A method of forming a multilayer insulation material formed of an acoustical composite layer and a first thermal layer is provided. The acoustical and insulting layer is formed of a polymer based thermoplastic material and reinforcing fibers. Preferably the reinforcing fibers are wet use chopped strand glass fibers (WUCS). The acoustical composite layer may be formed by opening the WUCS fibers, blending the reinforcement and polymer fibers, forming the reinforcement and polymer fibers into a sheet, and then bonding the sheet. A first thermal layer formed of one or more polymer based thermoplastic organic materials is then positioned on a first major surface of the acoustical composite layer. A second thermal layer of polymeric fibers may be optionally positioned on a second major surface of the acoustical composite layer. The multilayer acoustic material may be utilized in semi-structural and acoustical applications.