System and method for directing a fluid through a die

Abstract

The present invention relates to a system and method for directing a fluid through a die. One embodiment of the present invention is especially useful to thoroughly cool an extrudate by directing a cooling fluid toward a surface of the extrudate (e.g., an interior surface that defines a hollow portion of an extrudate). In another embodiment of the present invention, a fluid may be directed through a die for forming a layer or portion of a product. More particularly, a fluid may be directed through a die to form an external or core layer of a product from a foamed or unfoamed material including, but not limited to, a cellulosic-filled plastic composite. For example, the present invention includes a system and method for through the die foaming of extruded products.

What is claimed is:  
     
         1 . A method for directing fluid through a die, said method comprising: 
 providing a die, said die having a flow channel and a passage, said passage lined with an insulating material;    extruding a material through said flow channel;    directing a fluid through said passage;    forming a product of said material extruded through said flow channel, said product having a hollow; and    releasing said fluid from said passage into said hollow of said product.    
     
     
         2 . The method of  claim 1  wherein said insulating material is selected from the group consisting of ceramic insulation and putty ceramics.  
     
     
         3 . The method of  claim 1  wherein said material is a cellulosic-filled plastic composite.  
     
     
         4 . The method of  claim 1  wherein said fluid is a cellulosic-filled plastic composite.  
     
     
         5 . The method of  claim 1  wherein said fluid is a foamed plastic.  
     
     
         6 . The method of  claim 1  wherein said fluid is a cooling fluid.  
     
     
         7 . The method of  claim 6  wherein said cooling fluid has a temperature between about 80 degrees Fahrenheit and about minus 325 degrees Fahrenheit.  
     
     
         8 . The method of  claim 6  wherein said cooling fluid has a temperature between about 68 degrees Fahrenheit and about minus 300 degrees Fahrenheit.  
     
     
         9 . The method of  claim 6  wherein said cooling fluid has a temperature between about 32 degrees Fahrenheit and about minus 275 degrees Fahrenheit.  
     
     
         10 . The method of  claim 6  wherein said cooling fluid has a temperature between about minus 100 degrees Fahrenheit and about minus 250 degrees Fahrenheit.  
     
     
         11 . The method of  claim 6  wherein said cooling fluid is selected from liquid oxygen, liquid nitrogen, liquid neon, liquid hydrogen, and liquid helium.  
     
     
         12 . The method of  claim 6  wherein said cooling fluid is selected from the group consisting of liquids, gases, and vapors.  
     
     
         13 . The method of  claim 1  wherein said fluid is extruded through said passage.  
     
     
         14 . The method of  claim 1  wherein said passage intersects said flow channel.  
     
     
         15 . A die adapted to be used with at least one extruder, said die comprising: 
 a flow channel adapted to receive extruded material and form a product having a hollow; and    a passage adapted to receive a fluid, said passage lined with an insulating material;    wherein said passage is adapted to release said fluid in said hollow of said product.    
     
     
         16 . The die of  claim 15  wherein said insulating material is selected from the group consisting of ceramic insulation and putty ceramics.  
     
     
         17 . The die of  claim 15  wherein: 
 said flow channel is adapted to be in fluid communication with a first extruder; and  
 said passage is adapted to be in fluid communication with a second extruder.  
 
     
     
         18 . A die adapted to be used with at least one extruder, said die comprising: 
 a flow channel adapted to receive extruded material and form a product having a hollow; and    a passage intersecting said flow channel, said passage adapted to receive a fluid, said passage lined with an insulating material;    wherein said passage is adapted to release said fluid in said hollow of said product.    
     
     
         19 . The die of  claim 18  wherein said insulating material is selected from the group consisting of ceramic insulation and putty ceramics.  
     
     
         20 . The die of  claim 18  wherein: 
 said flow channel is adapted to be in fluid communication with a first extruder; and  
 said passage is adapted to be in fluid communication with a second extruder.