Thermal and sound insulation materials from waste wool and recycled polyester fibers and their biodegradation studies

This paper reports a study on thermal and sound insulation samples developed from waste wool and recycled polyester fibers (RPET) for building industry applications. Waste wool fiber is a potential source of raw material for thermal and sound insulation applications, but its quantities are limited. In order to overcome the above problems, waste wool fibers were mixed with RPET fibers in 50/50 proportions in the form of a two layer mat. Another set of three samples from 100% waste wool and 100% RPET fibers were also prepared. All samples were tested for thermal insulation, acoustic, moisture absorption and fire properties. Also, behavior of the samples under high humidity conditions was evaluated. An extensive biodegradability study was conducted to analyze the conversion of organic carbon into carbon dioxide by composting method for 50 days. Two layer 50% waste wool and 50% RPET mat provided the best insulation, acoustic, moisture absorption and fire properties. The RPET/waste wool mats were absorbing more than 70% incident noise in the frequency range of 50-5700 Hz. The RPET/waste wool mats have adequate moisture resistance at high humidity conditions without affecting the insulation and acoustic properties. 65-70% biodegradation was achieved for wool/RPET mats for 50 days composting period.