Consolidation of GF/PP commingled yarn composites

Consolidation quality and corresponding mechanical properties of GF/PP thermoplastic composites manufactured from a commingled yarn system have been investigated. A small compression mould with a laboratory hot press was used to apply the different processing variables (i.e. pressure, holding time and processing temperature). The consolidation quality of finished samples was characterized mainly through (a) microscopic studies of the material's microstructure, (b) density measurements, and (c) evaluations of mechanical properties using a small transverse flexure testing facility. A model for qualitatively describing the impregnation and consolidation processes in commingled yarn based thermoplastic composites was applied to predict variations of void content during consolidation and the time, temperature and pressure required to reach full consolidation. Based on a desired, minimum level of void content (X _v =2.0%), optimum processing windows for manufacturing of GF/PP commingled yarn composites are suggested.