Infusion fabric allowing high resin infusion rates

Abstract

A reinforcement fabric includes a first layer of collimated continuous fibers, a second layer selected from a group consisting of veil, continuous filament mat, chopped strand mat, direct chopped mat, direct continuous mat, collimated continuous fibers, woven fabric, non-woven fabric, scrim and combinations thereof as well as a surface adhesive that adheres the first and second layers together. The surface adhesive is selected from a group consisting of hot melt adhesive and web bonded adhesive. The surface adhesive has a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 1300 at application temperature. A method is also provided for the production of the reinforcement fabric.

1 . A reinforcement fabric, comprising:
 a first layer of collimated continuous fibers;   a second layer selected from a group consisting of veil, continuous filament mat, chopped strand mat, direct chopped mat, direct continuous mat, collimated continuous fibers, woven fabric, non-woven fabric, scrim and combinations thereof; and   a surface adhesive, said surface adhesive adhering said first and second layers together, said surface adhesive being selected from a group consisting of a hot melt adhesive and a web bonded adhesive, said surfacing adhesive having a melt flow index range of about 5 to about 500 at melt temperature and about 900 to about 2500 at application temperature.   
     
     
         2 . The reinforcement fabric of  claim 1  wherein said reinforcement fabric is stitchless. 
     
     
         3 . The reinforcement fabric of  claim 1 , wherein said collimated continuous fibers are selected from a group of materials consisting of glass fibers, carbon fibers, graphite fibers, vitreous carbon fibers, non-graphite carbon fibers, boron monolithic graphite fibers, boron monolithic non-graphite carbon fibers, silicone, aramid, ceramic fibers, thermoset polymer fibers, thermoplastic polymer fibers, natural fibers and mixtures thereof. 
     
     
         4 . The reinforcement fabric of  claim 1 , wherein said second layer is constructed from a material selected from a group of materials consisting of glass fibers, carbon fibers, graphite fibers, vitreous carbon fibers, non-graphite carbon fibers, boron monolithic graphite fibers, boron monolithic non-graphite carbon fibers, silicone, aramid, ceramic fibers, thermoset polymer fibers, thermoplastic polymer fibers, natural fibers and mixtures thereof. 
     
     
         5 . The reinforcement fabric of  claim 1 , wherein said collimated continuous fibers have a strand size of between about 100 to about 10,000 tex and a filament diameter of between about 9 to about 30 microns. 
     
     
         6 . The reinforcement fabric of  claim 1 , wherein said collimated continuous fibers have a strand size of between about 600 to about 8,000 tex and a filament diameter of between about 12 to about 26 microns. 
     
     
         7 . The reinforcement fabric of  claim 1 , wherein said chopped fibers have a strand size of between about 1,000 to about 8,000 tex and a filament diameter of between about 6 to about 30 microns. 
     
     
         8 . The reinforcement fabric of  claim 7 , wherein said chopped fibers have a tex of between about 10 to about 1,000 in split strands. 
     
     
         9 . The reinforcement fabric of  claim 1 , wherein filaments in said veil are stranded, fully dispersed or a combination of stranded and fully dispersed. 
     
     
         10 . The reinforcement fabric of  claim 1 , further including a size including reagents selected from a group consisting of water, acetic acid, a lubricant, a film former, a silane coupling agent, a biocide and mixtures thereof. 
     
     
         11 . The reinforcement fabric of  claim 1 , wherein said surface adhesive is selected from a group consisting of PE, microcrystalline wax, EVA, modified EVA, ethylene-acrylic ester copolymer, ethylene-acrylic ester-maleic anhydride terpolymers, copolyesters, copolyamides, amorphous polypropylene, synthetic rubbers, acrylic block copolymers, and combinations thereof. 
     
     
         12 . The reinforcement fabric of  claim 1 , wherein said surface adhesive has a tack between about 0.5 and about 1 N/m. 
     
     
         13 . The reinforcement fabric of  claim 1 , wherein said reinforcement fabric has a weight per unit area of between about 0.5 and about 3 kg/sm and comprises between about 30 and about 80 weight percent first layer, between about 20 and about 70 weight percent second layer and between about 0.1 and about 2 weight percent surface adhesive. 
     
     
         14 . The reinforcement fabric of  claim 1 , wherein said surface adhesive is at a density of between about 2 and about 30 gsm. 
     
     
         15 . The reinforcement fabric of  claim 1 , wherein said first layer has a weight of between about 0.3 and about 1.5 kg/sm. 
     
     
         16 . The reinforcement fabric of  claim 1 , wherein said first layer has a porosity of between about 1000 and about 9000 l/sm/s. 
     
     
         17 . A method for producing a reinforcement fabric, comprising:
 forming a collimated sheet from continuous fibers;   providing a surface adhesive selected from a group consisting of a hot melt adhesive and a web bonded adhesive having a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 2500 at application temperature; and   consolidating said collimated sheet with a layer of material selected from a group consisting of veil, continuous filament mat, chopped strand mat, direct chopped mat, direct continuous mat, collimated continuous fibers, woven fabric, non-woven fabric, scrim and combinations thereof.   
     
     
         18 . The method of  claim 17  wherein said forming step includes feeding a plurality of continuous fibers from a creel. 
     
     
         19 . The method of  claim 17 , wherein said forming step includes providing said surface adhesive as a web. 
     
     
         20 . The method of  claim 17 , wherein said forming step includes making said surface adhesive into a web in line. 
     
     
         21 . The method of  claim 17 , wherein said forming step includes extruding said surface adhesive as a hot melt. 
     
     
         22 . The method of  claim 21 , including applying said hot melt adhesive in a pattern selected from a group consisting of a sinusoidal pattern, a loop pattern, a straight line pattern and combinations thereof. 
     
     
         23 . The method of  claim 17 , further including applying said surface adhesive at an areal density of between about 2 and about 30 gsm. 
     
     
         24 . The method of  claim 17 , further including completing said consolidating at a rate of between about 50 and about 500 meters/minute. 
     
     
         25 . The method of  claim 17 , further including utilizing surface adhesive having a tack of between about 0.5 and 1.0 N/m. 
     
     
         26 . A reinforcement fabric, comprising:
 a surfacing veil;   a continuous filament mat;   at least one sheet of collimated continuous fibers;   a layer of woven or non-woven fabric; and   a surface adhesive, said surface adhesive being selected from a group consisting of a hot melt adhesive and a web bonded adhesive having a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 2500 at application temperature.   
     
     
         27 . A reinforcement fabric, comprising:
 a surfacing veil;   a layer of chopped fibers;   a sheet of collimated continuous fibers;   an infusion media layer selected from a group of materials consisting of veil, continuous filament mat, chopped strand mat, direct chopped mat, direct continuous mat, collimated continuous fibers, woven fabric, non-woven fabric, scrim and combinations thereof;   a layer of woven fabric, non-woven fabric or chopped fibers; and   a surface adhesive, said surface adhesive being selected from a group consisting of a hot melt adhesive and a web bonded adhesive having a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 1300 at application temperature.   
     
     
         28 . A reinforcement fabric, comprising:
 a surfacing veil;   an infusion media layer selected from a group of materials consisting of veil, continuous filament mat, chopped strand mat, direct chopped mat, direct continuous mat, collimated continuous fibers, woven fabric, non-woven fabric, scrim and combinations thereof;   a sheet of collimated continuous fibers;   a first reinforcing layer of unidirectional fabric extending in a direction about +45 degrees relative to said collimated continuous fibers;   a second reinforcing layer of unidirectional fabric extending in a direction about −45 degrees relative to said collimated continuous fibers; and   a surface adhesive, said surface adhesive being selected from a group consisting of a hot melt adhesive and a web bonded adhesive having a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 2500 at application temperature.   
     
     
         29 . The reinforcement fabric of  claim 28 , further including a second sheet of collimated continuous fibers and a surfacing adhesive underlying said second reinforcing layer. 
     
     
         30 . A reinforcement fabric, comprising:
 a surfacing veil;   a continuous filament mat;   at least one sheet of collimated continuous fibers;   a first reinforcing layer of unidirectional fabric extending in a direction of about +45 degrees relative to said collimated continuous fibers;   a second reinforcing layer of unidirectional fabric extending in a direction of about −45 degrees relative to said collimated continuous fibers; and   a surface adhesive, said surface adhesive being selected from a group consisting of a hot melt adhesive and a web bonded adhesive having a melt flow index range of about 5 to about 500 at room temperature and about 900 to about 2500 at application temperature.   
     
     
         31 . The reinforcement fabric of  claim 30 , further comprising a layer of chopped fibers. 
     
     
         32 . The reinforcement fabric of  claim 30 , further including at least one additional reinforcing layer underlying said second reinforcing layer.