Thermal Insulation Properties of Cellulosic-based Nonwoven Composites

The use of cellulosic fibers, such as cotton, kenaf, ramie, jute, flax, and bagasse, in the manufacturing of nonwoven composites for a variety of automotive parts, such as headliners, wall panels, and trunk liners, can significantly enhance their ‘end of life’ biodegradability and also improve their thermal insulation properties. Currently, automotive nonwovens are made from synthetic, petro-based polymer materials that are not biodegradable, thus creating significant environmental problems. Three different sets of ‘sandwich-type’ nonwoven materials are manufactured by layering the cellulosic webs, with recycled thermoplastic synthetic fibers and/or using readily biodegradable binders such as polyvinyl alcohol (PVA) and Eastar Biocopolymer (EBC). A ‘steady state’ heat flow meter is used for the evaluation of the thermal insulation properties of these biodegradable, low-cost nonwoven composites. The results show that the thermal insulation properties of cellulosic-based nonwoven composite materials vary significantly, depending on the type of the vegetable fibers, the ratios of the cellulosic to synthetic fibers, the nature and quantity of the binder, the design, and the resulting bulk density of the composites.