Thermal Shroud and Method of Making Same

Abstract

An injection molding hot runner nozzle and a method of making such a nozzle are disclosed that improves heat transfer along the length of the nozzle. The nozzle includes a nozzle body and a heating element located on an outer surface of the nozzle body having a form-fitting thermally conductive shroud that conforms to a profile of the nozzle and the heating element.

1 - 26 . (canceled) 
   
   
       27 . An injection molding nozzle comprising:
 a nozzle body defining a melt channel and having a heating element groove in an outer surface thereof;   a heating element disposed in the heating element groove of the nozzle body; and   a tubular thermal shroud coupled to the nozzle body and the heating element combination wherein the tubular thermal shroud contacts and is intimately form fit over each of the nozzle body and the heating element such that an inner diameter of the tubular thermal shroud varies along a longitudinal length thereof.   
   
   
       28 . The nozzle of  claim 27 , wherein the tubular thermal shroud is made of a material that is more thermally conductive than a material used to form the nozzle body. 
   
   
       29 . The nozzle of  claim 28 , wherein the material of the tubular thermal shroud is selected from a group consisting of copper, a copper alloy, aluminum and an aluminum alloy. 
   
   
       30 . The nozzle of  claim 27 , wherein the heating element extends radially outward beyond the outer surface of the nozzle body. 
   
   
       31 . The nozzle of  claim 27 , wherein the heating element is substantially flush with the outer surface of the nozzle body. 
   
   
       32 . The nozzle of  claim 27 , wherein the heating element is recessed from the outer surface of the nozzle body. 
   
   
       33 . The nozzle of  claim 27 , wherein an outer diameter of the tubular thermal shroud varies along the longitudinal length thereof. 
   
   
       34 . The nozzle of  claim 33 , wherein the inner and outer diameters of the tubular thermal shroud generally match the profile of the combined nozzle body and heating element. 
   
   
       35 . The nozzle of  claim 27 , wherein a contour of the heating element is formed in an outer surface of the tubular thermal shroud. 
   
   
       36 . An injection molding nozzle comprising:
 a nozzle body defining a melt channel and having a heating element groove in an outer surface thereof;   a heating element disposed in the heating element groove of the nozzle body to be recessed within the outer surface of the nozzle body; and   a tubular thermal shroud disposed over the nozzle body and the heating element, wherein the tubular thermal shroud directly contacts the nozzle body and the heating element, and wherein inner and outer diameters of the tubular thermal shroud vary along a longitudinal length of the tubular thermal shroud such that the tubular thermal shroud is intimately form fit to the combined nozzle body and the heating element to be at least partially recessed within the outer surface of the nozzle body.   
   
   
       37 . The nozzle of  claim 36 , wherein the tubular thermal shroud is formed from a material that is more thermally conductive than a material that forms the nozzle body. 
   
   
       38 . The nozzle of  claim 36 , wherein the inner and outer diameters of the tubular thermal shroud generally match the profile of the combined nozzle body and heating element. 
   
   
       39 . An injection molding nozzle comprising:
 a nozzle body defining a melt channel;   a heating element wound around an outer surface of the nozzle body; and   a tubular thermal shroud intimately form fit over the nozzle body and the heating element, wherein a contour of the heating element is formed in an outer surface of the tubular thermal shroud.   
   
   
       40 . The nozzle of  claim 39 , wherein inner and outer diameters of the tubular thermal shroud generally match the profile of the nozzle body and heating element thereunder. 
   
   
       41 . The nozzle of  claim 39 , wherein the tubular thermal shroud is formed from a material that is more thermally conductive than a material that forms the nozzle body.