Surface-treated multi-layered polymer film
OwnerMichael Cleckner, Scott Wilkinsinventors
Life of this patent
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Abstract
A sealable polymeric film structure comprising (a) a core layer including a thermoplastic polymer, the core layer having a machine side and a product side that is on a side of the film opposite from the machine side; and (b) a sealable skin layer positioned on the product side of the core layer, the sealable skin layer including a thermoplastic polymer, wherein an exterior surface of the sealable skin layer has a receding Cahn value of at least about 0.48; and wherein in some heat—sealable embodiments, the sealable skin layer sealed to itself has a MST of from about 175° F. to about 220° F., with a jaw pressure of 20 psi for 0.75 seconds and a minimum acceptable seal strength of 200 g/in at 175° F., on a Wrap-Ade™ Crimp Sealer Model J or K.
Claims26
A method of preparing a heat-sealable polymeric film structure including a product side and a machine side, the method comprising the steps of:
- (a) coextruding:
- i) a core layer including a thermoplastic polymer, the core layer having a machine side and a product side opposite from the machine side;
- and
- ii) a heat-sealable skin layer positioned on the product side of the core layer, the heat-sealable skin layer including a thermoplastic polymer;
- wherein the product side exterior surface of the coextruded film structure has a receding Cahn value of at least about 0.48;
- wherein the sealable skin layer when sealed to itself has a MST of from about 175° F. to about 220° F., with a jaw pressure of 20 psi for 0.75 seconds and a minimum acceptable seal strength of 200 g/in at 175° F., on a Wrap-Ade™ Crimp Sealer Model J or K;
- (b) orienting the coextruded film structure in at least one direction;
- and
- (c) surface treating the product side exterior surface of the film with one of corona treatment, flame treatment, and plasma treatment.
A method of packaging a product within a heat-sealable polymeric film, the method comprising the steps of:
- (a) drawing a heat-sealable polymeric film structure through a packaging machine from an inlet side of the packaging machine to an outlet side of the packaging machine, the heat-sealable polymeric film structure including a product side and a machine side, the multilayer film comprising (i) a core layer comprising a thermoplastic polymer, the core layer having a machine side and a product side, and (ii) a heat-sealable skin layer comprising a thermoplastic polymer, wherein an exterior surface of the heat-sealable skin layer has a receding Cahn value of at least about 0.48, and wherein the sealable skin layer when sealed to itself has a MST of from about 175° F. to about 220° F., with a jaw pressure of 20 psi for 0.75 seconds and a minimum acceptable seal strength of 200 g/in at 175° F., on a Wrap-Ade™ Crimp Sealer Model J or K, wherein the product side exterior surface of the film is surface treated with one of corona treatment, flame treatment, and plasma treatment;
- and
- (b) positioning a product on the product side of the heat-sealable multilayer film;
- (c) engaging a first exterior portion of the product surface of the heat-sealable skin layer with one of (i) a second exterior portion of the product surface and (ii) the machine side exterior surface of the film, to form a seal area over the engaged portions of the heat-sealable skin layer and create a product space with the film;
- and
- (d) applying heat to at least a portion of the seal area to bond the heat-sealable skin layer to the engaged exterior portion machine side to encase at least a portion of the product within the product space.
A packaged product encased in a heat-sealable film structure, comprising:
- a product;
- and
- a packaging film at least partially encasing the product, the packaging film comprising a product side and a machine side;
- (a) a core layer including a thermoplastic polymer, the core layer having a machine side and a product side;
- and
- (b) a heat-sealable skin layer positioned on the product side of the film, the heat-sealable skin layer including a thermoplastic polymer, wherein an exterior surface of the sealable skin layer has a receding Cahn value of at least about 0.6 to about 0.85, and wherein the heat-sealable skin layer sealed to itself has a MST of from about 175° F. to about 220° F., with a jaw pressure of 20 psi for 0.75 seconds and a minimum acceptable seal strength of 200 g/in at 175° F., on a Wrap-Ade™ Crimp Sealer Model J or K.
Dependencies are inferred from the claim text.