@inproceedings{c9f0554f4ba049448084e4c2d063522f,
title = "A novel process for production of spherical PBT powders and their processing behavior during laser beam melting",
abstract = "Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles are produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.",
keywords = "downer reactor, dry coating, polybutylene terephthalate (PBT), selective laser beam melting of polymers, wet grinding",
author = "Jochen Schmidt and Marius Sachs and Meng Zhao and Stephanie Fanselow and Katrin Wudy and Maximilian Drexler and Dietmar Drummer and Wirth, {Karl Ernst} and Wolfgang Peukert",
note = "Publisher Copyright: {\textcopyright} 2016 AIP Publishing LLC.; 31st International Conference of the Polymer Processing Society, PPS 2015 ; Conference date: 07-06-2015 Through 11-06-2015",
year = "2016",
month = mar,
day = "9",
doi = "10.1063/1.4942343",
language = "English",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics Inc.",
editor = "Byungohk Rhee",
booktitle = "Proceedings of PPS 2015",
}