Induction heat sealable closure liner or lidding configured for paper recycling stream
The liner of the present invention provides a simple, cost-effective solution that will allow consumers to recycle the entire liner in a paper recycling stream. As a result, manufacturers currently selling products without liners will now be able to include liners on their containers and provide a totally recyclable container package, including the container, cap and liner (each recyclable in a respective plastic or paper recycling stream), while providing the benefits that liners provide, including maintaining product integrity and barrier properties, extending shelf life, providing tamper evidence, preventing leakage, preventing products from being contaminated and/or damaged by consumers sampling the products, and/or otherwise creating an un-saleable product due to leakage, contamination or damage.
1 . An induction heat-sealable closure liner or lidding configured for recycling in a paper recycling stream, the liner or lidding having a composite layer structure comprising:
a paperboard layer;
a metal foil layer for inductive heating; and
a heat sealant coating;
wherein the paperboard layer is white paperboard or brown paperboard,
for white paperboard the paperboard layer has a pulp weight of at least 85% by weight based on the total weight of the composite layer structure, and for brown paperboard the paperboard layer has a pulp weight of at least 90% by weight based on the total weight of the composite layer structure
the remaining weight percent of the composite layer structure comprising the metal foil layer and heat sealant coating are such that the total composite layer structure is recyclable in a paper recycling stream, wherein repulping of the composite layer structure achieves a pulp yield of at least 80% by weight of the paperboard layer for white paperboard and at least 85% for brown paperboard,
the metal foil layer has a basis weight in a range of 10 to 55 pounds per ream, where a ream comprises 3000 square feet, and
the metal foil layer has a thickness of 1 mil or less.
2 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the heat sealant layer comprises one or more of: a solvent-based heat sealant coating, a water-based heat sealant coating, or a resin-based heat sealant coating that is melted to form the coating.
3 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the heat sealant coating is a solvent-based heat sealant coating having a basis weight in a range of 2.5 to 4 pounds per ream where a ream comprises 3000 square feet.
4 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the heat sealant coating is a resin-based heat sealant coating having a basis weight in a range of 14 to 20 pounds per ream where a ream comprises 3000 square feet.
5 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the metal foil layer has a thickness of no greater than 0.5 mils.
6 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the total liner thickness is in a range of 11 mils to 110 mils.
7 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the total liner thickness is in a range of 12.6 to 14.8 mils.
8 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard layer has a thickness in a range of 12 to 14 mils;
the metal foil layer has a thickness in a range of 0.35 to 0.5 mils; and
the heat sealant is a solvent-based heat sealant coating having a thickness in a range of 0.2 to 0.3 mils.
9 . The induction heat-sealable closure liner or lidding of claim 1 , wherein
the liner further includes an adhesive boding the paperboard layer to the metal foil layer.
10 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard layer comprises wood fiber or other cellulose fiber.
11 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard layer is comprised of greater than 80% cellulosic fiber.
12 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard layer has a thickness range of 10 to 100 mil;
the metal foil layer has a thickness range of 0.25 to 1 mil; and
the heat sealant is a heat seal coating having a thickness in a range of 0.2 to 6 mil.
13 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard comprises white paperboard having a basis weight in a range of 90 to 350 pounds per ream where a ream comprises 3000 square feet, and the heat sealant coating is solvent-based.
14 . The induction heat-sealable closure liner or lidding of claim 13 , wherein:
the composite layer structure comprises:
1) Al foil having a basis weight of 10 to 55 pounds per ream
2) White paperboard having a basis weight of 90 to 350 pounds per ream
3) Solvent-based heat sealant coating having a basis weight of 2.5 to 4 pounds per ream
4) Lamination adhesive having a basis weight of 1 to 2 pounds per ream,
where a ream comprises 3000 square feet.
15 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard comprises brown paperboard having a basis weight in a range of 150 to 550 pounds per ream where a ream comprises 3000 square feet, and the heat sealant coating is solvent-based.
16 . The induction heat-sealable closure liner or lidding of claim 15 , wherein:
the composite layer structure comprises:
1) Al foil having a basis weight of 10 to 55 pounds per ream
2) Brown paperboard having a basis weight of 150 to 550 pounds per ream
3) Solvent-based heat sealant coating having a basis weight of 2.5 to 4 pounds per ream
4) Lamination adhesive having a basis weight of 1 to 2 pounds per ream,
where a ream comprises 3000 square feet.
17 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard comprises white paperboard having a basis weight in a range of 185 to 440 pounds per ream where a ream comprises 3000 square feet, and the heat sealant coating is resin-based.
18 . The induction heat-sealable closure liner or lidding of claim 17 , wherein:
the composite layer structure comprises:
1) Al foil having a basis weight of 10 to 55 pounds per ream
2) White paperboard having a basis weight of 185 to 440 pounds per ream
3) Resin-based heat sealant coating having a basis weight of 14 to 20 pounds per ream
4) Lamination adhesive having a basis weight of 1 to 2 pounds per ream,
where a ream comprises 3000 square feet.
19 . The induction heat-sealable closure liner or lidding of claim 1 , wherein:
the paperboard comprises brown paperboard having a basis weight in a range of 295 to 695 pounds per ream where a ream comprises 3000 square feet, and the heat sealant coating is resin-based.
20 . The induction heat-sealable closure liner or lidding of claim 19 , wherein:
the composite layer structure comprises:
1) Al foil having a basis weight of 10 to 55 pounds per ream
2) Brown paperboard having a basis weight of 295 to 695 pounds per ream
3) Resin-based heat sealant coating having a basis weight of 14 to 20 pounds per ream
4) Lamination adhesive having a basis weight of 1 to 2 pounds per ream,
where a ream comprises 3000 square feet.