WO2002077354A1 - A process and device for washing laundry in a washing machine - Google Patents

Abstract

A process for washing laundry in a washing machine using a water-soluble package containing a detergent composition, the process comprising the steps of:- placing the or each water-soluble package in a flexible receptacle (2), the receptacle (2) having a plurality of apertures (5) for permitting the passage of an aqueous solution there through; and- placing the receptacle (2) having one or more water-soluble packages (10) contained therein in a washing machine together with the laundry to be washed; and- carrying out a washing operation.

Description

A PROCESS AND DEVICE FOR WASHING LAUNDRY IN A WASHING

MACHINE

INTRODUCTION

The invention relates to the process and device for washing laundry in a washing machine using a water soluble package containing a detergent composition for release on dissolution of the package.

Detergent compositions for machine washing of laundry are provided in many forms such as free-flowing powders, liquids, and more recently unit dose forms such as compressed powder tablets and water-soluble packages of detergent composition.

Tablets and water soluble packages have several advantages over free-flowing powdered products: they do not require measuring and are thus easier to handle and dispense into the wash load, and in the case of tablets, they are more compact, hence facilitating more economical storage.

It is a requirement that tablets have adequate strength when dry (to withstand transportation / handling) , however this can produce a tablet which dissolves slowly when added to wash water such that undissolved detergent residues may remain at the end of a washing cycle and this can stain laundry. It is known to include materials e.g. urea, whose function is to enhance disintegration of tablets when placed in wash water. It is also known to use dispensing devices to aid dissolution. For example DK-B-165 759 discloses a dispensing device having a flexible fluid permeable sleeve arranged in an enclosing manner about rigid hollow body forming an annular chamber between the sleeve and the body, the body having an inlet opening for insertion of the tablet. EP-A1- 0628 652 describes a similar dispensing device. Both of these devices include relatively complicated means for delivering a tablet from the opening in the hollow body to the annular chamber, are expensive to make and complicated in use .

EP-Al-0-473-532 discloses a further dispensing device for use with detergent tablets which comprises a water permeable fabric bag having a slotted opening and a freely movable body within the bag to effect the disintegration of the tablet. If however, the fabric bag described above was analysed after a washing operation, a large number of detergent residues would be embedded in the material of the bag. This results in detergent being wasted and the bag having decreased water permeability.

WO98/40550 discloses a flexible net bag for use with compacted detergent tablets.

Water-soluble packages generally comprise a detergent composition contained in an envelope or capsule of water- soluble film, such as polyvinyl alcohol. These offer additional advantages in that, the packaging allows for handling of the product without direct contact with the detergent composition. This is especially advantageous when the detergent composition includes aggressive cleaning components which would irritate the skin on direct contact.

Also, unlike tablets, water-soluble packages enable discretising of particulate detergent composition without the need for compaction. Therefore the problems in solubility arising from compaction are not encountered with water-soluble packages of particulate detergent.

A further advantage of water-soluble packaging is that it allows discretising of liquid detergent into a unit dose format, and liquid is far more readily dissolvable than compressed powder tablets and so not prone to the dissolution problems encountered with tablets.

However an unexpected problem encountered with certain types of water-soluble packages is that they can be susceptible to "lodging" i.e. the packages end up in porthole, primarily at the start of the wash. This happens in particular in machines where the space between the door and the drum is such that it can accommodate a package . As the trend in new machines is to reduce the levels of water even to the extent that the level of water is below the porthole, in such machines lodged packages are not then dissolved in the main wash. This will have an effect on performance and is also believed to increase the risk of residues as discussed below. Top loaders do not have this problem. Thus the significant increase in solubility offered by the liquid unit dose format (i.e. water-soluble packages containing liquid detergent) and also detergent types e.g. free-flowing powder, gels etc., can be severely compromised by the susceptibility of certain packages to lodging.

It also desirable, for a number of reasons, not least of which are aesthetic considerations, that the water soluble package has a smooth, curved appearance. However, this shape is believed to exacerbate the lodging problem in that once the package enters the door region, it is not then easily caught up in the wash due to its smooth shape.

Another, problem is that the water soluble package itself may become tacky when damp so that lodging can be exacerbated as the dampened package may adhere to the washing machine door .

A further problem is that limited wetting of a lodged package may result in partial dissolution of the package film which may then remain as a gelatinous/sticky residue at the end of the wash. This is unpleasant for the user who may then be faced with the task of physically removing the residue if this has adhered to the door seal.

A further problem arises out of the tendancy of many users to over load the washing machine with laundry. In this situation, if a water-soluble package becomes lodged in the door porthole, the rotating laundry then prevents the package from entering the main wash. It is an object of the present invention to provide a process and dispensing device, which overcome at least some of the above mentioned problems. In particular it is an object of invention to provide a simple, cheap, efficient and easy to use dispensing device for water-soluble packets of detergent .

Statements of Invention

According to the invention there is provided a process for washing laundry in a washing machine using a water-soluble package containing a detergent composition, the process comprising the steps of placing the or each water-soluble package in a flexible receptacle, the receptacle having a plurality of apertures for permitting the passage of an aqueous solution there through and placing the receptacle having one or more water-soluble packages contained therein in a washing machine together with the laundry to be washed and carrying out a washing operation.

A preferred form of dispensing receptacle is a flexible net bag. Preferably the receptacle is loosely fitting with respect to the or each water-soluble package contained therein.

With this arrangement, the receptacle containing one or more water-soluble packages is drawn into the rotating laundry load from the door region.

The apertures preferably have an average mesh size of between 1mm and 10mm. The process according to the invention may includes a receptacle having apertures with an average dimension equivalent to a mesh size of approximately 5mm. The process is particularly ideal for water-soluble packages containing at least some particulate detergent.

The process of the invention is suitable for water soluble packages of all forms of detergent including liquid, gel, paste or particulate detergent and any combinations thereof.

The process of the invention is also ideal for water soluble packages of having a volume of approximately 18- 50 ml. The process is particularly advantageous for smaller packages having a volume of approximately 18 - 25 ml.

Preferably, the receptacle is configured such that it is easily drawn into the rotating load from a lodged position in the door porthole. To this end the receptacle, may include a member or members extending from the body of the receptacle. With this arrangement the members can function to draw the receptacle into the rotating load. The member (s) may take any suitable form, and may be elongate and flexible, e.g. a strip or strips of material extending from the receptacle body. The member (s) may be integral with the receptacle body and/or may be conveniently provided by closure members such as those described below. For example, the drawstring closure device which in a closed position may provide member or members extending from the receptacle body. The receptacle body may itself be elongate so as to encourage entrapment within the rotating wash load from a lodged position in the door porthole.

The process according to the invention will preferably include a reusable receptacle which comprises an opening for reception of the detergent package and closure means for preventing the passage of the package out of the receptacle through the opening, the process thus including an initial step of placing a detergent package in the receptacle.

The receptacle may comprise a flexible net bag in which the opening is formed by a mouth of the bag.

The invention includes the use of a flexible bag such as a net bag, it is ideal to incorporate a volume adding member to the bag such as for example a rigid plastic support ring at the mouth of the bag which may act to hold the bag open. Alternatively, the volume-adding member may be a constituent part of another part of the bag such as a base or mid- position. The advantage of this arrangement is that it will facilitate finding the bag after completion of the process and will favour water flow through the device.

The process includes the use of a closure means, which facilitates the insertion of a package into the receptacle but prevents the package passing out of the receptacle during normal operation. Various ways of doing this are provided in accordance with the invention, for example, a zip closure, a drawstring closure and a purse-type closure arrangement which preferably comprises a pair of lips which form the mouth of the bag and move together and apart to open and close the receptacle. This is ideal for flexible net bag type receptacles .

The closure will preferably comprise a plurality of resiliently flexible members, ideally fingers, mounted across the opening. Typically, the members will be mounted on a mouth of the opening and will project radially at least partially across the opening. Preferably a centre portion of the opening will remain uncovered. When the receptacle comprises a flexible net bag, the projecting members will preferably be mounted on an annular support which ideally will be attached to the mouth of the bag and define the opening .

Alternatively, the receptacle may comprise two parts which when connected together form a housing for a water-soluble package. Ideally, the parts are connected by a hinge means.

The receptacles described above in connection with the process of the invention are produced from a material capable of withstanding temperatures for the machine washing or drying of laundry, especially up to 150°C.

The invention also provides a dispensing device for carrying out the process according to the invention, in combination with at least one water-soluble package containing a detergent composition, which device broadly comprises a receptacle having a plurality of apertures for permitting the passage of an aqueous solution there through. The dispensing device is preferably a flexible net bag which is loosely fitting with respect to the or each package contained therein, wherein the apertures have an average mesh size of between 1mm and 10mm. Ideally a mouth of the bag will be supported by a substantially rigid annular support having a closure as described above.

The invention also provides a dispensing device for holding a water-soluble package containing a detergent composition which is active during the machine washing of laundry, the device being of the type comprising a receptacle for housing the detergent, and a means for allowing the passage of water through the receptacle.

The invention also provides a dispensing device according to the invention in combination with a water-soluble package containing a detergent composition.

The water-soluble package may take any suitable form, and may comprise a water-soluble film envelope or capsule. In one embodiment the package is polyvinyl alcohol or a polyvinyl alcohol derivative.

Detailed Description of the Invention

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings in which: - Figure 1 is a perspective view of a dispensing device according to the invention;

Figure 2 is a top plan view of the device of Figure 1 ;

Figure 3 is a perspective view of the device of figure 1 with a water-soluble package containing a liquid detergent composition partially inserted therein;

Figure 4 is a perspective view of a dispensing device according to an alternative embodiment of the invention in an open configuration;

Figure 5 is a top plan view of the device of Figure 4;

Figure 6 is a partially side-on perspective view of the device of Figure 4 in a closed orientation;

Figure 7 is a perspective view of an alternative embodiment of the invention having a draw-string closure in an open orientation; and

Figure 8 is a perspective view of the device of Figure 7 with the drawstring closure in a closed orientation; and

Figure 9 is a perspective view of a device of Figure 7 with a pair of water-soluble packages containing a liquid detergent composition, inserted in the device; and

Referring to the drawings, and initially to Figures 1 and 3 thereof, there is illustrated a dispensing device according to the invention indicated generally by the reference numeral 1 and comprising a receptacle for a water-soluble package containing a liquid detergent composition in the form of a flexible net bag 2 having a open mouth 3, which is connected to and supported in an open configuration by a rigid annular support 4 , and apertures 5 having an average dimension which in this embodiment is equivalent to a mesh size of approximately 5mm. A closure 8 for the mouth 3 comprises sixteen resiliently flexible fingers 9 mounted to the support 4 and extending radially across a portion of the mouth 3 of the bag 2 this forming a partial barrier which is sufficient in size and of sufficient resiliency to prevent a water-soluble package containing liquid detergent 10 passing out of the bag 2 during a conventional operation.

In use and referring to Figure 3, a water-soluble package 10 containing liquid detergent is placed in the device 1 by pushing the package 10 against the barrier 8 until the radial fingers 9 bend sufficiently to allow the package 10 past the barrier 8. The package shown is relatively small, approximately 4.5 cm in diameter (when examined in plan view and excluding the seal trim area. Generally two packages will be used in a conventional operation, one package may suffice for light soiling or a half load. The device 1 and packages 10 (only one shown) contained therein are then placed in a washing machine together with the laundry to be washed and a washing operation was carried out during which the detergent package (s) within the bag 2 will dissolve releasing the liquid detergent into the wash. In the case of a water-soluble package containing at least some particulate matter, any undissolved particulate of a size less than 5mm will pass out of the bag 2 and be dissolved outside the bag 2. When the washing operation has been completed, the device 1 is removed from the machine and stored for subsequent use .

Referring to Figures 4 to 6, another embodiment of the invention is described in which parts similar to those described with reference to Figures 1 to 3 are given the same reference numerals. In this embodiment, the device, indicated by the reference numeral 20, includes the purse type closure 21 connected to the mouth 3 of the bag 2, which closure 21 comprises a pair of rigid semi-circular lips 22a, 22b, hingedly connected at each end, and movable together and apart to open and close the mouth. A clip 23 is provided on one of the lips 22a to lock the lips in a closed orientation. The use of this embodiment of the invention is similar to that described previously with the exception for the operation of the closure means which will be readily apparent .

Referring to Figures 7 and 8, a further embodiment of the invention is described in which parts similar to those described with reference to Figures 1 to 3 are assigned the same reference numerals. In this embodiment, the device indicated by the reference numeral 30 includes a drawstring closure arrangement 31 and a supporting ring 32 located on a base 33 of the device 30, the operation and construction of which will be apparent to those skilled in the art. Figure 9 illustrates the device of Figure 7 having a pair of water-soluble packages 10 containing a liquid detergent composition contained therein.

When packages are dosed in a washing machine without the use of a dosing device there is a substantial risk of lodging; i.e. the packages end up in porthole, primarily at the start of the wash. This happens in particular in machines where the space between the door and the drum is such that it can accommodate a package or packages. The residence time of packages in a porthole depends on water intake level. As the trend in new machines is to reduce the levels of water even to the extent that the level of water is below the porthole, it is understandable that in such machines packages do not completely dissolve in the main wash. This will have an effect on performance and level of residues. Top loaders do not have this problem.

When packages are dosed via a device which is configured such that there is a barrier to prevent the packages falling out of the device, the problem of lodging is solved. A preferred feature of such a device is that it should have some volume otherwise packages together with device may experience some lodging. To circumvent this low risk of lodging, but also to make it easier to find the dosing device after the wash and to favour the water flow through the net, a net may include some plastic part giving it some volume. This plastic part can be part of the opening system (e.g. A purse type opening with a click mechanism or a plastic system with a package push through mechanism) or is part of the net (e.g. A plastic ring attached to the bottom of the net) . In the latter example the opening is reclosable by a rope or zipped mechanism.

To investigate the affect of a receptacle on the dissolution of a lodged water-soluble package containing detergent, water soluble packages (referred to as 'capsules' in Table l)were placed in the door porthole of the respective washing machines, at the start of the wash.

Before placing the packages in the machine, the door opening and rubber seal was dried to prevent premature dissolution or weakening of the film of the positioned packages.

Table 1

The above tests show how specific wash conditions seem to show increased susceptibility to lodging of packages. With full laundry load washes the incorporation of the packaged liquid detergent into the rotating wash load could not take place before the package dissolved. Eventually, the packages were wetted by splashing from the drum, and the incidence of packages being moved by laundry fabric sticking out into the door area was minimal . It seems to be the case that lodged packages do not become incorporated into the rotating wash load and wash water due to the hindrance of the clothes preventing the packages being drawn into the wash.

However, when a net was used for these heavy load wash programmes, the net was seen to be pulled into the rotating wash, which brought the packages into the wash thereby assuring quick and even dissolution of package film and liquid.

Coloured/short wash cycles showed that even though the liquid in the package was released there was still some residue remaining at the end of the wash cycle. This was surprising given the solubility of the liquid detergent. The incidence of residues can be particularly disconcerting for many users .

However, for these coloured/short washes, when the packages were placed in the net prior to being placed in the lodging position, the net was drawn into the rotating laundry load which then brought the packages into the wash load quickly. The net also functioned to increase the solubility of the detergent ensuring that the package (film and liquid detergent) was completely dissolved within 2 minutes.

These findings were also confirmed by visual observation of the washing process, the receptacle at the end of the wash and the material remaining on the rotating sieve.

The process and device of the invention may be varied in many ways without departing from the invention.

Claims

1. A process for washing laundry in a washing machine using a water-soluble package containing a detergent composition, the process comprising the steps of : -

placing the or each water-soluble package in a flexible receptacle (2) , the receptacle (2) having a plurality of apertures (5) for permitting the passage of an aqueous solution there through; and

placing the receptacle (2) having one or more water- soluble packages (10) contained therein in a washing machine together with the laundry to be washed; and

carrying out a washing operation.

2. A process according to claim 1 wherein the receptacle is a net bag (2) which is loosely fitting with respect to the or each package (10) contained therein.

3. A process according to claim 2 wherein the apertures

(5) have an average mesh size of between 1 and 10mm.

4. A process according to claim 3 wherein the apertures (5) have an average mesh size of approximately 5mm.

5. A process according to any preceding claim in which the detergent composition comprises a liquid and/or gel and/or paste detergent composition.

6. A process according to any preceding claim wherein the detergent composition comprises a particulate detergent composition.

7. A process according to any preceding claim wherein the receptacle (2) is reusable and comprises an opening (3) for reception of the or each package (10) and closure means (8) for preventing the passage of the package (10) out of receptacle (2) through the opening (3) the process including the initial step of placing a detergent package (10) in the receptacle.

8. A process according to claim 7 in which the opening (3) in the receptacle (2) is formed by a mouth (3) of the receptacle.

9. A process according to claim 8 in which the mouth (3) of the receptacle includes a support (4) , which support defines the opening.

10. A process according to any of claims 7 to 9 in which the closure means (8) comprises a plurality of resiliently flexible members (9) mounted across the opening .

11. A process according to claim 10 in which the opening (3) is defined by an annular support (4) and in which the closure means comprises a plurality of resiliently flexible members such as fingers (9) mounted on the annular support, which members project radially at least partially across the opening (3) .

12. A process according to any of the claims 7 to 9 in which the closure means (8) comprises a diaphragm mounted across the opening (3) , which diaphragm includes an aperture for insertion of a package.

13. A process according to claim 12 in which the diaphragm comprises a resiliently deformable material .

14. A process according to any of claims 7 to 9 in which the closure means comprises zip means.

15. A process according to any of claims 7 to 8 in which the opening is defined by a pair of lips (22a) , which lips are movable together in a purse like manner to close the opening.

16. A process according to any of claims 7 to 8 in which the closure means comprises a drawstring arrangement (31) .

17. A process according to any preceding claim in which the receptacle (2) is produced from a material capable of withstanding temperatures for the machine washing or drying of laundry, especially up to 150°C.

18. In combination, a dispensing device for carrying out the process of any claims 1 to 17 and at least one water-soluble package (10) containing a detergent composition, the dispensing device comprising a receptacle (2) for housing a package, the receptacle having a plurality of apertures (5) for permitting the passage of an aqueous solution there through.

19. A dispensing device according to claim 18, characterised in that the receptacle is a flexible net (2) bag which is loosely fitting with respect to the package or packages (10) contained therein.

20. A dispensing device according to claim 18, wherein the apertures (5) have an average mesh size of between 1 and 10mm.

21. A dispensing device according to claim 18, in combination with a water-soluble package (10) having volume of approximately 18 - 50 ml.

22. A dispensing device according to claim 18, in combination with a water-soluble package (10) having volume of approximately 18 - 25 ml.

23. A process substantially as hereinbefore described with reference to the accompanying examples and drawings.

24. A dispensing device substantially as hereinbefore described with reference to the accompanying drawings.