SOUND AND THERMAL INSULATION PROPERTIES OF SANDWICH COMPOSITES MADE OF WASTE KEVLAR® MATERIALS

Abstract

This paper examines the thermal and acoustic insulation characteristics of sandwich composites with waste Kevlar® fiber-reinforced face materials and polyurethane/paper cardboard cores. Waste Kevlar® short fibers (carding waste) were reinforced into the sandwich composites’ core part in varying ratios (2%, 5%, and 10%). Kevlar® fabric edge waste (waste of weaving process) was used to produce the face materials of sandwich composites. Sandwich composites were also stitched using Kevlar® yarns to observe the effect of the through-thickness reinforcement on sound and thermal insulation properties. The sound insulation test results showed that reinforcement of short Kevlar® fibers into the core parts of sandwich composites somewhat raised their sound absorption coefficients. Because the stitching holes created air spaces for sound vibrations, the sound absorption coefficient values improved. The sound transmission losses of sandwich composites were also increased up to 30 dB after short Kevlar® fiber addition. The thermal conductivity coefficient of sandwich composites decreased, indicating that the addition of Kevlar® fibers increased their insulation properties.