Three part high moisture barrier for packages
A three part laminated material for use in making blister packages and a method of making such a material. The material is comprised of a central core layer of poly chloro-tri-fluoro ethylene to each side of which a separate polymer film is adhesively attached. The method of making the material involves use of a corona treater, a vertical forced air convection dryer, a horizontal convection dryer, a motor driven rewind, a chilled cylinder, a primary unwind and at least one laminating unwind. In the preferred embodiment, each of the polymer films is polyvinyl chloride, although a variety of different films may be used. The disclosed material provides a high moisture barrier, a stable inter-laminar structure and outer surfaces which lend themselves well to bonding with other materials.
1. A method employing a corona treater, a vertical forced air convection dryer, a horizontal convection dryer, a motor driven rewind and a chilled cylinder for making a three part, unoriented thermoformable laminated sheet material having a crystallinity level of 35% or less for use in a blister package wherein the laminated material has a first outer layer formed from a first polymer film stored on a first unwind, a core layer formed of poly chloro-tri-fluoro ethylene sheet material stored on a first laminating unwind and a second outer layer formed from a second polymer film stored on a second laminating unwind comprised of the steps of:
unwinding the first polymer film from the first unwind;
passing the unwound first polymer film through the corona treater;
applying a water-based adhesive to the corona-treated surface of the first polymer film using reverse gravure coating;
transporting the adhesive-coated first polymer film through a vertical forced air convection dryer;
unwinding the poly chloro-tri-fluoro ethylene sheet material from the first laminating unwind;
moving the poly chloro-tri-fluoro ethylene sheet material through the corona treater;
laminating the surface of the first polymer film with dried adhesive directly to one side of the poly chloro-tri-fluoro ethylene sheet material by means of a hot nip;
transporting the resulting two layer laminated structure through the horizontal forced air convection dryer;
cooling the two layer laminated structure by moving it across the chilled cylinder;
rewinding the two layer laminated structure onto the motor driven rewind;
unwinding the two layer laminated structure from the rewind;
passing the two layer laminated structure through the corona treater;
applying a water-based adhesive to the corona treated surface of the poly chloro-tri-fluoro ethylene sheet material using reverse gravure coating;
transporting the adhesive-coated two layer laminated structure through the vertical forced air convection dryer;
unwinding the second polymer film from the second laminating unwind;
moving the second polymer film through a corona treater;
laminating the corona treated surface of the second polymer film directly to the remaining exposed surface of the poly chloro-tri-fluoro ethylene sheet material by means of a hot nip;
transporting the resulting three layer laminated structure through the horizontal forced air convection dryer;
cooling the three layer laminated structure by moving it across the chilled cylinder; and
rewinding the three layer laminated structure onto the rewind.
2. The method of claim 1 wherein the dyne level of each of the polymer films and the poly chloro-tri-fluoro ethylene sheet material is raised to approximately 50 dyne during corona treatment.
3. The method of claim 1 wherein both the first and the second polymer films are PVC.
4. The method of claim 1 wherein the first polymer film may be any one selected from the group consisting of PVC, PETG, a rubber modified nitrile polymer, polypropylene or polystyrene.
5. The method of claim 4 wherein the second polymer film may be any one selected from the group consisting of PVC, PETG, a rubber modified nitrile polymer, polypropylene or polystyrene.
6. The method of claim 5 wherein the first and the second polymer film are each the same material.
7. The method of claim 5 wherein the first and the second polymer film are each different materials.
8. A method employing a corona treater, a vertical forced air convection dryer, a horizontal convection dryer, a motor driven rewind and a chilled cylinder for making a three part, unoriented thermoformable laminated sheet material having a crystallinity level of 35% or less for use in a blister package wherein the laminated material has a first outer layer formed from a first polymer film stored on a primary unwind, a core layer formed of poly chloro-tri-fluoro ethylene sheet material stored on a laminating unwind and a second outer layer formed from a second polymer film stored on the primary unwind comprised of the steps of:
unwinding the first polymer film from the primary unwind;
passing the unwound first polymer film through the corona treater;
applying a water-based adhesive to the corona-treated surface of the first polymer film using reverse gravure coating;
transporting the adhesive-coated first polymer film through a vertical forced air convection dryer;
unwinding the poly chloro-tri-fluoro ethylene sheet material from the laminating unwind;
moving the poly chloro-tri-fluoro ethylene sheet material through the corona treater;
laminating the surface of the first polymer film with dried adhesive directly to one side of the poly chloro-tri-fluoro ethylene sheet material by means of a hot nip;
transporting the resulting two layer laminated structure through the horizontal forced air convection dryer;
cooling the two layer laminated structure by moving it across the chilled cylinder;
rewinding the two layer laminated structure onto the motor driven rewind;
transferring the two layer laminated structure onto the laminating unwind;
further unwinding the second polymer film from the primary unwind;
passing the second polymer film through the corona treater;
applying a water-based adhesive to the corona treated surface of the second polymer film using reverse gravure coating;
transporting the adhesive-coated second polymer film through the vertical forced air convection dryer;
unwinding the two layer laminated structure from the laminating unwind;
moving the two layer laminated structure through a corona treater;
laminating the corona treated surface of the poly chloro-tri-fluoro ethylene of the two layer laminated structure directly to the adhesive-treated surface of the second polymer film by means of a hot nip;
transporting the resulting three layer laminated structure through the horizontal forced air convection dryer;
cooling the three layer laminated structure by moving it across the chilled cylinder; and
rewinding the three layer laminated structure onto the rewind.
9. The method of claim 8 wherein the dyne level of each of the polymer films and the poly chloro-tri-fluoro ethylene sheet material is raised to approximately 50 dyne during corona treatment.
10. The method of claim 8 wherein the first and the second polymer film are each the same material.
11. The method of claim 10 wherein the first and the second polymer films may be any one selected from the group consisting of PVC, PETG, a rubber modified nitrile polymer, polypropylene or polystyrene.
12. The method of claim 8 wherein the first and the second polymer film are each different materials, the second polymer film is stored on a second primary unwind and the further unwinding step occurs from the second primary unwind.
13. The method of claim 12 wherein the first polymer film may be any one selected from the group consisting of PVC, PETG, a rubber modified nitrile polymer, polypropylene or polystyrene.
14. The method of claim 13 wherein the second polymer film may be any one selected from the group consisting of PVC, PETG, a rubber modified nitrile polymer, polypropylene or polystyrene.