(2a) Novel Approaches for the Production of Polymer Powders for Additive Manufacturing
Two innovative methods for production of spherical polymer micro particles for SLS will be discussed: The first approach is a process chain consisting of wet grinding of polymers in a stirred media mill followed by rounding of the obtained irregular-shaped particles in a heated downer reactor and subsequent dry coating of the spherical particles for improvement of powder flowability. The process chain is applicable to a various thermoplasts and will be discussed for pure polymers (polystyrene, polybutylene terephthalate) and for filled polymer systems. Bulk powder properties and polymer structures are thoroughly characterized along the process chain. The second approach, melt emulsification with subsequent dry coating, will be exemplified for polypropylene. In this process a polymer melt is emulsified by elongational and shear stresses in a rotor stator device.
Both approaches allow for production of spherical polymer micro particles of good flowability which are promising, novel powder materials for SLS.
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