| CPC B65D 81/34 (2013.01) [B32B 1/00 (2013.01); B32B 27/08 (2013.01); B32B 27/304 (2013.01); B32B 27/34 (2013.01); B32B 27/36 (2013.01); B65B 1/02 (2013.01); B32B 2307/306 (2013.01); B32B 2307/31 (2013.01); B32B 2307/738 (2013.01); B32B 2439/70 (2013.01); Y10T 428/1334 (2015.01); Y10T 428/31736 (2015.04); Y10T 428/31739 (2015.04); Y10T 428/31786 (2015.04); Y10T 428/31797 (2015.04)] | 15 Claims |
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1. A package comprising
(i) a laminate comprising the following substantially coextensive layers in the following order
(a) a non-sealable, self-supporting, thermoformable copolyester film layer having a first surface and a second surface, said second surface constituting an outermost, exposed surface of the laminate,
wherein the copolyester contains terephthalic acid, azelaic acid and one or more glycols,
wherein non-sealable means that the thermoformable copolyester film layer has a heat-seal strength of less than 200 g/25 mm, wherein heat-seal strength is determined by bonding the thermoformable copolyester film layer to itself at 160° C. for 0.5 seconds under a pressure of 80 psi (0.55 N/mm2), cooling it to room temperature, cutting it into 25 mm wide strips, and measuring the force required under linear tension per unit width to peel the layers apart at a constant speed of 0.25 m/minute;
(b) a laminating adhesive layer on the first surface of the thermoformable copolyester film layer, wherein the laminating adhesive layer is derived from a solventless polyurethane system; and
(c) a self-supporting, thermoformable structural film layer having a first surface and a second surface, said first surface contacting the laminating adhesive layer;
wherein polyethylene terephthalate constitutes at least 80% by weight of the self-supporting thermoformable copolyester film layer;
the thermoformable structural film layer comprises a polyamide;
and wherein the laminate is in the shape of a thermoformed receptacle having a pocket with a flange and an opening, the second surface of the copolyester film layer forming an inner surface of the pocket and a mating surface of the flange; and
(ii) a heat-sealable film comprising a polyamide film laminated to a self-supporting polyester film wherein said self-supporting polyester film has on a surface thereof a substantially coextensive heat-seal layer,
wherein the opening of the receptacle is closed by the heat-sealable film,
wherein the heat-seal layer of the heat-sealable film is in contact with and bonded to the mating surface of the flange of the thermoformed receptacle; and
wherein the heat-seal layer ruptures and vents the package at a temperature in a range from 150° F. (65.6° C.) to 450° F. (232.2° C.).
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