Patent ID: 8479478

Claim:
A method of packaging a product within a heat-sealable polymeric film on a packaging machine, the method comprising the steps of: (a) drawing the heat-sealable polymeric film structure through the packaging machine from an inlet side of the packaging machine to an outlet side of the packaging machine, the heat-sealable polymeric film structure having a product side and a machine side, the heat-sealable polymeric film structure comprising: (i) a core layer having a machine side and a product side opposite from the machine side, wherein the core layer comprises a polymer matrix and optionally a cavitating agent; (ii) a heat-sealable skin layer on the product side of the core layer, the heat-sealable skin layer having a product side exterior surface with a product side surface energy having a receding DCA Cahn value of at least about 0.48; wherein the heat-sealable skin layer comprises a polymer material selected from the group consisting of polyethylene, polybutene, polylactic acid, propylene-ethylene copolymers, propylene-butylene copolymers, propylene-ethylene-butylene terpolymers and ethylene-propylene-butylene terpolymers; (b) positioning a product on the product side exterior surface of the heat-sealable skin layer; (c) engaging a first portion of the product side exterior surface of the heat-sealable skin layer with a second portion of the product side exterior surface of the heat-sealable skin layer, whereby a seal area is formed over the engaged portions of the product side exterior surfaces of the heat-sealable skin layers, or optionally engaging a first portion of the product side exterior surface of the heat-sealable skin layer with a portion of the machine side of the heat-sealable polymeric film structure, whereby a seal area is formed over the engaged portions of the product side exterior surface of the heat-sealable skin layer and the machine side of the heat-sealable polymeric film, whereby a product space is created within the product side of the heat-sealable polymeric film structure; and (d) applying heat to at least a portion of the seal area to form a seal and encase at least a portion of the product within the product space, wherein the seal formed has the following sealing properties: (A) a minimum sealing temperature (MST) of from about 175° F. to about 220° F. with a jaw pressure of 20 psi for 0.75 seconds, and (B) a minimum acceptable seal strength of 200 g/in at 175° F., wherein the product is substantially frozen and comprises at least one of water, an aqueous-based product, or dairy-based product.