Influence of process parameters on porosity and mechanical properties of structural thermoplastic composites made by hotpressing

For the characterization of structural plastic composites, layers of glass fibre fabrics and polyamide sheets were alternately stacked and pressed to consolidated composite under different processing pressures and temperatures. To investigate the influence of the fabric type in correlation with the process parameters, different types of glass fibre fabric were used. From the produced sheets test specimens were cut out for tensile-, bending- and Charpy-impact characterization. We found that with higher processing pressure the porosity content decreases while the impact- and bending strength stay fairly constant. In addition we found, that the twill weaved fabrics are easier penetrated by the thermoplastic matrix than plain weave which leads to better mechanical properties with comparable fibre volume fraction.