Eva-evoh delamination seal
AssigneePechiney Emballage Flexible Europe
InventorDuane H. Buelow
Life of this patent
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Abstract
Multilayer films and packaging structures having a delamination seal and an oxygen barrier layer are disclosed. The delamination structure adjacent to the EVOH oxygen barrier layer binds well to the EVOH layer and also retains its ability to delaminate. The multilayer films, and packages in which they are utilized, have several layers including a first, external layer; a second, tie layer comprising a mixture of polybutylene and an anhydride modified polyethylene such that a peelable bond is formed between said first, external layer and said second, tie layer; a third, core layer comprising ethylene vinyl alcohol which functions as an oxygen barrier layer; a fourth, tie layer comprising an anhydride modified polyethylene and a fifth, external layer.
Claims29
A package comprising:
- a first package wall having a multilayer film construction, said multilayer film construction comprising:
- a first, external layer;
- a second, tie layer comprising a blend of about 65% to 90% by weight an anhydride modified polyethylene and about 10% to 35% by weight of a compound selected from the group consisting of polybutylene, polypropylene and a styrene-butadiene copolymer such that a peelable bond is formed between said first, external layer and said second, tie layer;
- a third, core layer comprising ethylene vinyl alcohol;
- a fourth, tie layer comprising an anhydride modified polyethylene and a fifth, external layer;
- and
- a second package wall joined at a portion of its perimeter to said first package wall;
- wherein said first, external layer of said first package wall is heat sealed to said second package wall to create a sealed package such that a bond is formed between said first, external layer of said first package wall and said second package wall having a greater bond strength than said peelable bond such that upon application of digital pull-apart force said first and second package walls will remain bonded together and delamination will occur at said peelable bond between said first, external layer and said second, tie layer of said first package wall wherein said package is opened by the use of digital force.
A package comprising:
- a first package wall having a multilayer film construction, said multilayer film construction comprising:
- a first, external layer comprising an ethylene vinyl acetate copolymer;
- a second, tie layer comprising a blend of about 65% to 90% by weight an anhydride modified polyethylene and about 10% to 35% by weight of a compound selected from the group consisting of polybutylene, polypropylene and a styrene-butadiene copolymer such that a peelable bond is formed between said first, external layer and said second, tie layer;
- a third, core layer comprising ethylene vinyl alcohol;
- a fourth, tie layer comprising an anhydride modified polyethylene and a fifth, external layer comprising an ethylene vinyl acetate copolymer;
- and
- a second package wall joined at a portion of its perimeter to said first package wall;
- wherein said first, external layer of said first package wall is heat sealed to said second package wall to create a sealed package such that a bond is formed between said first, external layer of said first package wall and said second package wall having a greater bond strength than said peelable bond such that upon application of digital pull-apart force said first and second package walls will remain bonded together and delamination will occur at said peelable bond between said first, external layer and said second, tie layer of said first package wall wherein said package can be opened by digital force.
A multilayer film construction comprising:
- a first, external layer;
- a second, tie layer comprising a blend of about 65% to 90% by weight of an anhydride modified polyethylene and about 10% to 35% by weight of a compound selected from the group consisting of polybutylene, polypropylene and a styrene-butadiene copolymer such that a peelable bond is formed between said first, external layer and said second, tie layer;
- a third, core layer comprising ethylene vinyl alcohol;
- a fourth, tie layer comprising an anhydride modified polyethylene;
- and
- a fifth, external layer.
A multilayer film construction comprising:
- a first, external layer comprising an ethylene vinyl acetate copolymer;
- a second, tie layer comprising a blend of about 65% to 90% by weight of an anhydride modified polyethylene and about 10% to 35% by weight of a compound selected from the group consisting of polybutylene, polypropylene and a styrene butadiene copolymer such that a peelable bond is formed between said first external layer and said second tie layer;
- a third, core layer comprising ethylene vinyl alcohol;
- a fourth, tie layer comprising an anhydride modified polyethylene;
- and
- a fifth, external layer comprising an ethylene vinyl acetate copolymer.
Dependencies are inferred from the claim text.