Process and Mold for Thermoforming Containers

Abstract

Methods of manufacturing water-soluble containers using a horizontal intermittent motion thermoforming machine which comprises the steps of: a) locating a first water-soluble film over a mould, said mould containing a plurality of pocket forming cavities, defined by side walls and a base, in a 2-dimensional array, each cavity being surrounded by a planar surface of the mould on all sides in which the shortest dimension of the planar surface between two adjacent cavities is at least 3 mm and between an edge of the mould and the closest cavity is at least 1.5 mm; b) thermoforming the first film to produce a plurality of pockets; c) at least partially filling the pockets with a composition; and d) sealing the plurality of the at least partially filled pockets. The cavities are positioned in the array such that there are a plurality of continuous strips of uninterrupted planar surface of the mould from a leading to a trailing edge of the mould, for receiving support means fitted to the machine for supporting the film.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a continuation of U.S. patent application Ser. No. 10 / 362,615, now pending, filed Nov. 29, 2004. U.S. patent application Ser. No. 10 / 362,615 is incorporated herein in its entirety by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a method of manufacturing water-soluble containers and a mould for use therein.[0004]2. The Related Art[0005]It is known to package chemical compositions which may be of a hazardous or irritant nature in water soluble or water dispersible materials such as films. The package can simply be added to water in order to dissolve or disperse the contents of the package into the water.[0006]For example, WO 89 / 12587 discloses a package which comprises an envelope of a water soluble or water dispersible material which comprises a flexible wall and a water-soluble or water-dispersible heat seal. The package may contain an organic liquid comprisi...

AI Technical Summary

Problems solved by technology

Immediately after the containers are prepared, they have a limp, unattractive appearance.

It is, however, extremely difficult to manufacture products using PVOH and other materials having similar physical characteristics, partly because of their hygroscopic nature, but mainly due to the fact that the material is very soft and floppy, making it extremely difficult to handle and cut.

PVOH and similar films do not have this strength or rigidity and would stretch, thin and tear if subjected to such handling.

Furthermore, thermo- and other such forming processes impose a significant amount of drawing and stretching of the material.

This means that the amount of material available for deforming is greater, but it is a very labour intensive, slow and therefore costly process to achieve the manufacture of this type of product.

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