Abstract: A first polymer (preferably in granular form) is exposed to a gas at a pressure higher than atmospheric pressure to introduce the gas into the polymer. This occurs at a temperature from the glass transition temperature to the melting temperature when the first polymer is crystalline or semi-crystalline in nature, or at a temperature below the glass transition temperature when the first polymer is amorphous in nature. Optionally, the gas-laden polymer may then be mixed with a second polymer. The polymer is then melted to produce a foamed article.

Abstract: Fluoropolymer foams are prepared by mixing fluoropolymer resin with blowing agents and additives to produce foamable compounds at temperatures below the activation temperature of the blowing agent. The compounded material is expanded at temperatures above both the softening point of the fluoropolymer resin and the activation temperature of the blowing agent. The resulting fluoropolymer foam can be fabricated into any desired shape, such as pipes, sheets, tapes, blocks and rods, using techniques such as cutting, welding, thermoforming and adhesive bonding. Alternatively the fluoropolymer compound may be expanded directly into the desired shape, for example, by expanding the compound in a mold.

Abstract: Closed cell silicone foams are formed by subjecting a silicone base to an inert gas at an elevated pressure, preferably after a pre-curing step, reducing the pressure to allow the base to expand to produce closed cell silicone foam and curing this expanded foam at an elevated temperature.

Abstract: Closed cell polyamide foams are prepared by subjecting a polyamide resin to inert gases at an elevated pressure and at a temperature above the softening point of the resin and reducing the pressure while the temperature is maintained above the softening point of the resin, resulting in expansion of the resin.

Abstract: Described is a process for making closed cell fluoropolymer foam, and the foam so made. The process includes subjecting a fluoropolymer resin an inert gas at a pressure higher than atmospheric to drive gas into the resin, raising the temperature of the resin to or above its softening point, and reducing the pressure while maintaining the temperature at or above the softening point of the resin, in order to expand the resin to result in closed cell fluoropolymer foam. The resin is cross-linked prior to expansion. The resulting foams can be used in various applications, such as in flotation devices and for making thermal and/or acoustic insulation.

Abstract: Fluoropolymer foams are prepared by mixing fluoropolymer resin with blowing agents and additives to produce foamable compounds at temperatures below the activation temperature of the blowing agent. The compounded material is expanded at temperatures above both the softening point of the fluoropolymer resin and the activation temperature of the blowing agent. The resulting fluoropolymer foam can be fabricated into any desired shape, such as pipes, sheets, tapes, blocks and rods, using techniques such as cutting, welding, thermoforming and adhesive bonding. Alternatively the fluoropolymer compound may be expanded directly into the desired shape, for example, by expanding the compound in a mould.

Abstract: Described is a process for making closed cell fluoropolymer foam, and the foam so made. The process includes subjecting a fluoropolymer resin an inert gas at a pressure higher than atmospheric to drive gas into the resin, raising the temperature of the resin to or above its softening point, and reducing the pressure while maintaining the temperature at or above the softening point of the resin, in order to expand the resin to result in closed cell fluoropolymer foam. The resin is cross-linked prior to expansion. The resulting foams can be used in various applications, such as in flotation devices and for making thermal and/or acoustic insulation.