WO2005059229A1

WO2005059229A1 - Process and dispensing device for washing laundry in a washing machine

Info

Publication number: WO2005059229A1
Application number: PCT/EP2004/014073
Authority: WO
Inventors: Harriet Frédérique Jeannette HOMMES
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 2003-12-18
Filing date: 2004-12-09
Publication date: 2005-06-30
Also published as: EP1694901A1; GB0329327D0

Abstract

A method for washing fabric in a washing machine by employing a dispensing receptacle (1) for dispensing at least two unit dose products (10), the method comprising the steps of:- - placing the dispensing receptacle (1) having the at least two unit dose products (10) contained therein in a washing machine together with the laundry to be washed; and - carrying out a washing operation, wherein at least two of the unit dose products have different dissolution profiles.

Description

PROCESS AMD DISPENSING DEVICE FOR WASHING LAUNDRY IN A WASHING MACHINE

The invention relates to a process for washing fabric in a washing machine by employing a receptacle for dispensing a plurality of unit dose laundry products.

Unit dose laundry products have advantages in that they do not require measuring and are thus easier to handle and dispense into the washload.

However, a problem arises with the modern washing operation because is that it is normally a single process in which many washing related functions can be undertaken, but it is either impossible or inconvenient for the user to intervene and dose at different stages once the wash cycle has begun. Even if a machine allows user intervention during the wash cycle, this can be inconvenient for the modern user who may be time-pressed. Thus, many automatic washing process effectively involve only one dosing event i.e. at the beginning of the washing cycle. After this point, user intervention may be impossible or inconvenient.

Unit dose products combining multiple functions of the washing process are known, however such combinations can be expensive and environmentally undesirable e.g. due to the necessary segregation of some incompatible components or complicated manufacturing required to combine incompatible components. It is an object of the present invention to address the above problem and maximise the effective part of the washing cycle in a cost effective manner.

Accordingly, the invention provides a method for washing fabric in a washing machine by employing a dispensing receptacle (1) for dispensing at least two separate unit dose products (10), the method comprising the steps of:- placing the dispensing receptacle (1) having the at least two unit dose products (10) contained therein in a washing machine together with the laundry to be washed; and carrying out a washing operation, wherein at least two of the unit dose products have different dissolution profiles.

With a method of the invention, the effective parts of the washing cycle can be maximised in an effective manner as products with different dissolution profiles provide dissolution across a greater part of the cycle without the need for complicated unit dose products.

Because separate unit dose products are used, greater flexibility is provided. The user can select different unit dose products according to the particular washing requirements.

The unit dose products may comprise two or more compacted laundry tablets having different dissolution profiles. For example, one tablet may dissolve quickly, so as to be available in the early stages of the wash cycle. Another tablet may dissolve more slowly so as to be available later in the wash cycle.

Each unit dose product may be packaged separately from the other unit dose product (s) so that the user can select different unit dose products from different packages.

Tablet dissolution profiles are generally affected by the amount of compaction of the tablet, the amount of binding agent and disintegrates used.

Accordingly, in one embodiment, the unit dose products comprise two or more compacted laundry tablets each have different levels of: (a) binding agent and/or,

(b) distegranting promoting components and/or

(c) compacting pressure.

A wash cycle may include multiple successive wash and drain stages. Advantageously therefore, a first unit dose product may dissolve sufficiently quickly so that a greater amount of the composition is available for an initial wash stage (e.g. "pre-wash") and a second product may dissolve relatively slowly (relative to dissolution speed of first product), so that e.g. after mid-cycle rinse and drain stage/s a greater amount of the second product is retained in the dispensing receptacle to be available for (a) later washing stage (s) which may include a further, main' wash, conditioning, softening, freshening e.g. perfume treatment or any combination thereof. The unit dose products may comprise at least one laundry tablet and at least one water soluble capsule containing a laundry fluid e.g. a liquid, gel or paste. The laundry capsule containing a liquid may dissolve very early in the wash (almost as soon as a part of the capsule has dissolved or ruptured to release the liquid) , whereas the tablet may dissolve more slowly so as to make functional ingredients of the tablets available later in the cycle. Such functional ingredients may include fabric softening / conditioning agents.

Alternatively or additionally, at least one of the unit dose products may be a compacted granular composition and may comprise a fabric softener or fabric conditioner.

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-6-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 compositions

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 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 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 (Cι₀-C₂₂ preferably Cχ₂ Cχ₈) . 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. Pentacrythritol 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 pentacrythritol 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) follow:

Monopentaerythritol Esters

R₁-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 Mono s tear ate

R_x = CH₃- (CH₂) ₁₆-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 R_x = CH₃-(CH₂)₁₆-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 ) ₂₀-COO- R₂ = CH₃- ( CH₂ ) ₂₀-COO- R₃ = OH R₄ = OH Dipentaerythritol Esters

HO-CH₂-C(CH₂ORι) (CH₂OR₃) -CH₂-0-CH₂-C (CH₂OR₂₃) (CH₂OR₄) -CH₂-OH Dipentaerythritol Tetralaurate

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

Dipentaerythritol Tetrastearate

Rx = CH₃-(CH₂)i₆-CO R₂ = CH₃-(CH₂)₁₆-CO R₃ = CH₃-(CH₂)i₆-CO R₄ = CH₃-(CH₂)i₆-CO Pentaerythritol 10 Ethylene Oxide Ester

R₁-CH₂-C(CH₂-0-( CH₂-CH₂0)_nH) (CH₂-0- ( CH₂-CH₂0) _n*H) - CH₂-R₂ n + A = 10

Monopentaerythritol 10 Ethylene Oxide Distearate

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

Pentaerythritol 4 Propylene Oxide Esters

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

Ri = CH₃- (CH₂) i₆-C00- R₂ = OH

Monopentaerythritol 4 Propylene Oxide Distearate

R_x = CH₃- (CH₂) i₆-C00- R₂ = CH₃- (CH₂) i₆-C00-

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 addition to the above compositions) .

The combination of bentonite and organic fatty softening material may be generally from about 10% to about 99% bentonite and from 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 dispensing receptacle

The dispensing receptacle may take any suitable form, and in one embodiment it is a dispensing net structure comprising a loosely fitting net bag, wherein the apertures of the net have an average mesh size of between 1 mm and 10mm.

In this specification the term "mesh size" is understood as the 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 receptacle of the invention will be flexible at least in part, however, more rigid or resiliently deformable materials may be used.

A loosely fitting net with the above mesh size reduce the incidence of dye damage, ie. the effect of direct contact between the unit dose product such as a tablet and the clothes and the incidence of e.g. tablet residues remaining in the machine after a washing operation decreases. The greater volume of a loose fitting bag (when compared with an elastic sleeve) , results in a decreased incidence of the bag becoming lodged in the port hole of the machine during washing and allows tablets contained within the bag to mechanically act against each other thereby improving the rate of dissolution of a tablet unit dose. Further as the unit dose products are not held in a tightly conforming arrangement (as is the case with an elastic net sleeve) , a greater surface area of the products is exposed to the wash water.

In one embodiment of the process, the average mesh size of the net is at least 3mm. In one embodiment it is approximately 5mm.

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.

The device may comprise a compressible flotation device which may have an outer barrier.

A flotation device aids flotation of the receptacle in the wash liquor thereby enhancing dispersal of the laundry unit dose products throughout the laundry. The outer barrier can further enhance flotability as well as protect the flotation devices if formed from e.g. foam, sponge. Compressibility of the flotation device allows for its deformation 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 in compressed or expanded form, e.g. after absorption of wash liquor. This feature is advantageous over a rigid volume adding function as it can simplify the device, reduce costs and any risk of damage by a rigid structure. The closure device can be of low weight and compress to fit in a smaller pack with reduced environmental impact.

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 2 total surface area within the range 350 - 450 cm . 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 e.g. two tablets (each in the region of 3- 4.5 cm diameter and 1.5 - 2.5 cm height).

Further, in a second aspect, the invention provides a dispensing receptacle in combination with a plurality of unit dose products, wherein at least two of the unit dose products have different dissolution profiles, together with instructions given in relation to least one of the unit dose products, for use of the dispensing receptacle in a washing process according to the first aspect of the invention and preferred features as above.

Detailed Description of a non limiting embodiment 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: -

Fig 1 shows a dispensing receptacle according to the invention;

Fig 2 shows an enlarged section of an exemplary net structure of the receptacle of fig 1; Fig 3 shows a closure device; and

Fig 4 shows an alternative receptacle according to the invention containing two laundry tablets inserted therein.

The device

Referring to figures 1-3 there is illustrated a dispensing device according to the invention indicated generally by the reference numeral 1.

The device of figures l-3comprises a re-usable receptacle for laundry unit dose products and is 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. The dispensing device includes a compressible flotation device 20 which comprises a polypropylene foam and is wholly contained within a barrier sack or pillowcase 28. The barrier sack 28 comprises a tightly woven polyester sack which protects the foam during the wash cycle. The advantage of this feature is that any disintegration of the foam due to the mechanical action of the washing machine does not affect performance of the flotation device as it is retained within the barrier 28.

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.

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 2 12 cm x 16cm, and provides approximately 382 cm 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. 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 alternative device of figure 4 has the same features as that of figures 1-3 except that the former device has no floatation foam.

Method of washing

A first laundry tablet (examples shown designated reference numeral 10 in the figure 4) A having formulation A and a second laundry tablet B having formulation B is placed in the device 1 by inserting the tablets through the open mouth. The toggle 35 is then pressed between the users fingers to close the device.

The device 1 and tablets A and B contained therein are then placed in a washing machine together with the laundry to be washed and a washing operation is carried out. The compressible flotation foam aids flotation of the net in the wash liquor, increasing dispersal of the laundry tablet composition in the liquor. Undissolved particulate disintegration products of the tablet of a size less then 5 mm pass out of the bag 2 and are 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.

During the washing operation, the detergent tablet (s) within the bag 2 disintegrate and dissolve at different rates. Laundry tablet A dissolves faster for greater cleaning at the beginning of the wash, whereas tablet B dissolves more slowly so that washing functions can be easily and cheaply provided across a greater part of the wash cycle, as required without overcomplicated unit dose products or undue environmental impact .

Laundry Tablet Formulation A 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 3E0) 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/ ( Il*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.

Tablet formulation B Tablet B provides fabric conditioning properties, with a different dissolution profile (slower dissolution - a 60g tablet disperses in water within 20 minutes when introduced in a wash load at the beginning of the wash in a European Miele W832 front loading washing machine set at Program White Colours at 40 degrees C) to that of tablet A. Tablet B is a compacted granular unit dose composition was prepared from the following ingredients.

The method of manufacture consisted of mixing all the ingredients with the exception of perfume in a Loedige- type mixer. The resulting blend was dried in an oven and perfume was then added to the dried powder. The powder was then compacted to tablet form using an alternative or rotative press mounted with appropriate dyes or Graseby tabletting press.

The resulting combination provides good washing performance in a cost effective and simple manner.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments which are described by way of example only.

Claims

1. A method for washing fabric in a washing machine by employing a dispensing receptacle (1) for dispensing at least two separate unit dose products (10) , the method comprising the steps of:- placing the dispensing receptacle (1) having the at least two unit dose products (10) contained therein in a washing machine together with the laundry to be washed; and carrying out a washing operation, wherein at least two of the unit dose products have different dissolution profiles.

2. A method according to claim 1 wherein at least of the one unit dose products is a non-particulate laundry product.

3. A method according to claim 2 wherein at least of the one unit dose products is a tablet.

4. A method according to any preceding claim wherein the unit dose laundry product (s) comprise (s) a detergent composition or component.

5. A method according to any preceding claim wherein at least one of the unit dose products is a water soluble capsule containing a laundry composition.

6. A method according to any_. preceding claim wherein the laundry composition is a fluid.

7. A method according to any preceding claim wherein at least one of the unit dose products is a compacted tablet comprising a fabric conditioning or fabric softening composition.

8. A method according to claim 7 wherein the fabric softening/conditioning composition comprises a softening clay.

9. A method according to any of claims 7 - 8 wherein the fabric softening / conditioning composition also comprises an organic fatty softening material.

10. A method according to any of claims 7 - 9 wherein the compacted granular fabric softener composition is essentially free of a soap surfactant.

11. A method according to any of claims 7 - 10 wherein the softening clay is a montmorillonite-containing clay and said organic fatty softening material is a pentaerythritol compound ("PEC") selected from the group consisting of a higher aliphatic acid ester of 30 pentaerythritol, an oligomer of pentaerythritol, a lower alkylene oxide derivative of an oligomer of pentaerythritol, and a mixture thereof.

12. A method according to any of claims 7 - 11 wherein said softening clay is a montmorillonite-containing clay and said organic fatty softening material is a fatty alcohol.

13. A method according to any of claims 7 - 12 whereinsaid fabric softener comprises a liquid fatty ester.

14. A method 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.

15. A method according to claim 10 wherein the net has an average mesh size of 1 - 10mm.

16. A method according to claim 14 or 15 wherein the device comprises a compressible flotation device having an outer barrier.

17. A dispensing receptacle in combination with a plurality of unit dose wherein at least two of the unit dose products have different dissolution profiles, together with instructions given in relation to least one of the unit dose products, for use of the dispensing receptacle in a washing process according to any of the claims 1-16.

18. A combination according to claim 17 wherein at least one the unit dose products comprises a fabric conditioning or softening composition.