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CN-122029029-A - Inductively heat sealable liner for paper or plastic recycling streams, and inductively heat seal applicator

CN122029029ACN 122029029 ACN122029029 ACN 122029029ACN-122029029-A

Abstract

A metal foil-free gasket forming structure and method such that the entire gasket can be recycled in a corresponding paper or plastic recycling stream. A separate applicator is provided comprising a metal layer for heat sealing the liner to the container rim by induction heating. The applicator is removable, allowing a plastic closure cap to be mounted on the rim of the container sealed by the liner to provide the final product for sale to the consumer, who then removes the cap, peels or pierces the liner, and accesses the product through the opening of the container. The applicator may also be reusable, i.e., it may be used to attach subsequent liners to other container rims. As a result, the liner can be fully recovered in the paper or plastic recovery stream. In one embodiment, the entire container package may be recycled, i.e., the plastic container may be recycled in a plastic recycling stream, the plastic container lid may be recycled in a plastic recycling stream (the same or different from the container recycling stream), and the entire liner may be recycled in a paper or plastic recycling stream (the recycling stream may be the same as one or more of the container and lid recycling streams). As a result, this is at the same time a sustainable packaging solution, in which the application device that generates heat for induction heat sealing can also be reused.

Inventors

  • M.SHA
  • D. Carrespodi
  • T. Fleig

Assignees

  • 德尼培股份有限公司

Dates

Publication Date
20260512
Application Date
20241011
Priority Date
20231113

Claims (14)

  1. 1. An apparatus for induction heat sealing a liner to a container rim comprising: an induction heat sealable, foil-free and fully recyclable gasket (10), the gasket (10) being made of paper or plastic recyclable in a corresponding paper or plastic recycling stream, and a heat seal layer, which is also recyclable in a corresponding paper or plastic recycling stream; a detachable and reusable induction heat seal application device (110) comprising a metal dish (130D), a metal ring (130R) or a metal cover (120M); Wherein the reusable applicator (110) is configured to be placed over the liner (10) and container rim (22L) upon induction heat sealing the liner to the rim, and then the device (110) is removable from the liner-sealed rim to allow the container lid (40) to be placed over the liner and rim to provide a fully recyclable liner (10), the liner (10) being recyclable in a corresponding paper or plastic recycling stream.
  2. 2. The apparatus of claim 1 wherein the container lid (40) is recyclable in a plastic recycling stream, thereby providing a fully recyclable lid and liner assembly.
  3. 3. The apparatus of claim 1 wherein the container (20) is recyclable in a plastic recycling stream, thereby providing a fully recyclable liner and container assembly.
  4. 4. The device of claim 1, wherein the lid (40), the liner (10) and the container (20) are recyclable in a plastic recycling stream, thereby providing a fully recyclable lid, liner and container assembly.
  5. 5. The device of claim 1, wherein the container (20) and the lid (40) are each recyclable in a plastic, glass, paper or metal recycling stream, thereby providing a fully recyclable lid, liner and container assembly.
  6. 6. The apparatus of claim 1, wherein the pad comprises: A paperboard layer (105) having a thickness in the range of 2 to 27 mils, and/or a paperboard layer in the range of 25 pounds per ream to 350 pounds per ream, wherein each ream comprises 3000 square feet; a heat seal layer (106) having a thickness in the range of 0.15 to 3.5 mils, and/or a paperboard layer in the range of 2 pounds per ream to 50 pounds per ream, wherein each ream comprises 3000 square feet.
  7. 7. The apparatus of claim 1, wherein the pad comprises: A plastic layer (105) having a thickness in the range of 0.5 to 15 mils, and/or a plastic layer in the range of 25 pounds per ream to 225 pounds per ream, wherein each ream comprises 3000 square feet, and A heat seal layer (106) having a thickness in the range of 0.15 to 3.5 mils, and/or a heat seal layer in the range of 2 pounds per ream to 50 pounds per ream, wherein each ream comprises 3000 square feet.
  8. 8. The device of claim 1, wherein the reusable applicator comprises a metal dish (130D) within a cap (120P), the cap (120P) configured to be secured to a pad and a rim.
  9. 9. The device of claim 1, wherein the reusable applicator comprises a metal ring (130R) within a cap (120P), the cap (120P) configured to be secured to a liner and a rim.
  10. 10. The device of claim 1, wherein the reusable applicator comprises a metal cap (120M) configured to be secured to the liner and the rim.
  11. 11. A method for induction heat sealing a liner to a container rim comprising: providing a liner (10) and a heat seal layer, the liner (10) being made of paper or plastic recyclable in a corresponding paper or plastic recycling stream, and the heat seal layer being equally recyclable in a corresponding paper or plastic recycling stream; Placing a removable and reusable induction heat seal application device (110) and the liner (10) over the rim (22L) of the container (20) to form a device/liner/rim assembly (110/10/22L); placing an induction heat head (8) over the device/gasket/rim assembly (110/10/22L) and activating the induction heat head (8) to induction heat seal the gasket to the rim (22L); Detaching the induction heating head (18) and the device (110) from the gasketed lip; Mounting a container lid (40) to the rim sealed by the gasket; repeating the step of induction heat sealing the liner to the container rim with the apparatus (110), and Recovering the liner, or one or more of the liner, and the container lid (40) and the container (20), in a corresponding paper or plastic recovery stream.
  12. 12. The method of claim 10, wherein, The removable and reusable induction heat seal application device (110) includes a metal ring within a cap, and the cap is used to secure the device to the liner and the rim.
  13. 13. The method of claim 10, wherein, The removable and reusable induction heat seal application device (110) includes a metal dish within a cover, and the cover is used to secure the device to the liner and the rim.
  14. 14. The method of claim 10, wherein, The removable and reusable induction heat seal application device (110) includes a metal cover, and the metal cover is used to secure the device to the liner and rim.

Description

Inductively heat sealable liner for paper or plastic recycling streams, and inductively heat seal applicator Technical Field The present invention relates to an induction heat sealable gasket configured to be fully recyclable in a paper or plastic recycling stream and free of metal. Background Gaskets or seals have been used on containers for many years to prevent leakage or contamination and to extend the shelf life of the substances or products contained within the containers. For example, liners are used on containers to hold cosmetics, foods, beverages, pharmaceuticals, and other substances in the form of liquids, pastes, gels, granules, powders, and the like. Gaskets for this purpose are usually placed at the opening of the container or in some cases the gasket is placed inside the cap and then the cap combined with the gasket is covered at the opening (rim) of the container. The liner is typically attached to the container rim (around the opening) by an induction heat sealing process. This requires the inclusion of a metal foil layer in the liner structure to transfer heat to the bottommost heat seal layer to adhere the liner to the container rim. The bond is temporary or permanent, allowing the customer (user) to peel or puncture the liner from the container rim to remove it. Thus, the liner has a variety of functions including providing tamper-evident functions and preventing leakage, contamination or deterioration of the product within the container. Induction heat seal gaskets require a metal layer for heat conduction, which in prior gaskets prevents recycling of the gasket in a paper or plastic recycling stream. The heat seal layer, as well as the use of various types of plastic and wax layers in the hybrid composite structure, also impedes the recovery of the liner in a single recovery stream. As a result, even though the lid and/or container may be recycled, these liners may still produce non-recyclable waste. Furthermore, prior art liners may delaminate during the peeling step, resulting in liner residue remaining on the container, and/or the liner being configured to retain one or more layers in the lid for resealing when separated, both of which further inhibit recycling of these structures. It would therefore be desirable to provide a fully recyclable induction heat sealable gasket structure that is suitable for recycling in a paper or plastic recycling stream, while also providing desirable characteristics, namely tamper proof, barrier properties against product deterioration, leakage prevention, and delamination prevention when removed from the container rim. Disclosure of Invention The present invention relates to a structure and method for forming a metal foil-free liner such that the entire liner can be recycled in a corresponding paper or plastic recycling stream. For example, the liner may comprise a plastic (e.g., PET) support layer, and a heat seal layer having a composition and weight percent conforming to a plastic (e.g., PET) recycle stream. In another example, the liner includes a paper (also known as pulp or paperboard) support layer, and a heat seal layer having a composition and weight percent consistent with the paper recovery stream. The present invention also provides a self-contained applicator comprising a metal layer for heat sealing the liner to the container rim by induction heating. The applicator may be placed over the liner and rim, the device/liner/rim assembly placed under the induction heat head, and the applicator then transfers heat to the heat seal layer (on the bottom surface of the liner) to bond the liner to the rim. The applicator is removable, allowing a plastic closure cap to be mounted on the rim of the container sealed by the liner to provide the final product for sale to the consumer, who then removes the cap and peels the liner and accesses the product through the opening of the container. The applicator may also be reusable, i.e., it may be used to attach subsequent liners to other container rims. As a result, the liner can be fully recovered in the paper or plastic recovery stream. In one embodiment, the entire container package may be recycled, i.e., the plastic container may be recycled in a plastic recycling stream, the plastic container lid may be recycled in a plastic recycling stream (the same or different from the container recycling stream), and the entire liner may be recycled in a paper or plastic recycling stream (the recycling stream may be the same as one or more of the container and lid recycling streams). The vessel can be made of metal or molded fiber/pulp material that can be recycled in the metal or paper recycling stream, respectively. Likewise, the container cover can employ molded fiber/pulp materials that can be recycled in the paper recycling stream. As a result, this is at the same time a sustainable packaging solution, in which the application device that generates heat for induction heat sealing can also be reused. The r