Methods of producing thermoplastic composites using fabric-based thermoplastic prepregs

Abstract

A thermoplastic product includes a fabric-based reinforcing sheet and a polymerized thermoplastic material. The fabric-based reinforcing sheet is wound about a mandrel to form a plurality of layers having a cross-sectional shape that corresponds to the mandrel. The fabric-based reinforcing sheet includes a plurality of fiber bundles, which may have a bidirectional orientation or configuration. A polymerized thermoplastic material is disposed within each layer of the fabric-based reinforcing sheet. The polymerized thermoplastic material bonds each layer of the fabric-based reinforcing sheet to an adjacent layer.

What is claimed is: 
     
         1 . A thermoplastic product comprising:
 a main body comprising:
 a single fiber-based reinforcing sheet that is wound about a mandrel to form a plurality of layers of the fiber-based reinforcing sheet having a cross-sectional shape corresponding to the mandrel, the fiber-based reinforcing sheet comprising a nonwoven material having randomly oriented entangled fibers; and 
 a polymerized thermoplastic material within each layer of the fiber-based reinforcing sheet, the polymerized thermoplastic material bonding each layer of the fiber-based reinforcing sheet to an adjacent layer of the fiber-based reinforcing sheet; 
 wherein the plurality of layers of the fiber-based reinforcing sheet and the polymerized thermoplastic material form a unitary thermoplastic product; and wherein the fiber-based reinforcing sheet is wound about the mandrel while the fiber-based reinforcing sheet is oriented circumferentially such that edges of each layer of the plurality of layers are parallel with the circumferential direction of the mandrel. 
   
     
     
         2 . The thermoplastic product of  claim 1 , wherein the thermoplastic product comprises a hollow interior. 
     
     
         3 . The thermoplastic product of  claim 1 , wherein the mandrel is maintained within an interior of the thermoplastic product. 
     
     
         4 . The thermoplastic product of  claim 1 , wherein the main body comprises a cylindrical configuration. 
     
     
         5 . The thermoplastic product of  claim 1 , wherein the main body comprises a non-circular shaped cross section. 
     
     
         6 . The thermoplastic product of  claim 1 , wherein fibers of the fiber-based reinforcing sheet consists of randomly oriented entangled fibers. 
     
     
         7 . The thermoplastic product of  claim 1 , wherein the fiber-based reinforcing sheet further comprises a plurality of fiber bundles that are oriented along a first direction and a second direction having an angled orientation relative to the first direction. 
     
     
         8 . A reinforced thermoplastic product comprising:
 a tube shaped main body having a hollow interior, the tube shaped main body comprising:
 a fiber-based reinforcing sheet that is positioned about an axis of the tube shaped main body so as to form a plurality of circumferentially positioned layers, the fiber-based reinforcing sheet including a nonwoven material having randomly oriented entangled fibers; and 
 a thermoplastic polymer material that is saturated within each of the circumferentially positioned layers of the fiber-based reinforcing sheet; 
   wherein the layers of the fiber-based reinforcing sheet and the thermoplastic polymer material form a unitary thermoplastic product;   wherein the fiber-based reinforcing sheet comprises chopped fibers; and   wherein the fiber-based reinforcing sheet is oriented circumferentially about the axis of the tube shaped main body such that edges of each layer of the plurality of circumferentially positioned layers are oriented parallel with the circumferential direction of the tube shaped main body.   
     
     
         9 . The reinforced thermoplastic product of  claim 8 , wherein the tube shaped main body comprises a cylindrical configuration. 
     
     
         10 . The reinforced thermoplastic product of  claim 8 , wherein the tube shaped main body comprises a non-circular shaped cross section. 
     
     
         11 . The reinforced thermoplastic product of  claim 8 , wherein the tube shaped main body includes one or more layers of the fiber-based reinforcing sheet. 
     
     
         12 . The reinforced thermoplastic product of  claim 8 , wherein the fiber-based reinforcing sheet further comprises continuous fibers. 
     
     
         13 . The reinforced thermoplastic product of  claim 12 , wherein the continuous fibers consist of a plurality of fiber bundles that are oriented along a first direction and a second direction, the second direction having an angled orientation relative to the first direction. 
     
     
         14 . The reinforced thermoplastic product of  claim 13 , wherein the first direction is aligned with the axis of the tube shaped main body or the second direction is aligned circumferentially around the tube shaped main body. 
     
     
         15 . The reinforced thermoplastic product of  claim 12 , wherein fibers of the fiber-based reinforcing sheet consist of chopped fibers. 
     
     
         16 . The reinforced thermoplastic product of  claim 8 , wherein fibers of the fiber-based reinforcing sheet comprise carbon fibers, basalt fibers, metal fibers, ceramic fiber, natural fibers, synthetic organic fibers, aramid fibers, or other inorganic fibers. 
     
     
         17 . The reinforced thermoplastic product of  claim 8 , wherein fibers of the fiber-based reinforcing sheet include a fiber sizing that enhances bonding between the fibers and the thermoplastic polymer material. 
     
     
         18 . A method of forming a reinforced thermoplastic product, the method comprising:
 providing the fiber-based reinforcing sheet of  claim 1 ; and   winding the fiber-based reinforcing sheet about a mandrel to form a plurality of layers of the fiber-based reinforcing sheet around the mandrel;   wherein the fiber-based reinforcing sheet is oriented circumferentially about the mandrel such that edges of each layer of the plurality of layers are parallel with a circumferential direction of the mandrel.   
     
     
         19 . The method of  claim 18 , further comprising applying heat to the fiber-based reinforcing sheet as it is wound about the mandrel. 
     
     
         20 . The method of  claim 19 , further comprising applying pressure to the fiber-based reinforcing sheet as it is wound abo