Method and system for forming reinforcing fibers and reinforcing fibers having particulate protuberances directly attached to the surfaces

Abstract

Reinforcing fibers with small particles having a longest average dimension of approximately 0.01 nanometer to approximately 30 micrometers physically and/or chemically bonded directly to their surfaces to form protuberances thereon and a method and system for making these modified fibers are disclosed. The particles directly bonded to the surfaces of the fibers, serve to enhance physical properties of composite articles which incorporate such fibers as reinforcement.

1 - 14 . (canceled) 
   
   
       15 . Reinforcing fibers selected from the group consisting of glass, glassy material, ceramic material, carbonaceous material, metal, polymeric material, and mixtures thereof, having particulate protuberances attached directly to the surfaces thereof wherein the particles are physically and/or chemically bonded to the surfaces of the fibers with the particles forming such protuberances having a longest number average dimension within the range of approximately 0.01 nanometer to approximately 30 micrometers. 
   
   
       16 . Chopped reinforcing fibers selected from the group consisting of glass, glassy material, ceramic material, carbonaceous material, metal, polymeric material, and mixtures thereof, having particulate protuberances on the surfaces thereof wherein the particles are physically and/or chemically bonded to the surfaces of the fibers with the particles forming such protuberances having a longest number average dimension within the range of approximately 2 nanometers to approximately 30 micrometers and the reinforcing fibers having average lengths of approximately 2 mm to approximately 250 mm. 
   
   
       17 . A fibrous mat comprising reinforcing fibers selected from the group consisting of glass, glassy material, ceramic material, carbonaceous material, polymeric material, and mixtures thereof, having particulate protuberances on the surfaces thereof wherein the particles are physically and/or chemically bonded to the surfaces of the fibers with the particles forming such protuberances having a longest number average dimension within the range of approximately 2 nanometers to approximately 30 micrometers. 
   
   
       18 . A method for forming a moldable mixture containing fibers having particulate protuberances physically and/or chemically directly bonded to the surfaces thereof, comprising dispersing such fibers in a matrix material selected from a group consisting of thermoplastic polymer, thermosetting polymer, polymer precursor, ceramic forming material, asphalt, bitumen, metal, alloy, glass, glassy material, hydraulic setting material, and mixtures thereof, to form a mixture suitable for forming fiber reinforced or long-fiber reinforced composite products with the particles forming such protuberances having a longest number average dimension of approximately 0.01 nanometer to approximately 30 micrometers. 
   
   
       19 . The method of  claim 18 , further comprising the step of forming the mixture into pellets. 
   
   
       20 . The method of  claim 18 , wherein the fibers having adhering particulate protuberances have average lengths in the range of approximately 2 mm to approximately 250 mm. 
   
   
       21 . The method of  claim 18 , wherein the matrix material is polymeric and additionally includes regrind, recycle, and/or reclaim. 
   
   
       22 . The method of  claim 18  wherein the matrix material is selected from the group consisting of polyolefins, polyamides, polyesters, polycarbonates, polyacetals, styrenic polymers, polyethers, polyetheretherketones, urethanes, liquid crystal polymers, polybenzimidazoles, polyether sulfones, polyphenylene sulfides, and thermosetting polymers. 
   
   
       23 . A fiber reinforced or long-fiber reinforced composite article formed by the molding of the molded mixture produced by the method of  claim 18 . 
   
   
       24 . A system for forming reinforcing fibers having particulate protuberances physically and/or chemically directly attached to the surfaces of the fibers, the system comprising a device having a bottom surface for forming a molten material into fibers, a device for suspending particles having a number average longest dimension in the range of approximately 0.01 nanometer to approximately 30 micrometers in a fluid, a device for spraying the suspension of particles onto the surfaces of the fibers in a region within about 50 centimeters from the bottom surface of the device for forming a molten material into fibers, and a device for pulling the fibers through said region.