Abstract: Shaped microcellular structures having substantially non-cellular skins are produced from reactive liquid polymer systems incorporating thermoplastic microspheres containing volatile materials such as low boiling point halogenated or non-halogenated organic materials. Use of thermoplastic microspheres encapsulating such volatile materials facilitates the removal of the shaped foamed structure from molds, eliminating the need for release agents. Various products based on this process, such as bathroom fixtures, bicycle and wheel chair tires, shoe soles, and automotive parts, are provided.

Abstract: Methods and apparatus for molding a solid article incorporating one or more vulnerable inserts are disclosed. Centrifugal casting methods for producing a finished article composed of single or multiple curable fluid compounds utilize a self-releasing securing device for holding an insert stably and insulatedly protected within a mold.

Abstract: A microcellular polyurethane composite material comprising desiccated rubber particles embedded in a microcellular matrix of polyurethane. Rubber particles derived from tires and other sources are combined with a desiccant to remove moisture present in the particles. The resulting desiccated rubber particles and desiccant are mixed with a polyol, polyisocyanate, catalyst, and blowing agent to form a precursor blend which is cured to produce a microcellular polyurethane composite. The resulting microcellular rubber-polyurethane composite may be used for tires, shoe and boot soles, surface coatings, and other applications requiring a material which is structurally strong and wear resistant. The desiccated rubber particles may be premixed with the polyol and/or added simultaneously with the polyol, polyisocyanate, catalyst, and blowing agent during composite molding.