| US 7,540,834 B2 | ||
| Backseamed casing and packaged product incorporating same | ||
| Ram K. Ramesh, Greenville, S.C. (US); and Michael J. Rosinski, Woodruff, S.C. (US) | ||
| Assigned to Cryovac, Inc., Duncan, S.C. (US) | ||
| Filed on Jan. 18, 2001, as Appl. No. 9/764,673. | ||
| Application 09/764673 is a division of application No. 08/968016, filed on Nov. 12, 1997, granted, now 6,221,410. | ||
| Application 08/968016 is a continuation of application No. 08/539919, filed on Oct. 06, 1995, abandoned. | ||
| Application 08/539919 is a continuation in part of application No. 07/951245, filed on Sep. 25, 1992, abandoned. | ||
| Prior Publication US 2001/0041201 A1, Nov. 15, 2001 | ||
| Int. Cl. B31C 11/04 (2006.01) | ||
| U.S. Cl. 493—294 [493/269; 493/297; 429/127; 428/216; 428/504] | 28 Claims |
| 1. A process for making a backseamed casing, comprising:
(A) preparing a multilayer heat-shrinkable film comprising:
(i) a first outer layer serving as an inside casing layer, the first outer layer comprising a first polyolefin comprising
at least one member selected from the group consisting of:
(a) ethylene/unsaturated acid copolymer, propylene/unsaturated acid copolymer, and butene/unsaturated acid copolymer, wherein
the unsaturated acid is present in an amount of at least 4 weight percent, based on the weight of the copolymer; and
(b) anhydride-containing polyolefin comprising an anhydride-functionality, wherein the anhydride functionality is present
in an amount of at least 1 weight percent, based on the weight of the anhydride-containing polyolefin;
(ii) a second layer comprising at least one member selected from the group consisting of polyester and a first polyamide;
and
(iii) a third layer serving as an outside casing layer, the third layer comprising at least one member selected from the group
consisting of second polyolefin, polystyrene, and a second polyamide; and
wherein the second layer is between the first layer and the third layer, with the film having has a thickness of at least
5% of a total thickness of the heat-shrinkable casing film;
(B) wrapping the film longitudinally around a forming shoe with opposing length film sheet edges being overlapped or abutted
with one another;
(C) sealing the film longitudinally to form a backseam; followed by
(D) forwarding the film.
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