Abstract: The manufacture is carried out by impregnating bundles of filaments of fibrous-reinforcing material in a bath made up of an emulsion of a thermoplastic resin and a blowing agent. The emulsion-impregnated reinforcing filament bundles are then squeezed and dried to form resin coatings, and then collected to provide a single bunch of the fiber-reinforced thermoplastic resin material. This bunch is subsequently heated and allowed to expand in a tunnel and also cooled in a tunnel to produce a fiber-reinforced thermoplastic resin of a cellular structure. During the impregnation with the emulsion in a bath, the bundles are slackened and repeatedly beaten in the condition of free tension to cause the filament bundles to be substantially frayed to facilitate the impregnation. An apparatus utilizable in the practice of the above method is also disclosed.

Abstract: A method of manufacturing a fiber-reinforced thermoplastic resin of cellular structure comprises immersing bundles of filaments of fibrous reinforcing material in a bath containing an emulsion of thermoplastic resin added with a blowing agent, drying the emulsion-impregnated reinforcing filaments, preheating the dried reinforcing filaments, compressing the preheated reinforcing filaments to provide an integrally bonded block of fiber-reinforced thermoplastic resin, and allowing the block to expand. The fiber-reinforced thermoplastic resin of cellular structure is advantageously employed as a light-weight, high strength construction material.