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US5397640A Expired / Lapsed US ⏱️ 0.0 years remaining

Biaxially oriented heat-shrinkable film

Assignee: Curwood Inc
•
Filing: 1994-01-31
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Granted: 1995-03-14
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Expires: 2014-01-31
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Abstract

Abstract An improved biaxially oriented heat-shrinkable film of the type used for packaging food, such as poultry, processed meat, and fresh meat.

Inventors

  • 👤 Paul N. Georgelos
  • 👤 James E. Pelkie
  • 👤 Darrel L. Wilhoit

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 11:34
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B32; B32B; B32B27/00; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; C08L23/0846; C08L23/0853; C08J2323/00; C08J2323/02; C08J2323/04; C08L2205/00; C08L2205/02; C08L2205/03; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 100 words
A biaxially oriented heat-shrinkable film comprising a three component blend of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 and having a melting point between about 55° C. and about 85° C. as major components, wherein said VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. % with a vinyl acetate content of less than about 18 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.
Claim 2
Dependent Claim 100 words
A biaxially oriented heat-shrinkable film comprising a three component blend of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 and having a melting point between about 55° C. and about 85° C. as major components, wherein said VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. % with a vinyl acetate content of less than about 18 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.
Claim 3
Dependent Claim 15 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein, said film is a monolayer.
Claim 4
Dependent Claim 21 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said blend comprises at least one layer of a multilayer film.
Claim 5
Dependent Claim 22 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said VLDPE has a melting point of at least about 115° C.
Claim 6
Dependent Claim 24 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said EVA has a vinyl acetate content of less than about 15 wt. %.
Claim 7
Dependent Claim 26 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said VLDPE comprises between about 25 and about 30 wt. % of said three component blend.
Claim 8
Dependent Claim 26 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said EVA comprises between about 33 and about 38 wt. % of said three component blend.
Claim 9
Dependent Claim 26 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said plastomer comprises between about 33 and about 38 wt. % of said three component blend.
Claim 10
Dependent Claim 49 words
A biaxially oriented heat-shrinkable film according to claim 1 wherein said VLDPE comprises between about 25 and about 30 wt. %, said EVA comprises between about 33 and about 38 wt. %, and said plastomer comprises between about 33 and about 38 wt. % of said three component blend.
Claim 11
Dependent Claim 50 words
A biaxially oriented heat-shrinkable film according to claim 3 wherein said multilayer film comprises at least three layers including an oxygen barrier core layer between a first outer layer and a second outer layer, and said three component blend comprises at least one of said first and second outer layers.
Claim 12
Dependent Claim 47 words
A biaxially oriented heat-shrinkable film according to claim 3 wherein said multilayer film comprises three layers including an oxygen barrier core layer between a first outer layer and a second outer layer, and said first and second outer layers each comprise an identical said three component blend.
Claim 13
Dependent Claim 12 words
A biaxially oriented heat-shrinkable film according to claim 1 which is irradiated.
Claim 14
Dependent Claim 12 words
A biaxially oriented heat-shrinkable film according to claim 11 which is irradiated.
Claim 15
Dependent Claim 54 words
An irradiated biaxially oriented heat-shrinkable film according to claim 1 which has at least about 50% shrink in both the machine and transverse directions at 90° C., haze of less than about 6%, gloss of at least about 77 Hunter Units and hot water seal strength of at least 15 seconds at 95° C.
Claim 16
Dependent Claim 124 words
In a method for manufacturing a biaxially oriented heat-shrinkable film wherein a primary tube is extruded, cooled, reheated and stretched in the machine direction and inflated in the transverse direction by internal gas to form a bubble, then collapsed and withdrawn as biaxially oriented thinner film: the improvement comprising forming the primary tube from a three component blend of major constituents consisting of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 wherein the VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.
Claim 17
Dependent Claim 124 words
In a method for manufacturing a biaxially oriented heat-shrinkable film wherein a primary tube is extruded, cooled, reheated and stretched in the machine direction and inflated in the transverse direction by internal gas to form a bubble, then collapsed and withdrawn as biaxially oriented thinner film: the improvement comprising forming the primary tube from a three component blend of major constituents consisting of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 wherein the VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.
Claim 18
Dependent Claim 79 words
An irradiated biaxially oriented heat-shrinkable bag formed from film comprising a three component blend of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 as major components, wherein said VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.
Claim 19
Dependent Claim 79 words
An irradiated biaxially oriented heat-shrinkable bag formed from film comprising a three component blend of very low density polyethylene (VLDPE), ethylene vinyl acetate (EVA) and ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 as major components, wherein said VLDPE comprises between about 24 and about 38 wt. %, said EVA comprises between about 28 and about 40 wt. %, and said plastomer comprises between about 33 and about 45 wt. % of said three component blend.

References Cited (Backward Citations)

US4952451A Cited
EP0436196A2 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-03-13 1998-09-12 1999-03-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-03-13 2002-09-12 2003-03-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-03-13 2006-09-12 2007-03-14 $7700.00 Window Closed / Lapsed

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