Coalescence behavior of polyamide 12 as function of zero-shear viscosity and influence on mechanical performance

Cholewa S, Jaksch A, Drummer D (2022)

Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2022

Event location: Austin, Texas US

Abstract

The favored material for powder bed fusion of polymers (PBF-LB/P) is polyamide-12. Its molecular weight increases from post-condensation at elevated temperatures in the building chamber, consequently having different properties when reused. An important aspect of PBF directly affected hereby is the coalescence behavior, as it significantly determines the surface quality, porosity, and thus the component’s mechanical properties. However, detailed studies on coalescence are limited to virgin powders with low viscosity; therefore, coalescence behavior of polyamide-12 with different molecular weights is investigated using hot stage microscopy. Additionally, the zero-shear viscosity is determined using the Carreau model, allowing comparison of experimental results to sintering models. Furthermore, the mechanical properties and surface qualities are analyzed, and components with adequate values are made with two-cycle reprocessed powder. Since surface flaws do not exist uniformly across all components, the orange peel effect is not attributed solely to the increased viscosity of the reused powder.

Authors with CRIS profile

Simon Cholewa Lehrstuhl für Kunststofftechnik Andreas Jaksch Lehrstuhl für Kunststofftechnik Dietmar Drummer Lehrstuhl für Kunststofftechnik

Related research project(s)

Process strategies for the production of thin-walled components during selective laser beam melting of plastics (SFB 814 (T3)) CRC 814 - Additive Manufacturing (SFB 814) Jan. 1, 2021 - Dec. 31, 2023 Process-adapted material characterization for laser beam melting (A3) (SFB 814 (A3)) CRC 814 - Additive Manufacturing (SFB 814) July 1, 2011 - June 30, 2023

How to cite

APA:

Cholewa, S., Jaksch, A., & Drummer, D. (2022). Coalescence behavior of polyamide 12 as function of zero-shear viscosity and influence on mechanical performance. In Proceedings of the SFF 2022. Austin, Texas, US.

MLA:

Cholewa, Simon, Andreas Jaksch, and Dietmar Drummer. "Coalescence behavior of polyamide 12 as function of zero-shear viscosity and influence on mechanical performance." Proceedings of the SFF 2022, Austin, Texas 2022.

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