Pa 12 powder for use in a generative layer-wise manufacturing method

Abstract

A powder mixture is described, which is suitable for a layer-wise manufacturing of a three-dimensional object by solidifying a building material in powder form. The powder mixture consists of a mixture of a first polyamide 12 powder and a second polyamide 12 powder, wherein the first polyamide 12 powder is characterized by an increase of its viscosity number determined in accordance with ISO 307 that is less than 10%, when the powder is exposed for 20 hours to a temperature that lies 10° C. below its melting temperature under nitrogen atmosphere, and the second polyamide 12 powder is characterized by an increase of its viscosity number, determined in accordance with ISO 307, by 15% or more, when the powder is exposed for 20 hours to a temperature that lies 10° C. below its melting temperature under nitrogen atmosphere. In particular, the proportion of the first polyamide 12 powder in the mixture must lie between 10 and 30 percent by weight for obtaining manufactured objects that do not only have good mechanical properties, but also do show a small warpage and a high surface quality.

Dependencies are inferred from the claim text.