Post-Forming of Thermoplastic Ducts

Abstract

An apparatus and method are provided for thermoplastically forming a contour in a thermoplastic duct defining a passage. The apparatus includes a longitudinal collar that defines a cavity and a rigid inner support structure extending longitudinally in the cavity. The collar and/or the inner support structure define a mold contour. One or more heaters are configured to heat at least a formation portion of the duct to a formation temperature. An expansion member, such as an expandable elastomer, which is disposed between an inner surface of the collar and an outer surface of the inner support structure, is configured to urge the formation portion of the duct against the mold contour to thermoplastically form the duct.

1 . A method of thermoplastically forming a contour in a thermoplastic duct, the method comprising: 
 providing a thermoplastic duct between a collar and an inner support structure;    heating at least a formation portion of the duct to at least a formation temperature; and    urging an expansion member against the duct to thermoplastically form the formation portion of the duct radially against a mold contour defined by one of the collar and inner support structure.    
   
   
       2 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said providing step comprises providing a cured thermoplastic duct formed of a reinforced thermoplastic composite material.  
   
   
       3 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said heating step comprises heating the formation portion of the duct to a temperature of at least a glass transition temperature.  
   
   
       4 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said urging step comprises expanding the expansion member radially outward against the formation portion of the duct to urge the formation portion against the collar.  
   
   
       5 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 4 , wherein said expanding step comprises adjusting a longitudinal width of a channel to compress the expansion member in the longitudinal direction and expand the expansion member radially outward.  
   
   
       6 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 4 , wherein said urging step comprises delivering fluid to an inflatable bladder to inflate the bladder and expand the bladder radially outward against the formation portion of the duct.  
   
   
       7 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said urging step comprises expanding the expansion member radially inward against the formation portion of the duct to urge the formation portion against the inner support structure.  
   
   
       8 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said urging step comprises heating the expansion member to expand the expansion member radially to form the formation portion of the duct.  
   
   
       9 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , further comprising separably adjusting at least one portion of the collar to remove the duct therefrom.  
   
   
       10 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , wherein said heating step comprises electrically energizing at least one resistive heater to generate heat and conducting heat from the at least one heater to the formation portion of the duct.  
   
   
       11 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , further comprising, subsequent to said heating step and at least partially concurrent to said urging step, cooling the joint to a temperature at least less than a glass transition temperature.  
   
   
       12 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , further comprising providing the collar and the inner support structure, the collar extending longitudinally from a first end to a second end and having an inner surface extending at least partially between the first and second ends, the inner surface defining a cavity, the inner support structure extending longitudinally in the cavity and having an outer surface opposing the inner surface of the collar, the collar defining a mold contour, the expansion member being formed of an elastomeric material, the inner support structure defining a channel for receiving the expansion member, and a width of the channel being adjustable in the longitudinal direction of the collar to compress the expansion member in the longitudinal direction and urge the expansion member radially toward the mold contour such that the expansion member is configured to urge a formation portion of the duct against the mold contour and thereby thermoplastically form the duct.  
   
   
       13 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 12  wherein said heating step comprises providing a plurality of heaters extending at least partially through the inner support structure and configured to heat a formation portion of the duct to at least a formation temperature.  
   
   
       14 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1 , further comprising providing the inner support structure, the inner support structure being a rigid structure extending longitudinally in a cavity of the collar and including first and second portions, the first portion defining a face having an aperture configured to at least partially and longitudinally receive the second portion, and at least one heater extending at least partially through the inner support structure and configured to be disposed within the passage of the duct.  
   
   
       15 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1  wherein said heating step comprises heating the duct with a plurality of heaters extending at least partially through said inner support structure.  
   
   
       16 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 1  wherein said heating step comprises heating the duct with at least one heater positioned radially outside the collar and configured to radiate heat radially inward to the duct.  
   
   
       17 . A method of thermoplastically forming a contour in a thermoplastic duct, the method comprising: 
 configuring a rigid inner support structure to extend longitudinally in a passage of the duct such that a mold contour defined by an outer surface of the inner support structure and corresponding to a desired configuration of the duct is located proximate to a formation portion of the duct;    disposing heat shrinkable tape circumferentially around the formation portion of the duct; and    heating the heat shrinkable tape and at least a formation portion of the duct to at least a formation temperature, such that the tape contracts radially inward urging the formation portion of the duct radially against the mold contour and thermoplastically forming the duct.    
   
   
       18 . A method of thermoplastically forming a contour in a thermoplastic duct according to  claim 17 , further comprising adjusting a consolidation joining head radially inward against an interface portion of the duct defined by longitudinal edges of the duct to urge the interface portion against the inner support and heating the interface portion to at least a glass transition temperature, thereby consolidation joining the interface portion.