Optimisation of Process Parameters in Kenaf/Polypropylene Composites in Connection Moulding

Abstract

Renewable natural fibres like kenaf can be used to produce composites as replacement to plastic boards in household and industrial applications. The objective of this study is to optimise the process parameters for compression moulding of kenaf polypropylene composite to get maximum tensile, flexural and impact strength values for three different blend ratios. Three levels of temperature (160oC, 180oC and 200 oC), compression pressure (7, 9 and 11 Mpa) and time of application (10,20 and 30 min ) for producing kenaf/ polypropylene blend ratios of 50:50, 65:35 and 80:20 have been used. The samples were produced through carding for web formation, needle punching for non woven making and finally in compression moulding machine for boards making. All the composite boards were analysed for tensile, flexural and impact strength. The tensile and flexural strengths have positive correlations with time and temperature and contact pressure in all the blend ratios kenaf / polypropylene. The impact strength has positive correlation with time, temperature whereas it has negative correlation with contact pressure in all the blend ratios. The highest tensile strength and flexural strength is achieved with 65:35 kenaf / polypropylene blend at 200 o C temperature, 11Mpa pressure and 10 minutes duration in compression moulding machine. The highest Impact strength is achieved with 80:20 blends at 180 o C, 7 Mpa pressure and 30 minutes duration. The tensile and flexural strength is the highest at the blend ratio of 65:35 whereas the Impact strength increases with the increase kenaf content up to 80%