Modifying surface properties of polyamide powders for selective laser sintering

The purpose of this work was determination of the changes in surface properties of Polyamide-12 powder used in Selective Laser Sintering (SLS). The powders of original polyamide Duraform PA(tm) (3D Systems) were investigated. Also the powders remaining around the product after the sintering process were investigated. The difference in the chemical structure of the Polyamide-12 powder surface layers has been established. The reason is the increased content of oxygen-containing groups in the surface layers. To a greater extent, this difference was revealed for powders left after sintering and intended for reuse. Aliphatic chains are subject to oxidative degradation in the surface layers of the original powder. In the powder remaining after sintering, terminal carbonyl and amine groups are subject to oxidative degradation.