IMPROVED ADHESION OF FDM PRINTED LAYER TO A METAL PART

Abstract

The invention provides a method for providing a composite object (400) comprising a 3D printed part (1) adhering to a metal part (420), wherein: the method comprises the step of providing the metal part (420) followed by a 3D printing stage comprising layer-wise depositing 3D printable material (201) by means of fused deposition modeling on the metal part (420), to provide the composite object (400); wherein the 3D printed part (1) comprises a layer (322) of 3D printed material (202); the 3D printing stage comprises guiding the 3D printable material (201) through a printer nozzle (502) at a nozzle temperature TN; during a first 3D printing stage of the 3D printing stage, wherein 3D printable material (201) is deposited on the metal part (420), the following applies: (i) the 3D printable material (201) comprises first 3D printable material (2011) comprising a thermoplastic material (401) and metal particles (410); wherein metal (411) of the metal particles (410) has a melting temperature TP, and (ii) TN>TP.

Claims

1. A method for providing a composite object comprising a 3D printed part adhering to a metal part wherein: the method comprises the step of providing the metal part followed by a 3D printing stage comprising layer-wise depositing 3D printable material by means of fused deposition modelling on the metal part, to provide the composite object; wherein the 3D printed part comprises a layer of 3D printed material; the 3D printing stage comprises guiding the 3D printable material through a printer nozzle at a nozzle temperature T.sub.N; during a first 3D printing stage of the 3D printing stage, wherein 3D printable material is deposited on the metal part, the following applies: (i) the 3D printable material comprises first 3D printable material comprising a thermoplastic material and metal particles; wherein metal of the metal particles has a melting temperature T.sub.P, and (ii) T.sub.N>T.sub.P.

2. The method according to claim 1, wherein the thermoplastic material has a change temperature T.sub.C selected from a glass transition temperature T.sub.G and a melting temperature T.sub.M, wherein |T.sub.CT.sub.P|50 C., wherein T.sub.NT.sub.C50 C., and wherein T.sub.NT.sub.P50 C.

3. The method according to claim 1, wherein T.sub.C<T.sub.P.

4. The method according to claim 1, wherein T.sub.C>T.sub.P.

5. The method according to claim 1, wherein the 3D printing stage comprises a second 3D printing stage comprising: depositing the 3D printable material on a previously deposited layer, wherein the 3D printable material comprises second 3D printable material comprising a lower content of metal than the first 3D printable material or comprising no metal particles; wherein the metal of the metal particles comprises one or more of indium and tin.

6. The method according to claim 1, wherein the method comprises: using a 3D printer comprising a core-shell nozzle, wherein the core-shell nozzle comprises a core nozzle and a shell nozzle; wherein the method further comprises guiding during the 3D printing stage (i) the first 3D printable material through the shell nozzle and (ii) the second 3D printable material, comprising a lower content of metal than the first 3D printable material or comprising no metal particles, through the core nozzle.

7. The method according to claim 1, wherein the method comprises: executing a pretreatment stage preceding the 3D printing stage, wherein the pretreatment stage comprises one or more of (i) cleaning the metal part, (ii) roughening of the metal part, (iii) providing one or more indentations in the metal part, and (iv) providing one or more metal part protrusions to the metal part.

8. The method according to claim 1, wherein the first 3D printable material further comprises second metal particles, wherein the metal particles have a first melting temperature T.sub.P1 and wherein the second metal particles have a second melting temperature T.sub.P2, wherein T.sub.N>T.sub.P1 and wherein T.sub.N<T.sub.P2, and wherein the first 3D printable material comprises the metal particles and the second metal particles at a total concentration selected from the range of 10-50 vol. %.

9. The method according to claim 8, wherein the metal particles are spherical, and wherein the second metal particles have at least one aspect ratio of at least 10.

10. A core-shell filament for producing a 3D printed part by means of fused deposition modelling for use in the method according to claim 1, the core-shell filament comprising: (i) a shell comprising the first 3D printable material, and (ii) a core comprising a second 3D printable material comprising a lower content of metal than the first 3D printable material or comprising no metal particles.

11. A composite object comprising a 3D printed part (1) adhering to a metal part, wherein the 3D printed part (1) comprises a layer of 3D printed material, wherein at least part of the 3D printed material comprises a first 3D printed material comprising a thermoplastic material and metal particles comprising metal, wherein at least part of the metal is attached to the metal part, wherein the thermoplastic material has a change temperature T.sub.C selected from a glass transition temperature T.sub.G and a melting temperature T.sub.M, wherein the metal has a melting temperature T.sub.P, wherein |T.sub.CT.sub.P|50 C.; wherein the metal comprises one or more of indium and tin; and wherein the first 3D printed material comprises the metal particles at a concentration selected from the range of 10-50 vol. %.

12. The composite object according to claim 11, wherein the metal part comprises one or more of an electrical component, an electrically conductive track, electromagnetic shield, a heatsink and a heat spreader.

13. The composite object according to claim 11, comprising (i) a first layer configured in contact with the metal part, wherein at least a part of the first layer comprises the first 3D printed material and (ii) a second layer comprising second 3D printed material comprising a lower content of metal than the first 3D printed material or comprising no metal, wherein the first 3D printed material further comprises second metal particles, wherein the metal particles have a first melting temperature T.sub.P1 and wherein the second metal particles have a second melting temperature T.sub.P2, wherein T.sub.P2T.sub.P1>100 C.

14. The composite object according to claim 11, wherein at least part of the 3D printed part comprises a core-shell layer comprising a core and a shell, wherein the shell at least partly encloses the core, wherein the shell comprises the first 3D printed material, and wherein the core comprises the second 3D printed material as defined in claim 13.

15. A lighting device comprising the composite object according to claim 11, wherein the composite object is configured as one or more of (i) at least part of a lighting device housing, (ii) at least part of a wall of a lighting chamber, and (iii) an optical element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0125] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0126] FIGS. 1a-1c schematically depict some general aspects of the 3D printer and of an embodiment of 3D printed material;

[0127] FIGS. 2a-2c schematically depict some further aspects of the invention;

[0128] FIGS. 3a-3e schematically depict some aspects of metal particles;

[0129] FIGS. 4a-4d schematically depict some further aspects of the invention;

[0130] FIGS. 5a-5c schematically depict some further aspects of the invention;

[0131] FIG. 6 schematically depicts some aspects of the pretreatment of the metal part; and

[0132] FIG. 7 schematically depicts an application. The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0133] FIG. 1a schematically depicts some aspects of the 3D printer. Reference 500 indicates a 3D printer. Reference 530 indicates the functional unit configured to 3D print, especially FDM 3D printing; this reference may also indicate the 3D printing stage unit. Here, only the printer head for providing 3D printed material, such as an FDM 3D printer head is schematically depicted. Reference 501 indicates the printer head. The 3D printer of the present invention may especially include a plurality of printer heads (see below). Reference 502 indicates a printer nozzle. The 3D printer of the present invention may especially include a plurality of printer nozzles, though other embodiments are also possible. Reference 320 indicates a filament of printable 3D printable material (such as indicated above). Instead of a filament also pellets may be used as 3D printable material. Both can be extruded via the printer nozzle.

[0134] For the sake of clarity, not all features of the 3D printer have been depicted, only those that are of especial relevance for the present invention (see further also below). Reference 321 indicates extrudate (of 3D printable material 201).

[0135] The 3D printer 500 is configured to generate a 3D printed part 1 by layer-wise depositing on a receiver item 550, which may in embodiments at least temporarily be cooled, a plurality of layers 322 wherein each layer 322 comprises 3D printable material 201, such as having a melting point T.sub.m. The 3D printable material 201 may be deposited on a substrate 1550 (during the printing stage). By deposition, the 3D printable material 201 has become 3D printed material 202. 3D printable material 201 escaping from the nozzle 502 is also indicated as extrudate 321. Reference 401 indicates thermoplastic material.

[0136] The 3D printer 500 may be configured to heat the filament 320 material upstream of the printer nozzle 502. This may e.g. be done with a device comprising one or more of an extrusion and/or heating function. Such device is indicated with reference 573, and is arranged upstream from the printer nozzle 502 (i.e. in time before the filament material leaves the printer nozzle 502). The printer head 501 may (thus) include a liquefier or heater. Reference 201 indicates printable material. When deposited, this material is indicated as 3D printed material, which is indicated with reference 202.

[0137] Reference 572 indicates a spool or roller with material, especially in the form of a wire, which may be indicated as filament 320. The 3D printer 500 transforms this in an extrudate 321 downstream of the printer nozzle which becomes a layer 322 on the receiver item or on already deposited printed material. In general, 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. Hence, the printer nozzle is sometimes (also) indicated as extruder nozzle. Arranging layer 322 by layer 322, a 3D printed part 1 may be formed. Reference 575 indicates the filament providing device, which here amongst others include the spool or roller and the driver wheels, indicated with reference 576.

[0138] Reference Ax indicates a longitudinal axis or filament axis.

[0139] Reference 300 schematically depicts a control system. The control system may be configured to control the 3D printer 500. The control system 300 may be comprised or functionally coupled to the 3D printer 500. The control system 300 may further comprise or be functionally coupled to a temperature control system configured to control the temperature of the receiver item 550 and/or of the printer head 501. Such temperature control system may include a heater which is able to heat the receiver item 550 to at least a temperature of 50 C., but especially up to a range of about 350 C., such as at least 200 C.

[0140] Alternatively or additionally, in embodiments the receiver plate may also be moveable in one or two directions in the x-y plane (horizontal plane). Further, alternatively or additionally, in embodiments the receiver plate may also be rotatable about z axis (vertical). Hence, the control system may move the receiver plate in one or more of the x-direction, y-direction, and z-direction.

[0141] Alternatively, the printer can have a head can also rotate during printing. Such a printer has an advantage that the printed material cannot rotate during printing.

[0142] Layers are indicated with reference 322, and have a layer height H and a layer width W.

[0143] Note that the 3D printable material is not necessarily provided as filament 320 to the printer head. Further, the filament 320 may also be produced in the 3D printer 500 from pieces of 3D printable material. Hence, the nozzle 502 may effectively produce from particulate 3D printable material 201 a filament 320, which upon deposition is indicated as layer 322 (comprising 3D printed material 202). Note that during printing the shape of the extrudate may further be changes, e.g. due to the nozzle smearing out the 3D printable material 201/3D printed material 202. FIG. 1b schematically depicts that also particulate 3D printable material 201 may be used as feed to the printer nozzle 502.

[0144] Reference D indicates the diameter of the nozzle (through which the 3D printable material 201 is forced). However, the nozzle is not necessarily circular.

[0145] FIG. 1b schematically depicts in 3D in more detail the printing of the 3D printed part 1 under construction. Here, in this schematic drawing the ends of the layers in a single plane are not interconnected, though in reality this may in embodiments be the case. Reference H indicates the height of a layer. Layers are indicated with reference 322. Here, the layers have an essentially circular cross-section. Often, however, they may be flattened, such as having an outer shape resembling a flat oval tube or flat oval duct (i.e. a circular shaped bar having a diameter that is compressed to have a smaller height than width, wherein the sides (defining the width) are (still) rounded).

[0146] Hence, FIG. 1a schematically depict some aspects of a fused deposition modeling 3D printer 500, comprising (a) a first printer head 501 comprising a printer nozzle 502, (b) a filament providing device 575 configured to provide a filament 320 comprising 3D printable material 201 to the first printer head 501, and optionally (c) a receiver item 550, which can be used to provide a layer of 3D printed material 202.

[0147] FIG. 1b schematically depict some aspects of a fused deposition modeling 3D printer 500 (or part thereof), comprising a first printer head 501 comprising a printer nozzle 502, and optionally a receiver item (not depicted), which can be used to which can be used to provide a layer of 3D printed material 202. Such fused deposition modeling 3D printer 500 may further comprise a 3D printable material providing device, configured to provide the 3D printable material 201 to the first printer head.

[0148] In FIGS. 1a-1b, the first or second printable material or the first or second printed material are indicated with the general indications printable material 201 and printed material 202, respectively. Downstream of the nozzle 502, the filament 320 with 3D printable material becomes, when deposited, layer 322 with 3D printed material 202. In FIG. 1b, by way of example the extrudate is essentially directly the layer 322 of 3D printed material 202, due to the short distance between the nozzle 502 and the 3D printed material (or receiver item (not depicted).

[0149] FIG. 1c schematically depicts a stack of 3D printed layers 322, each having a layer height H and a layer width W. Note that in embodiments the layer width and/or layer height may differ for two or more layers 322. The layer width and/or layer height may also vary within a layer. Reference 252 in FIG. 1c indicates the item surface of the 3D printed part (schematically depicted in FIG. 1c).

[0150] Referring to FIGS. 1a-1c, the filament of 3D printable material that is deposited leads to a layer having a height H (and width W). Depositing layer 322 after layer 322, the 3D printed part 1 is generated. FIG. 1c very schematically depicts a single-walled 3D printed part 1.

[0151] FIG. 2a schematically depicts some aspects of the method for providing an arrangement 400 comprising a 3D printed part 1 adhering to a metal part 420. Especially, the method may comprise providing the metal part 420 followed by a 3D printing stage comprising layer-wise depositing an extrudate 321 comprising 3D printable material 201 by means of fused deposition modeling on the metal part 420. In this way, the composite object 400 of the metal part 420 and the 3D printed part 1 may be provided. Especially, the 3D printed part 1 comprises a layer 322 of 3D printed material 202. The 3D printing stage especially may comprise guiding the 3D printable material 201 through a printer nozzle 502 at a nozzle temperature T.sub.N wherein 3D printable material 201 is deposited on the metal part 420. In embodiments, during a first 3D printing stage of the 3D printing stage, the 3D printable material 201 may comprise first 3D printable material 2011 comprising a thermoplastic material 401 and metal particles 410 at least partly embedded therein. The metal particles 410 that form such connection, may be referred to as connecting particles 414. The connecting particles 414 may especially be deformed during deposition. The connecting particles 414 may in embodiments comprise metal particles that were molten, deformed and solidified. The thermoplastic material 401 has a change temperature T.sub.C selected from a glass transition temperature T.sub.G and a melting temperature T.sub.M. The metal 411 of the metal particles 410 has a melting temperature T.sub.P. In specific embodiments T.sub.N>T.sub.P, especially wherein T.sub.NT.sub.P50 C. Especially, in embodiments T.sub.N>T.sub.C, such as in embodiments T.sub.NT.sub.C50 C. In further embodiments |T.sub.CT.sub.P|50 C. This may facilitate handling of the 3D printable material 201. In embodiments, the metal part may (temporarily) be heated to a temperature higher than T.sub.P.

[0152] In specific embodiments of the invention T.sub.C<T.sub.P. However, in alternative embodiments T.sub.C>T.sub.P. Especially T.sub.C may be selected from the range of 150-300 C. In specific embodiments, the method may further comprise controlling during the first 3D printing stage an extrusion rate VE and the nozzle temperature T.sub.N to melt at least 50 wt % of the metal 411 in the first 3D printable material 2011. In further embodiments, the metal part may be heated to a temperature >T.sub.P. In specific embodiments, the metal 411 of the metal particles 410 may comprise one or more of indium and tin or alloys thereof. As indicated in FIG. 2a, the layer has a layer height H. The metal particles 410 have particle dimensions depicted in FIG. 3 and explained below. In specific embodiments of the method, H<L3.

[0153] FIG. 2b schematically depicts an embodiment of the composite object 400 of the invention. Especially, the composite object 400 comprises a metal part 420 and a 3D printed part 1. The 3D printed part 1 comprises a layer 322 of 3D printed material 202, wherein at least part of the 3D printed material 202 comprises a first 3D printed material 2012 comprising a thermoplastic material 401 and metal particles 410 at least partly embedded therein comprising metal 411. In the depicted embodiment, at least part of the metal 411 may be attached to the metal part 420.

[0154] FIG. 2c schematically depicts an embodiment of the composite object that may be obtained by the method of the invention wherein the 3D printing stage comprises a second 3D printing stage. Especially, the second 3D printing stage may comprise depositing the 3D printable material 201 on a previously deposited layer 322 i.e. a first layer 1322. Especially, the 3D printable material 201 comprises second 3D printable material 2021 which may comprise a lower content of metal 411 than the first 3D printable material 2011 or may comprise no metal particles 410 (as in the depicted embodiment). The depicted embodiment comprises a first layer 1322 configured in contact with the metal part 420. Especially at least a part of the first layer 1322 may comprise the first 3D printed material 2012 (comprising the metal 411 attached to the metal part 420). In embodiments, the composite object may comprise a second layer 2322 comprising second 3D printed material 2022 comprising a lower content of metal 411 than the first 3D printed material 2012 or comprising no metal 411.

[0155] FIGS. 3a-3b schematically depict embodiments of particles 410. FIG. 3a depicts a particle 410 that has a rectangular prism shape, wherein the rectangular prism 415 has a length L1, a width L2 and a height L3, wherein L1L2L3. FIG. 3b schematically depicts a particle that has a less regular shape such as pieces of broken glass, with a virtual smallest rectangular prism 415 enclosing the particle. The rectangular prism 415 has a length L1, a width L2 and a height L3 wherein L1L2L3. Further, the rectangular prism 415 has a first aspect ratio is AR1=L1/L3 and a second aspect ratio is AR2=L2/L3.

[0156] Further, note that the particles are not essentially oval or rectangular prismoids. The particles may have any shape, especially wherein length L1 is in the range from 30-3000. Of course, the particles may comprise a combination of differently shaped particles. In specific embodiments, the metal particles 410 may be substantially spherical as schematically depicted in FIG. 3c. Alternatively (or additionally), the metal particles 410 may comprise a plurality of extensions 412 as schematically depicted in FIG. 3d. However, the metal particles may in embodiments have any shape.

[0157] FIG. 3e schematically depict some embodiments of the metal second metal particles 409. As schematically shown in embodiment I the second metal particles 409 may comprise a plurality of extensions 412. Alternatively, the second metal particles 409 may be substantially spherical (not shown as separate embodiment in this drawing). Alternatively, as schematically depicted in embodiments II-IV, the second metal particles may have a large aspect ratio, such as at least 10. In embodiment II, a rod-like shaped second metal particle 409 is schematically depicted, and in embodiment III, a thread-like shaped second metal particle 409 is schematically depicted. Embodiment IV schematically depicts an associated of a first metal particle 410 and a second metal particle 409. Especially when the latter has a much higher aspect ratio, and extends relative to the former, good connections may be provided.

[0158] Also, the particulate material that is embedded in the 3D printable material or is embedded in the 3D printed material may include a broad distribution of particles sizes.

[0159] In specific embodiments, the aspect ratios AR1 and AR2 may be individually selected from the range of 1-10000. Especially at least one of AR1 and AR2 is at least 5.

[0160] In alternative embodiments, the aspect ratios AR1 and AR2 may be individually selected from the range of 1-2.

[0161] Referring to FIG. 4a, the method may comprise using a 3D printer 500 comprising a core-shell nozzle 5024, wherein the core-shell nozzle 5024 comprises a core nozzle 5025 and a shell nozzle 5026. In embodiments, the shell nozzle may at least partly enclose the core nozzle 5025. The method may further comprise guiding during the 3D printing stage the first 3D printable material 2011 through the shell nozzle 5026 or the core nozzle 5025. Additionally or alternatively, the method may comprise guiding the second 3D printable material 2021, comprising a lower content of metal 411 than the first 3D printable material 2011 or comprising no metal particles 410, through the other one of the shell nozzle 5026 and the core nozzle 5025. In the embodiment depicted in FIG. 4a, the first 3D printable material 2021 is guided through the shell nozzle 5026 and the second 3D printable material 2021 is guided through the core nozzle 5025. In the depicted embodiment, the core-shell layer 5322 has a shell thickness H2, wherein H2<L3. In specific embodiments, the first 3D printable material 2011 may comprise the metal particles 410 at a concentration selected from the range of 10-50 vol. %.

[0162] FIG. 4b schematically depicts the composite object 400 wherein at least part of the 3D printed part 1 comprises a core-shell layer 5322 comprising a core 330 and a shell 340. In embodiments, the shell 340 at least partly encloses the core 330. Especially, the core 330 comprises core material 331 and the shell 340 comprises shell material 341. In the depicted embodiment, the shell 340 comprises the first 3D printed material 2012, and the core 330 comprises the second 3D printed material 2022. In the depicted embodiment, at least part of the metal 411 may be attached to the metal part 420.

[0163] FIG. 4c depicts a specific embodiment of the composite object 400 which may be obtained by the method comprising guiding during the second 3D printing stage only second 3D printable 2021 and no first 3D printable material 2011 through the core-shell nozzle 5024.

[0164] As schematically depicted in FIGS. 2c and 4c, in embodiments the first metal particles and optional second metal particles may in embodiments essentially only be available in a single layer 322 (here the first layer 1322).

[0165] FIG. 4d depicts a specific embodiment of the composite object 400 which may be obtained by the method comprising guiding during the first 3D printing stage only first 3D printable 2011 and no second 3D printable material 2021 through the core-shell nozzle 5024 and guiding during the second 3D printing stage only second 3D printable 2021 and no first 3D printable material 2011 through the core-shell nozzle 5024. This method may especially facilitate alternating between the first 3D printing stage and second 3D printing stage. In the depicted embodiment, a first layer 1322 comprises both metal particles 410 and second metal particles 409. Another first layer 1322 of the depicted embodiment comprises only metal particles 410 and no second metal particles 409. In alternative embodiments, all first layers 1322 may comprise metal particles 410 and second metal particles 409. In yet alternative embodiments, all first layers 1322 may comprise only metal particles 410 and no second metal particles 409. Referring to FIG. 4d, the first 3D printed material may comprise the metal particles and the second metal particles at a total concentration selected from the range of 10-50 vol. %.

[0166] FIG. 5a schematically depicts a filament 320 for producing a 3D printed part 1 by means of fused deposition modelling. The filament 320 may especially comprise first 3D printable material 2011 comprising a thermoplastic material 401 and metal particles 410 at least partly embedded therein. The filament has a thickness Hr. The filament may have a thickness H.sub.F. In embodiments 0.2L3/H.sub.F1, such as 0.33L3/H.sub.F1, e.g. 0.5L3/H.sub.F1, like 0.6L3/H.sub.F0.9. In other embodiments 0.2L3/H.sub.F0.7, like 0.2L3/H.sub.F0.6, such as 0.2L3/H.sub.F0.5. As indicated above, the thermoplastic material 401 has a change temperature T.sub.C selected from a glass transition temperature T.sub.G and a melting temperature T.sub.M. The metal 411 of the metal particles 410 has a melting temperature T.sub.P. In specific embodiments, |T.sub.CT.sub.P|50 C. Especially, the metal 411 of the metal particles 410 may comprise one or more of indium and tin.

[0167] FIG. 5b schematically depicts a further embodiment of a filament. Especially, the filament 320 may comprise a core-shell filament 1320 comprising a core 330 comprising second 3D printable material 2021 comprising a lower content of metal 411 than the first 3D printable material 2011 or comprising no metal particles 410, and comprising a shell 340 comprising the first 3D printable material 2011. In specific embodiments, the core-shell filament has a shell thickness H.sub.2F, wherein 0.5L3/H.sub.2F1.

[0168] FIG. 5c schematically depicts embodiments of a core-shell nozzle 5024, wherein the core-shell nozzle 5024 comprises a core nozzle 5025 and a shell nozzle 5026. Especially, the shell nozzle may at least partly enclose the core nozzle 5025.

[0169] FIG. 6 schematically depicts some further embodiments of the method of the invention. In specific embodiments, the method may comprise executing a pretreatment stage preceding the 3D printing stage. Especially, the pretreatment stage may in embodiments comprise one or more of (i) cleaning the metal part 420, (ii) roughening of the metal part 420, (iii) providing one or more indentations 421 in the metal part 420, and (iv) providing one or more metal part protrusions 422 to the metal part 420.

[0170] FIG. 7 schematically depicts an embodiment of a lamp or luminaire, indicated with reference 2, which comprises a light source 10 for generating light 11. The lamp may comprise a housing or shade or another element, which may comprise or be the composite object 400. Here, the half sphere (in cross-sectional view) schematically indicates a housing or shade. The lamp or luminaire may be or may comprise a lighting device 1000 (which comprises the light source 10). Hence, in specific embodiments the lighting device 1000 comprises the composite object 400 comprising 3D printed part 1 and metal part 420. The composite object 400 may be configured as one or more of (i) at least part of a lighting device housing, (ii) at least part of a wall of a lighting chamber, and (iii) an optical element. Hence, the 3D printed part may in embodiments be reflective for light source light 11 and/or transmissive for light source light 11. Here, the 3D printed part may e.g. be a housing or shade. The housing or shade comprises the composite object 400.

[0171] The term plurality refers to two or more.

[0172] The terms substantially or essentially herein, and similar terms, will be understood by the person skilled in the art. The terms substantially or essentially may also include embodiments with entirely, completely, all, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term substantially or the term essentially may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0173] The term comprise includes also embodiments wherein the term comprises means consists of.

[0174] The term and/or especially relates to one or more of the items mentioned before and after and/or. For instance, a phrase item 1 and/or item 2 and similar phrases may relate to one or more of item 1 and item 2. The term comprising may in an embodiment refer to consisting of but may in another embodiment also refer to containing at least the defined species and optionally one or more other species.

[0175] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0176] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

[0177] 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.

[0178] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0179] 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 description and the claims, the words comprise, comprising, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to.

[0180] The article a or an preceding an element does not exclude the presence of a plurality of such elements.

[0181] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and 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.

[0182] The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

[0183] The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

[0184] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

[0185] It goes without saying that one or more of the first (printable or printed) material and second (printable or printed) material may contain fillers such as glass and fibers which do not have (to have) influence on the on T.sub.g or T.sub.m of the material(s).