Abstract: A syntactic structural foam product in flat sheet form or curved three-dimensional form adaptable to such uses as a light weight structural core for composite laminates, is made of a mixture of hollow ceramic microspheres and dry resin powder, of either thermosetting or a high-temperature thermoplastic resin, distributed in the interstices of the mass of microspheres for integration of the mixture into desired form upon heating and cooling. The dry resin powder in an other embodiment of the invention includes unexpanded expandable powder which will expand into microballoons in the confined spaces in which they reside and effect a bonding relation with surrounding particles upon supply of heat to the mixture.

Abstract: The invention disclosed herein is a synthetic reinforcing strand of filaments in which the strand density is reduced by spacing the filaments apart along their length with heat expandable hollow particles such as plastic microspheres expanded into microballoons and the method of making such strands. Also embodied in the invention are methods utilizing such strands in processes for making composite structures.

Abstract: Vibration damping material in which polyvinyl chloride (PVC) and a particle filler such as fly ash or talc are amalgamated into a matrix by combination with a small percentage by weight of blown asphalt in a heat working process, such as extrusion, for forming a product such as a sheet of the material. By use of blown asphalt as a compatibilizer and amalgamator, waste or recycled PVC such as of electrical wire strippings combined with a filler has provided excellent damping characteristics.

Abstract: A syntactic structural foam product in flat sheet form or curved three-dimensional form adaptable to such uses as a light weight structural core for composite laminates, is made of a mixture of hollow ceramic microspheres and dry resin powder, of either thermosetting or a high-temperature thermoplastic resin, distributed in the interstices of the mass of microspheres for integration of the mixture into desired form upon heating and cooling. Resin powder collected as a waste by-product from resin coating materials can be recycled in the production of the desired product.

Abstract: A syntactic structural foam product in flat sheet form or curved three-dimensional form adaptable to such uses as a light weight structural core for composite laminates, is made of a mixture of hollow ceramic microspheres and dry resin powder, of either thermosetting or a high-temperature thermoplastic resin, distributed in the interstices of the mass of microspheres for integration of the mixture into desired form upon heating and cooling. The dry resin powder in another embodiment of the invention includes unexpanded expandable powder which will expand into microballoons in the confined spaces in which they reside and effect a bonding relation with surrounding particles upon supply of heat to the mixture. The foam product is produced by thoroughly intermixing and depositing the mixture as a layer over a surface having a release agent thereover within a dimension defined region.