Effects of surface roughness on the properties of glass fibre filled micro injection moulded plastic parts

Abstract

The aim of this study was to investigate the effect of surface roughness on the properties of microparts moulded from glass fibre reinforced polymers. This was achieved by injection moulding of microparts with different surface roughness values from Polypropylene (PP) and Polyamide 6 (PA6), both containing 30 % glass fibre. Characterisation tests were conducted on micro injected parts and the mechanical properties obtained were compared to the ones in the respective raw material’s datasheet. Such properties included, tensile and elastic modulus, strain, melting and crystallisation temperatures as well as crystallisation degree. The tensile modulus of both the PP-30GF and PA6-30GF specimens revealed that the surface roughness appears to marginally influence the properties of the part. However, all tensile test results were considerably lower compared to the values in the datasheet. This is due to various glass fibre related factors not being favourable for the production of microparts. On the other hand, the results showed that the other mechanical properties of both materials did not vary for different surface roughness of the specimens.