To improve soundproof performance by making working in assembling easy by a method wherein a board having thermoplastic resin flake as a main constituent is used as an inner face material, a honeycomb structure body or porous fiberboard is used as an intermediate layer, and an outer face material is arranged.
As thermoplastic resin capable of being used for thermoplastic resin flake of an inner face material 1, polyolefin resin such as polypropylene, polyethylene, etc., is exemplified. Though virgin material may be used therefor, since waste material or recovered material which is produced in molding and processing of the film, sheet, etc., magnetic tape waste is preferably used. As material of a honeycomb structure of the intermediate layer 2, because of low cost, light weight, and excellent processability, paper or impregneted paper is preferable. Further, as porous fiberboard, expanded material wherein fiber- reinforced thermoplastic resin sheet is shaped by heating is preferable, and glass fiber reinforced polyolefin is preferable. Then, as outer face material 3, resinous sheet, plywood, veneer, metal sheet, etc., can be used.
SUZUKI HISAKAZU
TANAKA KENJI
SHINTANI AKIRA
