Journal article
Constant Temperature Approach for the Assessment of Injection Molding Parameter Influence on the Fatigue Behavior of Short Glass Fiber Reinforced Polyamide 6



Publication Details
Authors:
Mrzljak, S.; Delp, A.; Schlink, A.; Zarges, J.; Hülsbusch, D.; Heim, H.; Walther, F.
Publication year:
2021
Journal:
Polymers
Pages range:
1569
Volume number:
13
Issue number:
10
ISSN:
2073-4360

Abstract

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared
to polymers, while still also enabling almost unlimited geometric variations of components at largescale
production. PA6-GF30 represents one of the most used SGFRP for series components, but
the impact of injection molding process parameters on the fatigue properties is still insufficiently
investigated. In this study, various injection molding parameter configurations were investigated on
PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests
were performed using multiple amplitude tests, considering surface temperature-adjusted frequency
to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to
20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during
injection molding lead to an increase of 16% regarding fatigue life. In situ X-ray microtomography
analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths
in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values
at the same stress level for different injection molding process parameters were identified. The results
prove that the injection molding parameters have a high influence on the fatigue properties and thus
offer a large optimization potential, e.g., with regard to the component design.



Authors/Editors

Last updated on 2021-04-08 at 14:25

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