THE DEVELOPMENT OF GLASS-FIBER-REINFORCED POLYSTYRENE FOR PULTRUSION - II - EFFECT OF PROCESSING PARAMETERS FOR OPTIMIZING THE PROCESS

This paper presents a novel process developed to manufacture polystyre ne (PS) pultruded composites. The effects of the processing parameters on the mechanical properties (tensile strength, flexural strength, fl exural modulus, etc.) of the glass fiber reinforced PS composites by p ultrusion have been studied. The processing parameters investigated in clude die temperature, pulling rate tin-line speed), postcure temperat ure and time, filler type and content, and glass fiber content. The op timum die temperature was determined from DSC diagrams, molecular weig ht, and mechanical properties tests. It was found that the mechanical properties increased with increasing die temperature and glass fiber c ontent, and with decreasing pulling rate. The optimum die temperature, pulling rate, and glass fiber content were determined to be 160-200 d egrees C, 20-60 cm/min and 50-60 vol%, respectively. The mechanical pr operties reached a maximum value at 10 phr kaolin, and then decreased. However, the properties decreased with increasing talc content. The m echanical properties increase at a suitable postcure temperature and t ime. Furthermore, the properties that decreased as a result of composi te degradation after long postcure time are discussed.