Effects of processing parameters on the mechanical behavior of continuous glass fiber/polypropylene composites

Abstract

Fiber reinforced polymeric composite materials have an increasing demand in industrial applications. Easy and rapid processing capability, high impact and delamination resistance, low moisture absorption and infinite shelf life of the raw materials are the attractive properties of continuous fiber reinforced thermoplastic composite materials. Therefore, thermoplastic based composites find in many application areas in automobile, aerospace, construction, defense, transportation and marine industries. In recent years, hybrid fabrics; composed of continuous glass fibers and polymer fibers such as polypropylene (PP), have been used to fabricate thermoplastic composite with higher fiber volume fraction and improved performance. In this study, hybrid fabrics were developed by commingling the continuous PP and glass fibers using air jet and direct twist hybrid yarn preparation techniques. The hybrid commingled fabrics obtained with 450 fiber orientation and non-crimp fabric pattern. Non-crimp fabrics were obtained various fiber sizing that are compatible and incompatible with PP matrix to investigate the effect of interfacial adhesion on the properties of the thermoplastic composites. Composite panels were produced from these fabrics via hot press compression method. Microstructural properties of the composites were investigated by matrix burn-out test and optical and scanning electron microscopy (SEM) analyzes. Tensile, compression, flexural and interlaminar peel tests were used to investigate the mechanical properties of the composites. Impact properties of the composites were examined by charpy impact test. Results showed that laminates of the fabrics fabricated by air jet hybrid yarn preparation technique exhibit superior properties to those fabricated by direct twist covering hybrid yarn preparation technique. The results also showed that the fabrics with polypropylene compatible sizing results with enhanced composite properties.