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Title: A novel process route for the production of spherical SLS polymer powders

Abstract

Currently, rapid prototyping gradually is transferred to additive manufacturing opening new applications. Especially selective laser sintering (SLS) is promising. One drawback is the limited choice of polymer materials available as optimized powders. Powders produced by cryogenic grinding show poor powder flowability resulting in poor device quality. Within this account we present a novel process route for the production of spherical polymer micron-sized particles of good flowability. The feasibility of the process chain is demonstrated for polystyrene e. In a first step polymer microparticles are produced by a wet grinding method. By this approach the mean particle size and the particle size distribution can be tuned between a few microns and several 10 microns. The applicability of this method will be discussed for different polymers and the dependencies of product particle size distribution on stressing conditions and process temperature will be outlined. The comminution products consist of microparticles of irregular shape and poor powder flowability. An improvement of flowability of the ground particles is achieved by changing their shape: they are rounded using a heated downer reactor. The influence of temperature profile and residence time on the product properties will be addressed applying a viscous-flow sintering model. To further improve themore » flowability of the cohesive spherical polymer particles nanoparticles are adhered onto the microparticles’ surface. The improvement of flowability is remarkable: rounded and dry-coated powders exhibit a strongly reduced tensile strength as compared to the comminution product. The improved polymer powders obtained by the process route proposed open new possibilities in SLS processing including the usage of much smaller polymer beads.« less

Authors:
; ; ; ; ; ;  [1]
  1. Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 4, D-91058 Erlangen (Germany)
Publication Date:
OSTI Identifier:
22391884
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 1664; Journal Issue: 1; Conference: PPS-30: 30. International Conference of the Polymer Processing Society, Cleveland, OH (United States), 6-12 Jun 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ADDITIVES; COMPARATIVE EVALUATIONS; GRINDING; LASER RADIATION; NANOPARTICLES; PARTICLE SIZE; POLYSTYRENE; POWDERS; SINTERING; SPHERICAL CONFIGURATION; STRESSES; SURFACES; TEMPERATURE DEPENDENCE; TENSILE PROPERTIES; VISCOUS FLOW

Citation Formats

Schmidt, Jochen, Sachs, Marius, Blümel, Christina, Winzer, Bettina, Toni, Franziska, Wirth, Karl-Ernst, and Peukert, Wolfgang. A novel process route for the production of spherical SLS polymer powders. United States: N. p., 2015. Web. doi:10.1063/1.4918518.
Schmidt, Jochen, Sachs, Marius, Blümel, Christina, Winzer, Bettina, Toni, Franziska, Wirth, Karl-Ernst, & Peukert, Wolfgang. A novel process route for the production of spherical SLS polymer powders. United States. https://doi.org/10.1063/1.4918518
Schmidt, Jochen, Sachs, Marius, Blümel, Christina, Winzer, Bettina, Toni, Franziska, Wirth, Karl-Ernst, and Peukert, Wolfgang. 2015. "A novel process route for the production of spherical SLS polymer powders". United States. https://doi.org/10.1063/1.4918518.
@article{osti_22391884,
title = {A novel process route for the production of spherical SLS polymer powders},
author = {Schmidt, Jochen and Sachs, Marius and Blümel, Christina and Winzer, Bettina and Toni, Franziska and Wirth, Karl-Ernst and Peukert, Wolfgang},
abstractNote = {Currently, rapid prototyping gradually is transferred to additive manufacturing opening new applications. Especially selective laser sintering (SLS) is promising. One drawback is the limited choice of polymer materials available as optimized powders. Powders produced by cryogenic grinding show poor powder flowability resulting in poor device quality. Within this account we present a novel process route for the production of spherical polymer micron-sized particles of good flowability. The feasibility of the process chain is demonstrated for polystyrene e. In a first step polymer microparticles are produced by a wet grinding method. By this approach the mean particle size and the particle size distribution can be tuned between a few microns and several 10 microns. The applicability of this method will be discussed for different polymers and the dependencies of product particle size distribution on stressing conditions and process temperature will be outlined. The comminution products consist of microparticles of irregular shape and poor powder flowability. An improvement of flowability of the ground particles is achieved by changing their shape: they are rounded using a heated downer reactor. The influence of temperature profile and residence time on the product properties will be addressed applying a viscous-flow sintering model. To further improve the flowability of the cohesive spherical polymer particles nanoparticles are adhered onto the microparticles’ surface. The improvement of flowability is remarkable: rounded and dry-coated powders exhibit a strongly reduced tensile strength as compared to the comminution product. The improved polymer powders obtained by the process route proposed open new possibilities in SLS processing including the usage of much smaller polymer beads.},
doi = {10.1063/1.4918518},
url = {https://www.osti.gov/biblio/22391884}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 1664,
place = {United States},
year = {Fri May 22 00:00:00 EDT 2015},
month = {Fri May 22 00:00:00 EDT 2015}
}