Filament-wound reinforced plastic articles and process of making and using same

Claim 1

In a process of producing a filament-wound reinforced substantially pore-free plastic article by wetting and impregnating fibrous material with a plastic material and winding the wetted and impregnated fibrous material around a mandrel of a shape corresponding to the inner structure of the desired plastic article, the improvement which consists in the steps of a. wetting and impregnating the filamentary fibrous material with a liquid molten polymerizable bisimide having a melting point below 200°C., which melting point is at least 20°C. below the temperature at which substantial polymerization sets in, said wetting and impregnating step being carried out at a temperature above the melting point of said bisimide and below that at which substantial polymerization takes place, at which temperature said bisimide has a viscosity substantially lower than 800 centistokes; b. winding the thus wetted and impregnated filamentary fibrous material around a winding mandrel of the desired shape to produce the respective wound article; and c. heating said wound article at a temperature sufficient to effect addition polymerization and to cause hardening and curing to the filament-wound, reinforced plastic article.