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:
Closed cell fluoropolymer foams are prepared by subjecting a fluoropolymer 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. The resin is cross-linked prior to expansion to result in a low density, high quality product.
Abstract:
A thermal insulator for a body is a composite comprising a first material, and a second material located proximate the first material,wherein the first material is a polymeric foam which is less likely to be degraded by heat than the second material and wherein the first material has a thermal conductivity of less than 0.15 W/mK at 150°C. A method of forming the same is also provided
Abstract:
A helical elongate polymeric foam body is provided for insulating a water pipe, wherein the foam forming the helix has a thermal conductivity of less than 0.15 W/mK at 0°C.
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:
A process for making a three dimensional foam article of non-uniform shape employs a two-stage nitrogen autoclave process and a pre-form which has a non-uniform cross- section in at least one dimension.
Abstract:
A G-shaped elongate polymeric foam body is provided for insulating a water pipe, wherein the foam forming the G-shape has a thermal conductivity of less than 0.15 W/mK at 0°C.
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:
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.