Enabling triboelectric charging as a powder charging method for electrophotographic powder application in laser-based powder bed fusion of polymers by triboelectric charge control

Kopp SP, Düsenberg B, Eshun PM, Schmidt J, Bück A, Roth S, Schmidt M, Kopp SP (2023)

Publication Language: English

Publication Type: Journal article

Publication year: 2023

Journal

Additive Manufacturing Elsevier

Pages Range: 103531

Article Number: 103531

DOI: 10.1016/j.addma.2023.103531

Open Access Link: https://doi.org/10.1016/j.addma.2023.103531

Abstract

Substituting conventional doctor blade- or roller-based powder application methods for laser-based powder bed fusion of polymers (PBF-LB/P) by electrophotographic powder application (EPA) offers significant advantages. In particular, the selective powder deposition enabled by EPA allows high powder efficiency and the possibility to locally adjust part properties during their fabrication. However, defined charging of powder particles is crucial for achieving an accurate selective deposition of powder layers by means of electrophotography. This is the first comprehensive study on the specific triboelectric charge control of polymer particles for their subsequent use in electrophotographic powder application for PBF-LB/P. For this purpose, approaches for charge control of toner particles in the context of digital (2D) printing technologies are adapted and applied to polypropylene (PP) feedstocks for PBF-LB/P. In order to show transferability to other polymers, the charge control method developed in this paper is also applied to polyamide 12 (PA12) high density polyethylene (HDPE) and polystyrene (PS). For successful EPA, unipolar charging of polymer particles is crucial. However, non-functionalized PP shows a strongly bipolar triboelectric charging, which is unsuitable for EPA. The charge control method developed in this work shifts this strongly bipolar triboelectric charging to a unipolar charging. This is achieved by the synergy of both functionalizing the particle surface with charge control agents (CCAs) and choosing suitable carrier particles known from two-component toners. The developed method allows to control crucial parameters of triboelectric charging, namely polarity, amount of charge and resulting surface potential. Furthermore, the presented results provide new insights into the transfer behavior of charged PP particles in an external electric field. Finally, this enables the triboelectric charging mechanism to be used for electrophotographic powder application in PBF-LB/P.

Authors with CRIS profile

Björn Düsenberg Professur für Partikeltechnik Jochen Schmidt Sonderforschungsbereich 814/3 Additive Fertigung Andreas Bück Professur für Partikeltechnik Michael Schmidt Lehrstuhl für Photonische Technologien Sebastian-Paul Kopp Lehrstuhl für Photonische Technologien

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies Lehrstuhl für Photonische Technologien Sonderforschungsbereich 814/3 Additive Fertigung

Related research project(s)

Efficient additive manufacturing of multi-material parts (B6) (SFB 814 (B6)) CRC 814 - Additive Manufacturing (SFB 814) July 1, 2011 - June 30, 2023

Involved external institutions

Bayerisches Laserzentrum gemeinnützige Forschungsgesellschaft mbH (BLZ) DE Germany (DE)

How to cite

APA:

Kopp, S.-P., Düsenberg, B., Eshun, P.M., Schmidt, J., Bück, A., Roth, S.,... Kopp, S.-P. (2023). Enabling triboelectric charging as a powder charging method for electrophotographic powder application in laser-based powder bed fusion of polymers by triboelectric charge control. Additive Manufacturing, 103531. https://doi.org/10.1016/j.addma.2023.103531

MLA:

Kopp, Sebastian-Paul, et al. "Enabling triboelectric charging as a powder charging method for electrophotographic powder application in laser-based powder bed fusion of polymers by triboelectric charge control." Additive Manufacturing (2023): 103531.

BibTeX: Download