Polymer-based build material for selective sintering

Patent metadata

Field	Value
Publication number	US-2022010144-A1
Application number	US-201917291891-A
Country	US
Kind code	A1
Filing date	Nov 7, 2019
Priority date	Nov 12, 2018
Publication date	Jan 13, 2022
Grant date	—

Abstract

Plastic powder for use as a building material for manufacturing a three-dimensional object by layer-by-layer melting and solidification by hardening of the building material at the positions corresponding to the cross-section of the three-dimensional object in the respective layer by exposure to radiation, preferably by exposure to NIR radiation, wherein the plastic powder comprises a dry blend of polymer-based particles and particles of a NIR absorber, wherein the NIR absorber comprises carbon black or is carbon black and wherein the weight percentage of carbon black in the total weight of polymer and carbon black particles is in the range of at least 0.02% and at most 0.45%, and/or wherein the carbon black has a mean primary particle diameter in the range of from 15 nm to 70 nm, preferably of at least 26 nm and/or at most 58 nm.

First claim

1 . A plastic powder for use as a building material for additively manufacturing a three-dimensional object by selectively solidifying the building material at the positions corresponding to the cross-section of the three-dimensional object in the respective layer by exposure to NIR radiation,
wherein the plastic powder comprises a dry mixture of polymer-based particles and particles of a NIR absorber, wherein the NIR absorber comprises carbon black, and wherein the weight percentage of the NIR absorber in the total weight of the plastic powder is in the range of 0.02% and 0.45%.

2 . The plastic powder according to claim 1 , wherein the weight percentage of the NIR absorber in the total weight of the plastic powder is at least 0.07% and/or at most 0.15%.

3 . The plastic powder according to claim 1 ,
wherein the plastic powder comprises a dry mixture of polymer-based particles and particles of a NIR-absorber and the NIR-absorber comprises carbon black, wherein the carbon black has an average primary particle diameter in the range of from 15 nm to 70 nm.

4 . The plastic powder according to claim 1 ,
wherein in the CIE L*a*b* colour model the lightness value (L* value) of the plastic powder, measured spectrophotometrically, is at most 75.00.

5 . The plastic powder according to claim 1 ,
wherein the plastic powder comprises reflection particles having a surface which at least partially reflects the NIR radiation.

6 . The plastic powder according to claim 1 ,
wherein the carbon black has at least one of the following properties: (i) it is amorphous industrial carbon black (definition according to EC number 215-609-9, CAS number 1333-86-4); (ii) the C content is more than 96% in quantitative elemental analysis.

7 . The plastic powder according to claim 1 ,
wherein in the powder analysis of the plastic powder by means of a rheometer at aeration 1.0 mm/s, the power consumption is at most 200 mJ.

8 . The plastic powder according to claim 1 ,
wherein the polymer-based particles comprise as polymer material at least one polymer selected from at least one polyaryletherketone (PAEK), polyarylether sulfone (PAES), polyamide, polyester, polyether, polylactide, polyolefin, polystyrene, polyphenylene sulfide, polyvinylidene fluoride, polyphenylene oxide, polyimide, polyetherimide, polycarbonate, and/or at least one copolymer which includes at least one of the preceding polymers or their monomer units, and/or at least one polymer blend comprising at least one of said polymers or copolymers.

9 . A method of preparation of a plastic powder according to claim 1 , wherein the preparation comprises at least the following steps:
(i) providing the polymer-based particles and the particles of the NIR absorber; and (ii) dry mixing at least the polymer-based particles and the particles of the NIR absorber, wherein the NIR absorber comprises carbon black, and wherein the weight percentage of the NIR absorber in the total weight of the plastic powder is in the range of 0.02% and 0.45%.

10 . The method of preparation of a plastic powder according to claim 9 ,
wherein the mixing of the polymer-based particles and the particles of the NIR absorber is carried out in one process step.

11 . The method of preparation of a plastic powder according to claim 9 ,
wherein the polymer-based particles are provided together with the reflective particles, which are dry-mixed with the particles of the NIR absorber.

12 . The method of preparation of a plastic powder according to claim 9 , wherein the plastic powder is provided without additional flow aids.

13 . A three-dimensional object which has been manufactured by selectively solidifying a pulverulent building material at the positions corresponding to the cross-section of the three-dimensional object in the respective layer by exposure to radiation,
wherein a plastic powder according to claim 1 has been used as the building material.

14 . A method for manufacturing a three-dimensional object by selectively solidifying a pulverulent building material at the positions corresponding to the cross-section of the three-dimensional object in the respective layer by exposure to radiation,
wherein a plastic powder according to claim 1 is used as the building material, and wherein the building material is selectively solidified by exposure to electromagnetic radiation emitted by a radiation source.

15 . A system for manufacturing three-dimensional objects by selectively solidifying a pulverulent building material at the positions corresponding to the cross-section of the three-dimensional object in the respective layer by exposure to radiation, wherein the system comprises at least one radiation source adapted to emit electromagnetic radiation specifically in a wavelength or wavelength range located in the NIR, a process chamber designed as an open container with a container wall, a support located in the process chamber, wherein the process chamber and the support are movable relative to one another in the vertical direction, a storage container and a recoater movable in the horizontal direction, wherein the storage container is at least partially filled with a plastic powder according to claim 1 as building material.

16 . The method according to claim 14 ,
wherein the electromagnetic radiation is specifically emitted in the NIR range within a window of at most 50 nm, and/or wherein the radiation source emits electromagnetic radiation in the range from 500 nm to 1500 nm.

17 . The method according to claim 14 ,
wherein the radiation source comprises at least one laser diode.

18 . The method according to claim 14 , wherein the radiation source emits electromagnetic radiation at a wavelength selected from the group consisting of 980±7 nm, 940±7 nm, 810±7 nm and 640±7 nm.

19 . The system according to claim 15 , wherein the electromagnetic radiation is specifically emitted in the NIR range within a window of at most 50 nm and/or wherein the radiation source emits electromagnetic radiation in the range from 500 nm to 1500 nm.

20 . The system according to claim 15 , wherein the radiation source comprises at least one laser diode.

Assignees

• Eos Gmbh Electro Optical Systems

Inventors

• Hotter Andreas
• Paternoster Stefan
• Pfisterer Heiko
• Gerg Malin
• Mattes Thomas
• Christ Marius

Classifications

• C09D177/02

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C09D177/10 takes precedence) · CPC title

• C09D5/035 Primary

  Coloring agents, e.g. pigments (C09D5/032 takes precedence) · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/153

  using layers of powder being selectively joined, e.g. by selective laser sintering or melting · CPC title

• B29K2077/00

  Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material · CPC title