Pultruded part reinforced by longitudinal and transverse fibers and a method of manufacturing thereof

Abstract

A method for forming a pultruded part includes collating reinforcing fibers by providing a first layer of reinforcing rovings extending in the longitudinal pultrusion direction, applying onto the first layer an intermediate layer of reinforcing fibers at least some of which include at least portions thereof which extend in the transverse direction and covering the intermediate layer with a second layer of rovings extending in the longitudinal direction. To the collated fibers is applied a resin so as to permeate through the layers and the materials are passed through a die to set the resin. The first and second layers are arranged to form first and second opposed surfaces of the part with the intermediate layer therebetween. The resin is a two part urethane resin which has sufficient strength to prevent the fibers from the first and second layers at the first and second surfaces respectively from breaking through the surface on bending of the wall thus allowing the use of the rovings at the surfaces with the transverse fibers therebetween so that the transverse fibers can be formed from loose or chopped fiber material from rovings rather than more expensive mat.

We claim:  
     
         1 . A pultruded part comprising: 
 a wall having a first surface and a second surface spaced by a thickness of the part, the wall extending longitudinally in a pultrusion direction and having a transverse width transverse to the longitudinal pultrusion direction;    reinforcing fibers within the wall;    a non-linear resin material permeated through the fibers and filling the thickness between the surfaces so as to define the surfaces;    the reinforcing fibers including a first layer of fibers extending in the longitudinal pultrusion direction and located at the first surface;    the reinforcing fibers including a second layer of fibers extending in the longitudinal pultrusion direction and located at the second surface;    the reinforcing fibers including an intermediate layer of fibers at least some of which include at least portions thereof which extend in the transverse direction and located between the first and second layers.    
     
     
         2 . A pultruded part comprising: 
 a wall having a first surface and a second surface spaced by a thickness of the part, the wall extending longitudinally in a pultrusion direction and having a transverse width transverse to the longitudinal pultrusion direction;    the wall defining a peripheral wall fully surrounding a hollow interior such that the first surface faces outwardly and the second surface faces inwardly;    reinforcing fibers within the wall;    a non-linear resin material permeated through the fibers and filling the thickness between the surfaces so as to define the surfaces;    the reinforcing fibers including a first layer of fibers extending in the longitudinal pultrusion direction and located at the first surface;    the reinforcing fibers including a layer of fibers at least some of which include at least portions thereof which extend in the transverse direction and located at the second surface.    
     
     
         3 . The pultruded part according to  claim 1  wherein the resin is a cross-linked resin.  
     
     
         4 . The pultruded part according to  claim 1  wherein the resin is a urethane resin.  
     
     
         5 . The pultruded part according to  claim 4  wherein the resin is a two part material set by catalytic action.  
     
     
         6 . The pultruded part according to  claim 4  wherein the resin is thermo-set.  
     
     
         7 . The pultruded part according to  claim 1  wherein the transverse layer of fibers comprises a mat.  
     
     
         8 . The pultruded part according to  claim 1  wherein the transverse layer of fibers comprises a plurality of cut fibers.  
     
     
         9 . The pultruded part according to  claim 1  wherein the transverse layer of fibers comprises wholly cut fibers.  
     
     
         10 . The pultruded part according to  claim 1  wherein the transverse layer of fibers comprises primarily fibers extending transverse to the longitudinal direction.  
     
     
         11 . The pultruded part according to  claim 1  wherein the transverse layer of fibers comprises wholly fibers extending transverse to the longitudinal direction.  
     
     
         12 . The pultruded part according to  claim 1  wherein at least some of the fibers of the transverse layer of fibers are substantially straight and extend fully across the width of the part from one side to the other side.  
     
     
         13 . The pultruded part according to  claim 1  wherein the reinforcing fibers consist only of the first layer, the second layer and the transverse layer.  
     
     
         14 . The pultruded part according to  claim 1  wherein the transverse layer has a weight of less than 1 oz/square foot preferably less than 0.5 oz/square foot and more preferably less than 0.25 oz/square foot.  
     
     
         15 . The pultruded part according to  claim 1  wherein the transverse layer is a scrim or mesh having openings for penetration of the resin between the fibers.  
     
     
         16 . The pultruded part according to  claim 1  wherein the transverse layer is formed of glass or polymer fibers or metal strands.  
     
     
         17 . The pultruded part according to  claim 1  wherein the wall includes a leg portion thereof in which the reinforcing fibers consist solely of the longitudinal fibers.  
     
     
         18 . The pultruded part according to  claim 17  wherein the leg portion is connected to a main body portion only at one end so as to define a second free end.  
     
     
         19 . The pultruded part according to  claim 17  wherein the leg portion has a wall that is thicker than that of the main body portion.  
     
     
         20 . The pultruded part according to  claim 17  wherein the main body portion defines a hollow section and the leg portion extends from one end at the hollow section to an opposed free end.  
     
     
         21 . The pultruded part according to  claim 1  wherein the transverse fibers are formed of metal strands which provide both transverse strength and the characteristic of electrical conductivity and/or ferromagnetism for the part.