Method Of Compression Molding Motor Vehicle Components And Parts Made Therefrom

Abstract

The invention is a method to make compression molded motor vehicle parts from a charge of composite material with resin and fibers, such as sheet molded compound. The parts have voids, such as holes and gaps, that form in the compression mold under heat and pressure and not in secondary processing steps. The resin in the charge is melts in a reservoir in the mold to form resinous material from the charge. A flow front of resinous material is allowed to flow into a flow path around a restriction corresponding to the shape of the void from the reservoir. The flow front carries sufficient reinforcing fibers into the flow path. At least part of a border for the void forms in the flow path. The configuration is allowed to at least partially set.

1 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers during compression molding, the method comprising the steps of:
 providing complementary first and second mold portions;   placing a charge of the composite material into a reservoir in one of the mold portions;   closing the first and second mold portions to form a mold having a restriction, and a flow path bordering the restriction and being in fluid communication with the reservoir;   melting the resin in the charge with heat and pressure applied to the closed mold to form resinous material within the mold;   forming a flow front of resinous material;   allowing the flow front of resinous material to flow from the reservoir into the flow path;   allowing sufficient reinforcing fibers in the resinous material to flow into the flow path;   forming a configuration of the part within the closed mold under heat and pressure;   at least partially setting the configuration of the part within the closed mold;   forming a border defining at least part of a void in the configuration within the flow path in the closed mold at the restriction; and   wherein at least part of the border forms from the resinous material in the flow path.   
     
     
         2 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 1 , wherein all of the void in the configuration of the part forms in the closed mold. 
     
     
         3 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 1 , the method further comprising the step of:
 keeping at least part of the flow path free from the charge of composite material before melting the resin in the charge.   
     
     
         4 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 3 , wherein the flow path is constricted. 
     
     
         5 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 4 , wherein the resin is a thermoset. 
     
     
         6 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 5 , wherein the fibers are glass. 
     
     
         7 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 4 , wherein the charge is sheet molding compound. 
     
     
         8 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 1 , the method further comprising the steps of:
 forming a second flow front of resinous material;   allowing the second flow front of resinous material to flow into the flow path bordering the restriction from a second direction and to meet the first flow front; and   wherein sufficient reinforcing fibers are located where the first and second flow fronts meet.   
     
     
         9 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 8 , wherein the resin is a thermoset. 
     
     
         10 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 9 , wherein the fibers are glass. 
     
     
         11 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 8 , wherein the charge is sheet molding compound. 
     
     
         12 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 1 , the method further comprising the steps of:
 providing an additional restriction in the closed mold;   providing an additional flow path bordering the additional restriction in the closed mold;   forming an additional flow front of resinous material;   allowing the additional flow front to flow into the additional flow path bordering the additional restriction;   allowing sufficient reinforcing fibers in the resinous material to flow into the additional flow path; and   forming an additional void in the configuration within the closed mold at the additional restriction under heat and pressure.   
     
     
         13 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 12 , the method further comprising the step of:
 keeping at least part of the flow paths free from the charge of composite material before melting the resin in the charge.   
     
     
         14 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 13 , wherein the resin is a thermoset. 
     
     
         15 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 14 , wherein the fibers are glass. 
     
     
         16 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 13 , wherein the charge is sheet molding compound. 
     
     
         17 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 12 , the method further comprising the steps of:
 forming a second flow front of resinous material around one of the restrictions;   allowing the second flow front of resinous material to flow into one of the flow paths bordering one of the restrictions from a second direction and to meet the one of the flow fronts; and   wherein sufficient reinforcing fibers are located where the second flow front meets one of the flow fronts.   
     
     
         18 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 17 , wherein the void corresponds to an opening in the configuration. 
     
     
         19 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 18 , wherein the additional void corresponds to a gap in the configuration. 
     
     
         20 . A method of making a motor vehicle part from a composite material comprising a resin, and fibers of  claim 19 , wherein the additional flow path corresponds to a finger in the configuration. 
     
     
         21 - 25 . (canceled)