can then be adjusted so that the zero height is at the height of the fabric. The nozzle array is then activated to print piercing elements on the fabric and connect them to the fastening element below the fabric, as described in detail above. The object is then printed, with the bottom layer of the object connected to the piercing elements.

[0277] Example 3 Sticking due to upside-down double-sided printing

[0278] The fabric is placed on the jig. Optionally, one or more printing fluids are applied to the fabric. The nozzle array is then activated to print a base structure on a receiving surface or tray of the system. An object is then printed on the base structure. Printing is optionally and preferably paused to position the jig over the printed object. The support material is optionally and preferably removed from the printed object. After being placed on the printed object, the z-height of the print block can then be adjusted so that the zero height is at the height of the fabric. The nozzle array is then activated again to print piercing elements into the fabric to connect with the object below the fabric. A securing element is then printed to connect with the piercing element.

[0279] Example 4 Printing objects on the wrong side of the fabric

[0280] The fabric is placed on the jig. Optionally, one or more primer solutions are applied to the fabric. The nozzle array is then activated to print a base structure on a receiving surface or tray of the system. A first object is then printed onto the base structure. Printing is optionally and preferably paused to position the jig over the first object. The support material is optionally and preferably removed from the first object. Once positioned over the first object, the z-height of the print block can then be adjusted to make the zero height the height of the fabric. The nozzle array is then activated again to print piercing elements into the fabric to connect to the first object below the fabric. A second object is then printed and connected to the piercing elements.

[0281] While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0282] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, and patent application was specifically and individually indicated to be incorporated by reference. Furthermore, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent used as section headings, they should not be construed as necessarily limiting.

[0283] Additionally, any priority document of this application is incorporated herein by reference in its entirety.

Claims

1. 1. A system for three dimensional printing, comprising: an array of nozzles for dispensing build material; a work tray configured to move vertically; a ramp structure mountable or positionable on the work tray to define a space above the work tray, the ramp structure having an upper surface configured to support a horizontal portion of a fabric, the space being configured to receive a hanging portion of the fabric folded at an end of the ramp structure into the space below the ramp structure and above the work tray; a fixture configured to apply fabric to the lamp structure; a computerized controller configured to operate at least the nozzle array to dispense build material onto the attached fabric in a configuration pattern corresponding to the shape of the object and to control the nozzle array to dispense the build material only onto the top surface, and configured to adjust the vertical position of the work tray to compensate for the height of the ramp structure above the work tray; A system comprising:

2. The system of claim 1 , further comprising a robotic mechanism connected to the fixture and configured to position the fixture on the work tray.

3. The system of claim 2 , wherein the robotic mechanism is configured to reverse the orientation of the fixture relative to a horizontal plane.

4. 3. The system of claim 2, wherein the computerized controller is configured to operate at least the nozzle array to dispense the build material onto the work tray and to operate the robotic mechanism to position the jig on the work tray after the dispense of the build material onto the work tray and before the dispense of the build material onto the affixed fabric.

5. 5. The system of claim 1, further comprising a position tracking system configured to determine a position of the fixture relative to the work tray, wherein the computerized controller is configured to perform an alignment procedure based on the position and to operate the nozzle array in response to the alignment.

6. The system of claim 5 , wherein the fixture comprises a mark, the mark being identifiable by the position tracking system to determine the position.

7. 5. The system of claim 1, further comprising a stationary platform surrounding the work tray, the jig comprising a frame configured to attach the fabric to the platform around a periphery of the work tray.

8. The system of claim 7 , wherein at least one of the platform and the frame comprises protruding elements or a roughened surface.

9. The system of claim 7 , wherein both the platform and the frame include complementary protruding elements or roughened surfaces.

10. 5. The system according to claim 1, further comprising a radiation source, and wherein the work tray has a reflectivity of at least 50% with respect to radiation emitted from the radiation source.

11. The system of any one of claims 1 to 4, wherein the work tray comprises a fluid flow path, and the system comprises a fluid delivery system for generating a fluid flow within the fluid flow path.

12. an additive dispensing system in fluid communication with a container containing an additive other than a build material for three-dimensional printing, for dispensing the additive onto the fabric; The system of any one of claims 1 to 4, wherein the nozzle array and the additive dispensing system are configured to move independently along a horizontal direction.

13. an additive dispensing system in fluid communication with a container containing an additive other than a build material for three-dimensional printing, for dispensing the additive onto the fabric; The system of any one of claims 1 to 12, wherein the nozzle array and the additive dispensing system are configured to move independently along a vertical direction.

14. 5. The system of claim 1, wherein the work tray is in operative association with a radiation source configured to emit radiation upward to solidify the dispensed build material from below.

15. The system according to any one of claims 1 to 4, wherein the edge of the upper surface of the work tray is at least one of a fillet and a chamfer.

16. A system as described in any one of claims 1 to 4, comprising a stationary platform that folds around the work tray, and the computerized controller is configured to terminate the ejection of the build material when the nozzle array is over the gap between the lamp structure and the stationary platform.

17. 5. The system of claim 1, wherein the object is selected from the group consisting of a lens or prismatic object, an object that reflects visible light, an object that is transparent to visible light but reflects non-visible light, a fluorescent object, and a waveguide.

18. The system of any one of claims 1 to 4, wherein the object is capable of changing optical, mechanical and / or geometric properties in response to environmental changes.

19. 20. The system of claim 18, wherein the environmental change comprises at least one change selected from the group consisting of a temperature change, a humidity change, and a change in the electromagnetic content of the environment.

20. The system according to any one of claims 1 to 4, wherein the object includes a drug.

21. 21. The system of claim 20, wherein the agent is selected from the group consisting of an antibacterial agent and an antiviral agent.

22. The system of any one of claims 1 to 4, wherein the object includes a cosmetic product.

23. The system of any one of claims 1 to 4, wherein the object comprises a heating element.

24. The system of any one of claims 1 to 4, wherein the object comprises a cooling element.

25. The system of any one of claims 1 to 4, wherein the object includes a circuit.

26. The system of any one of claims 1 to 4, wherein the object includes a cavity for receiving a foreign object.

27. The system of any one of claims 1 to 4, wherein the object comprises a female or male part of a snap connector.

28. 1. A system for three dimensional printing, comprising: an array of nozzles for dispensing build material; a work tray configured to move vertically; a ramp structure mountable or positionable on the work tray to define a space above the work tray, the ramp structure having an upper surface configured to support a horizontal portion of a fabric, the space being configured to receive a hanging portion of the fabric folded at an end of the ramp structure into the space below the ramp structure and above the work tray; an imaging system positioned to image the fabric; a computerized controller configured to receive image data from the imaging system, process the image data to identify a pattern on the fabric, operate at least the nozzle array to dispense build material onto the horizontal portion of the fabric in a configuration pattern corresponding to a shape of an object at locations selected relative to the identified pattern on the fabric, and control the nozzle array to dispense the build material only on the top surface, and to adjust a vertical position of the work tray to compensate for a height of the lamp structure above the work tray; A system comprising:

29. 30. The system of claim 28, wherein the imaging system comprises a pixelated image sensor.

30. 30. The system of claim 28, wherein the imaging system comprises a scanner.

Images