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 comprises a rubbery polyurethane, an olefin polymer, and a filler. The laminated structure comprises the housing, the composition, and a sheet metal liner. The composition 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.

Abstract: A tire for a wheelchair wheel or the like in the form of a composite extrusion comprising a relatively soft, elastomeric casing extruded over a semirigid core. End faces of a length of extruded stock are joined by thermal fusion developed by a ferromagnetic element inserted in the tire and exposed to high frequency electromagnetic radiation.

Abstract: A closure for a hole in a panel, such as a body panel in an automotive vehicle, is provided. The closure includes a plate with dimensions which are complementary to the hole. A gasket member is secured to the top of the plate. The plate includes means to secure the plate to the body panel. The gasket has dimensions which are somewhat larger than the hole, so that the gasket overlies the panel defining the hole, as well as the plate. The gasket has a first or bottom side low melt layer and a second or top side copolymer layer. The total thickness of the gasket ranges from about 0.0030 inch to about 0.0065 inch. Upon exposure to elevated temperatures during baking, the gasket melts over the plate and adheres to the panel to cause a seal between the plate and the panel.

Abstract: A closure for a panel hole which includes a heat activatable gasket that permanently expands into positive fluidtight sealing engagement with opposed marginal surfaces of the panel and a rigid closure plate.