CPC C08L 59/02 (2013.01) [B28B 1/001 (2013.01); B28B 11/243 (2013.01); B33Y 70/10 (2020.01); C04B 35/62227 (2013.01); C04B 35/634 (2013.01); C04B 35/638 (2013.01); B33Y 10/00 (2014.12); C04B 2235/6021 (2013.01); C04B 2235/6026 (2013.01)] | 9 Claims |
1. A process for the production of a three-dimensional green body by a fused filament fabrication process, comprising: heating a mixture (M) to a temperature (TM), and
depositing the mixture (M) into a build chamber using a layer-based additive technique to form the three-dimensional green body, wherein the temperature of the build chamber is in the range of from 50° to 80° C.,
wherein the mixture (M) comprises:
(a) from 40 to 70% by volume of an inorganic powder (IP) based on the total volume of the mixture (M),
(b) from 30 to 60% by volume based on the total volume of the mixlure (M) of a binder (B) consisting of
(b1) from 70 to 96% by weight of at least one polyoxymethylene (POM) based on the total weight of the binder (B),
(b2) from 2 to 15% by weight of at least one polyolefin (PO) based on the total weight of the binder (B),
(b3) from 2 to 26% by weight of at least one further polymer (FP) based on the total weight of the binder (B), wherein the at least one further polymer (FP) is polytetrahydrofuran,
said method further comprising, after the depositing, removing at least 95% by weight of component (b1), based on the total weight of component (b1), from the three-dimensional green body to form a three-dimensional brown body;
wherein the removal is carried out by acidic treatment and at a temperature in the range from 20 to 180° C.;
wherein the particle size of the inorganic powder (IP)) is from 0.1 to 80 μm.
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