Patent ID: 11926123
Assignee: MUCELL EXTRUSION, LLC
Field: Other special machines (Mechanical engineering)
Classification: CPC B | IPC B

Claim 20:
21. A method of making a creased, folded or scored multilayer film, comprising:
co-extruding a first foam layer, a second foam layer, two solid skin layers comprising HDPE and one solid layer comprising ethylene vinyl alcohol (EVOH) to form a multilayer film,
wherein the first foam layer includes a plurality of cells, wherein at least 10% of the cells are closed cells,
the second foam layer includes a plurality of cells, wherein at least 10% of the cells are closed cells,
the first and second foam layers are disposed between the two solid skin layers comprising HDPE,
the solid layer comprising ethylene vinyl alcohol (EVOH) is between the first foam layer and the second foam layer, the first foam layer is between one of the solid skin layers and the solid layer comprising EVOH, and the second foam layer is between one of the solid skin layers and the solid layer comprising EVOH,
and the multi-layer film has an overall thickness equal to or greater than 8 mils; and
creasing, folding or scoring the multi-layer film,
wherein the ratio of the oxygen transmission rate of the creased, folded or scored film in cc/m2/24hr, according to ASTM D3985, over that of an identical film prior to creasing, folding or scoring is less than 1.1.