Packaging laminate, method of producing a packaging container and the packaging container

Abstract

Packaging laminate (10) for a packaging container, which packaging laminate comprises a structural base layer (4), and an inside layer (6). According to the invention, said inside layer (6) comprises a sealing ply (2) of a heat sealable thermoplastic material, which sealing ply is arranged to be the outermost layer on one side of the laminate (10), intended to be arranged on the inside of said container, said heat sealable thermoplastic material exhibiting a melt enthalply lower than 115 J / g. The invention also relates to a method of producing packaging containers from the packaging laminate, and to a packaging container produced from the packaging laminate.

Description

[0001] The invention relates to a packaging laminate for a packaging container, preferably for liquid food contents, which packaging laminate comprises a structural base layer, and an inside layer. The invention also relates to a method of producing a packaging container from the packaging laminate, and to the packaging container built up from the packaging laminate.PRIOR ART AND PROBLEMS[0002] Food packaging processes of today (with the term "food" is meant all sorts of solid and liquid food, such as juices, milk and other beverages as well as pastes, soups, jellies and cheese) often are of the "form-fill-seal" type and may be carried out by shaping a continuously moving web-shaped packaging laminate made of a flexible laminate into a continuously running tube, continuously filling the tube with the desired food product to be packaged and by sealing and finally cutting off sealed packages from the tube.[0003] The packaging processes are often high speed continuous processes, wherei...

AI Technical Summary

Benefits of technology

[0012] Of course, the prime object of the invention is to provide strong and liquid-tight transversal seals in packaging containers produced from the packaging laminate according to the invention, also at the overlaps between the transversal seals and the longitudinal seal in the packaging container.

[0018] The sealing window concept is well known by the skilled man and is defined as the energy range within which sealing is possible. A low lowermost limit means that an acceptable seal takes place at low energy levels, which in turn decreases the sensibility of the ultrasonic vibration heat sealing system to the mechanical settings and to other prevailing circumstances. Even if a low pressure is applied in some spots along the sealing area, the energy converted into heat will be enough to melt the heat sealable thermoplastic sealing ply having a low melt enthalpy, thus allowing a strong and liquid-tight seal to be formed. A high uppermost limit of the sealing window means that a considerable energy supply can be allowed.

[0020] It has moreover surprisingly been found that the openability of an opening device consisting of a perforation partly passing through the transversal seal is very good, despite the fact that the transversal seal is so strong.

[0035] It is an advantage of the invention that the beneficial properties of the second ply 2 will allow decreased grammages of the first 1, third 3 and fourth 7 plies, thus counteracting an increased cost due to the material of the second ply 2 being relatively expensive.

Problems solved by technology

Especially, the object is to provide a packaging laminate which is more forgiving to prevailing circumstances such as poor tolerances in the mechanical settings of the sealing machine, poor tube guiding, disturbed movements of the anvil jaws, poor parallelism between the ultrasonic horns and the cutting rails, presence of foreign matter in the area of the seals, etc.

Images