Method and apparatus for scrapless thermoforming

Abstract

A thermoforming machine includes a loading station configured to load a thermoplastic billet onto a frame. The frame has an outer ring and a billet support blade defining a channel therebetween. The billet support blade engages the billet to maintain the billet on the frame during heating of the billet. A heating apparatus is configured to heat the billet and a forming station is configured to form the billet into a container.

1 . A method of forming a container from a plastic billet, comprising the steps of: 
 loading the billet onto a frame having a perimeter portion, the frame having a blade for supporting the billet, the blade comprising a thin wall of material disposed interior of the perimeter portion, defining a channel between the blade and the perimeter portion;    heating the billet to a temperature suitable for thermoforming; and    forming a container from the billet.    
   
   
       2 . The thermoforming machine of  claim 1 , wherein the billet is a non-uniform shape.  
   
   
       3 . The thermoforming machine of  claim 1 , further comprising the step of unloading the formed container from the frame.  
   
   
       4 . The thermoforming machine of  claim 1 , wherein the frame is separately attached to a transport tray.  
   
   
       5 . The thermoforming machine of  claim 1 , further comprising the step of coining the billet to force an edge of the billet into the channel prior to heating the billet.  
   
   
       6 . The thermoforming machine of  claim 5 , wherein the billet is pre-heated prior to the coining step.  
   
   
       7 . The thermoforming machine of  claim 1 , wherein the billet is formed at a temperature below the melting point of the billet.  
   
   
       8 . The thermoforming machine of  claim 1 , wherein an outer edge of the billet deforms into the channel when the billet is heated.  
   
   
       9 . The thermoforming machine of  claim 1 , wherein the blade is a continuous segment of material.