Method and apparatus for making a blister pack with indicia
View Patent ↗The invention herein relates to a method and apparatus for forming (or cold-forming) an embossed blister from a laminated film wherein an indicia is formed on the base of the blister. In particular, the invention involves a single pass process of combining the formation of a blister and the formation of an indicia (embossing) on the blister, wherein the blister-forming pin contains a face with an indicia and is adapted to controllably stretch the laminated film during blister formation to minimize stretching of the film at the base of the blister. The invention is particularly useful in manufacturing processes which involve the formation of blisters having laminated films which contain a metal foil and polymer layer, wherein improved control in the stretching of the laminate during blister formation is desirable.
1. A method for making an embossed blister formed from a laminated film comprising forming a blister by advancing a pin having a face with an indicia thereon in transversal direction relative to the film plane towards and into engagement with a platen bearing an indicia forming die thereon and located on the opposite side of said film wherein said advancing movement of the pin controllably stretches the film around the blister in a manner minimizing stretching of the film located at the base of the blister.
2. The method according to claim 1 wherein the method for making an embossed blister from a laminated film is a cold forming method.
3. The method according to claim 1 wherein the laminated film comprises a metal foil and at least one polymeric layer on either side of said foil.
4. The method according to claim 3 wherein the metal foil is composed of aluminum.
5. The method according to claim 1 wherein the pin face comprises a slightly concave surface having a peripheral edge.
6. The method according to claim 1 wherein the pin body is adapted to progressively engage the film and comprises at least two contiguous frusto-conical portions adjacent to the pin face having different apex angles in a gradient.
7. The method according to claim 1 wherein the portion of the pin body adjacent to the pin face and the pin face itself comprise different materials having differing friction parameters.
8. The method according to claim 1 wherein the platen bearing an indicia forming die is located in a base which is not configured to form a mold against which the laminated film is contoured.
9. A method for making an embossed blister formed from a laminated film comprising forming a blister by advancing a pin having a face with an indicia thereon in a transversal direction relative to the film plane towards and into engagement with a platen bearing an indicia forming die thereon located on the opposite side of said film wherein said pin face has a slightly concave surface and peripheral edge, and the pin body is adapted to progressively engage the film and comprises at least two contiguous frusto-conical portions adjacent to the pin face having different apex angles; and wherein said advancing movement of the pin controllably stretches the film around the blister in a manner minimizing stretching of the film located at the base of the blister.