Process for molding a fiberglass reinforced article

Abstract

A process for producing fiberglass reinforced molded articles of superior surface quality involves preparation of a mat of glass fiber comprised of a majority of fibers having a diameter of less than one micron and a minority of fibers having a diameter greater than one micron. A sizing is applied to the fibers. The sizing includes a coupling agent preselected to be compatible with the moldable material, e.g. nylon. The glass fiber mat is comminuted into pieces shaped and dimensioned for combination with the moldable material to form a composite having a range of to 50% of glass fiber by weight. The composite is then molded by a conventional process to yield a fiberglass reinforced article with superior surface quality.

What is claimed is: 
     
       1. A process for molding an article reinforced with glass fiber without substantial impairment of surface quality comprising the steps of: preparing a mat of glass fiber .Iadd.from bulk glass fiber .Iaddend.comprised of a majority of .Iadd.smaller diameter .Iaddend.glass fibers having a diameter less than one micron and a minority of .Iadd.larger diameter .Iaddend.glass fibers having a diameter greater than one micron by applying to .Iadd.the .Iaddend.bulk .Iadd.glass .Iaddend.fiber sizing including up to 50% by weight of polymer compatible with . .the.!. .Iadd.a .Iaddend.moldable plastic material;   comminuting the mat of glass fiber into .Iadd.glass fiber mat .Iaddend.pieces shaped and dimensioned for combination with . .a.!. .Iadd.the .Iaddend.moldable .Iadd.plastic .Iaddend.material;   combining the glass fiber .Iadd.mat .Iaddend.pieces with the moldable .Iadd.plastic .Iaddend.material to define a moldable composite having a range of 2% to 50% of glass fiber by weight; and   molding the article from the composite.   
     
     
       2. The process of claim 1 wherein the majority of sub-micron glass fibers comprise 50-90% of the weight of the . .article.!. .Iadd.bulk glass fiber.Iaddend.. 
     
     
       3. The process of claim 1 wherein the larger diameter glass fibers have diameters in the range of . .6.!. .Iadd.3 .Iaddend.to 18 microns. 
     
     
       4. The process of claim 1 wherein the smaller diameter glass fibers have diameters in the range of 0.2 to 1 micron. 
     
     
       5. The process of claim 1 wherein the article is injection molded. 
     
     
       6. The process of claim 1 wherein the moldable .Iadd.plastic .Iaddend.material is a thermoplastic resin. 
     
     
       7. The process of claim 1 wherein the moldable .Iadd.plastic .Iaddend.material is a thermosetting resin. 
     
     
       8. The process of claim 1 wherein the mat of glass fiber . .product.!. is comminuted by cutting. 
     
     
       9. The process of claim 8 wherein the mat of glass fiber . .product.!. is cut into elongated strips. 
     
     
       10. The process of claim 8 wherein the mat of glass fiber . .product.!. is diced. 
     
     
       11. An article made in accordance with the process of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. 
     
     
       12. The process as defined in claim 1 wherein said polymer . .is.!. .Iadd.and .Iaddend.said moldable plastic .Iadd.are the same .Iaddend.material. 
     
     
       13. A process for making fiber-reinforced polymer products comprising: forming a layer of bulk fiber with a majority of parts by weight of glass fibers of less than 1 micron;   applying a sizing to said layer of bulk fiber including up to 50% of a predetermined polymer, said predetermined polymer being compatible with the polymer to be reinforced by the fiber;   drying said sized layer of bulk fiber to form a mat;   comminuting said mat into pieces and mixing said pieces with said . .predetermined.!. polymer .Iadd.to be reinforced .Iaddend.to form a moldable composite; and   molding the product from said composite .   
     
     
       14. The process as defined in claim 13 wherein said sizing comprises an aqueous emulsion.