Food Sachet or Container

Abstract

A sachet or food container is formed of two plastics sheets joined to one another around the edges of an internal pocket of the sachet or container by welded seals. The compositions of the two plastics sheets differ one from the other and are selected such that the strength of the seals is controllable by varying at least one welding parameter selected from temperature, pressure and dwell time. The two sheets are welded to one another using a first set of welding parameters to produce strong seals in some of the seam regions bounding the internal pocket, while other seam regions bounding the pocket are welded using a second set of welding parameters to produce weak seals at which the sachet will burst open preferentially when the pocket is pressurised.

Description

FIELD OF THE INVENTION [0001] The present invention relates to the manufacture of sachets for use in a beverage machine and of packets and containers for enabling food to be heated in a microwave oven. BACKGROUND OF THE INVENTION [0002] Beverage machines are known which inject a liquid, usually hot water, under pressure into a sachet having a sealed pocket containing an infusible product, such as ground coffee or tea leaves, or soluble solids such as hot chocolate powder or granules. The sachet bursts under the pressure of the injection water and a beverage is dispensed into a cup. One example of such a pressure rupturable sachet is to be found in GB 2392374. [0003] It is desirable to design sachets of this kind such that they will always burst in the same place and dispense the beverage in a controlled manner. This is in order to avoid soiling the machine itself, the outside of the dispensing cup or the machine operator. [0004] The same requirement for a controlled release of the p...

AI Technical Summary

Benefits of technology

[0012] According to the present invention, there is provided a sachet or food container formed of two plastics sheets joined to one another around the edges of an internal pocket of the sachet or container by welded seals, wherein the compositions the two plastics sheets differ one from the other and are selected such that the strength of the seals is controllable by varying at least one welding parameter selected from temperature, pressure and dwell time, and wherein the two sheets are welded to one another using a first set of welding parameters to produce strong seals in some of the seam regions bounding the internal pocket, while other seam regions bounding the pocket are welded using a second set of welding parameters to produce weak seals at which the sachet will burst open preferentially when the pocket is pressurised.

Problems solved by technology

Thus while welding polypropylene to itself and easy peel materials to themselves did not produce satisfactory result, good results were obtained by welding a polypropylene layer to an easy peel layer.

Images