Patent ID: 7337928

Claim:
A leak proof pressure activated self opening closure seal for sealing over an interior nozzle opening of a cartridge type container used for dispensing flowable material when said cartridge is pressurized by an application gun; (a) said cartridge type container comprising: a hollow cylindrical tube sealed at one end by a sliding interior piston; an opposite end sealed by a wall end; said wall end incorporating a hollow exterior dispensing nozzle with an interior opening in its base; said interior opening having a peripheral surface area extending radially around said interior opening perpendicular to the bore of said nozzle providing a planar surface for bonding said closure seal over said interior opening of said nozzle of said wall end of said cartridge type container; (b) said closure seal comprising: a first layer of frangible sheet material, a second layer of adhesive, a third layer of strengthening sheet material, a fourth layer of adhesive; (c) wherein said second layer of adhesive, said third layer of strengthening sheet material and said fourth layer of adhesive each contain a duplicate cut out void configuration that are in alignment with each other; (d) wherein said first layer of frangible sheet material, said second layer of adhesive, said third layer of strengthening sheet material, and said fourth layer of adhesive are permanently laminated together forming said closure seal; (e) wherein said duplicate cut out void configuration creates a weak area in said closure seal by leaving only said first layer of frangible sheet material covering over said duplicate cut out void configuration; (f) wherein an annular portion of said closure seal is bonded to said peripheral surface area of said dispensing nozzle of said wall end by said fourth layer of adhesive sealing over said interior opening of said dispensing nozzle of said cartridge type container; (g) wherein said closure seal is of sufficient strength to remain intact and retain said flowable material in said cartridge type container when said cartridge type container is filled with said flowable material; (h) wherein said closure seal is of sufficient weakness to break open only in said weak area of said duplicate cut out void configuration thereby allowing said flowable material to dispense out from said dispensing nozzle when said cartridge type container is pressurized by said application gun.