Method of manufacturing a composite reinforcing structure

Abstract

A compound composite structure is a combination of plastics and other materials forming a structure usable in the fabrication of manufactured products or components. A compound composite structure is composed of a thermoplastic resin material bonded to, by mixture with, a composite reinforcing structure. The composite reinforcing structure consists of fibers imbedded in a thermoplastic resin material. The composite reinforcing structure may be formed by passing extruded plastic resin material through a die which imbeds fibers. The compound composite structure may be formed by mounting a preformed composite reinforcing structure in a molding die and by injecting thermoplastic resin material into the molding die.

What is claimed is: 
     
       1. A method of manufacturing a composite reinforcing structure comprising the steps of: extruding a mass of fluid thermoplastic resin material in a flowable state and having no discrete shape into and longitudinally through an elongated, stationary die having no relatively movable components, said die having a continuous, fully open central passage extending longitudinally therethrough, and a plurality of lobes projecting radially inwardly into said central passage from spaced apart locations along the length of the inside, opposite side walls of said central passage in interleaving relation to each other to form a convoluted passage through which said thermoplastic resin material flows;   simultaneously introducing a plurality of continuous lengths of reinforcing fiber strands into said die central passage at different locations therein;   separately passing each of said fiber strands longitudinally within and along the length of said central passage over and between said interleaving lobes in the presence of said flowing mass of thermoplastic material to thoroughly contact and coat each of said fiber strands with said thermoplastic material; and   drawing said thermoplastic resin material and said coated fiber strands from said die, longitudinally thereof, to thereby produce a solid plastic .[.rod.]. member having said fiber strands extending longitudinally therein generally parallel to the longitudinal axis of said .[.rod.]. member inside of said plastic material.   
     
     
       2. The method of claim 1 further including a step of mixing a bonding additive with said thermoplastic resin material.