Increasing flowability and bulk density of PE-HD powders by a dry particle coating process and impact on LBM processes
Abstract
Purpose
The purpose of this paper is to demonstrate the processability of cohesive PE-HD particles in laser beam melting processes (LBM) of polymers. Furthermore, we present a characterization method for polymer particles, which can predict the quality of the powder deposition via LBM processes.
Design/methodology/approach
This study focuses on the application of dry particle coating processes to increase flowability and bulk density of PE-HD particles. Both has been measured and afterwards validated via powder deposition of PE-HD particles in a LBM machine.
Findings
For efficient coating in a dry particle coating process, the PE-HD particles and the attached nanoparticles need to show similar surface chemistry, i.e. both need to behave either hydrophobic or hydrophilic. It is demonstrated that dry particle coating is appropriate to enhance flowability and bulk density of PE-HD particles and hence considerably improves LBM processes and the resulting product quality.
Originality/value
At present, in LBM processes mainly polyamide (PA), 12 particles are used, which are so far quite expensive in comparison to, for example, PE-HD particles. This work provides a unique and versatile method for nanoparticulate surface modification which may be applied to a wide variety of materials. After the coating, the particles are applicable for the LBM process. Our results provide a correlation between flowability and bulk density and the resulting product quality.
Keywords
Acknowledgements
This study has been supported by Deutsche Forschungsgemeinschaft (DFG) within the framework of the collaborative research center SFB 814 “Additive Fertigung” (A2, A3, B6). Financial support is gratefully acknowledged.
Citation
Blümel, C., Sachs, M., Laumer, T., Winzer, B., Schmidt, J., Schmidt, M., Peukert, W. and Wirth, K.-E. (2015), "Increasing flowability and bulk density of PE-HD powders by a dry particle coating process and impact on LBM processes", Rapid Prototyping Journal, Vol. 21 No. 6, pp. 697-704. https://doi.org/10.1108/RPJ-07-2013-0074
Publisher
:Emerald Group Publishing Limited
Copyright © 2015, Emerald Group Publishing Limited