Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering


Cell structures in polymers, Glass fibre reinforced composite, MuCell®, Nylon, Vibration welding, Weld strength


Edrisy, Afsaneh


Eichhorn, Stephan




In this research, three different nylon-fibre glass composites with 30–35 wt. % glass fibre and one with 50 wt. % glass fibre were fabricated using the microcellular (MuCell®) injection moulding process with the weight reduction from 4 to 10% and were tested through burst and fatigue tests. Microstructural observation and thermal analyze were also employed to investigate the effect of the MuCell® process on mechanical properties. In the first phase of this study, the B3WG6-GPX material exhibited the highest weld strength as well as the longest fatigue life. As a result, it was selected for further investigation in the second phase. It is important to note that all samples failed at the weld region during the burst tests. Additionally, a microstructural analysis by scanning electron microscopy (SEM) and optical microscopy found uniform cells at the weld region of the MuCell®-processed parts, which suggested that cells can be generated in the molten polymer during vibration welding. In contrast to the fact that the weld depth (1.511 mm) for the selected sample during vibration welding was much lower than the none-cell region thickness. We concluded that the formation of the cells in the weld region is mainly responsible for the weaker welds.