Heat sealing pressure monitoring system

Abstract

The method provides for monitoring pressure applied by a heat sealing tool. The heat sealing tool seals a lidstock to the flange of a rigid polymeric container with a well containing a contact lens and an aqueous storage solution. The flange includes an upper sealing surface and a lower surface. The tool includes a first plate adapted to contact the lower surface of the flange and a second plate adapted to press the lidstock against the sealing surface of the flange.

1 . A method comprising monitoring pressure applied by a heat sealing tool, wherein said heat sealing tool seals a lidstock to a rigid polymeric container comprising a well containing a contact lens and a storage solution, and a flange with an upper sealing surface and a lower surface, wherein the tool comprises a first plate adapted to contact the lower surface of the flange and a second plate adapted to press the lidstock against the sealing surface of the flange. 
     
     
         2 . The method according to  claim 1 , wherein the first plate elevates the container and the second plate is heated. 
     
     
         3 . The method according to  claim 2 , wherein the first plate is in connection with a pressure transducer that measures pressure applied by the first and second plates to the container flange and lidstock. 
     
     
         4 . The method according to  claim 3 , wherein the pressure transducer is connected to a controller. 
     
     
         5 . The method according to  claim 1 , wherein the second plate is curved with an identical curvature as the sealing surface of the flange. 
     
     
         6 . The method according to  claim 1 , wherein the first plate is curved with substantially the same curvature as the lower surface of the flange. 
     
     
         7 . The method according to  claim 1 , further comprising setting off an alarm if the monitored pressure is not within a predetermined range during the heat sealing operation.