Barrier film for packaging material
AssigneeStora Enso OYJ
InventorsAnna Kauppi, Juha Korvenniemi, Isto Heiskanen, Kaj Backfolk
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Abstract
The present invention relates to a barrier film for a paper or paperboard-based packaging material, said barrier film comprising cellulosic fibers and highly refined cellulose wherein the barrier film comprises less than 50 wt-% of highly refined cellulose based on the total fiber content and the barrier film having an air permeance above 2000 pm/Pas and a geometric mean tensile index above 70 Nm/g. The invention also relates to a paper or paperboard-based packaging material comprising the barrier film and a method for producing said film.
Claims23
A barrier film for a paper or paperboard-based packaging material, said barrier film comprising:
- cellulosic fibers and highly refined cellulose, wherein the barrier film comprises less than 50 wt-% of highly refined cellulose based on a total fiber content, and
- wherein the barrier film has an air permeance above 2,000 pm/Pas and a geometric mean tensile index above 70 Nm/g.
A method for manufacturing a barrier film for a paper or paperboard based packaging material, comprising the steps of:
- a) providing a first suspension comprising cellulose fibers,
- b) providing a first suspension comprising highly refined cellulose,
- c) mixing said first suspension comprising cellulose fibers and said first suspension comprising highly refined cellulose to form a first mixture wherein said first mixture comprises less than 50 wt % of highly refined cellulose based on a total fiber content,
- d) applying said first mixture to a first substrate,
- e) dewatering said first mixture on said substrate to form a first wet web, and,
- f) drying and optionally pressing said wet web to form a barrier film wherein said barrier film has an air permeance above 2,000 pm/Pas and a geometric mean tensile index above 70 Nm/g.
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Dependencies are inferred from the claim text.