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US 2017/0232652 A1Published application
Gas-permeable barrier film and method of making the gas-permeable barrier film
AssigneeBerry Plastics Corporation
InventorsVadim G. ZAIKOV, Jeffrey A. MIDDLESWORTH, Bradley SONNENTAG, Brooke D. KITZMILLER
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Abstract
Gas-permeable barrier films include a polyolefin and an inorganic filler dispersed in the polyolefin. Methods for forming polymeric films and articles of manufacture prepared therefrom are described.
Claims20
A process for making a gas-permeable barrier film comprising the steps of
- extruding a composition that comprises a polyolefin and an inorganic filler to form a molten web, the inorganic filler having an average particle size less than about 9.5 microns,
- casting the molten web against a surface of a chill roll to form a quenched film, and
- stretching the quenched film to form a gas-permeable barrier film having a Gurley porosity of less than about 300 seconds.
A process for making a gas-permeable barrier film comprising the steps of
- extruding a composition that comprises polyethylene, polypropylene, or a combination thereof and an alkaline earth metal carbonate to form a molten web, the alkaline earth metal carbonate comprising at least about 50% by weight of the gas-permeable barrier film,
- casting the molten web against a surface of a chill roll under negative pressure by a vacuum box to form a quenched film,
- stretching the quenched film by cross-directional intermeshing gear (CD IMG) stretching followed by post-stretching in a machine direction to form a gas-permeable barrier film having a Gurley porosity of less than about 300 seconds and a basis weight of between about 70 gsm and about 80 gsm, and
- annealing the gas-permeable barrier film at a temperature of between about 75 and about 225 degrees Fahrenheit.
1 more element
Dependencies are inferred from the claim text.