Amcor Flexibles Singen Gmbh

Christoph Dietrich

Sven Bauer

Klaus Hafner

Bert De Schoenmaker

Steven Welvaert

Composite film () for closing a container () by sealing the composite film () against a circumferential sealing surface () of the container () or of a cap ring () to be connected to the container (). The composite film () comprises an outer support layer () made of a metal film and an inner multilayer membrane () laminated to the outer support layer () using a bonding layer (). The membrane () has a consecutive layer structure from the outside to the inside consisting of a backbone layer () made of polypropylene, an intermediate layer () made of a partially crystalline polyamide and a cohesively breakable peeling layer () made of polypropylene, polyethylene and talc, wherein between the intermediate layer () and the backbone layer () as well as between the intermediate layer () and the peeling layer () there is arranged a tie layer () made of a maleic acid anhydride grafted polypropylene. The membrane has further an innermost sealing layer () made of a random copolymer comprising monomers of propylene, ethylene and butylene, wherein the random copolymer is grafted with maleic acid anhydride. The softening point of the sealing layer () lies at least between 15 and 25&#xb0; C. lower than that of the tie layers (). A use and a method of producing said composite film () are also disclosed.

Composite film

A composite film for closing a container by sealing the composite film against a circumferential sealing surface of the container or of a cap ring to be connected to the container has a support layer made of a metal film and a sealing layer connected to the metal film. The sealing layer comprises a coextruded layer with a cohesively breaking intermediate layer and adhesion promoter layers arranged on both sides of the intermediate layer. The composite film is suitable for tight sealing against sealing surfaces made of polished tinplate.

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Singen, Germany

Christoph Dietrich