Cryovac, Inc.

W. R. Grace Co.-conn.

Sealed Air Corporation

Blaine C Childress

Ronald D Moffitt

George Dean Wofford

Marvin Russell Havens

Solomon Bekele

Gautam P Shah

Robert Babrowicz

Kelly Ray Ahlgren

William Peyton Roberts

Dwight W Schwark

Vincent W Herran

Gloria G Toney

John G Bradfute

Martindale Nelson

Larry Bickle McAllister, Jr

Lawrence R Norpoth

Larry W Boyter

William John Gauthier

John R Wolf

Richard M Dayrit

Cedric M Lulham

Alan S Weinberg

W Scott Lambert

C Michael Lulham

Adam D Buccolo

Timothy Theodore Oberle

Cheryl M Banaszak

Kelly R Ahlgren

Gautem P Shah

Scott W Lambert

The present invention is directed to a heat-shrinkable, thermoplastic film or bag which contains at least one homogeneous ethylene alpha-olefin copolymer having a density of at least 0.90 g/cc. Oriented films made in accordance with the present invention exhibit improved optics and improved impact resistance. A homogeneous ethylene alpha-olefin may be present in a monolayer film either alone or in a blend or may be included in one or more layers of a multilayer film in accordance with the present invention.

Heat shrinkable films containing single site catalyzed copolymers

A film includes first and second outer layers, a core layer, and first and second substrate layers, each layer including a polymer; at least one of the substrate layers includes an amidic wax, and at least one of the outer layers includes an amidic wax present in an amount of 1% to 50% of the amount of wax in the first and second substrate layers respectively. The wax can be blended with a transition metal salt of stearic acid, or ester of stearic acid. Alternatively, a film includes first and second outer layers, and a substrate layer, each layer including a polymer; at least one of the first outer layer, second outer layer, and substrate layer including a blend of an amidic wax, and a transition metal salt of stearic acid, or ester of stearic acid.

Polymeric film with low blocking and high slip properties

The present invention is directed to a heat-shrinkable, thermoplastic film or bag which contains at least one homogeneous ethylene alpha-olefin copolymer with at least some limited long chain branching. Oriented films made in accordance with the present invention exhibit improved processability as well as improved physical properties such as excellent optics and impact resistance. A homogeneous ethylene alpha-olefin with long chain branching may be present in a monolayer film either alone or in a blend or may be included in one or more layers of a multilayer film in accordance with the present invention.

Heat shrinkable films containing single site catalyzed copolymers having long chain branching

Film and sheet materials, and articles made therefrom, such as bags, pouches, trays, etc., comprise one or more layers of homogeneous alpha-olefin/vinyl aromatic copolymer, preferably an ethylene/styrene copolymer. The alpha-olefin/vinyl aromatic copolymer has properties which can provide a desired performance characteristics such as impact resistance, printability, RF sealability, free shrink, optics, high permeability, etc. The homogeneous alpha-olefin/vinyl aromatic copolymer may be present in a monolayer film, either alone or in a blend, or may be included in one or more layers of a multilayer film. Also included is a multilayer thermoformable article comprising a web having a film of such alpha-olefin/vinyl aromatic copolymers thereto.

Film containing alpha-olefin/vinyl aromatic copolymer

A film includes a core layer including a homogeneous random alpha-olefin/cyclic olefin copolymer; and first and second outer layers including an olefinic polymer; the film having Young's modulus between about 50,000 and about 200,000 psi, free shrink between about 10% and about 80% at 240&#xb0; F., and shrink tension of less than about 400 psi, or a shrink force of between about 20 and about 180 grams, at 240&#xb0; F. First and second intermediate layers including an ethylene copolymer having a melt index less than about 2 g/10 minutes can be optionally included. Alternatively, a film includes a core layer including an ethylene copolymer having melt index less than about 2 g/10 minutes; first and second intermediate layers including a homogeneous random alpha-olefin/cyclic olefin copolymer; and first and second outer layers including an olefinic polymer; the film having properties as disclosed above.

High free shrink, high modulus, low shrink tension film with elastic recovery

A heat-shrinkable film containing a homogeneous ethylene/alpha-olefin copolymer has a high impact strength and a high free shrink. The film can be a monolayer film or multilayer film, with the homogeneous ethylene/alpha-olefin copolymer present alone or in a blend, and in one or more film layers. The film is especially suited for use in heat-shrinkable bags, which can be used for the packaging of various products, especially meat.

High impact strength film containing single site catalyzed copolymer

A film includes a core layer including a linear random alpha-olefin/vinyl aromatic copolymer; and first and second outer layers including an olefinic polymer; the film having Young's modulus between 50,000 and 200,000 psi, free shrink between 40 and 80% at 240&deg; F., and shrink tension of between 50 and 400 psi, or a shrink force of between 20 and 180 grams, at 240&deg; F. First and second intermediate layers including an ethylene copolymer having a melt index less than 2.0 can be optionally included. Alternatively, a film includes a core layer including an ethylene copolymer having melt index less than 2.0; first and second intermediate layers including a linear random alpha-olefin/vinyl aromatic copolymer; and first and second outer layers including an olefinic polymer; the film having properties as disclosed above.

Low shrink tension film

An oriented heat shrinkable film includes a layer including a multicomponent ethylene/alpha-olefin interpenetrating network resin having a melt index less than 1.4, the resin including a homogeneous component having a melt index of less than 1, and a density of at least 0.91 grams/cubic centimeter, and a heterogeneous component with a melt index of between 1.5 and 20; the film having a haze value (ASTM D 1003-95) less than or equal to 5, a peak load/mil value (ASTM D 3763-95a) of at least 155 newtons/mil, and a free shrink (ASTM D 2732-83) at a temperature of 200&deg; F. of at least 8% in either or both of the longitudinal and transverse directions. Films with substantially balanced free shrink are preferred, in particular those with a free shrink balance of less than or equal to 30%. Advantages in downgauging and/or mechanical properties are provided without substantially adversely affecting properties such as free shrink and optics.

Heat shrinkable film with multicomponent interpenetrating network resin

A multilayer, heat-shrinkable food packaging film useful for forming a post packaging pasteurization bag. The film includes at least three layers: 1) a first outer layer formed from a resin composition having a Vicat softening point of at least 100&deg; C., 2) a second outer layer having one or more thermoplastic gloss materials of polyester, ethylene/alpha-olefin copolymer having a melt index of greater than 1 g/10 minutes, styrene/butadiene block copolymer, and ethylene/styrene random copolymer, and 3) one or more inner layers between the first and second outer layers. At least one of the inner layers includes an ethylene/alpha-olefin copolymer. The film has a total free shrink of at least 40% at 85&deg; C. If the second outer layer includes polyester, then each of the inner layers of the multilayer film is devoid of a weight amount of polyamide or polyester greater than the weight amount of polyester in the second outer layer. The second outer layer may include sufficient thermoplastic gloss material to impart a gloss of greater than 60%. The film may also include an oxygen barrier internal layer. A post pasteurization bag made from the inventive film provides the appearance and shrink characteristics comparable to those of a barrier bag film yet can form heat seals that withstand the abuse and heat associated with post pasteurization.

Post pasteurization multilayered film

A patch bag has a heat-shrinkable patch adhered to a heat-shrinkable bag, the heat-shrinkable patch comprising homogeneous ethylene/alpha-olefin copolymer. The patch bag can be made by adhering a patch film to a film which is thereafter converted to a bag, or by adhering the patch to a pre-formed bag. A packaged product has a meat product in the patch bag, the meat product comprising bone.

Patch bag comprising homogeneous ethylene/alpha-olefin copolymer

A method includes the steps of providing a tubing having an inner annular layer comprising a crosslinked polymeric material, and an outer annular layer comprising a non-crosslinked polymeric material, or a material that is crosslinked to a lesser extent than the material of the inner layer; longitudinally slitting the tubing to form a folded film; and reverse centerfolding the folded film to provide a folded film having a lateral slit edge, and a lateral folded edge opposite said lateral slit edge, such that the inner annular layer becomes an outer layer, and the outer annular layer becomes an inner layer. A bag can be made from the reverse centerfolded film, and an article such as food can be packaged in the bag.

Method for making and converting a centerfolded film

Film and sheet materials, and articles made therefrom, such as bags, pouches, trays, etc., comprise one or more layers of a thermoplastic, homogeneous alpha-olefin/vinyl aromatic copolymer, preferably an ethylene/styrene copolymer. The alpha-olefin/vinyl aromatic copolymer has properties which can can provide a desired performance characteristics such as impact resistance, printability, RF sealability, free shrink, optics, as well as many others. The homogeneous alpha-olefin/vinyl aromatic copolymer may be present in a monolayer film, either alone or in a blend, or may be included in one or more layers of a multilayer film. Also included is a multilayer thermoformable article comprising a web having a film of such alpha-olefin/vinyl aromatic copolymers therto. Finally, also included is an RF-sealable film comprising such copolymers.

Growing community of inventors

Inman, SC, United States of America

Blaine C Childress