Water soluble package

Abstract

A water soluble package containing a fluid substance for release on dissolution of the package, the package having a dome shaped body portion for containing the fluid substance comprising a first sheet of a water soluble material thermoformed to form a body wall of the body portion, and a second sheet of water soluble material superposed on the first sheet and sealed thereto along a continuous region of the superposed sheets to form a base wall of the body portion.

Description

[0001] The invention relates to a water soluble package containing a fluid substance for release on dissolution of the package.[0002] Detergent compositions for the machine washing of laundry are provided in many forms. Probably the most prevalent form of laundry detergent is washing powder or granules. A problem with the use of these forms of detergent is that the product needs to be dosed into the machine in such a way that the detergent is quickly and thoroughly dissolved in the wash water of the machine without coming into contact with the laundry in a solid form. In this regard many dosing devices which seek to overcome this problem have been proposed. One such device disclosed in European Patent Nos. 0 343 070 and 0 343 069 teaches the use of a flexible fabric sock which holds the particulate detergent in the machine, the fabric of the sock being permeable to water so as to allow water enter the sock and carry the detergent out of the sock through the fabric walls in the form ...

AI Technical Summary

Benefits of technology

[0007] The applicants have surprisingly discovered that the above mentioned problems and disadvantages of prior art water soluble packages are substantially addressed by the packages according to the invention. In particular, the invention yields water soluble packages which are sufficiently robust to withstand (to a commercially acceptable level) the rigours of packaging and transport even when the fluid substance inside the package is a domestic consumer product such as a laundry detergent. The combination of thermoforming the packages of the invention and forming the packages into a dome shape confers surprising advantages on the packages of the invention. It is thought that thermoforming reduces stress on the film during forming compared to other forming techniques. As will be shown below, applicants have found that the dome is a shape which yields greater uniformity of film thickness over the package and greater impact resistance of the package.

Problems solved by technology

A problem with the use of these forms of detergent is that the product needs to be dosed into the machine in such a way that the detergent is quickly and thoroughly dissolved in the wash water of the machine without coming into contact with the laundry in a solid form.

A problem encountered with the provision of detergent tablets is that the tablets need to be strong enough to withstand storage and transport, yet weak enough to disintegrate and dissolve quickly in the washing machine.

A further problem is the need to prevent the tablets postingin the porthole and between the drums of conventional washing machines.

However, as many of the current detergent tablets contain bleach and other irritant substances, the problem of handling the tablets remains.

A problem with envelopes produced using this VFFS method is that, due to the constraints of the process, the resultant envelopes have seals which incorporate defined weak points where the seals overlap at corners.

This results in envelopes which are easily corrupted as a result of impacts suffered during transport.

The packaging and transport of water soluble packages containing fluid substances subjects the formed packages to considerable impact forces.

A particular problem is that when a number of such packages are loose packed in a larger container which is then transported, the impact forces suffered by the packages within the container can be severe.

The difficulty is that in such a situation it only takes one package in the larger container to break for the whole product to be ruined as far as the consumer is concerned because the fluid contents of the broken package may leak over any unbroken packages.

Consumer confidence in a product is likely to be badly damaged by such an occurrence.

The problem of minimising breakage to an acceptable level is particularly acute in the area of laundry detergents and other domestic consumer products and has not been solved until now.

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