Frangible bonding using blush lacquer and packaging bonded therewith

A package including a product enclosed by a substrate and a closure member, said substrate being bonded to said closure member by a frangible bonding system comprising a bonding agent in the form of a layer of dried blush lacquer formed of film-forming resin containing voids, the film-forming resin forming cohesive internal bonds of said layer of blush lacquer, and a layer of heat seal material bonded to said blush lacquer, said voids making said cohesive internal bonds of said layer of blush lacquer rupturable by peeling the closure member and the substrate from one another.

A package enclosing a sterilized product, said package having a substrate bonded to a closure member by a frangible bonding system to seal the product within the package, said substrate and said closure member each having internal bonds bonding it together internally, said bonding system comprising a bonding agent in the form of a layer of dried blush lacquer formed of film-forming resin containing voids, the film-forming resin forming cohesive internal bonds of said layer of blush lacquer, said voids making said cohesive internal bonds of said layer of blush lacquer rupturable by peeling the closure member and the substrate from one another, said bonding system having interlayer bonds bonding said system to said substrate and said closure member, respectively, the cohesive internal bonds of said layer of dried blush lacquer being weaker than the internal bonds of said substrate and said closure member and weaker than any other bonds of said bonding system between said substrate and said closure member, whereby the cohesive internal bonds of said blush lacquer rupture upon said peeling without any substantial failure of the other bonds of the bonding system, the sealed enclosed space within the package being relatively sterile, and the structure of the sealed package being substantially impermeable to bacteria.

A methof of packaging a sterilized product between a substrate and a cover layer, said method comprising coating the substrate with a blush lacquer formed of a film-forming resin disposed in a liquid vehicle composed of a solvent and non-solvent for said resin, the solvent being more volatile than the non-solvent, evaporating said vehicle to leave the resin as a dried blush lacquer, the solvent being evaporated in preference to the non-solvent, applying a layer of heat seal material to said dried blush lacquer, placing the cover layer on the heat seal material with the product therebetween, applying heat and pressure to heat seal the cover layer to said dried blush lacquer to seal the product therebetween, and effectively sterilizing the enclosed space.