EP1633919A1

EP1633919A1 - Dispensing device

Info

Publication number: EP1633919A1
Application number: EP04734219A
Authority: EP
Inventors: Roy Lever Faberge Europe VAN HEESEN
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2003-06-17
Filing date: 2004-05-21
Publication date: 2006-03-15
Also published as: GB0314050D0; WO2005003429A1

Abstract

A dispensing device (1) for treating laundry in a washing machine, the device comprising a receptacle (2) for housing one or more laundry unit dose products e.g. tablets, the device being characterised in that the device comprises a compressible flotation device (20).

Description

DISPENSING DEVICE

The invention relates to a process for washing laundry in a washing machine by employing a receptacle for dispensing at least one laundry tablet. The invention also relates to a dispensing device for carrying out the above process.

Dispensing devices for laundry tablet compositions are known.

It is an object of the present invention to provide an improved dispensing device and laundry treatment process in a washing machine using unit dose products by improving the travel of the device through the laundry to be treated during a treatment cycle.

According to a first aspect of the invention, there is provided a dispensing device for treating laundry in a washing machine, the device comprising a receptacle for housing one or more laundry unit dose products, the device being characterised in that the device comprises a compressible flotation device.

In a second aspect, the invention provides a process for treating laundry in a washing machine by employing the above, together with one or more laundry unit dose products comprising the step of inserting the one or more laundry unit dose products into the receptacle (and optionally closing the receptacle) ; inserting the receptacle into the washing machine together with the laundry to be treated and then performing a laundry treatment operation.

With this arrangement the receptacle can float in the wash liquor thereby enhancing travel of the laundry unit dose product composition throughout the laundry, thereby improving treatment of the laundry by said composition.

The compressibility of the flotation device means it can deform on contact with fabric/clothing during a wash cycle so minimising damage to such fabric/clothing.

The device can also be compressed during packing so that smaller packs with less headspace can be utilised.

The flotation device may also be configured to provide a volume adding function e.g by being resilient so it expands on removal of compression forces. The inclusion of such a volume adding member has been shown to decrease the incidence of lodging of the device within the door seal, posting of the device in the door seal, facilitate the finding of the device after a washing operation, and can favour water flow through the device. In many known devices, the volume adding function is provided by a rigid closure device. The use of the compressible flotation device to perform this function can simplify the device and reduce costs of the closure device and any risk of damage by a rigid structure. The closure device can be of low weight and small and so fit more easily into a smaller pack, reducing the amount of "dead" space in the pack (ie that volume not filled with unit dose product) .

This inturn has a positive environmental impact by reducing the amount of packaging material required for each pack. When great numbers of packs are produced and sold, this has also positive influence on transport costs .

In a preferred embodiment the compressible flotation device comprises a foam material which may comprise any suitable material such as polypropylene.

The flotation device may be fixed internally/or externally of the receptacle. If it is contained internally of the receptacle, it is preferred that the device, does not occupy excessive space such that there is insufficient space remaining for the unit dose product/s, unless the receptacle is quite large. The device may occupy no more than 20% of the surface area of receptacle, and preferably no more than 10 %. In a preferred embodiment, the device occupies 5-10%. This is particularly advantageous with a receptacle having a total surface area within the range 350 - 450 cm². This has the advantage of allowing a dispensing device of manageable size ( e.g. approximately 12 cm x 16cm) but which is loose fitting for two laundry unit dose products eg. tablets (each about 4.5 cm diameter and 1.5 cm height) and has an effective flotation device. With an internally situated flotation device, the latter may be shaped so that it presents a smooth boundary with the remaining internal receptacle space. This has the advantage that it does not interfere with free movement of unit dose products within the receptacle. For example, the flotation device may be a generally triangular in plan view and located in a corner of the receptacle, or be rectangular and located along a bottom or side strip.

The flotation device may in one or more parts or sections, occupying one or more locations in/on the receptacle.

Preferably the dispensing device comprises a net bag for which is preferably a loose fitting structure with a plurality of apertures for permitting the passage of an aqueous solution there through.^'

Preferably the net has an average mesh size of 1 - 15mm In one embodiment of the process, the average mesh size is at least 4mm and in one embodiment it is approximately 5mm. Alternatively the mesh size may be approximately 10mm.

The compressible floatation device may include an outer barrier.

Certain types of flotation material e.g. sponges may be damaged during wash cycle, packing, transportation.

The barrier can protect the floatation device during the wash cycle. A barrier can also provide protection during packing, transportation, when the flotation device is subject to contact pressure/friction due to close proximity with relatively hard tablets with which it is packed.

The barrier may also enhance flotability e.g. by trapping air.

The barrier may be a sack or sleeve which at least partially encloses the flotation device. Alternatively or additionally, the barrier may be a coating or treatment of one or more outer layers of the flotation device. In one embodiment the barrier is formed from the same material as the receptacle, but may have a different structure e.g. it may have a different mesh size, shape. The receptacle may have a mesh with apertures 1 - 15 mm whereas the barrier may have a mesh size of less than 1mm. The barrier may be a closely woven polyethylene sack. The barrier may be fixed to the flotation device e.g. by stitching.

Typically, the receptacle is reusable and comprises an opening for reception of the or each laundry unit dose product and closure means for closing the opening to prevent the passage of the or each tablet out of the receptacle through the opening, the process including the initial step of placing one or more laundry unit dose product in the dispensing receptacle prior to closing the opening. In this manner it is a simple operation to opening the receptacle and place one or more products therein and subsequently close the receptacle.

In a particularly preferred embodiment of the process, the closure comprises a drawstring arrangement, which ideally includes clamp means attached to the drawstring to lock the receptacle in an open or closed orientation.

Alternative or additionally, the opening may be defined by an annular support comprising a plurality of resiliently flexible members such as fingers mounted on the annular support, which members project radially at least partially across the opening. Alternatively, the closure may comprise a diaphragm mounted across the support, which diaphragm includes an aperture for insertion of a laundry unit dose product. Ideally, the diaphragm comprises a resiliently deformable material.

The closure means may comprise zip means. Alternatively the opening may be defined by a pair of lips, which lips are movable together and apart in a purse-like manner to open and close the opening.

Typically, the receptacle and compressible flotation device is produced from a material capable of withstanding temperatures for the machine washing or drying of laundry, especially up to 150°C. With regard to the net material one example is sold under the trade name NETLON. However other materials capable of withstanding the above temperatures are envisaged.

Further, the invention provides a dispensing device according to the invention in combination with a laundry unit dose product and instructions for use according to the second aspect of the invention. This laundry unit dose product may comprise for example a tablet and/or water soluble capsule containing a laundry composition and/or gel product (such as gel cube) and may comprise any suitable composition which may comprise a compacted particulate laundry composition containing one or more detergent-active compounds.

Tablet compositions

Laundry tablets for use in the present invention generally have a weight of from 2 to 200g, more preferably of from 20 to lOOg, most preferably of from 20 to 80g.

Surfactant compounds

The tablets of the invention typically comprise one or more organic surfactants. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch.

The surfactant may be anionic (soap or non-soap) , cationic, zwitterionic, amphoteric, nonionic or a combination of these.

Detergent-active compounds can be used include soaps and synthetic non-soap anionic and nonionic compounds.

Anionic surfactant may be present in an amount from 0.5 to 50% by weight, preferably from 2% or 4% up to 30% or 40% by weight of the composition. Suitable examples include alkyl benzene sulphonates, particularly sodium linear alkyl benzene sulphonates having an alkyl chain length of C8-C15; olefin sulphonates; alkane sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.

Suitable nonionic surfactant compounds include in particular the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide.

Specific nonionic surfactant compounds are alkyl (Cg22) phenol-ethylene oxide condensates, the condensation products of linear or branched aliphatic C 20 primary or secondary alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylene-diamine . In a fabric washing composition, these organic surfactants preferably provide from 5 to 50% by weight of the overall composition.

Water- softening agent Tablets for use according to this invention may contain a so-called water-softening agent, which serves to remove or sequester calcium and/or magnesium ions in the water. In the context of a detergent composition containing organic surfactant, a water-softening agent may be referred to as a detergency builder.

When a water-softening agent (or detergency builder) is present, the amount of it is likely to lie in a broad range from 5%wt, preferably 15%wt up to 98%wt of the composition. The amount is likely to be from 15 to 80%wt, more usually 15 to 60%wt of the composition. Water-softening agents may be provided wholly by water soluble materials, or may be provided in large part or even entirely by water-insoluble material with water-softening properties .

Alkali metal aluminosilicates are strongly favoured as environmentally acceptable detergency builders for fabric washing. Suitable crystalline sodium aluminosilicate ion- exchange materials are described, for example, in GB 1 429 143 (Procter & Gamble) . The preferred sodium aluminosilicates of this type are the well known commercially available zeolites A and X, the newer zeolite P described and claimed in EP-A-384 070 (Unilever) and mixtures thereof. This form of zeolite P is also referred to as "zeolite MAP". One commercial form of it is denoted "zeolite A24" (ex Ineos Silicas, UK) .

The builder may also be a water-soluble phosphorus- containing inorganic softener for example alkali-metal orthophosphates, metaphosphates, pyrophosphates and polyphosphates . Specific examples of inorganic phosphate detergency builders include sodium and potassium tripolyphosphates, orthophosphates and hexametaphosphates . Non-phosphorus water-soluble detergency builders may be organic or inorganic. Inorganics that may be present include alkali metal (generally sodium) carbonate; while organics include polycarboxylate polymers, such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphonates, monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono- di- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates and hydroxyethyliminodiacetates .

Bleach system Tableted compositions according to the invention may contain a bleach system. This preferably comprises one or more peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, which may be employed in conjunction with activators to improve bleaching action at low wash temperatures. If any peroxygen compound is present, the amount is likely to lie in a range from 10 to 85% by weight of the composition. If the tablet contains surfactant and detergency builder, the amount of peroxygen compound bleach is unlikely to exceed 25% of the composition.

Preferred inorganic persalts are sodium perborate monobydrate and tetrahydrate, and sodium percarbonate, advantageously employed together with an activator. Bleach activators, also referred to as bleach precursors, have been widely disclosed in the art.

Disintegration-promoting particles

As mentioned above, tablets may optionally contain disintegration-promoting particles to promote disintegration. Such particles typically contain at least

40% (of their own weight) of one or more materials selected from • compounds with a water-solubility exceeding 50 grams per 100 grams water; • water swellable materials such as for example cellulose, cross-linked polyethylene glycol, cross linked polyvinyl pyrrolidone or an acrylic/maleic copolymer • phase I sodium tripolyphosphate • sodium tripolyphosphate which is partially hydrated so as to contain water of hydration in an amount which is at least 0.5% by weight of the sodium tripolyphosphate in the particles.

The quantity of disintegration-promoting particles may be from 1 or 5% up to 30 or 40%wt of the tablet. The quantity may possibly be from 8% up to or 30%wt or more. However, it is within this invention that the amount of water-soluble disintegration-promoting particles is low, below 5%wt of the tablet or region, reliance being placed on water insoluble water swellable disintegration particles.

Further optional ingredients .

Detergency enzymes may be employed in tablets and are commonly employed in the form of granules or marumes, optionally with a protective coating, in amount of from about 0.1% to about 3.0%wt of the composition. These granules or marumes present no problems with respect to compaction to form a tablet.

The tablets of the invention may also contain a fluorescer (optical brightener) , for example, Tinopal (Trade Mark) DMS or Tinopal CBS available from Ciba-Geigy AG, Basel, Switzerland. Tinopal DMS is disodium 4, 4 'bis- (2-morpholino-4-anilino-s- triazin-β-ylamino) stilbene disulphonate; and Tinopal CBS is disodium 2, 2 ' -bis- (phenyl-styryl) disulphonate.

An antifoam material is advantageously included if organic surfactant is present; especially if a tablet is primarily intended for use in front-loading drum-type automatic washing machines.

Tablets may include an amount of an alkali metal silicate.

Fabric-softening or conditioning compostions

Laundry compositions may provide, in addition or as an alternative to other wash functions, fabric softening benefits. Such compositions may comprise a compacted granular fabric conditioning composition and may comprise a fabric softening clay optionally in combination with an organic fatty softening material. Especially preferred fabric softeners comprise a clay mineral softener, such as bentonite, in combination with a pentaerythritol ester compound as further described herein.

Useful combinations of such softener may vary from about 80%, to about 90%, by weight, of clay, and from about 10% to about 20%, by weight, of fatty softening material such as a pentaerytbritol compound (often abbreviated herein as "PEC"). The clays that are useful components of the invented products are those which cooperate with the organic fatty softener materials to provide enhanced softening of laundry. Such clays include the montmorillonite-containing clays which have swelling properties (in water) and which are of smectite structure, so that they deposit on fibrous materials, 3 especially cotton and cotton/synthetic.blends, such as cotton/polyester, to give such fibers and fabrics made from them a surface lubricity or softness. The best of the smectite clays for use in the present invention is bentonite and the best of the bentonites are those which have a substantial swelling capability in water, such as the sodium and potassium bentonites. Such swelling bentonites are also known as western or Wyoming bentonites, which are essentially sodium bentonite. Other bentonites, such as calcium bentonite, are normally non-swelling and usually are, in themselves, unacceptable as fabric softening agents. However, it has been found that such non- swelling bentonites exhibit even better fabric softening in combination with PEC's than do the swelling bentonites, provided that there is present in the softening composition, a source of alkali metal or other solubilizing ion, such as sodium (which may come from sodium hydroxide, added to the composition, or from sodium salts, such as builders and fillers, which may be functional components of the composition) . Among the preferred bentonites are those of sodium and potassium, which are normally swelling, and calcium and magnesium, which are normally non-swelling. Of these it is preferred to utilize calcium (with a source of sodium being present) and sodium bentonites. The bentonites employed may be produced in the United States of America, such as Wyoming bentonite, but also may be obtained from Europe, including Italy and Spain, as calcium bentonite, which may be converted to sodium bentonite by treatment with sodium carbonate, or may be employed as calcium bentonite. Also, other montmorillonite-containing smectite clays of properties like those of the bentonites described may be substituted in whole or in part for the bentonites described herein and similar fabric softening results will be obtained.

The swellable bentonites and similarly operative clays are of ultimate particle sizes in the micron range, e.g., 0,01 to 20 microns and of actual particle sizes in the range of No's. 100 to 400 sieves, preferably 140 to 325 sieves, U.S. Sieve Series. The bentonite and other such suitable swellable clays may be agglomerated to larger particle sizes too, such as 60 to 120 sieves, but- such agglomerates are not preferred unless they include the PEC('s) too (in any particulate products) .

The organic softener can be anionic, cationic or nonionic fatty chains (C10-C₂2 preferably C_i2 Cι₈) . Anionic softeners include fatty acids, soaps.

Preferred organic softeners are nonionics such as fatty esters, ethoxylated fatty esters, fatty alcohols and polyols polymers. The organic softener is most preferably a higher fatty acid ester of a pentaerythritol compound, which term is used in this specification to describe higher fatty acid esters of pentaerythritol, higher fatty acid esters of pentaerythritol oligomers, higher fatty acid esters of lower alkylene oxide derivatives of pentaerythritol and higher fatty acid esters of lower alkylene oxide derivatives of pentaerythritol oligomers. Pentaerythritol compound is often abbreviated as PEC herein, which description and abbreviation may apply to any or all of pentaerythritol, oligomers, thereof and alkoxylated derivatives thereof, as such, or more preferably and more usually, as the esters, as may be indicated by the context.

The oligomers of pentaerythritol are preferably those of two to five pentaerythritol moieties, more preferably 2 or 3, with such moieties being joined together through etheric bonds. The lower alkylene oxide derivatives thereof are preferably of ethylene oxide or propylene oxide monomers, dimers or polymers, which terminate in hydroxyls and are joined to the pentaerythritol or oligomer of pentaerythritol through etheric linkages. Preferably there will be one to ten alkylene oxide moieties in each such alkylene oxide chain, more preferably 2 to 6, and there will be one to ten such groups on a PEC, depending on the oligomer. At least one of the PEC OH groups and preferably at least two, e.g., 1 or 2 to 4, are esterified by a higher fatty acid or other higher aliphatic acid, which can be of an odd number of carbon atoms.

The higher fatty acid esters of the pentaerythritol compounds are preferably partial esters. And more preferably there will be at least two free hydroxyls thereon after esterification (on the pentaerythritol, oligomer or alkoxyalkane groups) . Frequently, the number of such free hydroxyls is two or about two but sometimes it may by one, as in pentaerytbritol tristearate. The higher aliphatic or fatty acids that may be employed as esterifying acids are those of carbon atom contents in the range of 8 to 24, preferably 12 to 22 and more preferably 12 to 18, e.g., lauric, myristic, palmitic, oleic, stearic and behenic acids. Such may be mixtures of such fatty acids, obtained from natural sources, such as tallow or coconut oil, or from such natural materials that have been hydrogenated. Synthetic acids of odd or even numbers of carbon atoms may also be employed. Of the fatty acids lauric and stearic acids are often preferred, and such preference may depend on the pentaerythritol compound being esterified.

Examples of some esters (PEC's) within the present invention follow: onopentaerythritol Esters

Rι-CH₂-C(CH₂-R₂) (CH₂-R₄)-CH₂-R₃

Monopentaerythritol Dilaurate Ri = CH₃- (CH₂) ιo-COO- R₂ = CH₃- (CH₂ ) ιo-COO- R₃ = OH R₄ = OH Monopentaerythritol Monostearate

Ri = CH₃-(CH₂)i₆-COO- R₂ = OH R₃ = OH R₄ = OH

Monopentaerythritol Distearate

Ri = CH₃-(CH₂)i₆-COO- R₂ = CH₃-(CH₂)i₆-COO- R₃ = OH R₄ = OH

Monopentaerythritol Tristearate

Ri = CH₃-(CH₂)i₆-COO- R₂ = CH₃-(CH₂)i₆-COO- R₃ = CH₃-(CH₂)i₆-COO- R₄ = OH

Monopentaerythritol Monobehenate

Ri = CH₃-(CH₂)₂o-COO- R₂ = OH R₃ = OH R₄ = OH

Monopentaerythritol Dibehenate

Ri = CH₃-(CH₂)₂o-COO- R₂ = CH₃-(CH₂)₂o-COO- R₃ = OH R₄ = OH Dipentaerythritol Esters

H0-CH₂-C (CH₂ORι) (CH₂OR₃) -CH₂-O-CH₂-C (CH₂OR₂₃) (CH2OR4) -CH₂-OH Dipentaerythritol Tetralaurate

Ri = CH₃-(CH₂)ιo-CO R₂ = CH₃-(CH₂)ιo-CO R₃ = CH₃-(CH₂)ιo-CO R₄ = CH₃-(CH₂)ιo-CO

Dipentaerythritol Tetrastearate

Ri = CH₃-(CH₂)i₆-CO R₂ = CH₃-(CH₂)i₆-CO R₃ = CH₃-(CH₂)₁₆-CO R₄ = CH₃-(CH₂)i₆-CO

Pentaerythritol 10 Ethylene Oxide Ester

Rι-CH₂-C(CH₂-0-( CH₂-CH₂0)_nH) (CH₂-0- ( CH₂-CH₂0) _n*H) - CH₂-R n + n* = 10 - I S

Monopentaerythritol 10 Ethylene Oxide Distearate

Ri = CH₃-(CH₂)i₆-C00- R₂ = CH₃-(CH₂)i₆-COO-

Pentaerythritol 4 Propylene Oxide Esters

Rι-CH₂-C(CH₂-0-( CH₂-CH-CH0)₂H) (CH₂-0-( CH₂-CH-CH₂0) ₂H) -CH₂-R₂ Monopentaerythritol Propylene Oxide Monostearate

R_x = CH₃-(CH₂)i₆-COO- R₂ = OH Monopentaerythritol 4 Propylene Oxide Distearate

Ri = CH₃-(CH₂)i₆-COO- R₂ = CH₃-(CH₂)₁₆-COO- Although in the formulas given herein some preferred pentaerythritol compounds that are useful are illustrated it will be understood that various other such pentaerythritol compounds within the description thereof may also be employed herein, including such as pentaerythritol dihydrogenated tallowate, pentaerythritol ditallowate, pentaerythritol dipalmitate, and dipentaerythritol tetratallowate .

In addition, to enhance the softening efficacy of the fabric conditioning compositions described above, or as an alternative, cationic softeners such as conventional quaternary ammonium softening compounds may optionally be added (in minor amounts if in addtion to the above compositions) .

The combination of bentonite and organic fatty softening material may be generally from about 10% to about 99% bentonite^ and fr-om about 1% to about 90% fatty softening material, preferably from about 50% to about 95% bentonite and about 5% to about 50% fatty softening material, and most preferably from about 80% to 90% bentonite and from about 10% to about 20% fatty softening-material.

Further ingredients

These which can optionally be employed in laundry tablets of the invention include anti-redeposition agents such as sodium carboxymethylcellulose, straight-chain polyvinyl pyrrolidone and the cellulose ethers such as methyl cellulose and ethyl hydroxyethyl cellulose, heavy metal sequestrants such as EDTA; perfumes; and colorants or colored speckles.

Particle size and distribution

Tablets may comprise a matrix of compacted particles. The composition before compaction may have an average particle size in the range of from 200 to 2000, urn, more preferably from 250 to 1400um. Fine particles, smaller than 180pm or 200, urn may be eliminated by sieving before tableting, if desired, although we have observed that this is not always essential. The starting composition before compaction may for example have a bulk density of at least 400 g/litre, preferably at least 500 g/litre, and most preferably at least 600 g/litre.

A composition which is compacted into a tablet or tablet region may contain particles which have been prepared by spray-drying or granulation and which contain a mixture of ingredients. Such particles may contain organic detergent surfactant and some or all of any water-softening agent (detergency builder) also present in the tablet.

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 an enlarged schematic view of the mesh of the receptacle of Figure 1; and

Figure 3 is an enlarged view of the closure device of the receptacle of

Referring to the drawings, there is illustrated a dispensing device according to the invention 1 comprising a receptacle for laundry tablets in the form of a flexible, loosely fitting, net bag 2 having a open mouth 3 and apertures 5 having an average mesh size of approximately 5 mm. (tablets not shown) .

The device includes a compressible flotation device 20 which comprises a polypropylene foam. The device has closure means generally indicated by the reference numeral 30 including a drawstring closure arrangement 31 having a simple small toggle clamp 35 movable thereon. The operation and construction of the drawstring closure will be apparent to those skilled in the art. The mesh has a hexagonal structure as shown more clearly in figure 2.

With this arrangement the net can float in the wash liquor thereby further enhancing travel of the net through the laundry and consequently dispersal of the laundry tablet composition.

The use of a compressible foam enables the provision of a volume adding function but without the drawbacks of using a rigid device. The inclusion of such a volume adding member has been shown to decrease the incidence of lodging of the bag within the door seal, posting of the device in the door seal, facilitate the finding of the bag after a washing operation, and can favour water flow through the device. In many known devices, the volume adding function is provided by a rigid closure device. The use of the compressible flotation device to perform this function means the rigid closure device 35 (shown in figure 3) is small, reducing its cost and any risk of damage of the laundry due to its rigidity/shape.

The foam is in the form of a triangular wedge (base x height: 5 cm x 5 cm) and is fixed (by stitching) internally of the net. The foam wedge has a thickness of approximately 1.75 cm thus adding volume but not occupy excessive space in the net so as to leave sufficient space for a tablet or tablets. The net is approximately 12 cm x 16cm, and provides approximately 382 cm² total surface area. The foam occupies approximately 7.5% of the total surface area of the net bag. These dimensions provide a bag of manageable size but which is loose fitting for two tablets (each about 4.5 cm diameter and 1.5 cm height) and has an effective combined flotation and volume adding device.

The foam is located in a corner of the net which allows presentation of a smooth boundary with the remaining internal net space. This has the advantage that it does not interfere with free movement of tablets within the net. A corner (or indeed side or base mounted flotation device enables fixation of the foam in/to the net without excessive duplicate fixing means (one stitching seam 25 is used to fix the wedge in place in the embodiment shown in the drawings) . This is particularly important as the process of net manufacture can be labour intensive and expensive.

The drawstring arrangement 35 (shown in figure 3) , which ideally includes clamp means attached to the drawstring to lock the bag in an open or closed orientation.

The compressible foam and closure clamp take up less space within a pack as the foam compresses easily and the clamp can be fairly small.

In a separate embodiment the compressible flotation device is wholly contained by a barrier sack (not shown) or "pillow-case". The barrier sack comprises a tightly woven polyester sack which protects the foam during the wash cycle. One advantage of this is that any disintegration of the foam due e.g. to the mechanical action of the wash cycle; rubbing against tablets during handling, transport, wash cycle does not affect the foam as it is contained within the barrier sack thereby maintaining its performance and extending the lifespan of the device.

In use a laundry unit dose product, were a laundry unit dose product e.g. detergent tablet 10 is placed in the device 1 by inserting the tablet 10 through the open mouth. The toggle 35 is then pressed between the users fingers in the direction of arrows X (figure 3).

Generally two tablets will be used in a convention operation. The device 1 and tablets (not shown) contained therein are then placed in a washing machine together with the laundry to be washed and a washing operation is carried out during which the detergent tablet (s) within the bag 2 will disintegrate and dissolve. The compressible flotation foam aids flotation of the net in the wash liquor, increasing dispersal of the laundry tablet composition in the liquor. Any undissolved particulate disintegration products of the tablet of a size less then 5 mm 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. The Tablet Formulation is as follows:

A detergent base powder, incorporating organic surfactants, a small percentage of crystalline sodium acetate trihydrate, and zeolite MAP was made using known granulation technology. It had the following composition, shown as parts by weight.

Ingredient Parts by Weight

Sodium linear alkylbenzene sulphonate 20.85 nonionic surfactant (C13-15 branched fatty alcohol 3EO) 3.07 nonionic surfactant C13-15 branched fatty alcohol 7EO) 5.98 Soap 1.62 zeolite A24 46.70 Sodium acetate trihydrate 5.92

Sodium carbonate 6.60 sodium carboxymethyl cellulose (SCMC) 0.64 additional moisture and minor ingredients 8.50 Total 100 The amount of zeolite MAP (zeolite A24) in the table above is the amount which would be present if it was anhydrous. Its accompanying small content of moisture is included as part of the moisture and minor ingredients. The base powder and other ingredients were mixed together as set out in the following table.

Comp A.

Base powder, as above 57.18

Antifoam (1) 2.30 Fluorescer (2) 1.59

Sodium percarbonate 19.23 TAED (3) 6.48

Sodium disilicate 4.07

Soil release polymer (4) 1.40

Acrylic/maleic copolymer (5) 1.53 EDTM phosphonate 0.95 Colored speckles 1.77

Cellulosic swelling disintegrant (6) 3.50

Total 100

Wherein: (1) Antifoam is 17%wt silicon oil, 71%wt sodium carbonate and the remainder petroleum jelly and phosphate ester.

(2) Fluorescer is 9.9%wt fluorescer and 82.5%wt sodium carbonate the remainder being minor ingredients (3) TAED is 83%wt TAED in 9%wt sodium sulphate the remainder being minor ingredients .

(4) Soil release polymer is 18%wt soil-release polymer, 44%wt zeolite MAP, 21%wt sodium carbonate and minor ingredients.

(5) Acrylic/maleic polymer is Sokolan CP5 ex BASE (91%wt active) (6) Cellulosic swelling disintegrant (Arbocel ex Rettenmaier)

Tablets were made by mixing the ingredients (except for the cellulosic swelling disintegrant) and finally adding the cellulosic swelling disintegrant.

Tablets were made in a labscale Graseby Specac tabletting press; tablets had a weight of 32.4 grams and a strength (expressed in terms of the diametrical fracture stress) of approximately 25k Pa. The diametrical stress is defined as DFS=2*Fmax/ ( π*D*t) with Fmax being the tablet strength expressed as the force required to break a tablet when it is applied on its circumference. D the tablet diameter and t its thickness.

When the tablets of this example are immersed in 1 litre of tap water 20 degrees C, they require about 220 seconds before 90%wt thereof is disintegrated and/or solubilised.

In this specification the term "mesh size" is understood that size of hole which would allow particles of equivalent size or diameter to pass through. Thus a net having a mesh size of 1mm will allow all particles of average diameter of lmm or less to pass through.

Generally the net bag of the invention will be flexible, however, more rigid or resiliently deformable materials may be used within the scope of the invention.

The above embodiments of the present invention have been described by way of example only and various alternative features or modifications from what has been specifically described and illustrated can be made within the scope of the invention, as will be readily apparent to persons skilled in the art.

Claims

1. A dispensing device for treating laundry in a washing machine, the device comprising a receptacle for housing one or more laundry unit dose product, the device being characterised in that the device comprises a compressible flotation device.

2. A dispensing device according to claim 1 wherein the flotation device is configured to provide a volume adding function.

3. A dispensing device according to any preceding claim wherein the flotation device comprises a foam material which may comprise any suitable material such as polypropylene.

4. A dispensing device according to any preceding claim in which the compresible flotation device includes a flotation device.

5. A dispensing device according to claim 4 wherein the barrier is a sack or sleeve at least partially encloses the flotation device.

6. A dispensing device according to any preceding claim wherein the flotation device occupies no more than 10 % of the total surface area of the receptacle.

7. A device according to any preceding claim wherein the flotation device occupies 5-10% of the receptacle .

8. A dispensing device according to any preceding claim wherein the flotation device is shaped to presents a smooth boundary with the remaining internal space of the receptacle.

9. A dispensing device according to any preceding claim wherein the flotation device is generally triangular in plan view.

10. A dispensing device according to any preceding claim wherein the flotation device is located in a corner of the receptacle.

11. A dispensing device according to any previous claim wherein the receptacle comprises a net structure having a loose fitting structure and plurality of apertures for permitting the passage of an aqueous solution there through.

12. A dispensing device according to any preceding claim wherein the net has an average mesh size of 1 - 15mm.

13. A device according to any preceding claim wherein the receptacle comprises an opening for reception of the or each laundry unit dose product and closure means for closing the opening to prevent the passage of the or each tablet out of the receptacle through the opening.

14. A dispensing device according to claim 13 wherein the closure comprises a drawstring arrangement, which optionally includes clamp means attached to the drawstring to lock the receptacle in an open or closed orientation.

15. A dispensing device according to any preceding claim in combination with one or more laundry unit dose products comprising one or more laundry tablets.

16. A dispensing device according to any preceding claim in combination with a laundry unit dose product comprising a water soluble capsule containing a liquid or gel laundry composition.

17. A process for treating laundry in a washing machine by employing a receptacle for dispensing one or more laundry unit dose products according to any preceding claim, the process comprising the steps of placing the dispensing receptacle having at least one laundry unit dose product contained therein in a washing machine together with the laundry to be washed.

18. A package for laundry unit dose products incorporating the device any of claims 1-16 including one or more laundry unit dose products in combination with instructions for use according to claim 17.

19. A dispensing device substantially as herein before described with reference to and/or as illustrated in the accompanying drawings .