Method of forming a tamper evident sealing liner

Abstract

A tamper evident safety seal is formed from a sealing liner having an integral tab portion, the tab being double folded for increased strength.

What is claimed is: 
     
       1. A method for forming a sealing liner for a plastic bottle cap, said liner being convertible to an improved tamper evident safety seal for a bottle, said method comprising providing a tape of a polymer coated metal foil laminated to paper;   passing said tape of said flexible laminate of polymer coated metal foil and paper to a folding station;   double folding said laminate tape .Iadd.at said folding station .Iaddend. into a S- or Z-shape configuration;   passing said double folded laminate tape to a stamping and assembly station and between a matching punch and a die such that said folded laminate tape has a .Iadd.continuous .Iaddend.folded flat edge lying within the periphery of the matching punch and die;   passing bottle caps beneath said die in sequence with said laminate .[.tap.]. .Iadd.tape .Iaddend.and   punching a sealing liner from said folded tape and simultaneously forcing same into .[.a.]. .Iadd.an inverted .Iaddend.cap disposed beneath said die.   
     
     
       2. A method according to claim 1 wherein said laminate comprises a first said polymer coated metal foil, a sheet of scrim material and a second polymer coated metal foil, as well as said paper, with said scrim material between said first and second metal foils. 
     
     
       3. A method according to claim 1 wherein said metal foil is aluminum foil. 
     
     
       4. A method according to claim 1 wherein said bottle caps are formed of polyethylene or polypropylene. 
     
     
       5. A method according to claim 1 further comprising providing a tape .[.or.]. .Iadd.secondary .Iaddend.liner material and .[.continuous.]. .Iadd.continuously .Iaddend.passing said .Iadd.secondary .Iaddend.liner material to said stamping and assembly station below said folded laminate tape.Iadd., and wherein said punching and forcing further causes punching of a secondary liner from said tape of secondary liner material and forcing of said secondary liner into said inverted cap beneath said sealing liner.Iaddend.. 
     
     
       6. A method according to 5 wherein said liner is formed of pulp, paperboard or foam plastic. .Iadd. 
     
     
       7.  A method for forming a sealing liner for a bottle cap, said liner being convertible to an improved tamper evident safety seal for a bottle, said method comprising: providing a flexible tape of a sealing liner material laminated to paper;   passing said flexible tape of said laminate of sealing liner material and paper to a folding station;   longitudinally double folding said flexible tape into a S-shaped or Z-shaped configuration at said folding station;   passing said double folded laminate tape to a stamping station and between a matching punch and a die such that said folded laminate tape has a continuous folded flat edge lying within the periphery of the matching punch and die;   passing a tape of secondary liner material beneath said die in sequence with said laminate tape; and   punching a sealing liner from said folded tape and simultaneously punching a secondary liner from said tape of secondary liner material. .Iaddend. .Iadd.8. A method according to claim 7 wherein said laminate comprises a first polymer coated metal foil, a sheet of scrim material and a second polymer coated metal foil, as well as said paper, with said scrim material between said first and second metal foils. .Iaddend. .Iadd.9. A method according to claim 7 wherein said flexible tape is aluminum foil. .Iaddend. .Iadd.10. A method according to claim 7, wherein said secondary   
     
     
        liner is formed of pulp, paperboard or foam plastic. .Iaddend. .Iadd.11. A method according to claim 7, wherein said longitudinal folding is carried out to provide two longitudinally extending folded flat edges. 
     
     
        .Iaddend. .Iadd.12.  A method according to claim 7 wherein said flexible tape of sealing liner material is a laminate of polymer-coated metal foil and paper. .Iaddend.