Method for manufacture of tubular multilayer structure from fiber-resin material

Abstract

A method of manufacturing a tubular multilayer structure made from a continuous fiber pre-impregnated with a thermoplastic resin includes feeding the material to a shaping station before the material is wound around the mandrel. The material is heated over a shaped hot plate while in the shaping station to lightly melt the material. The material is tensioned to at least 15,000 psi before the material is wound around the mandrel to ensure good bonding of the wound layers.

What is claimed is:  
     
         1 . In a method for manufacturing a tubular multilayer structure open at both axial ends wherein the tubular structure is made of a material comprising a continuous fiber pre-impregnated with a thermoplastic resin and wherein the tubular structure is formed by winding the material around a rotating heated mandrel, the improvement being in feeding the material from a supply station to a shaping station before the material is wound around the mandrel, heating the material over a shaped hot plate while in the shaping station to lightly melt the material without heating the entire wound structure, and tensioning the material to at least 15,000 psi before the material is wound around the mandrel to ensure good bonding of the wound layers.  
     
     
         2 . The method of  claim 1  wherein the material is tensioned in the range of 15,000-25,000 psi.  
     
     
         3 . The method of  claim 2  wherein the material is tensioned in the range of 20,000-25,000 psi.  
     
     
         4 . The method of  claim 1  wherein the material is tensioned at a tensioning station located upstream from the shaping station.  
     
     
         5 . The method of  claim 4  wherein the supply station and the tensioning station and the shaping station are mounted on a reciprocating table which moves parallel to the mandrel.  
     
     
         6 . The method of  claim 5  wherein the material is a continuous carbon fiber composite.  
     
     
         7 . The method of  claim 1  wherein the material is tensioned at a tensioning station located upstream from the shaping station.  
     
     
         8 . The method of  claim 1  wherein the material is a continuous carbon fiber composite.