Method for attaching fibrous batt to plastic substrate

Abstract

An improved, economical, high speed method for attaching a fibrous material to a plastic substrate involves positioning a fibrous material over a surface of a plastic substrate, directing a stream of heated air through the fibrous material and at the surface of the plastic substrate to melt the surface of the plastic substrate, compressing the fibrous material against the melted surface of the plastic substrate, and allowing the melted surface of the plastic substrate to cool and resolidify, whereby fibers of the fibrous material become embedded in the resolidified plastic.

The invention claimed is:  
     
         1 . A method of attaching a fibrous material to a plastic substrate comprising: 
 positioning the fibrous material over a surface of the plastic substrate;    directing a stream of heated air through the fibrous material and at the surface of the plastic substrate, the quantity and temperature of the heated air being sufficient to melt the surface of the plastic substrate;    compressing the fibrous material against the melted surface of the plastic substrate to cause fibers of the fibrous material to become immersed in the melted surface of the plastic substrate; and    allowing the melted surface of the plastic substrate to cool and resolidify, thereby embedding fibers of the fibrous material in the resolidified plastic.    
     
     
         2 . The method of  claim 1 , wherein the fibrous material is compressed by pressing a workpiece-engaging surface of a tool against the fibrous material, and wherein the stream of heated air is directed from the workpiece-engaging surface of the tool.  
     
     
         3 . The method of  claim 2 , wherein the workpiece-engaging surface of the tool is substantially flat.  
     
     
         4 . The method of  claim 3 , wherein the workpiece-engaging surface of the tool includes a plurality of passageways in communication with a supply of heated, pressurized air.  
     
     
         5 . The method of  claim 4 , wherein the plurality of passageways include a single passageway located at the center of the workpiece-engaging surface of the tool, and the remaining passageways are located near an edge of the workpiece-engaging surface of the tool.  
     
     
         6 . The method of  claim 5 , wherein each of the passageways, except for the passageway at the center of the workpiece-engaging surface, are about {fraction (1/16)} inch or less from an edge of the workpiece-engaging surface.  
     
     
         7 . The method of  claim 4 , wherein the workpiece-engaging surface of the tool has exactly five passageways including a passageway located at the center of the workpiece-engaging surface, and with each of the other four passageways located near an edge of the workpiece-engaging surface.  
     
     
         8 . The method of  claim 7 , wherein each of the passageways located near the edge of the workpiece-engaging surface is about {fraction (1/16)} inch or less from an edge of the workpiece-engaging surface.  
     
     
         9 . The method of  claim 6 , wherein the passageways near the edge of the workpiece-engaging surface are uniformly angularly spaced apart around the center of the workpiece-engaging surface.  
     
     
         10 . The method of  claim 2 , wherein the tool is made of brass.  
     
     
         11 . The method of  claim 2 , wherein the tool is made of ceramic.  
     
     
         12 . The method of  claim 2 , wherein the cumulative cross-sectional area of the passageways is about equivalent to the cross-sectional area of a single one-quarter inch diameter passageway.  
     
     
         13 . The method of  claim 8 , wherein each of the passageways has a cross-sectional diameter of about 0.063 inches.  
     
     
         14 . The method of  claim 1 , wherein the fibrous material is a shotty comprised of shredded and needled plastic materials.  
     
     
         15 . The method of  claim 1 , wherein the fibrous material is comprised of natural fibers, synthetic fibers, glass fibers or a combination thereof.  
     
     
         16 . The method of  claim 1 , wherein the plastic substrate is a polypropylene substrate, and ABS substrate, or a PET substrate.  
     
     
         17 . The method of  claim 1 , wherein the flow rate of the directed stream of heated air through the fibrous material is about 80 SCFM.  
     
     
         18 . The method of  claim 1 , wherein the fibrous material is compressed at a pressure of about 80 psi.