| abstract |
The present invention provides multilayer films, packages formed from such films, and methods of making the multilayer films. In one aspect, the multilayer film comprises a multilayer film comprising at least 3 layers, each layer having opposing face surfaces and arranged in the order A/B/C, wherein layer A comprises high density polyethylene, the high density polyethylene having a Mw,cc /Mn ,cc of at least 6.0, a Mz,abs of at least 500,000 g/mole as measured by triple detector GPC, and a density of 0.957 to 0.970 g/ cm3 , wherein the high density polyethylene comprising at least 90% by weight of layer A; layer B comprising a gas permeable layer wherein the top facial surface of layer B is in adhesive contact with the bottom facial surface of layer A; and layer C comprising high density polyethylene having Mw,cc /Mn ,cc of at least 6.0, Mz,abs of at least 500,000 grams/mole as measured by triple detector GPC, and a density of 0.957 to 0.970 g/ cm3 , wherein the high density polyethylene accounts for At least 90% by weight of layer C, and wherein the top facial surface of layer C is in adhesive contact with the bottom facial surface of layer B, wherein the film is oriented in the machine direction, and wherein when measured according to ASTM F-2476 at 23°C, 0 The film exhibits a normalized carbon dioxide transmission rate of at least 3000 cm3 mil/100 in2 /day when measured at % relative humidity and 1 atm, and wherein when measured at 23°C, 0% relative humidity according to ASTM D3985 The membrane exhibits a ratio of said carbon dioxide transmission rate to oxygen transmission rate of at least 4.0 when measured at 1 atm and 1 atm. |