Hollow wall base

Abstract

A method for manufacturing a flexible, extruded plastic wall base with a hollow core is presented. The method includes using extrusion die for heating and extruding plastics using a multi-functional insert within the die and air pressure to create a hollow core in the wall base. The hollow core allows less material to flow though the die so that the die stays hotter and the flow of the extruded plastic is not impeded. The resulting extruded plastic wall base is comprised of a generally thick portion, a generally thin portion and a profile on the face or front of the wall base.

1 . A method for making a hollow wall base from an extrudable thermoplastic material, said method comprising the steps of: 
 extruding heated back layer material from a first extruder;    extruding heated top coat layer from a second extruder;    fusing said top coat material onto said base material, forming fluid plastic material;    passing said fluid material into a die, the die having multi-functional inserts for forming a profile and spaces in the wall base to provide generally uniform wall thickness, the fluid material passing over the multi-functional insert;    applying air under pressure through appropriate passages in said die to temporarily lift and detach a front wall from said fluid material;    running cool water onto said front wall to cool said front wall;    pulling said wall base into at least one cooling tank, cooling said wall base;    using a mechanical puller to pull said wall base out of said at least one cooling tank;    passing said wall base into a cutter to cut the wall base into desired lengths; and    withdrawing the wall base.    
   
   
       2 . The method according to  claim 1  wherein the temperature in the die is between 300° F. and 325° F.  
   
   
       3 . The method according to  claim 1  wherein air pressure of about 2 psi is applied for about 2 to 3 seconds.  
   
   
       4 . The method according to  claim 1  wherein the profile formed by the multi-functional inserts is a wedge-shaped base with a lip at the bottom.  
   
   
       5 . The method according to  claim 1  wherein the profile formed by the multi-functional inserts is an undulating profile on a flat surface  
   
   
       6 . The method according to  claim 1  wherein the profile formed by the multi-functional inserts is one of regular and irregular curves.  
   
   
       7 . The method according to  claim 1  wherein the profile formed by the multi-functional inserts is multiple inclines.  
   
   
       8 . The method according to  claim 1  wherein the die is steel.  
   
   
       9 . A hollow wall base of varying thickness comprising: 
 a front wall defining a profile with portions of unequal thickness; and    spaces running through the wall base to define walls of generally uniform thickness.    
   
   
       10 . A hollow wall base having at least a partially undulating profile, said wall base comprising: 
 a thermoplastic body portion having a back wall having a generally flat configuration and an undulating front wall having an undulating configuration;    interior walls defining a space within said wall base, said walls being of generally uniform thickness and generally following the configuration of said front wall and said back wall.    
   
   
       11 . A hollow wall base according to  claim 10  wherein said front wall further has a generally flat front wall portion and said interior walls including supports extending between said flat front wall portion and said back wall.