The performance of cotton-kapok fabric-polyester composites

Cotton-kapok fabric, at a ratio of 2:3, has been incorporated with unsatura ted polyester resin in various fibre volume fractions. The fabric was also treated with 5% sodium hydroxide with the aim of improving fibre-matrix adh esion. A simple manual lay up technique was used in fabricating the composi tes. A hand operated hydraulic electrically heated press was used and the c omposites were cured at 100 degrees C for 60 min and post cured overnight i n the oven at 80 degrees C. Mechanical properties such as tensile strength, tensile modulus, impact strength, and flexural properties of composites no t subjected to weathering conditions and weathered composites have been eva luated. Composites with untreated fibres had higher fibre volume fractions than composites prepared using treated fibres. The tensile strength of comp osites with untreated fibres was higher than that of composites prepared us ing treated fibres but had, on average, higher tensile modulus than composi tes manufactured using untreated fibres. The impact strength decreased with increase in fibre volume fractions for both composites, with or without al kali treated fibres. Reductions in flexural strength and moduli were observ ed with weathered composites. The specific strength of the composites was c omparable to that of other vegetable fibre reinforced resins. (C) 1999 Else vier Science Ltd. All rights reserved.