Authors: L. Xie, D. Zhu, G. Ziegmann, L. Steuernagel
Affilation: Technology University of Clausthal, Germany
Pages: 292 - 295
Keywords: micro injection molding, cold/hot weld line, tensile test, polypropylene
Micro injection molding has been attracting more and more market attentions, due to realizing the large scale cost effective production of Micro Electronic Mechanic System (MEMS) components. However, there are some defects which cannot be avoided in micro injection molded parts, like the weld line. Two sorts of weld lines are mentioned: Hot and cold weld line. Many significant meaningful research achievements have been done, focusing on the weld line issue of normal size injection molding, but the aspect in the weld line developing in micro injection molding process is relative limited. In the presented study, two molds with variotherm unit are designed and constructed, in which the hot-/weld line micro dog bone tensile specimens (gage section dimension 0.1(Depth)×0.4(Width)×12(Length) mm) can be prepared. Polypropylene(PP) was used as the processing materials in the experiments. Micro injection molding experiments were carried out in various processing conditions. The micro injection molded weld line strength was characterized by tensile test. The results shows processing parameters impact the micro cold/hot weld line strength obviously. The influencing trends of processing parameters on weld line properties are respectively different.