Fluidity of rubber and TPE influenced by mold surface roughness

Abstract

This article is about the effect of cavity surface roughness on melt flow during injection molding. Test samples were chosen from groups of thermoplastic elastomers (TPE) and rubber compounds, which are commonly used materials within the automotive industry. The tool used for the test was an injection mold with an option to easily change individual plates with different value of roughness. Tests were conducted under varying manufacturing parameters, for example injection pressure and speed or the size of the gate. The results showed that the roughness of the cavity has an effect on the material flow. These findings contradict the current knowledge and allow the elimination of the expensive finishing operations from the manufacturing process of injection mold cavities. © 2019 Trans Tech Publications Ltd, Switzerland.