权利要求：
CLAIMS:
1. A 3D item (1) comprising 3D printed material (202), wherein the 3D item (1) comprises a plurality of layers (322) of 3D printed material (202), wherein: the 3D printed material (202) comprises (i) first 3D printed material (1202) comprising a fluoropolymer (1403) in a first outer region (1270) of the first 3D printed material (1202) enclosing a first inner region of the first 3D printed material (1202), and (ii) second 3D printed material (2202) free from a fluoropolymer (1403) in a second outer region (2270) of the second 3D printed material (2202) enclosing a second inner region of the second 3D printed material (2202);
(a) in one or more first sections (280) of two adjacent layers (322) at least one of the layers (322) comprises first 3D printed material (1202) comprising the fluoropolymer in the first outer region (1270), and (b) in one or more second sections (290) of two adjacent layers (322) the adjacent layers (322) both comprise second 3D printed material (2202) free from the fluoropolymer (1403) in the second outer regions (2270).
2. The 3D item (1) according to claim 1, comprising a first area (21) having a first area size Al selected from the range of 1-1600 mm2comprising nl first sections (280), wherein nl>4, wherein each first sections (280) has a section length (Lsl); wherein the first area (21) comprises a cumulative section length LS1> 20 mm; wherein each first section (280) is configured adjacent to a second section (290).
3. The 3D item (1) according to any one of the preceding claims, wherein the 3D printed material (202) is core-shell 3D printed material (202), and wherein one or more of the following applies:
(i) the core-shell 3D printed material (202) comprises a core (260) and a shell (270) surrounding at least part of the core (260), wherein the shell (270) comprises the fluoropolymer (1403); and (ii) the second outer region (2270) of the non-core-shell 3D printed material (202) is free from the fluoropolymer (1403); and
(a) the core-shell 3D printed material (202) comprises a core (260) and a shell (270) surrounding at least part of the core (260), wherein the core (260) comprises the
fluoropolymer (1403), wherein the shell (270) is free from the fluoropolymer (1403); and (b) the second outer region (2270) of the non-core-shell 3D printed material (202) comprises the fluoropolymer (1403).
4. The 3D item (1) according to any one of the preceding claims, wherein: the fluoropolymer (1403) comprises one or more of polyvinylfluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy polymer (PF A, MFA), fluorinated ethyl ene-propylene (FEP), polyethylenetetrafluoroethylene (ETFE), and a copolymer made from 2,2-bistrifluoromethyl-4,5-difluoro-l,3-dioxole (PPD) and tetrafluoroethylene (TFE); and the second 3D printed material (2202) comprise one or more of 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 polytethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), poly(m ethyl methacrylate) (PMMA), polystyrene (PS), and styrene acrylic copolymers (SMMA). one or more of the following applies: (a) in the one or more first sections (280) the adjacent layers (322) are movable relative to each other, and (b) in the one or more first sections (280) the adjacent layers (322) have an opening (295) between the adjacent layers (322); each first section (280) is configured between two second sections (290); and the layers (322) of the one or more first sections (280) have a layer height (HL1), wherein the one or more first sections (280) have a section length (Lsl), wherein 2< Lsl/HLl<40, and wherein Lsl <20 mm.
5. A lighting device (1000) comprising the 3D item (1) according to any one of claims 1 to 4, wherein the 3D item (1) 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.
6. A method for producing, by means of fused deposition modelling using a coreshell printer nozzle (502), the 3D item (1) according to any one of claims 1 to 4, wherein:
the method comprises layer-wise depositing 3D printable material (201) to provide the 3D item (1) comprising a plurality of layers (322) of 3D printed material (202); the 3D printable material (201) comprises (i) first 3D printable material (1201) comprising a fluoropolymer (1403) in a first outer region (1270) enclosing a first inner region, and (ii) second 3D printable material (2201) free from a fluoropolymer (1403) in a second outer region (2270) enclosing a second inner region;
(a) in one or more first sections (280) of two adjacent layers (322) at least one of the layers (322) comprises first 3D printed material (1202) comprising the fluoropolymer (1403) in the first outer region (1270), and
(b) in one or more second sections (290) of two adjacent layers (322) the adjacent layers (322) both comprise second 3D printed material (2202) free from the fluoropolymer (1403) in the second outer regions (2270), and wherein the method comprises controlling deposition of the relative amounts of first 3D printable material (1201) and the second 3D printable material (2201) to provide the one or more first sections (280) and one or more second sections (290).
7. The method according to claim 6, wherein the fluoropolymer (1403) comprises one or more of polyvinylfluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy polymer (PF A, MFA), fluorinated ethyl ene-propylene (FEP), polyethylenetetrafluoroethylene (ETFE), and a copolymer made from 2,2-bistrifluoromethyl-4,5-difluoro-l,3-dioxole (PPD) and tetrafluoroethylene (TFE).
8. The method according to any one of claims 6 and 7, wherein the second 3D printable material (2201) and the second 3D printed material (2202) comprise one or more of 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 polytethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), poly(m ethyl methacrylate) (PMMA), polystyrene (PS), and styrene acrylic copolymers (SMMA); and wherein the second 3D printable material (2201) and the second 3D printed material (2202) comprise a thermoplastic polymer.
9. The method according to any one of claims 6 to 8, wherein in at least one of the one or more first sections (280) of two adjacent layers (322) both layers (322) comprise first 3D printed material (1202) comprising the fluoropolymer (1403) in the first outer regions (1270).
10. The method according to any one of claims 6 to 9, wherein each first section (280) is configured between two second sections (290).
11. The method according to any one of claims 6 to 10, wherein the layers (322) of the one or more first sections (280) have a layer height (HL1), wherein the one or more first sections (280) have a section length (Lsl), wherein 2< Lsl/HLl<40, and wherein Lsl<20 mm; wherein the one or more first sections (280) have a interlayer space height (Hsl), wherein Hsl/Lsl<10.
12. The method according to any one of claims 6 to 11, comprising depositing 3D printable material (201) to provide (a) core-shell 3D printed material (202) and (b) non-coreshell 3D printed material (202); wherein one or more of the following applies:
(i) the core-shell 3D printed material (202) comprises a core (260) and a shell (270) surrounding at least part of the core (260), wherein the shell (270) comprises the fluoropolymer (1403); and (ii) the second outer region (2270) of the non-core-shell 3D printed material (202) is free from the fluoropolymer (1403); and
(a) the core-shell 3D printed material (202) comprises a core (260) and a shell (270) surrounding at least part of the core (260), wherein the core (260) comprises the fluoropolymer (1403), wherein the shell (270) is free from the fluoropolymer (1403); and (b) the second outer region (2270) of the non-core-shell 3D printed material (202) comprises the fluoropolymer (1403).
13. A filament (320) comprising 3D printable material (202), wherein the filament (320) comprises (i) a fluoropolymer (1403) in a first outer region (1270) enclosing a first inner region, and (ii) a second outer region (2270) enclosing a second inner region, wherein the second outer region (2270) is free from a fluoropolymer (1403).