Innerseal for a container and method of applying

• US 5,012,946 A
• Filed: 06/29/1990
• Issued: 05/07/1991
• Est. Priority Date: 02/27/1989
• Status: Expired due to Fees

• Current Assignee: Unipac Corporation
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: McCarthy, Theresa A.
• Primary Examiner(s): Marcus, Stephen
• Assistant Examiner(s): STUCKER, NOVA E
• Application Number:
  US07/546,669
• Time in Patent Office: 312 Days
• Field of Search: 215/232, 215/250, 220/258, 220/265, 220/270, 220/359, 229/3.5 MF, 229/125.33, 229/125.34, 229/125.35
• US Class Current: 220/258.2
• CPC Class Codes: B65D 2251/0015 of the 41-type
• CPC Class Codes: B65D 2251/0093 Membrane
• CPC Class Codes: B65D 2577/205 integral with the closure
• CPC Class Codes: B65D 51/20 Caps, lids, or covers co-operating with an inner closure arranged to be opened by piercing, cutting, or tearing B65D51/185 takes precedence; co-operating with an auxiliary container for additional articles or materials B65D51/28
• CPC Class Codes: B65D 77/20 by applying separate lids or covers , i.e. flexible membrane or foil-like covers

Abstract

An easily removable innerseal for a container and method of application relates to an improved arrangement having a body portion adapted for fitting over the upper rim of a container and a flexible element attached to the body portion for a user to grip. The body portion is provided with a lower bonding layer, which includes a first bonding portion and a second bonding portion adhered to the first portion, and a layer to prevent fluid from passing therethrough. The bonding force between the first and second bonding portions is designed to be weaker than the bonding force between the bonding layer and the container. In addition, the rupture strength of the first bonding portion is less than either of the bonding forces. As a result, the force required to remove the innerseal from the container is not dependent upon the amount of heat applied during sealing, because delamination will occur between the two bonding portions in an area over the container rim, leaving a residue of the first adhesive portion attached to the rim. By gripping the flexible element and pulling it upwardly, a user can remove the innerseal from the container without having to puncture or scrape the innerseal with a sharp object, which is frequently required to remove innerseals of the type commonly in use today. The method of application includes the steps of applying the body portion of the innerseal around the rim portion of a container and passing the container through an induction type heating station.

Claims

1. An improved easy opening innerseal for use with a container of the type having an opening defined by an upper rim, comprising:

a body portion having an upper surface and adapted for fitting over an upper rim of a container, said body portion including membrane means for preventing passage of fluid through said body portion, said membrane means including an adhesive layer; and

means adapted for bonding said body portion against the upper rim of the container;

said bonding means having a first bonding stratum for bonding against the container rim with a first bonding force and a second bonding stratum which is bonded to said adhesive layer of said membrane means on one side and adhered to said first bonding stratum on an opposite side with a second bonding force which is less than said first boding force, said first boding stratum being fabricated of a material which has a rupture strength that is less than either of said second bonding force and said first bonding force; and

gripping means attached to an outer periphery of said body means for a user to grip while removing said innerseal from a container, whereby a first part of said first bonding stratum will delaminate from said second bonding stratum over the container rim and remain adhered to the rim when said gripping means is pulled, while a second part of said first bonding stratum will remain adhered to said second bonding stratum, thereby exposing the opening.

2. An innerseal according to claim 1, wherein said membrane means comprises a fluid impermeable membrane.

3. An innerseal according to claim 2, wherein said membrane comprises a layer of aluminum foil.

4. An innerseal according to claim 1, wherein said first bonding strata has a lower melting temperature than said second bonding strata.

5. An innerseal according to claim 1, wherein said first bonding strata is comprised of a material selected from the group consisting essentially of polyester, polypropylene, polyethylene and EVA and laminates or blends thereof.

6. An innerseal according to claim 2, wherein said first bonding stratum portion comprises a layer of heat sealable film, and said second bonding stratum comprises a layer of pressure sensitive adhesive.

7. An innerseal according to claim 6, wherein said layer of heat sealable material comprises a material selected from the group consisting essentially of polyester, polypropylene, polyethylene and EVA and laminates or blends thereof.

8. An innerseal according to claim 1, wherein said gripping means and said body portion are formed of a continuously extending common layered material.

9. A sealed container of the type which is provided with a safety innerseal, comprising:

a container body having an upper rim; and

an innerseal comprising a body portion for fitting over said upper rim, said body portion having an upper surface and including membrane means for preventing passage of fluid through said body portion, said membrane means including an adhesive layer, means adapted for bonding said body portion against said upper rim, said bonding means having a first bonding stratum for bonding against said container rim with a first bonding force and a second bonding stratum which is bonded to said adhesive layer of said membrane means on one side and adhered to said first bonding stratum on an opposite side with a second bonding force which is less than said first bonding force, said first bonding stratum being fabricated of a material which has a rupture strength that is less than either of said second bonding force and said first bonding force; and

gripping means attached to an outer periphery of said body means for a user to grip while removing said innerseal from a container, whereby a first part of said first bonding stratum will delaminate from said second bonding stratum over the container rim and remain adhered to the rim when said gripping mean is pulled, while a second part of said first bonding stratum will remain adhered to said second bonding stratum, thereby exposing the opening.

10. An innerseal according to claim 9, wherein said membrane means comprises a fluid impermeable membrane.

11. An innerseal according to claim 10, wherein said membrane comprises a layer of aluminum foil.

12. An innerseal according to claim 9, wherein said first bonding strata has a lower melting temperature than said second bonding strata.

13. An innerseal according to claim 9, wherein said first bonding strata is comprised of a material selected from the group consisting essentially of polyester, polypropylene, polyethylene and EVA and laminates or blends thereof.

14. An innerseal according to claim 10, wherein said first bonding stratum comprises a layer of heat sealable film, and said second bonding stratum comprises a layer of pressure sensitive adhesive.

15. An innerseal according to claim 14, wherein said layer of heat sealable material comprises a material selected from the group consisting essentially of polyester, polypropylene, polyethylene and EVA and laminates or blends thereof.

16. An innerseal according to claim 9, wherein said gripping means and said body portion are formed of a continuously extending common layered material.