Packaging material

Abstract

A packaging laminate includes a core layer (or web) with through-holes covered on one side with a first outer layer, and on another side with a second outer layer, such that the first and second outer layers are sealed to each other within the through-holes. To provide a permanent seal between the outer layers, the web can be flame-treated to activate or polarize parts of the first outer layer within the through-holes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of, and claims priority under 35 U.S.C. § 120 to, U.S. patent application Ser. No. 10 / 258,969, which was filed on Mar. 13, 2003, as a 371 of International Application No. PCT / SE01 / 00985, filed on May 7, 2001, and this application claims priority under 35 U.S.C. § 119 to Swedish Patent Application No. 0001677-4, filed on May 8, 2000. The entire contents of each of these applications are hereby incorporated by reference in this application.FIELD OF THE INVENTION [0002] The present invention relates to a method of producing a packaging material comprising a core layer with through-going holes which are covered by a first layer applied on one side of the core layer, and a second layer applied on the other side of the core layer, the first and second layers being bonded to one another within the regions of the opening contour of the through-going holes, the method comprising the steps of providing a web of co...

AI Technical Summary

Benefits of technology

The present invention provides a method for producing a packaging material for a packaging container with a well-functioning opening arrangement of the container. The method involves coating a core layer with through-going holes with a first outer layer of thermoplastic, sealing the first outer layer to the core layer in the region inside the opening contour of the through-going holes, and then coating the other side of the core layer with a second outer layer. The second outer layer is sealed to the first outer layer in the region inside the opening contour of the through-going holes. The method ensures efficient and expedited opening function of the packaging container, even in cases where the container wall includes aluminum foil. The invention also provides a laminated packaging material for a packaging container with a well-functioning opening arrangement. The method and the laminated packaging material have improved sealing strength and can be used for packaging oxygen gas-sensitive liquid products.

Problems solved by technology

Both of these preconditions are, as a rule, easy to satisfy with packaging containers in which both of the respective outer layers of the packaging material consist exclusively of simple, easily sealed thermoplastic layers, while, on the other hand, it is not an uncommon occurrence that problems arise in packaging containers in which one or both of the outer layers of the packaging material also include a layer of another material than thermoplastic, such as, for example, an aluminum foil which is often employed in packaging containers for oxygen gas-sensitive products, such as juice, etc.

When the outer layer on the inside of the packaging wall also includes an aluminum foil which, by the intermediary of a sealing- or lamination layer, is connected to the outer layer on the inside of the packaging wall within the region of the opening contour of the hole, it occasionally happens that the seal between the two outer layers of the packaging wall is unintentionally ruptured when the opening strip or pull-tab is pulled off, and that the outer layer on the inside of the packaging wall at best is only partly removed from the hole.

Images