The Effect of Thickness on the Weld-Line Strength of Injection-Molded Thermoplastic Composites

Abstract

Weld lines are a major concern to designers since they result in poor mechanical properties. Designers may overdesign parts when considering anticipated failure modes and safety factors by locating weld lines in non-critical areas without taking into account material factors. This study focus on the effect of part thickness on the weld-line strength of injection-molded short-fiber-reinforced thermoplastic composites. Comparisons were made with specimens without weld lines. The use of design data which takes into account fiber orientation and part thickness will enable designers to more accurately predict the performance of an injection-molded thermoplastic composites under applied load.

Keywords:

• Fiber orientation
• Injection molding
• Thermoplastic composites
• Wall-thickness
• Weld-line strength

ACKNOWLEDGMENTS

Grateful acknowledgement is due to the Faculty of Engineering, Kasetsart University for the financial support of this investigation. The authors also would like to express their thanks to Global Connections Public Company Limited (Thailand) for cost-free supply of material and Research Development Institute of Production Technology (RDiPT) for mold design assistance.