Multi-layer web and process for forming scored lidding film for blister packages

Patent metadata

Field	Value
Publication number	US-11014729-B2
Application number	US-201916405211-A
Country	US
Kind code	B2
Filing date	May 7, 2019
Priority date	Mar 4, 2015
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

Multi-layer web and mechanical scoring process for forming lidding film for push through blister packages. The web is configured to resist the tensile forces encountered during manufacturing processes, including slitting, rewinding and heat sealing processes. A simplified web conversion process for creating mechanically scored lidding film for blister packages is provided at reduced investment and operational costs compared to prior art systems.

First claim

What is claimed is:

1. A multi-layer web comprising:
a multi-layer web of film windable on a core and adapted to be slit to form scored lidding film for blister packages, the film being formed without a metal layer and including an inner seal layer and an outer layer of different thermoplastic polymer materials,
the inner seal layer comprising a thermoplastic polymer material that softens at a lower melt temperature than the outer layer material in order to form a thermal weld seal with a base substrate of a blister package, the outer layer comprising a polyester material, including homopolymers, copolymers and blends thereof, that resists softening and maintains structural integrity of the film while the inner layer is softened to form the weld seal to the base substrate, and the outer layer has a scored area configured to rupture and release a product contained in a recess of a base substrate without breaking the weld seal,
the web being unwound from the core in a machine M direction transverse to a central longitudinal axis CL of the core on which the web is wound,
the scored area being sized to cover a plurality of recesses in a base substrate of a blister package and comprising a plurality of individual arrow shaped scored formations aligned in the M direction and spaced from one another, the scoring being uniformly distributed in the scored area, without the need for registering the scored formations with individual recesses in the machine M direction or a direction transverse thereto, and
the scored area being formed by passing the web against a scoring roller to mechanically score partially through the outer layer without scoring the inner seal layer, wherein the scoring depth is between 30% and 70% of the outer layer thickness, the inner seal layer comprises 5% to 30% of the total film thickness and the outer layer comprises 70% to 95% of the total film thickness, the total film thickness being of the multi-layer web of film, and the multi-layer web of film is from 20 to 80 micron in thickness.

2. A multi-layer web comprising:
a multi-layer web of film windable on a core and adapted to be slit to form scored lidding film for blister packages, the film being formed without a metal layer and including an inner seal layer and an outer layer of different thermoplastic polymer materials,
the inner seal layer comprising a thermoplastic polymer material that softens at a lower melt temperature than the outer layer material in order to form a thermal weld seal with a base substrate of a blister package, while the outer layer, comprising a polyester material, including homopolymers, copolymers and blends thereof, that resists softening and maintains structural integrity of the film while the inner layer is softened to form the weld seal to the base substrate, and the outer layer has a central scored area configured to rupture and release a product contained in a recess of a base substrate without breaking the weld seal,
the web being unwound from the core in a machine M direction transverse to a central longitudinal axis CL of the core on which the web is wound,
the central scored area extending in the machine M direction between opposing first and second non-scored edge grip areas aligned in the machine M direction, the central scored area being sized to cover a plurality of recesses in a base substrate of a blister package and comprising a plurality of individual arrow shaped scored formations aligned in the M direction and spaced from one another, the scoring being uniformly distributed in the central area in the machine M direction, without the need for registering the scored formations with individual recesses in the machine M direction,
the central scored area being formed by passing the web against a scoring roller to mechanically score partially through the outer layer without scoring the inner seal layer, wherein the scoring depth is between 30% and 70% of the outer layer thickness, the inner seal layer comprises 5% to 30% of the total film thickness and the outer layer comprises 70% to 95% of the total film thickness, the total film thickness being of the multi-layer web of film, and the multi-layer web of film is from 20 to 80 micron in thickness,
the opposing first and second edge grip areas being non-scored and each of a minimum width, transverse to the machine M direction, configured to provide structural integrity to the web during winding and unwinding of the web onto or from the core, and the non-scored edge grip areas being slittable to form a scored and slit lidding film for blister packages, the scored and slit lidding film having the central scored area between the first and second non-scored edge grip areas, wherein the central scored area comprises 75% to 99% of a total width of the slit lidding film and the remaining portions of the first and second non-scored edge grip areas together comprise 1% to 25% of the total width of the slit lidding film.

3. A scored and slit lidding film for blister packages which has been formed by slitting the multi-layer web of claim 2 , wherein the scored and slit lidding film has the central scored area between remaining portions of the first and second non-scored edge grip areas, wherein the central scored area comprises 75% to 99 % of a total width of the slit lidding film and the remaining portions of the first and second non-scored edge grip areas together comprise 1% to 25% of the total width of the slit lidding film.

4. A scored and slit lidding film of claim 3 , wherein the central scored area comprises 80% to 99% of the total width of the slit lidding film.

5. A scored and slit lidding film of claim 3 , wherein the central scored area comprises 85% to 99% of the total width of the slit lidding film.

6. A multi-layer web of claim 1 or claim 2 , or a scored and slit lidding film of claim 3 , wherein the scoring width is from 5 to 100 microns.

7. A scored and slit lidding film of claim 3 , combined with a thermoformed base substrate, the inner layer being weld sealed to the base substrate.

8. A scored and slit lidding film and base substrate of claim 7 , cut to form a single blister package.

9. A scored and slit lidding film and base substrate of claim 7 , made from materials compatible in recycling.

10. A scored and slit lidding film and base substrate of claim 7 , wherein the outer layer comprises semi-crystalline polyethylene terephthalate and the inner layer comprises an amorphous polyethylene terephthalate copolymer.

11. A multi-layer web of claim 1 or claim 2 , or a scored and slit lidding film of claim 3 , wherein the multi-layer web is formed by co-extrusion of the inner seal layer and outer layer, extrusion coating of the inner seal layer onto the outer layer, or coating of the inner seal layer onto the outer layer via solvent, water or solventless coating processes or by wet or dry bond lamination of the inner seal layer to the outer layer.

12. A multi-layer web of claim 1 or claim 2 , or a scored and slit lidding film of claim 3 , wherein the outer layer comprises polyethylene terephthalate, including homopolymers, copolymers and blends thereof.

13. A multi-layer web of claim 1 or claim 2 , or a scored and slit lidding film of claim 3 , wherein the inner layer comprises ethylene vinyl acetate, polyester, polyethylene, polypropylene, or acrylic, including homopolymers, copolymers and blends thereof.

14. A multi-layer web of claim 1 or claim 2 , or a scored and slit lidding film of claim 3 , wherein the outer layer comprises semi-crystalline polyethylene terephthalate and the inner layer comprises an amorphous polyethylene terephthalate copolymer.

Assignees

• Tekni Plex Inc

Inventors

• Van Landeghem Robin
• Bourgeois Philip

Classifications

• B32B3/30 Primary

  characterised by a layer formed with recesses or projections, e.g. {hollows, grooves, protuberances, ribs (apertured layer B32B3/266; layer with cavities or internal voids B32B3/26)} · CPC title

• B65B47/00

  Apparatus or devices for forming pockets or receptacles in or from sheets, blanks, or webs, comprising essentially a die into which the material is pressed or a folding die through which the material is moved · CPC title

• B32B2553/00

  Packaging equipment or accessories not otherwise provided for · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B2307/738

  Thermoformability · CPC title