Electrophotographic multi-material powder deposition for additive manufacturing

Abstract

In this paper, the use of electrophotographic polymer powder transfer for the preparation of multi-material layers is discussed with respect to the application in powder bed-based additive manufacturing technologies as selective laser sintering (SLS). Therefore, the challenges of this task are considered verifying the critical process steps in order to develop a concept for an electrophotograhic laser sintering machine. On that basis, an experimental setup with a two-chamber design is realized which enables the investigation of the electrophotographic powder transfer at typical process conditions of SLS. Using this setup, transfer tests of polypropylene powder patterns were performed and qualitatively analyzed by photographic imaging. The results confirm the high potential of the application of electrophotography for multi-material powder deposition and show how a residual electrophotographic powder deposition can be achieved in general, which is independent from the already produced part height, in order to build up three-dimensional multi-material components.

Analysis of Tribo-Charging during Powder Spreading in Selective Laser Sintering: Assessment of Polyamide 12 Powder Ageing Effects on Charging Behavior

“…This study’s aim is introducing a method and a model setup to quantify the electrostatic potentials during powder spreading by means of blade coating. Moreover, the technique represents a novel way for an in-line measurement and controlling system for powder application strategies that rely on electrostatic interactions, such as an electrophotographic multi-material powder deposition [24]. The applicability of the model setup is demonstrated for polyamide laser sintering powders.…”

Multimaterial powder bed fusion techniques

“…This will continue until the layer-on-layer setup metal–insulator–metal (MIM) is achieved. Stichel et al (2018) reported a particular technique using electrophotographic powder transfer for the multimaterial SLS printing process. For this purpose, they made a particular experimental setup [Figure 5(b)], including two chambers designed for transferring the positively charged powder to the substrate in a typical SLS process.…”

Recent progress and scientific challenges in multi-material additive manufacturing via laser-based powder bed fusion

“…Then they are blown off the mesh and deposited on the build platform to form a design pattern. Inappropriate parameters can cause the powder to fall unintentionally in certain areas, resulting in the contamination of the powder layer (Stichel et al 2018;Stichel et al 2020).…”