ES2334436T3 - WATER SOLUBLE CONTAINER. - Google Patents

Abstract

A water-soluble container, which contains a laundry detergent for release when the package dissolves, characterized in that: - the package has a body part for containing the laundry detergent fluid comprising a first sheet of a thermoformed water soluble material to form a body wall of the body part, and a second sheet of water soluble material superimposed on the first sheet and sealed thereto along a continuous region of the superimposed sheets for forming a generally rectangular or square base wall of the body part, - the body part of the container is generally dome-shaped, - the first and second sheets of water-soluble material comprise a polyvinyl alcohol or a derivative of polyvinyl alcohol, - the maximum height of the body wall above the base wall is less than or equal to the maximum width of the base wall, - the detergent e for washing clothes is a liquid or gel that has a viscosity of between 0.1 and 1 Pa.s (100 and 1000 centipoise) when measured at 20ºC and 105 s-1.

Description

Water soluble container.

Introduction

The invention relates to a soluble package in water according to claim 1, to a process for producing a container soluble in water, and a process for washing clothes.

The detergent compositions for washing Machine clothes are provided in many ways. Probably, the most frequent form of laundry detergent is in granules or washing powder. A problem with the use of these forms of detergent is that it is necessary to dose the product you need in the machine so that the detergent dissolves quickly and completely in the machine wash water without entering Contact with clothes in solid form. In this regard they have proposed many dosing devices that try to overcome this problem. A device of this type disclosed in the European patents Nos. 0343070 and 0343069 teaches the use of a Average flexible textile material containing detergent particulate in the machine, being the average textile material water permeable so that water enters the average and remove the detergent from the media through the walls of textile material in the form of aqueous solution. More recently it have proposed unit dose forms of detergent in the form of compressed tablets of detergent powder. A problem that is meets the provision of detergent tablets is that it is the tablets need to be strong enough to resist storage and transportation, although sufficiently weak to disintegrate and dissolve quickly in the washing machine. A additional problem is the need to prevent the pins "from fix "on the door and between the drums of the washing machines conventional.

More recently these problems have been treated by providing detergent tablets that have specific chemical disintegrants that allow rapid disintegration of the tablets in the aqueous environment of a washing machine, and by providing loose-fit net bags that they help the disintegration of the pills and avoid "fixation". However, since many of the pills Current detergents contain bleach and other irritating substances, The problem of handling the pills remains.

The provision has been known for some time of detergent compositions in water soluble films. The Most documents referring to this object describe water soluble film wraps formed using a path of Forming-filling-sealing vertical (VFFS). A problem with the envelopes produced using this method of VFFS is that, due to the limitations of the process, the resulting wraps have airtight seals that incorporate defined weaknesses where the seals overlap in the corners This results in corrupted wraps. easily as a result of impacts experienced during the transport. In an attempt to overcome the problems associated with such wrappers of VFFS, European Patent Application No. 0608910 describes thermoformed water soluble containers for pesticidal compositions Although this descriptive memory tries provide a solution to the problem of seals weak, document containers EP-A-0608910 have other points weak and are specifically designed to contain pesticidal compositions US 4973416 discloses a water soluble container according to the preamble of claim one.

Packaging and transport of soluble containers in water containing fluid substances subject to packaging trained to considerable impact forces. A particular problem is that when several packages of this type are packaged so bagged in a larger container that is then transported, the impact forces experienced by the containers within the Container can be large. The difficulty is that in a situation of this type it is enough that a container is broken in the larger container so that the whole product is damaged as far as the consumer, because the fluid content of the broken container can drip on any unbroken container. It is likely that trust of the consumer in a product is seriously damaged by a event of this kind. The problem of minimizing breakage to an acceptable level it is particularly acute in the area of laundry detergents and other consumer products domestic and has not been solved so far.

An object of the invention is to overcome at least some of the above disadvantages. A particular object of the invention is to provide a water-soluble container that contains a fluid substance for release when the package dissolves, a container that has a greater resistance to breakage compared to water-soluble packages.
known.

Exhibition of the invention

According to the invention, a package is provided Water soluble according to claim 1, a process for producing a water soluble container and a process for washing clothes.

Preferably, the body wall thermoforming of a container according to the invention is thick substantially uniform. By "substantially uniform" is it means that at any point the thickness of the film is measured thermoforming is preferably less than about ± 25%, even more preferably less than about ± 20% and most preferably less than about ± 15%, different from the original thickness of the previous thermoforming of the movie.

Preferably, the film has a thickness of between 10 and 1000 microns. More preferably the film has a thickness between 20 and 80 microns, most preferably between 40 and 60 microns

In a preferred process, the first sheet of Water soluble material is thermoformed by means of a plate heating. Preferably, the sheet of soluble material in water comes into intimate contact with the heating plate, normally applying a vacuum between the heating plate and the sheet of water soluble material. Generally, the vacuum applied it will be less than 6000 Pa (0.6 bar). Alternatively, the sheet can be brought into contact with the heating plate by blown. The thermoforming sheet can be removed from the plate heating by blowing or aspiration and into a mold with suitable dome shape. In one aspect of the invention, the process includes an additional stage of, before the substance is added fluid, apply a vacuum to the thermoformed body wall to maintain the shape of the body part at least until after the heat sealing stage.

Detailed description of the invention

The packages of the invention are illustrated with reference to the drawings in which:

Figures 1a, 1b, 1c and 1d show different views of a first container according to the invention in which the wall of base of the body part is circular.

Figures 2a, 2b, 2c and 2d show different views of a second container according to the invention in which the wall of base of the body part is square.

Figures 3a, 3b, 3c and 3d show different views of a third container according to the invention in which the wall of base of the body part is oval.

Figures 4a, 4b, 4c and 4d show different views of a fourth container according to the invention in which the wall of base of the body part is triangular.

Figures 5a, 5b, 5c and 5d show different views of a fifth container according to the invention in which the wall of base of the body part is rectangular.

Example

This example describes a process of thermoforming in which several packages are produced according to the invention from two sheets of water soluble material. TO in this respect recesses are formed in the sheet using a matrix of conformation that has a plurality of cavities with dimensions generally corresponding to the dimensions of the packages that They will occur. In addition, a single heating plate is used to thermoforming the film through all the cavities and, of the same mode, a single sealing plate is described.

A first sheet of film of polyvinyl alcohol is embedded on a matrix of shaping so that the film is placed over the plurality of conformation cavities in the matrix. Each cavity has generally dome shaped having a round edge, curving the edges of the cavities additionally to eliminate any sharp edge that could damage the film during the stages of forming or sealing the process. Each cavity also includes a raised surrounding tab. In order to maximize resistance of the container; the film is supplied to the forming matrix in a form free of folds and with minimal tension. In the stage of formed, the film is heated to 100 to 120 ° C, so preferably about 110 ° C, for up to 5 seconds, of preferably about 700 microseconds. One is used heating plate to heat the film, plate to be places to superimpose the conformation matrix. During this stage preheating, a vacuum of 0.5 MPa (0.5 bar) is introduced at through preheat plate to ensure contact narrow between the film and the preheating plate, guaranteeing this intimate contact that the film is heated from equitable and uniform way (the magnitude of the vacuum depends on the thermoforming conditions and the type of film used, without However, in the present context it was found that a vacuum less than 0.6 MPa (0.6 bar) was adequate). An uneven heating gives as a result a shaped container that has weak points. further from the vacuum, it is possible to blow air against the film to force it to come into intimate contact with the preheating plate.

The thermoformed film is molded into the cavities removing the film by blowing the plate heating and / or aspirating the film into the cavities forming in that way a plurality of recesses in the film that, once formed, they remain in their thermoformed orientation through the application of a vacuum through the walls of the cavities. This vacuum is maintained at least until the containers are sealed. A Once the recesses are formed and held in position by vacuum, the composition is added, in this case a liquid detergent non-aqueous, to each of the recesses. Then one overlaps second sheet of polyvinyl alcohol film on the first sheet through the filled recesses and thermosella to the same using a sealing plate. In this case the plate heat sealing, which is generally flat, works at a temperature from approximately 140 to 160 ° C, and brings the films into contact for 1 to 2 seconds and with a force of 8 to 30 kg / cm2, preferably from 10 to 20 kg / cm2. Raised eyelashes that surround each cavity ensure that the films seal each other along the flange to form a continuous seal. The curved edge of each cavity is at least partially formed by an elastically deformable material, such as for example Silicone rubber. This results in the application of force reduced at the inner edge of the sealing flange to prevent heat / pressure damage to the film.

Once sealed, the shaped containers are separate from the web of sheet film using cutting means. In this phase is possible to release the vacuum in the matrix and expel the containers formed from the forming matrix. In this way, the containers conform, fill and seal while they are embedded in the conformation matrix. They can also be cut also while they are in the conformation matrix.

During the stages of forming, filling and sealing the process, the relative humidity of the atmosphere is controlled at approximately 50% humidity. This is done to maintain the heat sealing characteristics of the film. When handling thinner films, it may be necessary to reduce the relative humidity to ensure that the films have a relatively low degree of plasticization and therefore are more rigid and easier to
drive.

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Experimental determination of the optimal packaging form i) Reduction of film thickness during thermoforming

The objective of this experimental work was create different forms of thermoforming containers from same material in the same conditions with the same depth of drawing and approximately the same volume.

Then the containers were tested shaped to determine the thickness at specific points using a micrometer Then the results were compared between shapes.

The conditions used were:

Movie:

Poly (vinyl alcohol) (supplied by Chris Craft with reference CC8534)

Thickness:

75 µm

Cavity Volume:

About 30 ml

Atmospheric condition:

17 ° C, 46% RH

Sensitivity of micrometer:

5 \ mum

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Measuring points

one

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The rectangular shape shown is used only As an example to show the various points.

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For a dome-shaped container only Points A and E are the same. Points B, C and D are all equivalents in the dome shape and were represented by the F point below.

2

The results were as follows:

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3

These results show that although the thickness reduction always takes place with the thermoforming:

a) for the dome shape, the reduction of thickness is uniform along the test points; Y

b) the dome has a lower level of thickness reduction than the others along the points of proof.

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ii) Impact tests

The purpose of this test was to show any difference, that exists, between the impact resistance of the form of dome and the other forms.

An impact test with drop of dart.

The test sample was placed on a hard surface immediately below the dart suspended. Be He dropped the dart, hitting the sample in the center. Then examined the sample and recorded any breakage or leakage. If not there was no breakage or leakage, the sample was subjected to impacts successive, each at a higher dart height, until it It caused the break.

Three forms of packaging were used, all of it material, padding and weight and approximate sizes. The test was repeated on both sides of the container (upper side of the base and lower side from the base) and several replicas were tested and a half.

Before the tests were exposed all samples at the conditions of the test site for 12 hours To achieve balance. The details of the test were:

Dart:

38mm smooth hemispherical impact surface diameter

Drop height:

615 mm

Surface:

Smooth non-elastic plate

Terms:

20 ° C, 70% RH

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Dome shapes were tested, triangle (i.e. triangular pyramid) and cube.

Each container was formed from polyvinyl alcohol supplied by Chris Craft with reference CC8534. The thickness of the film was 75 µm.

The results were as follows:

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4

The previous results show that the impact resistance of the dome is greater than that of the cube or the triangle.

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iii) Secondary packaging test

This experimental test was designed to establish any difference in impact survival between dome-shaped containers and triangular containers of a product of liquid detergent when multiple containers are contained in one hard cardboard box.

22 randomly shaped containers were placed dome according to the invention, which contained a liquid detergent for washing clothes, in a hard cardboard box. The box was composed of material "Ripple in M" of dimensions 170 x 85 x 54 mm which had a total full weight of 609 g.

The box was closed by sealing and subjected to a vertical drop of 1.2 m on a hard flat surface in the short dimensions

This test was repeated for triangular containers of the same weight and film.

The test results were that it found that 3 of the 22 dome-shaped containers had a small amount of leakage but with triangular containers, 7 of the 22 were leaking and in 5 cases the leak was very large.

Claims (15)

1. A water-soluble container, which contains a laundry detergent for release when the package dissolves, characterized in that: - the container has a body part for contain the laundry detergent fluid that comprises a first sheet of a water soluble material thermoforming to form a body wall of the part of body, and a second sheet of water soluble material superimposed on the first sheet and sealed thereto along a continuous region of the overlapping sheets to form a wall of generally rectangular or square base of the body part, - the body part of the container has generally dome shape, - the first and second sheets of material water soluble comprise a polyvinyl alcohol or a polyvinyl alcohol derivative, - the maximum height of the body wall per above the base wall is less than or equal to the maximum width of the base wall, - the laundry detergent is a liquid or gel having a viscosity between 0.1 and 1 Pa.s (100 and 1000 centipoise) when measured at 20 ° C and 105 s -1.

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2. A package according to claim 1, characterized in that the base wall is convex. 3. A package according to claim 1 or claim 2, characterized in that the viscosity of the laundry detergent is between 0.3 and 0.8 Pa.s (300 and 800 centipoise) when measured at 20 ° C and 105 s -1. 4. A package according to claim 3, characterized in that the viscosity of the laundry detergent is between 0.5 and 0.7 Pa.s (500 and 700 centipoise) when measured at 20 ° C and 105 s ^ {-one}. 5. A package according to claim 3, characterized in that the viscosity is approximately 0.3 Pa.s (300 centipoise) when measured at 20 ° C and 105 s -1. 6. A package according to claim 4, characterized in that the viscosity is approximately 0.6 Pa.s (600 centipoise) when measured at 20 ° C and 105 s -1. 7. A package according to any preceding claim, characterized in that the thermoformed body wall is of substantially uniform thickness. 8. A package according to any preceding claim, characterized in that the material has a thickness of between 20 and 80 microns. 9. A package according to claim 8, characterized in that the material is between 40 and 60 microns thick. 10. A package according to any preceding claim, characterized in that the laundry detergent comprises between 1 and 5% water. 11. A process for producing a water-soluble container that has a body part that contains a laundry detergent liquid or gel that has a viscosity of between 0.1 and 1 Pa.s (100 and 1000 centipoise) when measured at 20 ° C and 105 s -1 for release when the container dissolves, characterized in that the process comprises the steps of: thermoforming a first sheet of a water soluble material comprising a poly (alcohol vinyl) or a polyvinyl alcohol derivative to form a dome body wall of the body part; • place the liquid or detergent gel for washing clothes, which has a viscosity between 0.1 and 1 Pa.s (100 and 1000 centipoise) when measured at 20 ° C and 105 s -1, in the body part; • superimpose a second sheet of a water soluble material comprising a poly (alcohol vinyl) or a polyvinyl alcohol derivative on the first sheet; Y seal the first and second sheets to along a continuous region of the overlapping sheets that surround the laundry detergent to form a wall of generally rectangular or square base of the body part. 12. A process according to claim 11, characterized in that the first sheet of water-soluble material is thermoformed by means of a heating plate. 13. A process according to claim 11 or claim 12, characterized in that, prior to the addition of the substance, a vacuum is applied to the thermoformed body wall to maintain the shape of the body part at least until after The sealing stage. 14. A process according to any preceding claim, characterized in that the first and second sheets are heat sealed. 15. A process for washing clothes by machine using a container according to any of the claims 1 to 9, comprising the steps of: • place at least one container according with any of claims 1 to 9 in the machine together with the clothes to be washed; Y carry out an operation of washed.