| abstract |
The invention concerns constrained layer sound damping. A composition and a laminated structure are provided for the reduction of noise coming from housings such as oil pans for automobiles. The composition (30) comprises a rubbery polyurethane, an olefin polymer, and a filler. The laminated structure comprises the housing (10), the composition (30), and a sheet metal liner (40). The composition (30) contains a blowing agent which is activated to provide a single unitary structure which dampens noise. The polyurethane and olefin polymer are thoroughly intermixed with each other, but maintain their separate identities in the blend. |