Polymeric films and methods for making polymeric films
AssigneeBerry Plastics Corporation
InventorsJeffrey A. Middlesworth, Brooke D. Kitzmiller, Vadim G. Zaikov
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Abstract
Multi-layer films include at least one cavitated core layer that is microporous and breathable, and at least one skin layer. The cavitated core layer includes 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 multi-layer non-breathable film, the multi-layer non-breathable film comprising a first non-cavitated skin layer, a second non-cavitated skin layer, and at least one cavitated core layer disposed between the first non-cavitated skin layer and the second non-cavitated skin layer, the process comprising the steps of
- extruding two or more extrudable materials to form a molten web, wherein at least a first extrudable material comprises a first polyolefin and an inorganic filler and is configured to form the at least one cavitated core layer, and wherein at least a second extrudable material comprises a second polyolefin and is configured to form each of the first non-cavitated skin layer and the second non-cavitated skin layer,
- casting the molten web against a surface of a chill roll using an air knife, air blanket, a vacuum box, or a combination thereof and without use of a nip to form a quenched film, and
- stretching the quenched film to form the multi-layer film, wherein the stretching comprises cross-directional intermeshing gear (CD-IMG) stretching and machine direction (MD) stretching,
- wherein the first polyolefin and the second polyolefin are the same or different,
- wherein the process for making the multi-layer non-breathable film does not include machine direction intermeshing gear (MD-IMG) stretching, and wherein the MD stretching occurs after the CD-IMG stretching.
A process for making a multi-layer non-breathable film, the multi-layer non-breathable film comprising a first non-cavitated skin layer, a second non-cavitated skin layer, at least one cavitated core layer disposed between the first non-cavitated skin layer and the second non-cavitated skin layer, and at least one polar polymer layer disposed between the first non-cavitated skin layer and the second non-cavitated skin layer, the process comprising the steps of
- extruding three or more extrudable materials to form a molten web, wherein at least a first extrudable material comprises a first polyolefin and an inorganic filler and is configured to form the at least one cavitated core layer, wherein at least a second extrudable material comprises a second polyolefin and is configured to form each of the first non-cavitated skin layer and the second non-cavitated skin layer, and wherein at least a third extrudable material comprises a hygroscopic polymer and is configured to form the at least one polar polymer layer,
- casting the molten web against a surface of a chill roll using an air knife, air blanket, a vacuum box, or a combination thereof and without use of a nip to form a quenched film, and
- stretching the quenched film to form the multi-layer film, wherein the stretching comprises cross-directional intermeshing gear (CD-IMG) stretching and machine direction (MD) stretching,
- wherein the first polyolefin and the second polyolefin are the same or different,
- wherein the process for making the multi-layer non-breathable film does not include machine direction intermeshing gear (MD-IMG) stretching, and wherein the MD stretching occurs after the CD-IMG stretching.
Dependencies are inferred from the claim text.