Sound proof material and method for manufacturing the sound proof cover
A sound proof material here disclosed comprises an exterior material layer 8 including a holding material 3 made of a woven fabric and a skin material 2 made of a thermoplastic resin film, and a sound absorbing material layer 9 , the exterior material layer 8 being laminated on the sound absorbing material layer 9 so that the skin material 2 is located on the surface side of the sound proof material, whereby the sound proof material can endure long-time use without deterioration in moldability under inhibition of aging in severe operating environments so that the sound proof material can be suitably used while suppressing sound from a sound source around an engine installed in an engine compartment of an automobile.
1. A sound proof material characterized by comprising a sound absorbing material layer arranged to face a sound source and an exterior material layer laminated on the sound absorbing material layer, wherein
the exterior material layer comprises a holding material made of a woven fabric provided by weaving thermoplastic resin fibers by 2-way tricot weaving and a skin material made of a thermoplastic resin film, and is laminated on the sound absorbing material layer so that the skin material is placed on a surface side to form a rigid soundproof cover of a predetermined shape.
2. The sound proof material according to claim 1 , wherein the skin material is made of a non-stretched polyamide-based resin film which is stretchable with a stretch ratio of 5 to 500%.
3. The sound proof material according to claim 1 , wherein the holding material is made by weaving at least one selected from polypropylene-based resin fibers, polyester-based resin fibers, and polyamide-based resin fibers.
4. The sound proof material according to claim 1 , wherein a lining material made of a thermoplastic resin film is laminated on a side of the sound proof layer facing the sound source.
5. A method for manufacturing a sound proof cover characterized in that a sound proof material according to claim 1 is hot-press-formed into a predetermined shape.
6. The method for manufacturing a sound proof cover according to claim 5 , wherein a Young's modulus of the exterior material layer before the hot press forming is 0.005 to 0.5 GPa, and a Young's modulus of the exterior material layer after the hot press forming is 0.6 to 5.0 GPa.