Selective laser sintering of polymer blends: Bulk properties and process behavior

Physically mixed powderous polymer blends consisting of at least two different thermoplastic materials with complementary properties could allow the successful fabrication of components with tailored and graded properties. In this work, powderous polymer blends of the partially miscible and chemically reactive blend system PBT/PC were produced from wet grinded powders at different weight ratios of 90/10, 80/20, 70/30 and 60/40, respectively. The PBT/PC is used as a model system for a blend with a semi-crystalline and amorphous component, while being relevant for industrial use, such as automotive applications. Before the implementation into the selective laser sintering process (SLS), the bulk properties of the powders were analyzed. The quadratic monolayer test specimens were generated with different energy densities by variating the laser power. The specimens' geometrical and microstructural properties were studied. The investigations showed that an improvement of geometric properties in terms of layer development can be achieved by increasing the PC content and that it is possible to generate polymer blends with matrix and dispersed phase from PBT/PC blends.