Apparatus and Method for Sealing a Lidstock to a Container

Abstract

The invention relates to a method for heat sealing a lidstock to a container for a blister package, the container having a top surface comprising a substantially flat sealing flange surrounding a blister and a lip having at least one raised surface, the method comprising the steps of a) locating the lidstock on the top surface; b) providing a first seal between the lidstock and the at least one raised surface of the lip with a first heat sealing tool; c) providing a second hermetic seal between the lidstock and the sealing flange surrounding the blister with a second heat sealing tool. The invention also relates to a package for storing a hydrophilic contact lens comprising a lip having at least one raised surface and a removable lidstock sealed to a sealing flange and to the at least one raised surface. Also disclosed is an apparatus for heat sealing the lidstock to the container.

1 . A package for storing a hydrophilic contact lens comprising:
 a base having a top surface and a recess well having a perimeter in the top surface for storing a hydrophilic contact lens, said top surface comprising a substantially flat sealing flange surrounding the recessed well and a lip having at least one raised surface; and a removable lidstock sealed to said sealing flange and to the at least one raised surface of said lip.   
     
     
         2 . A package according to  claim 1 , wherein the lip has two mutually spaced raised surfaces. 
     
     
         3 . A package according to  claim 1 , wherein the lip has a curved upper surface, curved downwards with respect to the sealing flange. 
     
     
         4 . A package according to  claim 1 , wherein the lip includes an aperture. 
     
     
         5 . A package according to  claim 1 , wherein the area of each raised surface is 10 mm 2  or less. 
     
     
         6 . A package according to  claim 1 , wherein the base is a thermoformable polypropylene polymer. 
     
     
         7 . A package according to  claim 1 , wherein the lidstock is a laminated foil comprising a metal layer and a basal thermoplastic polymer layer. 
     
     
         8 . A package according to  claim 7 , wherein the basal thermoplastic polymer layer is polypropylene. 
     
     
         9 . A package according to  claim 1 , further comprising a hydrophilic contact lens and an aqueous solution contained in the recessed well. 
     
     
         10 . A package according to  claim 1 , especially a blister package for contact lens. 
     
     
         11 . A sealing apparatus for heat sealing a lidstock to a container for a blister package, the sealing apparatus comprising a support arm for supporting at least one sealing surface, the apparatus also including means for heating said at least one sealing surface. 
     
     
         12 . An apparatus as claimed in  claim 11  wherein the at least one sealing surface comprises an elongate sealing surface including a plurality of spaced apart channels provided along the elongate sealing surface, defining a plurality of sealing surfaces. 
     
     
         13 . An apparatus as claimed in  claim 12  wherein each of the plurality of heated surfaces includes individual heating means for individually heating each of the plurality of sealing surfaces.