FDM-printed luminous devices with enhanced glossy appearance

Abstract

The present invention provides a method for producing a 3D object (1) by fused deposition modeling, the method comprising a 3D printing stage, comprising: depositing an extrudate (321) comprising a 3D printable material (201) layer by layer to provide the 3D object (1) comprising a 3D printable material (202), wherein the 3D object (1) comprises a plurality of layers (322) of the 3D printable material (202), wherein the 3D printable material (201) comprises a core-shell 3D printable material (201), the core-shell 3D printable material (201) comprising (i) a core (221) comprising a core material (240), and (ii) a shell (222) comprising a shell material (250), wherein The core material (240) includes a core thermoplastic material (241) and a core additional material (242), wherein the shell material (250) includes a shell thermoplastic material (251) and shell particles (252), wherein the shell material (250) is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) include specular reflective particles, wherein the core additional material (242) includes one or more of diffuse reflective particles, white particles, black particles, colored particles and dye molecules, and wherein the core material (240) and the shell material (250) differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type and absorption of light.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a 3D (printed) object. Furthermore, the present invention relates to a software product for executing such a method. The present invention also relates to a 3D (printed) object obtainable using such a method. The present invention also relates to a filament for 3D printing. Furthermore, the present invention relates to a lighting device including such a 3D (printed) object. Still further, the present invention may also relate to a 3D printer, for example, a 3D printer used in such a method. Background Art

[0002] The use of particles comprising light reflective materials in 3D printing is known in the art.

[0003] WO2018 / 054724 describes a method for 3D printing a 3D object, the method comprising: providing a filament of a 3D printable material ("printable material") and printing the 3D printable material on a substrate during a printing phase, in particular with a fused deposition modeling (FDM) 3D printer, to provide the 3D object, wherein the printing phase comprises (a) providing a layer comprising particles on the substrate, wherein the particles have a major axis with a major axis length and a minor axis with a minor axis length, wherein the major axis length (LI) and the minor axis length have a first aspect ratio greater than 1, in particular at least 5, wherein, in particular on average, the major axes of the particles are arranged parallel to a tangent plane of the substrate, wherein in a specific embodiment, the particles comprise a light-reflective material, and (b) printing the 3D printable material on the layer on the substrate to provide the 3D object comprising the layer. In particular, the particles are flakes.

[0004] WO2018 / 224395 describes a method for 3D printing an optical component having multiple layers, each of which has a core and a shell encapsulating the core. The core is made of a first material, and the shell is made of a second material, wherein the first and second materials have different transmittances. Summary of the Invention

[0005] Over the next 10-20 years, digital manufacturing will increasingly transform the nature of global manufacturing. One aspect of digital manufacturing is 3D printing. Currently, many different technologies have been developed to produce a variety of 3D-printed objects using a variety of materials, such as ceramics, metals, and polymers. 3D printing can also be used to create molds, which can then be used to replicate objects.

[0006] For mold fabrication purposes, the recommended method is UV-curing (polyjet). This technique deposits a photopolymerizable material layer by layer, curing it after each deposition to form a solid structure. While this technique produces a smooth surface, photocurable materials are not very stable and have low thermal conductivity, making them unsuitable for injection molding applications.

[0007] The most widely used additive manufacturing technology is the process known as fused deposition modeling (FDM). Fused deposition modeling (FDM) is an additive manufacturing technique commonly used for molding, prototyping, and production applications. FDM operates on an "additive" principle by laying down material layer by layer; plastic or metal filaments are unwound from coils and supplied to produce the part. Optionally (for thermoplastic materials, for example), the filament is melted and extruded before being laid down. FDM is a rapid prototyping technique. Other terms used for FDM are "fused filament fabrication" (FFF) or "filament 3D printing" (FDP), which are considered equivalent to FDM. Typically, FDM printers use thermoplastic filaments that are heated to their melting point and then extruded layer by layer (or indeed, filament by filament) to create a three-dimensional object. FDM printers are relatively fast, low-cost, and can be used to print complex 3D objects. Such printers are used to print a variety of shapes using a variety of polymers. The technology has also been further developed for the production of LED lighting fixtures and lighting solutions.

[0008] It would appear desirable to be able to 3D print objects that reflect visible light. Furthermore, it would be desirable to be able to tune such reflective properties. Therefore, one aspect of the present invention is to provide an alternative 3D printing method and / or 3D (printed) object that preferably further at least partially avoids one or more of the aforementioned disadvantages, and / or overcomes or mitigates at least one of the disadvantages of the prior art, and / or provides a useful alternative.

[0009] To achieve a metallic appearance, the use of metal flakes has been suggested. Commercially available aluminum flakes are irregularly shaped, so-called corn flakes, or round, so-called dollar flakes. However, these flakes have a rough surface, and when printed, they appear rather dull, devoid of any specular reflective component. To achieve a more metallic appearance, pure metallic glitter can be used. Such glitter consists of particles of precisely cut aluminum foil. Unlike metal flakes, these pure metallic glitters can exhibit specular reflectivity and a metallic appearance. They differ from glitters that deposit a submicron-thick layer of aluminum on a polymer support because they can be processed at high temperatures, making them easily incorporated into polymers such as polycarbonate. In embodiments, the pure metallic glitter can have a thickness of at least 2 microns and a length-width dimension of at least 50 x 50 microns. Glass flakes coated with silver / aluminum can also be used. It has been observed that when these pure aluminum metallic glitters and / or specularly reflective glass flakes are used in combination with flakes that exhibit only diffuse reflectivity, an enhanced metallic appearance is achieved.

[0010] Therefore, in a first aspect, the present invention provides a method for producing a 3D object using fused deposition modeling. In particular, the method includes a 3D printing phase, wherein the 3D printing phase includes layer-by-layer deposition of an extrudate comprising a 3D printable material to provide a 3D object comprising the 3D printed material ("3D printed object"). In particular, 3D printing can be performed on a receiving object. In embodiments, the 3D object can include multiple layers of 3D printed material. In specific embodiments, the 3D printable material includes a core-shell 3D printable material, the core-shell 3D printable material including (i) a core comprising a core material (or "core component"), and (ii) a shell comprising a shell material (or "shell component"). In other specific embodiments, the core material includes a thermoplastic material denoted as a "core thermoplastic material" and a core additional material. Alternatively or additionally, in specific embodiments, the shell material includes a thermoplastic material denoted as a "shell thermoplastic material" and shell particles (which may also be denoted as "particle material"). In other specific embodiments, the shell material is light transmissive for one or more wavelengths in the visible wavelength range.Furthermore, in particular the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type and absorption of light.

[0011] Thus, in a specific embodiment, the present invention provides a method for producing a 3D object using fused deposition modeling, the method comprising a 3D printing stage, comprising: depositing an extrudate comprising a 3D printable material layer by layer to provide a 3D object comprising the 3D printable material, wherein the 3D object comprises a plurality of layers of the 3D printable material, wherein the 3D printable material comprises a core-shell 3D printable material, the core-shell 3D printable material comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and a core additive material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) comprise specular reflective particles, wherein the core additive material (242) comprises one or more of diffuse reflective particles, white particles, black particles, colored particles and dye molecules, and wherein the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflectance and absorption of light. The term "absorption of light" specifically refers to absorption of one or more wavelengths in the visible wavelength range, which is specifically defined as 380-780 nm. Due to the absorption of light, the core or the shell (or optionally, both) can be colored, gray, or black (it should be noted, however, that the shell is light-transmissive). Because the shell is light-transmissive, the core can be perceived through the shell.

[0012] It appears that with core-shell structures, enhanced optical properties can be achieved. For example, when a diffusely reflective or light-absorbing material is used in the core, a specularly reflective material in the shell can provide a more (specular) reflective appearance. As mentioned above, it has been observed that an enhanced metallic appearance is achieved when, for example, pure aluminum metallic glitter and / or specularly reflective glass flakes are used in combination with flakes that exhibit only diffuse reflection. However, it also appears that the appearance can be further enhanced when the polymer carrying the particles is physically separated.

[0013] In the following, some aspects are first described with respect to core-shell materials. General aspects regarding 3D printing, such as 3D printable materials and 3D printing materials, are further discussed below.

[0014] As described above, 3D printable materials include core-shell 3D printable materials. The core-shell 3D printable material can be provided as, for example, a filament of a core-shell material. Alternatively, a nozzle can be used to print two 3D printable materials in a core-shell configuration, whereby the core-shell 3D printable material exits the nozzle and is deposited as a 3D printing material. Such a nozzle can also be denoted as a "core-shell nozzle." In this way, the extrudate includes the deposited core-shell 3D printable material. Herein, the deposited material is denoted as the 3D printing material (i.e., herein, the core-shell 3D printable material).

[0015] Note that a 3D printed material may include core-shell layers as defined herein, or may include portions of core-shell layers as defined herein. All layers may be entirely core-shell, or one or more layers or portions of one or more layers may be core-shell.

[0016] As will be further explained below, 3D printable materials (and therefore also 3D printing materials in general) include thermoplastic materials. Therefore, in particular, both the core material and the shell material can include thermoplastic materials. In addition, to provide an optical effect, the core material and the shell material each include a particulate material. Therefore, in an embodiment, the core-shell 3D printable material includes (i) a core including a core material and (ii) a shell including a shell material. In particular, the core material includes a core thermoplastic material and a core additional material. In addition, in particular, the shell material includes a shell thermoplastic material and shell particles.

[0017] The thermoplastic materials of the core and shell can be different or the same. The thermoplastic materials of the core and / or shell can each comprise a combination of thermoplastic materials, wherein the core and shell can have one or more thermoplastic materials in common. In specific embodiments, the thermoplastic materials of the core and shell are substantially the same. Thus, in embodiments, the thermoplastic materials of the core and shell can have substantially the same chemical composition. For example, both can comprise or consist essentially of, for example, PE or PP, PC, PET, PS, PMMA, etc. (see also below).

[0018] In particular, the shell material is light transmissive to one or more wavelengths in the visible wavelength range. For example, the shell material may be light transmissive to blue, green, yellow, orange, or red light. Thus, at least a portion of the core is visible (to the human eye) through (at least a portion of) the shell.

[0019] Furthermore, the shell material can also be partially transmissive to one or more colors, so as to have a color in a transmissive state. In other words, it can absorb one or more colors and transmit the rest. It can also be color-neutral and absorb in the visible range, and partially transmit white light, so as to have a grayscale.

[0020] In particular, the shell material can be transmissive to at least a portion of visible light. More particularly, the shell material is at least partially transparent. Therefore, the shell material, and more particularly, the thermoplastic material and the particulate material, can be selected so that the shell material is transmissive. For example, the thickness of the shell, the size of the shell particles, and the volume percentage of the shell particles can be selected so that the shell is transmissive to one or more wavelengths in the visible light. In particular, the transmittance to one or more wavelengths in the visible light can be at least 30%, for example, at least 60%. More particularly, the average light transmittance in the visible wavelength range of 380-780 nm can be at least 30%, for example, at least 60%. The transmittance can be measured for the layer, or for the same layer but on the substrate, using visible light under normal irradiation.

[0021] In particular, in embodiments, the size and separation of the shell particles can be within the eye's resolution. In addition to the shell particles, the shell can also contain (non-particle) light-absorbing materials. In particular, the light-absorbing materials can be (sub) nanometer-sized (dye molecules) to impart a uniform (colored (e.g., white) or black) background. Thus, in embodiments, the shell material and shell thickness (including (dye) addition) can be specifically selected such that the shell is transmissive to one or more wavelengths in the visible light.

[0022] The shell material may also contain light scattering particles. In embodiments, the light scattering particles may not induce more than 20% back reflection. Thus, since the shell is transmissive to light, the core may be at least partially visible. Thus, the core is at least partially visible (through the shell).

[0023] In an embodiment, the layer thickness of the shell can be selected from the range of 5-500 μm, for example, from the range of 50-200 μm. The volume percentage of the shell particles relative to the shell material can be selected from the range of 0.1-10 vol.%, for example, in particular 0.5-5 vol.%. The relatively low volume percentage can also facilitate the uniform distribution of the shell particles across the shell material. In particular, the shell material can therefore always include shell particles and can optionally (also) include light absorbing additives. In an embodiment, the volume percentage of core particles in the core material can be higher than the volume percentage of shell particles in the shell material. In an embodiment, the volume percentage of core particles can be at least 2 vol.%, in particular at least 5 vol.%, for example at least 10 vol.%, for example up to about 30 vol.%. However, it should be noted that in addition to or as an alternative to the core particles, the core material can include a dye.

[0024] In particular, the core material (in the embodiment, particularly the core particles) and the shell material (in the embodiment, particularly the shell particles) differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and light absorption. Here, the term "color" may refer to any color, including black and white as "colors."

[0025] Thus, when the colors are different, for example, the core additional material and / or the dye can be black and the shell particles can be colored (one or more colors). In such a case, this can provide a colored speckled appearance, where the core can essentially provide a black background and the shell can include (specular) reflective particles.

[0026] Alternatively, the core additional material can be black or white, and the shell particles can be metallic, and in an embodiment have diffuse reflection or specular reflection. Alternatively, the core can have a blue color, and the shell particles have a yellow diffuse reflection color. Alternatively, in an embodiment, the core material can include a dye. Such a dye can be dispersed in the thermoplastic material in molecular form. Thereby, pigment particles can also be applied in the core, which can be black, white or have (another) color.

[0027] When the reflectivity is different, the core additional material may be more or less reflective than the shell particles. Alternatively or additionally, they may differ in directional reflectivity. In a particular embodiment, the shell particles may be metallic diffuse reflective and the core additional material may be specular reflective. However, in particular in other embodiments, the shell particles may be specular reflective and the core additional material, in particular the core particles, may be diffuse reflective. At least in a particular embodiment, the shell comprises specular reflective particles and the core comprises one or more of (i) particles that absorb and / or reflect but are not substantially specular reflective and (ii) a dye.

[0028] The reflectivity of the particles can be measured or defined as a bulk property. For example, a thick layer of granular material can be provided, the reflectivity of which under perpendicular irradiation of one or more wavelengths of visible light can be defined. When the type of reflection is different, the particles of the shell can, for example, be specularly reflective and the particles of the core can be diffusely reflective. When so-called reflective holographic particles are used, which cause diffraction, the directional reflectivity can be different. In particular, the reflectivity of the particles can be defined at the particle level. For example, plate-shaped particles, in particular plate-shaped particles having a layer of metal with a smooth surface such as silver or aluminum, can provide specular reflection, while particles with a rough surface, such as particles with wrinkles on dollar bills, can provide diffuse reflection.

[0029] Therefore, in an embodiment, the core additional material may include metal particles. In an embodiment, the metal particles are corrugated. In an embodiment, the metal particles have a (rough) diffuse reflective surface.

[0030] In an embodiment, the core additive material comprises particles having a symmetrical shape, such as a spherical shape, or an irregular shape.

[0031] In particular embodiments, the core may have a uniform color, while the shell particles in the shell are evenly distributed (as individual particles or clusters separated from each other); this may provide a speckled appearance.

[0032] The core additional material comprises one or more of diffusely reflective particles, white particles, black particles, colored particles, and dye molecules. As mentioned above, the shell particles may specifically comprise specularly reflective particles. Thus, the core additional material may be reflective and / or light-absorbing. The core additional material may comprise particles such as pigment particles. Alternatively or additionally, the core additional material may comprise a dye. In very specific embodiments, the dye may be a luminescent dye.

[0033] The shell particles include specular reflective particles. Such particles can be used to provide a sparkling appearance to a 3D object. For example, this can be used to create a desired appearance for distributing light, a metallic appearance, etc. For example, in an embodiment, such shell particles can include one or more of polymeric plate-like particles with a metal coating and glass sheets with a smooth metal coating that exhibits specular reflection. In other specific embodiments, the shell particles can include (crystalline) polyethylene terephthalate plate-like particles with an aluminum coating or a silver coating. In an embodiment, the polyethylene terephthalate can be biaxially oriented. The thickness of the carrier polymer can be in the range of 10-100 μm. The thickness of the aluminum layer can be selected from the range of, for example, 10-60 nm. In other embodiments, the shell can contain specular reflective plate-like particles, and in other embodiments, can have a thickness selected from the range of approximately 2-10 μm.

[0034] In a specific embodiment, at least one of the dimensions of the shell particles is selected from the range of 2 μm to 5 mm. In particular, this can apply to the largest dimension. However, this can also apply to two or more dimensions. Thus, in a specific embodiment, the shell particles have one or more dimensions selected from the particle length (L1), particle height (L2) and particle width (L3), and the particle length (L1), particle height (L2) and particle width (L3) have a length selected from the range of equal to or greater than 2 μm and equal to or less than 5 mm. In particular, such (one or more) dimensions can be selected from the range of 4 μm-2 mm.

[0035] When different optical particles are used (for shell particles and / or core particles), the (shell and core, respectively) dimensions L1 , L2 and L3 may refer to quantitatively averaged dimensions.

[0036] In a specific embodiment, the shell particles include glitter particles having various shapes, such as rectangular, hexagonal, round, etc. They can be made of the materials mentioned above. For example, the shell particles can include (crystalline) polyethylene terephthalate flake particles with an aluminum coating or a silver coating. They can also be so-called holographic glitter.

[0037] In particular embodiments, the shell particles may include one or more of the following: (i) polymer platelet particles with a metal coating or a metal oxide coating, (ii) glass platelets with a metal coating or a metal oxide coating, (iii) metal platelets, (iv) mica platelets with a metal coating or a metal oxide coating, (v) holographic glitter particles, and (vi) colored reflective particles. In addition, in particular embodiments, the shell material may optionally include a dye.

[0038] In embodiments, the dopant material (particularly in the shell) may include flake-shaped particles having a particle length (L1) and a particle height (L2), wherein the aspect ratio L1 / L2 is at least 5, such as 10, such as selected from the range of 10-1000. Thus, in specific embodiments. Thus, in embodiments, the dopant material may include flake-shaped particles having a particle length (L1) and a particle height (L2), wherein the aspect ratio L1 / L2 is at least 5, and wherein the method comprises printing one or more layers of 3D printed material having a layer height (H), wherein in embodiments, the layer height (H) is greater than the particle length (L1). Such a larger layer height may be particularly useful when the layers are stacked. Such a larger layer height may appear to have an advantageous effect on the reflective appearance. Furthermore, the flake-shaped particles may have a particle width (L3), wherein the aspect ratio L3 / L2 is at least 5, such as 10, such as selected from the range of 10-1000. In embodiments, L1 / L3 may be selected from a range of at least about 10, such as at least about 5. In an embodiment, L3 / L1 may also be selected from a range of at least about 10, such as at least about 5.

[0039] Thus, in an embodiment, the shell particles have a particle length (L1), a particle height (L2), and a particle width (L3), wherein the aspect ratio L1 / L2 is at least 5 and L3 / L2 is at least 5, and wherein the method comprises printing one or more layers of 3D printing material having a layer height (H), wherein the layer height (H) is greater than the particle length (L1), and wherein the layers are stacked.

[0040] The term "dopant material" herein refers specifically to particles that can be used as core-additive material or shell particles. The term "dopant material" is used to refer to particles in general. The terms "core-additive material" or "shell particles" and similar terms refer to the specific type of particle used in the core or shell, respectively.

[0041] In a specific embodiment, the shell particles may comprise polyethylene terephthalate flake particles having a metal coating, particularly an aluminum coating or a silver coating (also referred to as "glitter"). Such coatings can be used to provide specularly reflective particles. In particular, the shell particles may comprise crystalline polyethylene terephthalate flake particles. As used herein, the term "crystalline" with respect to polymers may also refer to "semi-crystalline."

[0042] Alternatively or additionally, in another particular embodiment, the shell particles may comprise glass particles coated with a specularly reflective metal such as silver (or aluminum).

[0043] Particles such as glass particles may also include color-providing additives such as metal oxides or (other) dyes to give the particles a colored appearance.

[0044] In the shell, due to the relatively low content, the particles and / or their clusters are separated from each other, giving a speckled appearance.Thus, the particles of the shell may provide a speckled appearance as the particles from the shell are separated from the particles of the core.

[0045] In particular, the particles in the shell are (substantially) homogeneously distributed.

[0046] In a specific embodiment, the core additional material can include diffuse reflective particles such as diffuse reflective aluminum dollar sheets, which can be evenly distributed in the core in a specific embodiment. It seems that the combination of diffuse reflective particles in the core and specular reflective particles in the shell improves the (specular) metallic appearance.

[0047] In a specific embodiment, the core additional material comprises flake particles, in particular flake particles with a rough surface, such as so-called dollar or corn flakes, which can be made of a metal such as aluminum, copper, etc. and exhibit diffuse reflection. The aluminum surface can be provided by aluminum flake particles or flake particles with an aluminum coating.

[0048] In an embodiment, the core additional material may include one or more of Al2O3, TiO2, one or more (other) pigments, dyes, dollar-shaped pieces, etc.

[0049] As described above, in embodiments, the core additive material comprises a "core particle" or a "core additive particle."

[0050] The core additive particles can have essentially any shape.

[0051] In other specific embodiments (assuming particles), the core-added material has a particle length (L1) and a particle height (L2), wherein the aspect ratio L1 / L2 is at least 3. However, in other embodiments, the core-added material has a particle length (L1) and a particle height (L2), wherein the aspect ratio L1 / L2 is at most 3.

[0052] Furthermore (assuming particles), in embodiments, the core additional material may have a particle width (L3) and a particle height (L2), wherein the aspect ratio L3 / L2 is at most 10, such as at most 3, such as selected from the range of 1-10. However, in other embodiments, the core additional material has a particle width (L3) and a particle height (L2), wherein the aspect ratio L3 / L2 is at least 3, such as at least 10, such as selected from the range of 10-1000.

[0053] In an embodiment (assuming particles), L1 / L3 may be selected from a range of at least about 5, such as at least about 10. However, in an alternative embodiment (assuming particles), L3 / L1 may also be selected from a range of at least about 5, such as at least about 10.

[0054] Thus, in an embodiment, the shell particles have a particle length (L1), a particle height (L2), and a particle width (L3), wherein the aspect ratio L1 / L2 is at least 3, and L3 / L2 is at least 3. It should be noted that the dimensions of the shell particles and the core additional material (L1, L2, L3, respectively) do not have to be the same.

[0055] In particular embodiments, the core may contain particles that are not asymmetric but have shapes such as spherical or irregular particles.

[0056] In particular, the core additional material is evenly distributed.

[0057] In this way, in an embodiment, the core may thus have a metallic appearance.

[0058] Furthermore, it also appears that the (specular) reflective appearance can be promoted by including white reflective particles or black (absorbing) particles in the core. Thus, in a specific embodiment, the core additional material includes one or more of the following: (i) diffusely reflective white particles, such as TiO2, and (ii) black absorbing particles, such as carbon or dyes and pigments that absorb other colors.

[0059] In a specific embodiment, the thermoplastic material of the core can also include a dye. In this way, the core can have a colored appearance that can be seen through the shell. In a specific embodiment, the core can also have a colored appearance when a dye or pigment is added to the white diffuse reflective mixture.

[0060] In particular, the particles in the core are (substantially) uniformly distributed.

[0061] As described above, the present invention provides a method for producing a 3D object using fused deposition modeling, the method comprising a 3D printing stage comprising depositing layer by layer an extrudate comprising a 3D printable material to provide (on a receiving object) a 3D object comprising the 3D printable material, wherein the 3D object comprises multiple layers of the 3D printable material. Other aspects related to these features are also described below. Herein, 3D printable materials and 3D printable materials are generally discussed, which can refer to shell 3D printable materials or core 3D printable materials, or both.

[0062] As described above, the method includes depositing a 3D printable material during the printing phase. Herein, the term "3D printable material" refers to the material to be deposited or printed, and the term "3D printing material" refers to the material obtained after deposition. These materials can be substantially the same, as 3D printable material specifically refers to the material in the printer head or extruder at high temperature, and 3D printing material refers to the same material, but deposited at a later stage. The 3D printable material is printed as a filament and deposited as such. The 3D printable material can be provided as a filament or formed into a filament. Therefore, regardless of the starting material used, a filament comprising the 3D printable material is provided by the printer head and 3D printing is performed. The term "extrudate" can be used to define the 3D printable material downstream of the printer head but not yet deposited. This latter material is denoted as "3D printing material." In practice, the extrudate comprises the 3D printable material because it has not yet been deposited. When the 3D printable material or extrudate is deposited, this material is denoted as 3D printing material. Essentially, the material is the same material in that the thermoplastic material upstream of the printer head and downstream of the printer head is essentially the same material when deposited.

[0063] Herein, the term "3D printable material" may also be referred to as "printable material." In embodiments, the term "polymer material" refers to a blend of different polymers, but in embodiments, it may also refer to a substantially single polymer type with different polymer chain lengths. Thus, the term "polymer material" or "polymer" may refer to a single type of polymer, but may also refer to a plurality of different polymers. The term "printable material" may refer to a single type of printable material, but may also refer to a plurality of different printable materials. The term "printing material" may refer to a single type of printing material, but may also refer to a plurality of different printing materials.

[0064] Therefore, the term "3D printable material" may also refer to a combination of two or more materials. Typically, these (polymeric) materials have a glass transition temperature T g and / or melting temperature T mThe 3D printable material will be heated by the 3D printer to at least the glass transition temperature, and typically at least the melting temperature, before it leaves the nozzle. Thus, in a specific embodiment, the 3D printable material comprises a 3D printable material having a glass transition temperature (T g ) and / or melting temperature (T m ) thermoplastic polymer, the printer head action includes heating the 3D printable material above the glass transition temperature, and if it is a semi-crystalline polymer, above the melting temperature. In another embodiment, the 3D printable material includes a thermoplastic polymer having a melting point (T m ) of a (thermoplastic) polymer, and the printer head action comprises heating the 3D printable material to be deposited on the receiving object to a temperature of at least the melting point. The glass transition temperature is generally not the same temperature as the melting temperature. Melting is a transition that occurs in crystalline polymers. Melting occurs when the polymer chains fall outside their crystalline structure and become a disordered liquid. The glass transition is a transition that occurs in amorphous polymers; that is, polymers whose chains are not arranged in an ordered crystal, but are merely scattered by any means, even if they are in the solid state. Polymers can be amorphous, essentially having a glass transition temperature but no melting temperature, or can be (semi-)crystalline, generally having both a glass transition temperature and a melting temperature, the latter generally being greater than the former. For example, the glass temperature can be determined using differential scanning calorimetry. The melting point or melting temperature can also be determined using differential scanning calorimetry.

[0065] As described above, the present invention thus provides a method comprising providing a filament of a 3D printable material and printing the 3D printable material on a substrate during a printing phase to provide the 3D object.

[0066] Materials that are particularly qualified as 3D printable materials can be selected from the group consisting of the following materials: metal, glass, thermoplastic polymer, silicone, etc. In particular, the 3D printable material includes a (thermoplastic) polymer selected from the group consisting of ABS (acrylonitrile butadiene styrene), nylon (or polyamide), acetate (or cellulose), PLA (polylactic acid), terephthalic acid (e.g., PET polyethylene terephthalate), acrylic (polymethacrylate, perspex, polyethyl methacrylate, PMMA), polypropylene, polycarbonate (PC), polystyrene (PS), PE (e.g., foamed impact polyethylene (or polyethylene), low density (LDPE) high density (HDPE)), PVC (polyvinyl chloride) polyvinyl chloride, thermoplastic elastomers such as copolyester elastomers, polyurethane elastomers, elastomers based on polyamide elastomers polyolefin elastomers, styrene-based elastomers, etc. Optionally, the 3D printable material comprises a 3D printable material selected from the group consisting of urea formaldehyde, polyester resin, epoxy resin, melamine formaldehyde, thermoplastic elastomer, etc. Optionally, the 3D printable material comprises a 3D printable material selected from the group consisting of polysulfone. Elastomers, particularly thermoplastic elastomers, are particularly attractive because they are flexible and can help to obtain relatively more flexible filaments including thermally conductive materials. Thermoplastic elastomers may include one or more of the following: styrenic block copolymers (TPS (TPE-s)), thermoplastic polyolefin elastomers (TPO (TPE-o)), thermoplastic vulcanizates (TPV (TPE-v or TPV)), thermoplastic polyurethanes (TPU (TPU)), thermoplastic copolyesters (TPC (TPE-E)) and thermoplastic polyamides (TPA (TPE-A)).

[0067] Suitable thermoplastic materials, such as those also mentioned in WO2017 / 040893, may include one or more of the following: polyacetals (e.g., polyethylene oxide and polyoxymethylene), poly(C 1-6alkyl) acrylates, polyacrylamides, polyamides (e.g., aliphatic polyamides, polyphthalamides, and polyaramides), polyamide-imides, polyanhydrides, polyarylates, polyarylethers (e.g., polyphenylene ethers), polyarylene sulfides (e.g., polyphenylene sulfide), polyarylene sulfones (e.g., polyphenylene sulfone), polybenzothiazoles, polybenzoxazoles, polycarbonates (including polycarbonate copolymers such as polycarbonate siloxanes, polycarbonate ethers, and polycarbonate ether siloxanes), polyesters (e.g., polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyarylates), and polyester copolymers such as polyester ethers), polyetheretherketones, polyetherimides (including copolymers such as polyetherimidesiloxane copolymers), polyetherketoneketones, polyetherketones, polyethersulfones, Polyimides (including copolymers such as polyimidesiloxane copolymers), poly(C1-6 alkyl)methyl methacrylates, polymethacrylamides, polynorbornenes (including copolymers containing norbornene units), polyolefins (e.g., polyethylene, polypropylene, polytetrafluoroethylene and copolymers thereof, such as ethylene α-olefin copolymers), polyoxadiazoles, polyoxymethylene, polytetrachlorophenyl ethers, polysilazanes, polysiloxanes, polystyrenes (including copolymers such as acrylonitrile-butadiene-styrene copolymers (ABS) and methyl methacrylate (MBS)), polysulfides, polysulfonamides, polysulfones, polysulfones, polysulfones, polysulfides, polytriazines, polyureas, polyurethanes, polyvinyl alcohols, polyvinyl esters, polyvinyl ethers, polyvinyl alcohol halides, polyvinyl ketones, polyvinyl sulfides, polyvinylidene fluoride, and the like, or a combination comprising at least one of the foregoing thermoplastic polymers. Examples of polyamides may include, but are not limited to, synthetic linear polyamides such as nylon-6,6, nylon-6,9, nylon-6,10, nylon-6,12, nylon-11, nylon-12, and nylon-4,6, preferably nylon 6 and nylon 6,6, or a combination comprising at least one of the foregoing. Polyurethanes that may be used include aliphatic, alicyclic, aromatic, and polycyclic polyurethanes, including those mentioned above. Also useful are poly(C 1-6 Alkyl) acrylate and poly (C 1-6 The polyolefin may include one or more of polyethylene, polypropylene, polybutene, polymethylpentene (and copolymers thereof), polynorbornene (and copolymers thereof), poly-1-butene, poly(3-methylbutene), poly(4-methylpentene), and copolymers of ethylene and propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 1-octadecene.

[0068] In a specific embodiment, the 3D printable material (and 3D printing material) includes one or more of the following: polycarbonate (PC), polyethylene (PE), low-density polyethylene (HDPE), polypropylene (PP), polyethylene naphthalate (PEN), styrene-acrylonitrile resin (SAN), polysulfone (PSU), polyphenylene sulfide (PPS) and semi-crystalline polyethylene terephthalate (PET), (PMMA), polystyrene (PS), and styrene acrylic copolymer (SMMA). In particular, the 3D printable material of the shell includes one or more translucent polymers (or transparent polymers).

[0069] The term 3D printable material is further explained below, but specifically refers to a thermoplastic material, optionally including additives, with a volume percentage of maximum about 60%, in particular maximum about 30 vol.%, such as maximum 20 vol.% (additives relative to the total volume of thermoplastic material and additives).

[0070] The printable material may therefore comprise two phases in an embodiment. The printable material may comprise a phase of a printable polymeric material, in particular a thermoplastic material (see also below), which phase is in particular a substantially continuous phase. In this continuous phase of the thermoplastic material, there may be polymer additives such as antioxidants, heat stabilizers, light stabilizers, UV stabilizers, UV absorbing additives, near-infrared absorbers, infrared absorbing additives, plasticizers, lubricants, release agents, antistatic agents, anti-fogging agents, antimicrobial agents, colorants, laser marking additives, surface effect additives, radiation stabilizers, flame retardants, anti-drip agents. The additives may have useful properties selected from optical properties, mechanical properties, electrical properties, thermal properties, and mechanical properties (see also above).

[0071] In an embodiment, the printable material may include a particulate material, i.e., particles embedded in a printable polymer material, the particles forming a substantially discontinuous phase. The amount of particles in the total mixture is specifically not more than 60 vol.%, relative to the total volume of the printable material (including the (anisotropically conductive) particles), in particular in applications for reducing the coefficient of thermal expansion. In order to achieve optical and surface-related effects, the amount of particles in the total mixture is equal to or less than 20 vol.%, for example up to 10 vol.%, relative to the total volume of the printable material (including the particles). Therefore, a 3D printable material particularly refers to a continuous phase of a basic thermoplastic material, in which other materials, such as particles, may be embedded. Similarly, a 3D printing material particularly refers to a continuous phase of a basic thermoplastic material, in which other materials, such as particles, are embedded. The particles may include one or more additives as defined above. Therefore, in an embodiment, the 3D printable material may include a particulate additive.

[0072] The printable material is printed onto a receiving object. In particular, the receiving object may be, or may consist of, a building platform. The receiving object may be heated during 3D printing. However, it is also possible to cool the receiving object during 3D printing.

[0073] The phrase "printing on a receiving object" and similar phrases include printing directly on the receiving object, or printing on a coating on the receiving object, or printing on a 3D printing material that was earlier printed on the receiving object. The term "receiving object" may refer to a printing platform, a print bed, a substrate, a support, a build plate or a build platform, etc. Instead of the term "receiving object", the term "substrate" may also be used. The phrase "printing on a receiving object" and similar phrases include also printing on a printing platform, a print bed, a support, a build plate or a build platform, etc. or on an independent substrate constituted thereof, etc. Therefore, the phrase "printing on a substrate" and similar phrases include printing directly on a substrate, or printing on a coating on a substrate, or printing on a 3D printing material that was earlier printed on a substrate, etc. In the following, the term substrate is further used, which may refer to a printing platform, a print bed, a substrate, a support, a build plate or a build platform, etc., or an independent substrate thereon or constituted thereof.

[0074] The 3D printed object is generated (during the printing phase) by depositing the printable material layer by layer. The 3D printed object may exhibit a characteristic ribbed structure (deriving from the deposited filament). However, it is also possible that after the printing phase, another phase is performed, such as a termination phase. This phase may include removing the printed object from the receiving object and / or one or more post-processing actions. One or more post-processing actions may be performed before removing the printed object from the receiving object and / or one or more post-processing actions may be performed after removing the printed object from the receiving object. Post-processing may include, for example, one or more of polishing, coating, adding functional components. Post-processing may include smoothing the ribbed structure, which may result in a substantially smooth surface.

[0075] Furthermore, the present invention relates to a software product that can be used to perform the method described herein. Therefore, in yet another aspect, the present invention also provides a computer program product that, when run on a computer functionally coupled to or comprised by a fused deposition modeling 3D printer, is capable of initiating the method described herein.

[0076] Thus, in one aspect, the present invention (thus) provides a software product which, when run on a computer, is capable of initiating (one or more embodiments of) the method (for producing a 3D object using fused deposition modeling) described herein.

[0077] With respect to the extrudate (also noted above), in the present invention, the extrudate is specifically a core-shell extrudate. During deposition, it is a core-shell layer. Thus, in particular, the method may also include creating the extrudate using a core-shell filament of a 3D printable material or using a core-shell nozzle. In either approach, a core-shell extrudate can be created.

[0078] In addition, as described above, the core material and the shell material can differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and light absorption. More particularly, the core additional material and the shell particles differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and light absorption. In a specific embodiment, the core particles and the shell particles differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and light absorption.

[0079] In yet another aspect, the present invention also provides a core-shell filament comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and a core additive material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) comprise specular reflective particles, wherein the core additive material (242) comprises one or more of diffuse reflective particles, white particles, black particles, colored particles, and dye molecules, and wherein the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflectance, and absorption of light. Further reference is made to the embodiments described above and / or below.

[0080] The method described herein provides a 3D-printed object. Therefore, the present invention also provides, in another aspect, a 3D-printed object that can be obtained using the method described herein. In another aspect, a 3D-printed object that can be obtained using the method described herein is provided. In particular, the present invention provides a 3D object comprising a 3D-printed material. In particular, the 3D object comprises multiple layers of 3D-printed material. As can be deduced from the above, in particular, the 3D-printed material comprises a core-shell 3D-printed material, which comprises (i) a core comprising a core material, and (ii) a shell comprising a shell material. In a specific embodiment, the core material comprises a core thermoplastic material and a core additive material, and the shell material comprises a shell thermoplastic material and shell particles. Furthermore, in particular, the shell material can be a translucent material and be light-transmissive for one or more wavelengths in the visible wavelength range. As described above, in specific embodiments, the core material and the shell material can differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and light absorption.

[0081] Thus, in particular, in an embodiment, the present invention provides a 3D object comprising a 3D printed material, wherein the 3D object comprises a plurality of layers of the 3D printed material, wherein the 3D printed material comprises a core-shell 3D printed material, the core-shell 3D printed material comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and a core additive material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) comprise specular reflective particles, wherein the core additive material (242) comprises one or more of diffuse reflective particles, white particles, black particles, colored particles, and dye molecules, and wherein the material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflectance, and absorption of light.

[0082] As described above, it appears that with a core-shell structure, enhanced optical properties can be achieved. For example, when a diffusely reflective or light-absorbing, light-reflective (which can be colored and / or have a diffusely reflective metallic appearance) material is applied in the core, a specularly reflective material in the shell can provide a more (specular) iridescent reflective appearance.

[0083] The 3D printed object can include multiple layers on top of each other, i.e., stacked layers. For example, in an embodiment, the width (thickness) and height of the (individually 3D printed) layers can be selected from a range of 100-5000 μm, such as 200-2500 μm, where the height is generally smaller than the width. For example, the ratio of height to width can be equal to or less than 0.8, such as equal to or less than 0.6.

[0084] Within a layer, there may also be variations in composition, for example when a core-shell printing process is applied and during the printing process it changes from printing a first material (and not printing a second material) to printing a second material (and not printing the first material).

[0085] At least a portion of the 3D printed object may include a coating.

[0086] In discussing the method, some specific embodiments of 3D printed objects have been described below. Some specific embodiments of 3D printed objects are discussed in more detail below.

[0087] As described above, in an embodiment, the shell particles may comprise (specular) reflective particles. In particular, in an embodiment, the shell particles comprise flaky particles having a metal coating, in particular an aluminum coating. Furthermore, the flaky particles may comprise (crystalline) polyethylene terephthalate. Alternatively or additionally, the shell particles may comprise solid flat metal particles having specular reflectivity. Alternatively or additionally, the shell particles may comprise glass particles coated with a specularly reflective metal. Alternatively or additionally, the shell particles may comprise mica particles coated with a specularly reflective metal. Alternatively or additionally, the shell particles may comprise holographic glitter particles. Furthermore, in addition or alternatively, the shell particles may comprise colored reflective particles. Thus, in an embodiment, the shell particles may comprise one or more glitter particles selected from the group comprising particles having a holographic coating and colored reflective particles. Thus, in particular, the shell particles are reflective.

[0088] As mentioned above, within the shell, the individual shell particles (or clusters thereof) may be (substantially) evenly distributed such that a speckled appearance may be provided.

[0089] In a specific embodiment, the shell particles have a particle length (L1) and a particle height (L2), wherein the aspect ratio L1 / L2 is at least 5. Alternatively or additionally, the shell particles have a particle width (L3), wherein the aspect ratio L3 / L2 is at least 5 (see also above). Furthermore, in a specific embodiment, one or more layers of the 3D printing material have a layer height (H), wherein the layer height (H) is greater than the particle length (L1), and wherein the layers are stacked.

[0090] In particular embodiments, the core additive material may include one or more of: (i) diffusely reflective particles and (ii) light absorbing particles, such as black particles in embodiments.

[0091] The shell may contain one or more of asymmetric particles and symmetric particles, such as spherical particles, irregular shapes, and the like.

[0092] The size of the shell particles can be selected from the range of, for example, 2 μm to 1 mm. In a specific embodiment, the dye can be nano-sized. The pigment can also be selected to be nano-sized.

[0093] The 3D printed object obtained (using the method described herein) can be functional in itself. For example, the 3D printed object can be a lens, a collimator, a reflector, etc. The 3D object obtained in this way can (alternatively) be used for decorative or aesthetic purposes. The 3D printed object can include or be equipped with functional components. In particular, the functional components can be selected from the group consisting of optical components, electrical components and magnetic components. The term "optical component" refers in particular to components with optical functions, such as lenses, reflectors, light-transmitting elements, optical filters, etc. The term optical component can also refer to a light source (like an LED). The term "electrical component" can refer to, for example, an integrated circuit, a PCB, a battery, a driver, and also to a light source (because a light source can be regarded as an optical component and an electrical component), etc. The term magnetic component can refer to, for example, a magnetic connector, a coil, etc. Alternatively, or in addition, the functional component can include a thermal component (for example, configured to cool or heat an electrical component). Therefore, the functional component can be configured to generate heat or dissipate heat, etc.

[0094] As described above, 3D printed objects can be used for different purposes. 3D printed objects can be used for lighting, etc. Therefore, in another aspect, the present invention also provides a lighting device comprising a 3D object as defined herein. In a specific aspect, the present invention provides a lighting device comprising (a) a light source configured to provide (visible) light source light, and (b) a 3D object as defined herein, wherein the 3D object can be configured as one or more of the following: (i) at least a portion of a housing, (ii) at least a portion of a wall of a lighting chamber, and (iii) a functional component, wherein the functional component can be selected from the group consisting of an optical component, a support, an electrically insulating component, a conductive component, a thermally insulating component, and a thermally conductive component. Therefore, in a specific embodiment, the 3D object can be configured as one or more of the following: (i) at least a portion of a lighting device housing, (ii) at least a portion of a wall of a lighting chamber, and (iii) an optical element. Since a relatively smooth surface can be provided, the 3D printed object can be used as a reflector or lens, etc. In an embodiment, the 3D object can be configured as a cover. A device or system may include multiple different 3D printed objects with different functions.

[0095] In particular, the shell particles may at least partially specularly reflect the light source light of the light source.

[0096] Returning to the 3D printing process, a 3D printed object as described herein can be provided using a specific 3D printer. Therefore, in another aspect, the present invention also provides a fused deposition modeling 3D printer comprising (a) a printer head comprising a printer nozzle, and (b) a 3D printable material providing device configured to provide 3D printable material to the printer head, wherein the fused deposition modeling 3D printer is configured to provide the 3D printable material, wherein the 3D printable material comprises a core-shell 3D printable material, the core-shell 3D printable material comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and a core additive material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, and wherein the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and absorption of light.

[0097] The printer nozzle may include a single opening. In other embodiments, the printer nozzle may be of the core-shell type, having two (or more) openings. The term "printer head" may also refer to multiple (different) printer heads; thus, the term "printer nozzle" may also refer to multiple (different) printer nozzles.

[0098] The 3D printable material providing device can provide a filament comprising a 3D printable material to a printer head, or can provide the 3D printable material in such a way that a filament comprising a 3D printable material is created with the printer head. Thus, in an embodiment, the present invention provides a fused deposition modeling 3D printer comprising (a) a printer head comprising a printer nozzle, and (b) a filament providing device configured to provide a filament comprising a 3D printable material to the printer head, wherein the fused deposition modeling 3D printer is configured to provide the 3D printable material to a substrate, wherein the 3D printable material comprises a core-shell 3D printable material, the core-shell 3D printable material comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and a core additive material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, and wherein the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and absorption of light.

[0099] In particular, the 3D printer comprises a controller (or is functionally coupled to a controller) configured to perform the method described herein in a control mode (or "operation mode"). In addition to the term "controller", the term "control system" may also be applied (e.g., see above).

[0100] The term "control" and similar terms specifically refer to at least determining the behavior of an element or supervising the operation of an element. Therefore, "control" and similar terms in this article can, for example, refer to imposing an action on an element (determining the behavior of an element or supervising the operation of an element), such as, for example, measuring, displaying, actuating, opening, offsetting, changing temperature, etc. In addition, the term "control" and similar terms can also include monitoring. Therefore, the term "control" and similar terms can include imposing an action on an element, and also imposing an action on an element and monitoring the element. Control of an element can be accomplished using a control system, which can also be referred to as a "controller". The control system and the element can therefore be functionally coupled, at least temporarily or permanently. The element can include a control system. In an embodiment, the control system and the element may not be physically coupled. Control can be performed via wired and / or wireless control. The term "control system" can also refer to multiple different control systems, which are particularly functionally coupled, and wherein, for example, one control system can be a master control system and one or more other control systems can be slave control systems. The control system can include or can be functionally coupled to a user interface.

[0101] The control system can also be configured to receive instructions from a remote control device and execute the instructions. In an embodiment, the control system can be controlled via an application on a device, such as a portable device like a smartphone or iPhone, a tablet computer, etc. The device is not necessarily coupled to the lighting system, but can be (temporarily) functionally coupled to the lighting system.

[0102] Therefore, in an embodiment, the control system can (also) be configured to be controlled by an application on a remote device. In such an embodiment, the control system of the lighting system can be a slave control system or controlled in slave mode. For example, the lighting system can be identifiable by a code, in particular a unique code for the respective lighting system. The control system of the lighting system can be configured to be controlled by an external control system, which can access the lighting system based on knowledge of the (unique) code (entered by a user interface using an optical sensor (e.g., a QR code reader)). The lighting system can also include a module for communicating with other systems or devices, for example based on Bluetooth, WiFi, LiFi, ZigBee, BLE, WiMAX, or another wireless technology.

[0103] The system, device or apparatus may perform actions in a certain "mode" or "operating mode" or "mode of operation". Similarly, in a method, actions, phases or steps may be performed in a "mode" or "operating mode" or "mode of operation" or "operational mode". The term "mode" may also be expressed as "control mode". This does not exclude that the system, device or apparatus may also be adapted to provide another control mode or multiple other control modes. Similarly, this may not exclude that one or more other modes may be executed before and / or after executing a mode.

[0104] However, in an embodiment, a control system is available that is adapted to provide at least a control mode. If other modes are available, selection of such modes can in particular be made via a user interface, but other options may also be possible, such as executing a mode based on sensor signals or (time) schedules. In an embodiment, an operating mode may also refer to a system or device or apparatus that is only capable of operating in a single operating mode (i.e., "on," with no other tunability).

[0105] Therefore, in an embodiment, the control system may perform control according to one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer.The term "timer" may refer to a clock and / or a predetermined time scheme.

[0106] Instead of the term "fused deposition modeling (FDM) 3D printer", the shortened term "3D printer", "FDM printer" or "printer" may be used. A printer nozzle may also be denoted as a "nozzle" or sometimes as an "extruder nozzle".

[0107] It can be inferred from the above that, in various aspects, the present invention provides a method for manufacturing a 3D object by fused deposition modeling, wherein the method includes the steps of depositing an extrudate layer by layer to provide a 3D object, wherein the extrudate includes a core component and a shell component, wherein the core component is diffusely reflective or light absorbing, wherein the shell component is light transmissive, and wherein the shell component includes a thermoplastic shell material and specularly reflective shell particles. In an embodiment, the present invention provides a method for producing a 3D object using fused deposition modeling, the method comprising a 3D printing stage, the 3D printing stage comprising: depositing an extrudate comprising a 3D printing material layer by layer to provide a 3D object comprising the 3D printing material, wherein the 3D object comprises multiple layers of the 3D printing material, wherein the 3D printable material comprises a core-shell 3D printable material, the core-shell 3D printable material comprising (i) a core comprising a core material, and (ii) a shell comprising a shell material, wherein the core material comprises a core thermoplastic material and an optional core additional material, wherein the shell material comprises a shell thermoplastic material and shell particles, wherein the shell material is light transmissive for one or more wavelengths in the visible wavelength range, and wherein the core material and the shell material differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type, and absorption of light. For example, the shell particles can be specularly reflective, and the core material can be white or diffusely reflective. Suitable thermoplastic materials that can have desired properties can be selected for the core. In particular, in this article, the core enhances the contrast of the shell material (including the particulate material). Thus, the present invention provides FDM-printed light-emitting devices, or other objects, with an enhanced glittering appearance. Thus, in particular embodiments, the core component of the extrudate can be diffusely reflective or light-absorbing. This can be achieved by using: (i) a diffusely reflective thermoplastic material, (ii) a light-absorbing thermoplastic material; (iii) a diffusely reflective additive, such as diffusely reflective particles; and / or (iv) a light-absorbing additive, such as light-absorbing particles, pigments, or dyes. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] By way of example only, embodiments of the present invention will now be described with reference to the accompanying drawings, in which corresponding reference numerals indicate corresponding parts, and in which:

[0109] Figures 1a-1c schematically depict some general aspects of embodiments of a 3D printer and 3D printing materials;

[0110] 2a-2f schematically depict aspects of embodiments of particles, wherein some shapes are depicted for reference purposes;

[0111] Figures 3a-3b schematically depict some other aspects of the present invention;

[0112] Figure 4 A lamp or light-emitting device is schematically depicted;

[0113] Figures 5a-5d depict examples of particles;

[0114] Figures 6a-6c schematically depict some other aspects;

[0115] Figures 7a-7c show photographs of fabricated examples. The schematic diagrams are not necessarily drawn to scale. DETAILED DESCRIPTION

[0116] Figure 1a schematically depicts some aspects of a 3D printer. Reference numeral 500 denotes a 3D printer. Reference numeral 530 denotes a functional unit configured to perform 3D printing, in particular FDM 3D printing; this reference numeral also denotes a 3D printing stage unit. Here, only a printer head for providing 3D printing material, such as an FDM 3D printer head, is schematically shown. Reference numeral 501 denotes a printer head. The 3D printer of the present invention may in particular include multiple printer heads (see below). Reference numeral 502 denotes a printer nozzle. The 3D printer of the present invention may in particular include multiple printer nozzles, although other embodiments are possible. Reference numeral 320 denotes a filament (e.g., as described above) that can print a 3D printable material. For the sake of clarity, not all features of the 3D printer are depicted, only those that are particularly relevant to the present invention (see also below). Reference numeral 321 denotes an extrudate (of the 3D printable material 201).

[0117] The 3D printer 500 is configured to generate a 3D object 1 by depositing a plurality of layers 322 on a receiving object 550, which in an embodiment is at least temporarily cooled, wherein each layer 322 comprises a 3D printable material 201, e.g., having a melting point T m 3D printable material 201 can be deposited on substrate 1550 (during the printing phase). By being deposited, 3D printable material 201 has become 3D printing material 202. 3D printable material 201 exiting nozzle 502 is also represented as extrudate 321. Reference numeral 401 denotes thermoplastic material.

[0118] The 3D printer 500 can be configured to heat the filament 320 material upstream of the printer nozzle 502. This can be accomplished, for example, using a device that includes one or more of extrusion and / or heating functions. Such a device is indicated by reference numeral 573 and is arranged upstream of the printer nozzle 502 (i.e., before the filament material exits the printer nozzle 502). The printer head 501 can (thus) include a liquefier or heater. Reference numeral 201 indicates printable material. When deposited, this material is referred to as (3D) printing material, indicated by reference numeral 202.

[0119] Reference numeral 572 denotes a spool or roller of material, particularly in the form of a thread, which can be designated as filament 320. The 3D printer 500 transforms this into an extrudate 321 downstream of the printer nozzle, which becomes a layer 322 on a receiving object or already deposited printing material. Typically, the diameter of the extrudate 321 downstream of the nozzle 502 is reduced relative to the diameter of the filament 320 upstream of the printer head 501. Therefore, the printer nozzle is sometimes (also) designated as an extrudate nozzle. Arranging layer 322 one after another and / or arranging layer 322t on layer 322 can form a 3D object 1. Reference numeral 575 denotes a filament supply device, which here includes a spool or roller designated by reference numeral 576 and a drive wheel, among others.

[0120] Reference symbol A denotes the longitudinal axis of the filament shaft.

[0121] Reference numeral C schematically illustrates a control system, for example, in particular a temperature control system, which is configured to control the temperature of the received object 550. The control system C may comprise a heater capable of heating the received object 550 to a temperature of at least 50°C, but in particular up to a range of about 350°C, for example at least 200°C.

[0122] Alternatively or additionally, in embodiments, the receiving plate can also be moved in one or both directions in the xy plane (horizontal plane). Furthermore, alternatively or additionally, in embodiments, the receiving plate can also be rotated about the z axis (vertical). Thus, the control system can move the receiving plate in one or more of the x, y, and z directions.

[0123] Alternatively, the printer may have a head that can also rotate during printing. Such a printer has the advantage that the printed material cannot be rotated during printing.

[0124] The layer is denoted by reference numeral 322 and has a layer height H and a layer width W.

[0125] Note that the 3D printable material need not be provided to the printer head as filament 320. Furthermore, filament 320 may also be produced in 3D printer 500 from multiple pieces of 3D printable material.

[0126] Reference symbol D represents the diameter of the nozzle (through which the 3D printable material 201 is extruded).

[0127] FIG1 b schematically shows in 3D form the printing of the 3D object 1 under construction in more detail. In this schematic diagram, the ends of the filament 320 in a single plane are not interconnected, although in the embodiment, this may be the case in reality. Reference numeral H indicates the height of the layer. The layer is indicated by reference numeral 203. Here, the layers have a substantially circular cross-section. However, they can often be flattened, for example having an external shape similar to a flat oval tube or a flat oval pipe (i.e. a circular strip whose diameter is compressed to have a height smaller than its width, wherein the sides (defining the width) are (still) round).

[0128] Thus, Figures 1a-1b schematically illustrate some aspects of a fused deposition modeling 3D printer 500, including (a) a printer head 501 including a printer nozzle 502, (b) a filament supply device 575 configured to supply filament 320 including 3D printable material 201 to the printer head 501, and optionally, (c) a receiving object 550. In Figures 1a-1b, the first or second printable material or the first or second printing material is represented by the general designations printable material 201 and printing material 202, respectively. Immediately downstream of the nozzle 502, upon deposition, the filament 320 comprising the 3D printable material becomes a layer 322 comprising the 3D printing material 202.

[0129] FIG1c schematically depicts a stack of 3D printed layers 322, each layer 322 having a layer height H and a layer width W. Note that, in embodiments, the layer width and / or layer height may be different for two or more layers 322. Reference numeral 252 in FIG1c denotes an object surface of the 3D object (schematically shown in FIG1c).

[0130] 1 a - 1 c , the deposited filaments of 3D printable material form layers having a height H (and a width W). Layers 322 are deposited one after another, resulting in a 3D object 1 .

[0131] Figure 2a schematically illustrates the reasoning behind understanding particles and some aspects thereof. Note that the particles used in the present invention are particularly relatively flat, see for example Figures 2d, 2e, and 5.

[0132] The particle 410 comprises material 411, or may consist essentially of such material 411. The particle 410 has a first dimension or length L1. In the example on the left, L1 is substantially the diameter of a substantially spherical particle. On the right, a particle having a non-spherical shape, such as an elongated particle 410, is shown. Here, by way of example, L1 is the particle length. L2 and L3 can be considered to be the height and width. Of course, the particle may comprise a combination of particles of different shapes.

[0133] Figures 2b - 2f schematically illustrate some aspects of the particles 410. Some of the particles 410 have: a longest scale A1 with a longest scale length L1, and a shortest scale A2 with a shortest scale length L2. As can be seen from the figure, the longest scale length L1 and the shortest scale length L2 have a first aspect ratio greater than 1. Figure 2b schematically depicts the particle 410 in 3D. The particle 410 has a length, a height, and a width, and the particle (or sheet) is generally of an elongated shape. Thus, the particle can have another axis (a short axis or a major axis), which is denoted herein as another scale A3. Essentially, the particle 410 is a thin particle, i.e., L2 < L1, particularly L2 << L1 and L2 << L3. For example, L1 can be selected from the range of 5 - 200 μm; like L3. For example, L2 can be selected from the range of 0.1 - 20 μm.

[0134] Figure 2c schematically depicts a particle with a more irregular shape, such as a piece of broken glass, and the imaginary smallest rectangular parallelepiped enclosing the particle.

[0135] Note that the symbols L1, L2, and L3, as well as A1, A2, and A3 are only used to denote the axes and their lengths, and the numbers are only used to distinguish the respective axes. Additionally, note that the particles are not generally elliptical or rectangular parallelepipeds. The particles can have any shape, where at least the longest scale is significantly longer than the shortest scale or the short axis, and can be generally flat. In particular, relatively regularly formed particles are used, i.e., the remaining volume of the imaginary smallest rectangular parallelepiped enclosing the particle is small, such as less than 50% of the total volume, like less than 25%.

[0136] Figure 2d schematically depicts a particle 410 including a coating 412 in a cross-sectional view. The coating can include a light-reflective material. For example, the coating can include (white) metal oxides. In other embodiments, the coating can consist essentially of a metal, such as an Ag coating. In other embodiments, the coating can be on only one or both of the large surfaces, and not on the thin side surfaces of the particle.

[0137] Figure 2e schematically depicts relatively irregularly shaped particles. The particle material used can include, for example, small pieces of broken glass. Thus, the particle material embedded in a 3D printable material or embedded in a 3D printed material can include a wide distribution of particle sizes. A rectangular parallelepiped can be used to define the (orthogonal) scales having lengths L1, L2, and L3.

[0138] Figure 2f schematically depicts cylindrical, spherical, and irregularly shaped particles, which will generally not be used herein (also see above).

[0139] As shown in Figures 2b-2f, the term "first dimension" or "longest dimension" specifically refers to the length L1 of the smallest rectangular cube (rectangular parallelepiped) that encloses the irregularly shaped particle. When the particle is substantially spherical, the longest dimension L1, the shortest dimension L2 and the diameter are substantially equal.

[0140] Figure 3a schematically depicts a filament 320 comprising a 3D printable material 201, for example as it exits a printer nozzle (not shown). The 3D printable material comprises a thermoplastic material 401 having particles 410 embedded therein.

[0141] FIG3 b schematically depicts a 3D object 1 showing a ribbed structure (derived from the deposited filament) having a height H. This height can also be expressed as a width. Here, a layer 322 of printed material 202 is schematically depicted, having a height H and a width W. FIG3 b can be viewed as a stack of layers 322, a plurality of adjacent stacks of which are shown in FIG1 b.

[0142] Figure 4 An embodiment of a lamp or lighting device, designated by reference numeral 2, is schematically depicted, comprising a light source 10 for generating light 11. The lamp may comprise a housing or cover or another element that may comprise or may be a 3D-printed object 1. Here, a hemisphere (in a cross-sectional view) schematically illustrates the housing or cover. The lamp or lighting device may be or may comprise a lighting device 1000 (comprising the light source 10). Thus, in a specific embodiment, the lighting device 1000 comprises a 3D object 1. This 3D object 1 may be configured as one or more of the following: (i) at least a portion of a lighting device housing, (ii) at least a portion of a wall of an illumination chamber, and (iii) an optical element. Thus, in embodiments, the 3D object may be reflective and / or transmissive to the light source light 11. Here, the 3D object may be, for example, a housing or cover. The housing or cover comprises an object part 400. See also above for possible embodiments of the object part 400.

[0143] FIG5 a schematically depicts an embodiment of glitter cut into hexagonal shapes. They are cut from 12 μm and 25 μm thick (polyester) foils that are metallized with an aluminum coating (e.g. in the range of about 10-60 nm). In embodiments, their size can be from about 50 μm up to 3 mm (L1, see also FIG2 e). FIG5 b depicts an embodiment of (conventional) corn flake type particles. FIG5 c depicts an embodiment of dollar shaped particles. FIG5 d depicts an embodiment of irregularly shaped particles. FIG5 e depicts an embodiment of essentially spherical shaped particles. The particles can be, for example, metal particles, or glass particles or polymer particles or mica particles coated with a metal coating such as Al or Ag (or Cu) or coated with a metal oxide coating.

[0144] 6 a shows a filament 320 , which is a core-shell filament that can be used for 3D printing with a simple nozzle, very schematically on the left. The core-shell filament 320 comprises a core 221 comprising a core material 240 and a shell 222 comprising a shell material 250 .

[0145] FIG6 b shows a nozzle 502 on the right side, which is a core-shell nozzle 502, which can be used to extrude a 3D printable material having a core-shell structure. Thus, in such an embodiment, filament can be used as an input material that is not a core-shell type, because the core-shell structure is created using the nozzle 502.

[0146] Figure 6b schematically shows a cross-section of the core-shell filament 320 on the left, as schematically depicted on the left side of Figure 5a. The core material 240 includes a core thermoplastic material 241 and a core additional material 242. The shell material 250 includes a shell thermoplastic material 251 and shell particles 252, and the shell thermoplastic material 251 can be different from or the same as the thermoplastic material 241 of the core 221. The shell material 250 is light-transmissive for one or more wavelengths in the visible wavelength range. In addition, the core material 240 and the shell material 250 differ in one or more optical properties selected from the group of color, reflectivity, reflection type and absorption of light. In a specific embodiment, the core additional material and the shell particles may differ in one or more optical properties selected from the group of color, reflectivity, reflection type and absorption of light. More specifically, in an embodiment, the core particles and the shell particles differ in one or more optical properties selected from the group of color, reflectivity, reflection type and absorption of light.

[0147] Such a (core-shell) filament 320 can be extruded to provide a core-shell layer (e.g., see also FIG6 a). Thus, a filament made of a core-shell layer can also be used. In such an embodiment, the printer head can have a single nozzle (i.e., not a core-shell type).

[0148] Figure 6b on the right side very schematically depicts in more detail an embodiment of a 3D object 1 including a 3D printing material 202. The 3D object 1 includes multiple layers 322 of the 3D printing material 202. The 3D printing material 202 comprises a core-shell 3D printing material 202, which includes a core 221 comprising a core material 240, and a shell 222 comprising a shell material 250. The core material 240 comprises a core thermoplastic material 241 and a core additive material 242. The shell material 250 comprises a shell thermoplastic material 251 and shell particles 252. The shell material 250 is light-transmissive for one or more wavelengths in the visible wavelength range. The core additive material, such as the core additive material 242, and the shell particles 252 differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflection, and absorption of light. In a specific embodiment, the shell particles 252 comprise specularly reflective particles.

[0149] Referring to FIG6c , in an embodiment, particles 410 comprise polymeric flake particles with a metal coating. Reference numeral 411 denotes a support material, such as a polymeric material, such as (biaxially oriented) PET film, and reference numeral 412 denotes a coating material, such as aluminum. Thus, in an embodiment, particles 410 comprising polyethylene terephthalate flake particles with an aluminum coating can be used. As schematically shown, the metal coating can be on only one side, but can also be conformal.

[0150] 6 c , for example, particles 410 include polymer flake particles with a metal coating, particularly particles 410 include polyethylene terephthalate flake particles with an aluminum coating, wherein the flake particles have a particle length L1 and a particle height L2, wherein the aspect ratio L1 / L2 is at least 5, wherein one or more layers 322 of 3D printing material 202 have a layer height H, wherein the layer height H is less than the particle length L2. In alternative embodiments, the layer height H can be greater than the particle length L2.

[0151] Such particles 410 depicted in FIG. 6 c may be used as shell particles 252 , for example.

[0152] To achieve a metallic appearance, the use of metal flakes has been suggested. Commercially available aluminum flakes are irregularly shaped, so-called cornflakes, or round, so-called dollar-shaped flakes. However, these flakes have a rough surface, and when printed, they appear rather dull and lack any specular reflective component. To achieve a more metallic appearance, specularly reflective flake particles with smooth surfaces, such as metallic glitter, can be used. Such glitter is precisely cut from metal flakes, such as aluminum, and has shapes such as hexagonal or rectangular. In contrast to metallic flakes with dollar- and cornflake-shaped particles, which are produced by flattening spherical or irregularly shaped metal particles, respectively, these pure metallic glitters exhibit specular reflection and a shimmering appearance. They differ from glitters that deposit a submicron-thick aluminum layer on a polymer support because they can be processed at high temperatures, making them easily incorporated into polymers such as polycarbonate. Pure metallic glitter can have a thickness of at least 2 microns and a length-width dimension of at least 50 x 50 microns. Silver / aluminum-coated glass flakes can also be used. It has been observed that when these pure aluminum metallic glitters and / or specularly reflective glass flakes are used in a mixture with flakes that exhibit only diffuse reflection, an enhanced metallic appearance is obtained. In this ID, we propose using a mixture of diffusely and specularly reflective particles to obtain a surface with a shimmering appearance. The shimmering appearance is enhanced when the polymers that carry the particles are physically separated. For example, they can be extruded into a core-jacket configuration, wherein the jacket is made of a transparent polymer including pure metallic glitter, and the core is made of a polymer with diffusely reflective metal flakes to obtain a further enhanced metallic appearance. In such a core-shell configuration, the glass flakes or glitter can be combined with another reflective or absorbing layer to create a decorative effect. The thickness of the jacket with reflective particles is preferably 10-500 μm, and the light transmittance through the layer is preferably 60-95%, wherein individual specularly reflective particles or clusters of such particles are dispersed in the jacket.

[0153] We produced cylindrical objects that included a specularly reflective metallic glitter in the sheath and various materials in the core. In one example, specularly reflective metallic particles in the sheath and diffusely reflective metallic particles in the core were applied. In another example, specularly reflective particles in the sheath and a diffusely reflective white polymer in the core. In yet another example, specularly reflective particles in the sheath and a black absorbing polymer in the core. Figure 7a shows specularly reflective metallic particles in the sheath (shell) and diffusely reflective metallic particles in the core. Figure 7b shows specularly reflective particles in the sheath and a diffusely reflective white polymer in the core. Figure 7c shows specularly reflective particles in the sheath and a black absorbing polymer in the core.

[0154] Specular reflective particles in the jacket give the object a shimmering, decorative appearance. Combined with diffuse reflective particles in the core, this gives the printed object a more metallic appearance. When a black core is combined with diffuse reflective particles, using white particles in the shell, or vice versa, creates a decorative and attractive surface.

[0155] The term "plurality" means two or more.

[0156] The terms "substantially" or "substantially" and similar terms herein will be understood by those skilled in the art. The terms "substantially" or "substantially" may also include embodiments with "entirely," "completely," "entirely," etc. Thus, in embodiments, the adjective "substantially" or "substantially" may also be removed. Where applicable, the terms "substantially" or "substantially" may also refer to 90% or higher, such as 95% or higher, particularly 99% or higher, even particularly 99.5% or higher, including 100%.

[0157] The term "comprising" also includes embodiments in which the term "including" means "consisting of."

[0158] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or". For example, the phrase "item 1 and / or item 2" and similar phrases can refer to one or more of item 1 and item 2. The term "comprising" can mean "consisting of" in one embodiment, but in another embodiment can also mean "containing at least the defined species and optionally containing one or more additional species".

[0159] Furthermore, the terms first, second, third, etc. in the description and claims are used to distinguish between similar elements and not necessarily to describe a sequential or chronological order. It should be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those described or illustrated herein.

[0160] An apparatus, device, or system may be described herein as being in operation. It will be apparent to one skilled in the art that the present invention is not limited to methods of operation or apparatus, devices, or systems in operation.

[0161] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0162] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0163] Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, the words "to comprise" and the like are to be construed in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including, but not limited to".

[0164] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0165] The invention can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In a device claim, an apparatus claim, or a system claim enumerating several means, several of these means may be embodied by the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0166] The present invention also provides a control system that can control an apparatus, device, or system that can perform the methods or processes described herein. Furthermore, the present invention provides a computer program product that, when executed on a computer functionally coupled to or included in the apparatus, device, or system, controls one or more controllable elements of such an apparatus, device, or system.

[0167] The present invention also applies to an apparatus, device or system comprising one or more of the characterizing features described in the specification and / or shown in the accompanying drawings. The present invention also relates to a method or process comprising one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

[0168] The various aspects discussed in this patent can be combined to provide additional advantages. In addition, those skilled in the art will understand that the various embodiments can be combined, and more than two embodiments can also be combined. In addition, some of the features can form several of one or more divisional applications.

[0169] It goes without saying that one or more of the first (printable or printed) material and the second (printable or printed) material may contain fillers such as glass and fibers that have an influence on the T of the material. g or T m No (pending) impact.

Claims

1. A method for producing a 3D object (1) by fused deposition modeling, the method comprising a 3D printing stage, the 3D printing stage comprising: Depositing an extrudate (321) comprising a 3D printable material (201) layer by layer to provide the 3D object (1) comprising a 3D printable material (202), wherein the 3D object (1) comprises a plurality of layers (322) of the 3D printable material (202), wherein the 3D printable material (201) comprises a core-shell 3D printable material (201), the core-shell 3D printable material comprising (i) a core (221) comprising a core material (240), and (ii) a shell (222) comprising a shell material (250), wherein the core material (240) comprises a core thermoplastic material (241) and A core additional material (242), wherein the shell material (250) includes a shell thermoplastic material (251) and shell particles (252), wherein the shell material (250) is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) include specular reflective particles, wherein the core additional material (242) includes one or more of diffuse reflective particles, white particles, black particles, colored particles and dye molecules, and wherein the core material (240) and the shell material (250) differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflection and absorption of light.

2. The method of claim 1 , wherein the shell particles (252) comprise one or more of: (i) polymer flake particles having a metal coating or a metal oxide coating, (ii) glass flakes having a metal coating or a metal oxide coating, (iii) metal flakes, (iv) mica particles having a metal coating or a metal oxide coating, (v) holographic glitter particles, and (vi) colored reflective particles, and wherein optionally, the shell thermoplastic material (251) further comprises a dye, wherein the method further comprises creating the extrudate (321) using a core-shell filament of a 3D printable material or using a core-shell nozzle.

3. The method of any one of the preceding claims, wherein the shell particles (252) comprise polyethylene terephthalate flake particles having an aluminum coating.

4. The method of claim 1 or 2, wherein the shell particles (252) have a particle length (L1), a particle height (L2), and a particle width (L3), wherein: The aspect ratio L1 / L2 is at least 5, and L3 / L2 is at least 5, and wherein the method includes printing one or more layers (322) of the 3D printing material (202) having a layer height (H), wherein the layer height (H) is greater than the particle length (L1), and wherein the layers (322) are stacked.

5. A method according to claim 4, wherein the shell particles (252) have one or more dimensions selected from the particle length (L1), the particle height (L2) and the particle width (L3), and the particle length (L1), the particle height (L2) and the particle width (L3) have a length selected from the range equal to and greater than 2 μm and equal to or less than 5 mm.

6. The method of claim 1 or 2, wherein the core additional material (242) comprises one or more of: (i) diffusely reflective particles, and (ii) light absorbing particles.

7. The method according to claim 1 or 2, wherein the core additional material (242) comprises metal particles, wherein the metal particles have corrugations, and / or wherein the metal particles have a diffusely reflective surface.

8. The method according to claim 1 or 2, wherein the 3D printable material (201) and the 3D printing material (202) include one or more of the following: polycarbonate (PC), polyethylene (PE), high-density polyethylene (HDPE), polypropylene (PP), polyoxymethylene (POM), polyethylene naphthalate (PEN), styrene acrylonitrile resin (SAN), polysulfone (PSU), polyphenylene sulfide (PPS) and semi-crystalline polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS), poly(methyl methacrylate) (PMMA), polystyrene (PS), and styrene acrylic copolymer (SMMA).

9. A core-shell filament (320) comprising (i) a core (221) comprising a core material (240), and (ii) a shell (222) comprising a shell material (250), wherein the core material (240) comprises a core thermoplastic material (241) and a core additive material (242), wherein the shell material (250) comprises a shell thermoplastic material (251) and shell particles (252), wherein the shell material (250) is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) comprise specular reflective particles, wherein the core additive material (242) comprises one or more of diffuse reflective particles, white particles, black particles, colored particles, and dye molecules, and wherein the core material (240) and the shell material (250) differ in one or more optical properties selected from the group consisting of color, reflectivity, type of reflectance, and absorption of light.

10. A 3D object (1) comprising a 3D printed material (202), wherein the 3D object (1) comprises a plurality of layers (322) of the 3D printed material (202), wherein the 3D printed material (202) comprises a core-shell 3D printed material (202), the core-shell 3D printed material comprising (i) a core (221) comprising a core material (240), and (ii) a shell (222) comprising a shell material (250), wherein the core material (240) comprises a core thermoplastic material (241) and a core additional material (242), wherein the shell The material (250) includes a shell thermoplastic material (251) and shell particles (252), wherein the shell material (250) is light transmissive for one or more wavelengths in the visible wavelength range, wherein the shell particles (252) include specular reflective particles, wherein the core additional material (242) includes one or more of diffuse reflective particles, white particles, black particles, colored particles and dye molecules, and wherein the core material (240) and the shell material (250) differ in one or more optical properties selected from the group consisting of color, reflectivity, reflection type and absorption of light.

11. The 3D object (1) of claim 10, wherein the shell particles (252) comprise specular reflective particles.

12. The 3D object (1) of any one of claims 10-11, wherein the shell particles (252) comprise polyethylene terephthalate platelet particles having a metal coating or a metal oxide coating, wherein the shell particles (252) have a particle length (L1) and a particle height (L2), wherein: The aspect ratio L1 / L2 is at least 5, and wherein the one or more layers (322) of the 3D printing material (202) have a layer height (H), wherein the layer height (H) is greater than the particle length (L1), and wherein the layers (322) are stacked.

13. The 3D object (1) according to any one of the preceding claims 10-11, wherein the core additional material (242) comprises one or more of the following: (i) diffusely reflective particles, and (ii) light absorbing particles.

14. A lighting device (1000), comprising a light source (10) and a 3D object (1) according to any one of the preceding claims 10-13, wherein the 3D object (1) is configured as one or more of the following: (i) at least a part of a lighting device housing, (ii) at least a part of a wall of a lighting room, and (iii) an optical element.

Images