Patent ID: 8686323

Claim:
A multilayer freezable, microwaveable package comprising: (a) a polyolefin film comprising an inner heat sealable layer, at least one core layer adjacent to the heat sealable layer, and an outer skin layer adjacent to the at least one core layer opposite the heat sealable layer, wherein the heat sealable layer comprises at least one polypropylene/alpha-olefin copolymer having a melt flow rate of about 0.5 g/10 min to about 45 g/10 min at about 230Â° C.; wherein the at least one core layer comprises a polymeric material having a melting point of at least 71Â° C.; and wherein the outer skin layer comprises at least one polyethylene resin having a melt flow index of about 0.50 g/10 min to about 20 g/10 min at about 190Â° C.; and (b) an outer protective layer bonded to the outer skin layer of the polyolefin film, the outer protective layer being formed from a heat resistant polymeric material; wherein the polyolefin film bonded to the outer protective layer forms a multilayer freezable, microwaveable film that can be exposed to a temperature of from about 0Â° C. to about âˆ’20Â° C. without fracturing and is temperature resistant at about 150Â° C.; wherein the heat sealable layer of the polyolefin film is sealed to itself to form the package; wherein the package further comprises at least one vent slit through the package, the at least one vent slit having a length from about 2 millimeters to about 12 millimeters; and wherein the package has a peak internal pressure of at least about 0.3 psi during microwave cooking when the internal temperature is at least about 71Â° C.