FIELD OF THE INVENTION

The field of the present invention relates to unit dose cleaning products.

The field of the present invention relates to unit dose cleaning products prepared by nonwoven websheet.

The field of the present invention relates to unit dose cleaning products prepared by nonwonen websheet made of hydrophobic polymer particularly of polyolefine based polymers.

The field of the present invention relates to nonwoven fabric construction suitable for use as detergent pouch. The field of the present invention relates to unit dose cleaning products containing detergent compositions in solid particulate form.

The field of the present invention relates to unit dose cleaning products containing detergent compositions for laundry or dishwashing or body cleansing.

BACKGROUND OF THE INVENTION Detergents are pre-portioned in pouches as pouches have been known for a long time. The employment of detergent pouches attracts the attention of consumers since the need for measuring off the detergent quantity required for a washing program from detergent powder box was obviated. Correspondingly, the pouch containing the detergent composition can be easily removed from the box involving plurality of such pouches and also, can be easily placed into the washing machines without any possible attendant spilling, dusting or inhaling of powder. The efficiency of cleaning operation as a result of precise dosing, avoiding of spills, wasteful overdosing and underdosing was improved accordingly. During the employment of pouches, the users’ hands do not come into contact with detersive and potentially skin irritating constituents of the cleaning composition, which is particularly important for users having an allergic reaction to detergent constituents. Additionally, the properties of the pouches have to be taken into consideration such as; the outer shells of the pouches have to be so dense to keep constituents enclosed. The material used for pouch construction must not be affected by the constituents and also, it has to be water permeable to enable the rapid leaching of the constituents by the wash water. The materials of outer shells, used in pouch formation must have high processability in filling and packaging machines. Additionally, the pouch material should be inexpensive for being preferred by the consumer. Pouches known in the art do not provide all these properties at the same time.

There have been numerous proposals in the art of marketing particulate detergent products as pouches. One proposal involves the preparation of pouches from water soluble film materials which has been known for a long time. Although it seems that these products gain much commercial success, they are not strong enough to enable required transport and storage properties since the water soluble film materials is vulnerable to moisture which weakens the structural integrity of products. These products are packed in close proximity with each other, so occasionally causing sticking of the pouches together which leads to rupturing or breaking of the films which causes further spoiling of the whole package.

The other proposal involves the preparation of detergent pouches by using water permeable water insoluble materials. During use, these products are placed in the drum of the washing machine together with the soiled and/or stained fabric load. Additionally, another difficulty in making products having pore sizes large enough to enable passage of water and dissolved ingredients but narrow enough to prevent the escape of constituents of the composition during storage, transportation, etc. Besides, as a result of narrow pore size, complete release of the ingredients can’t be possible and some residues are left inside the pouches which deteriorates the cleaning performance.

The nonwoven websheet prepared from hydrophobic polymeric materials such as polyester or polyolefine preferably from polypropylene has a slow water penetration into the inside of the nonwoven pouch. This causes a retarded dissolution of the cleaning composition inside of the pouch and retarded exit from the inside. As a result, the cleaning process starts quite late and as the result of the slow release ends late, which is not desired due to waste of time and energy.

The hydrophobic character of the nonwoven websheet fibers being polyolefine, polypropylene hinders water entry with a proper rate and speed, which makes the washing process unpractical and time consuming.

The nonwoven material used for these purposes are made from polymeric materials such as polyester or polyolefine, particularly polypropylene. The pouches formed with these polymer fibers tend to repel water. Consequently water penetration into the pouch becomes difficult. Thereby a retarded dissolving and release of the cleaning composition ingredients occur, which causes a delayed and not completed cleaning process in feasible time periods. To overcome this, bigger pore size application is necessary, which on the other hand cause spilling of the powdered ingredients of the detergent composition, which is not desirable as the content is lost. Additionally, spilled makes pouches sticky in presence of humidity and cause messy products, making its handling troublesome. There have been attempts to overcome said difficulties, to enable water penetration such as;

US5110640A offering a different approach for the complete transfer of ingredients of detergent pouch into the wash water. This application employs the water sensitive fibers which are formed into a web or sheet. These web or sheets are used to form a detergent pouch wherein when these pouch is wetted, the fibers loose a predetermined crimp. The length of fibers between bonding sites increases and the interstices enlarge so that the particles of detergent composition contained within the pouch can then pass through the wash liquor. Although this application offers an alternative solution for the complete transfer of the bag constituents, it suffers from insufficient increase of fiber lengths between bonding sites and insufficient enlargement of interstices. As a result of this, detergent composition contained within the bag can’t be delivered totally to the wash liquor that leads to ineffective cleaning performance and thus, unmeet consumer needs. However for achieving these goals crimped fibers are necessary and these should be bonded together to make a websheet which is more difficult and costly compared to noncrimped fibers.

Besides, bonding with crimped fiber is not mechanically robust enough to keep the particulate ingredients safely inside the pouch, by mechanical stress enlargement of the pores and spilling of the ingredients is possible.

These fibers, loosing their crimped character when wetted are made from nylon, acetate, rayon. Polypropylene is used as noncrimped fiber in less amount like 25% since crimped polypropylene do not show said behaviours when wetted. There is a need for a unit dose cleaning product prepared by water permeable but water insoluble material that prevents the outward passage of particles of the constituents of detergent composition in dry state while allowing total transfer of solubilized particles of the composition in feasible time periods when disposed in wash liquor. SUMMARY OF THE INVENTION

The present invention overcomes the above mentioned drawbacks by providing a unit dose cleaning product having an outer shell prepared by water permeable but water insoluble materials having hydrophilic spin finish layer enabling facile and rapid intrusion of water. The present invention overcomes above mentioned drawbacks by providing a unit dose cleaning product having an outer shell prepared by water permeable but water insoluble materials such as nonwoven websheet having hydrophilic spin finish treatment.

To this end, a nonwoven websheet of water permeable but water insoluble and hydrophobic material having hydrophilic spin finish treatment prepared by polyethylene or polypropylene as an outer shell is provided and then manufactured into unit dose cleaning product which is filled with particulate cleaning composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a. Top wiev of a unit dose cleaning product of the present invention prepared according to Example 5. FIG. 1b. Side wiev of a unit dose cleaning product of the present invention prepared according to Example 5.

FIG. 2. Layers of SSMMS nonwoven websheet according to Example 1.

FIG. 3. A picture of a unit dose cleaning product of the present invention prepared according to Example 5. FIG. 4. Kiss roll method.

DISCLOSURE OF THE INVENTION

The outer shell of the water permeable but water insoluble pouch of the present invention can be prepared from a nonwoven websheet. This nonwoven websheet is made from fibers or filaments of hydrophobic character such as polyolefin, polypropylene, polyethyleneteraphthalate, polyester, PVC, polyethylene. Preferably, polyester, polypropylene or any combinations or blends of those fibers and more preferably, polyethylene, polypropylene or mixtures thereof. Nonwoven webs used in the present invention can be made by spunmelt process which encompasses two processes such as spunbond and meltblown or the combinations of both. Spunbonding is based on extrusion of multiplicity of continuous thermoplastic polymer strands thorough a multiciplicity of die orifices in a downward direction onto a moving surface. These extruded strands are collected in randomly distributed mode which are then bonded together to provide integrity to the resultant non-woven web. The nonwoven web prepared by spunbonding has high strength, high porosity and good abrasion resistance. Meltblowing differs from spunboding. In meltblowing, extruded strands are broken up and then, before collecting onto a moving surface, these extruded strains are dispersed into individual fibers. The fibers first cooled by air then bonded together to obtain structural integrity. The nonwoven websheet prepared by meltblowing becomes very compact so that it can act as a barrier. The nonwoven websheet of the present invention is the combination of spunbonded and melt blown. The non-woven web of the present invention is then subjected to calender bonding at which the web is bonded by heating at least one of the rollers to soften the components, and synchronously, pressure is applied to make the softened polymers bonded.

The present invention comprises:

A unit dose cleaning product having an outer shell made of hydrophobic nonwoven websheet material and at least one compartment containing cleaning composition of solid particulate material sealed in said outer shell, wherein said outer shell comprises; i. at least one layer of spunbond (S) material located on the outer surface side of the outer shell,

ii. at least one layer of spunbond (S) material located on the other outer surface side of the outer shell,

iii. at least one layer of meltblown (M) material located between said spunbond (S) materials of i and ii, wherein; said outer shell comprises a hydrophilic spin finish treatment made with a hydrophilic spin finish composition.

The nonwoven websheet of the present invention comprises; A unit dose cleaning product having an outer shell made of a nonwoven websheet material having an exterior surface side and interior surface side containing cleaning composition of solid particulate material comprising;

At least one layer of spunbond (S) material located on the exterior surface side of the outer shell,

At least one layer of spunbond (S) material located on the interior surface side of the outer shell,

At least one layer of meltblown (M) material located between said spunbond materials (S) of the exterior and interior side of the outer shell. Wherein, said outer shell comprises a hydrophilic spin finish treatment made with a hydrophilic spin finish composition.

The spunbond layer of the present invention for polypropylene fiber material comprises fibers with diameter in the range of between 8- 25 micron, preferably 12- 20 micron. The spunbond fiber diameter below said values provides not the necessary strength and fiber diameters above said diameter fails to form nonwoven websheet with desired pore dimension to prevent spilling.

The meltblown layer of the present invention for polypropylene fiber material comprises fibers with diameter in the range of between 1.0- 3.0 micron, preferably 1.2- 2.0 micron. The meltblown fiber diameter below said values are not strong enough to resist mechanical stress and may broke; too high of diameter may fail to build a strong mesh and cause spilling.

The fibers in one layer can be same or different from the fibers employed in another layer (s).

The embodiments of the present invention can be comprised of three or four or five layers of combination of spunbond/meltblown construction wherein these constructions can be SMS, SSMS, SMMS, SSMMS, SMMMS or SSSMS. Preferably, the embodiment of the present invention can utilize five layers of combination of spunbond/meltblown construction.

Spunbond layers of the construction improve the strength and softness of the web, giving a fabric-like appearance while providing large pores. The inclusion of the meltblown layers makes the web more compact and reduces the pore size of the web wherein meltblown layers act as a barrier to prevent outward passage of the composition. The non-woven websheet construction of the present invention has sufficient wet strength which enables the product to survive during washing process without disintegrating.

The nonwoven websheet of the present invention has the weight ratio of said meltblown (M) material to the nonwoven websheet material of at most 15%, preferably 10%.

The nonwoven websheet has an outer surface side and an other outer surface side, whereas other surface side is positioned on the opposite surface side of the outer shell nonwoven websheet.

The nonwoven unit dose product of the present invention comprised of polypropylene fibers weighs about 10 to 100 gsm, preferably 15 to 70 gsm. Within these ranges the nonwoven websheet keeps the ingredients from spilling and has the necessary strength to withstand to mechanical stresses. Too high of nonwoven websheet weights cause delayed release of ingredients and economically not feasible due to failing to contribute to effectiveness. Wherein gsm stands for gram per square meter; g/m2.

The hydrophilicity of the nonwoven websheet is provided by using spin finish technology. The method applied for providing the feature of enhanced hydrophilicity is providing the spin finish treatment.

The hydrophilic spin finish treatment of the present invention is accomplished with a spin finish treatment composition which comprises mainly mixtures of cationic surfactants in an aqueous emulsion or a solid dispersion. Said composition further comprises cationic antistatic agents, cationic siloxanes, nonionic surfactant, quaternary ammonium compounds. Said composition may comprise partially modified polysiloxanes, cationic or anionic surfactants, blends of fatty acid or fatty alcohol ethoxylates, anionic surfactants such as phosphonates, sulphonates, sulfosuccinates. Such compositions have hydrophilic or permanent hydrophilic character.

Said treatment compositions may comprise at least one nonionic surfactant, at least one quaternary ammonium compound, cationically modified polydimethyl siloxane, whereas quaternary ammonium compound may be an esterquat compound. Nitrogen atom of said quaternary ammonium compound comprises alkyl carboxylated groups, alkyl hydroxyethyl, polyglycol residue and as counterion methylsulfate, acetate, phosphonate, Chloride; said polydimethyldisiloxanes have similar counterions. Said quaternary ammonium compound may be ditallow dimethyl ammonium compound, its chloride salt. Said nonionic surfactant may be fatty acid ester or ether such as fatty acid polyethylene glycol ester, fatty acid polyethylene glycol ester methyl ether. Said siloxane compounds may be alkoxylated polysiloxanes, ether polydimethyl siloxanes. Said composition may contain polyoxyalkylene modified dimethyl siloxanes, nonionic surfactants, quaternary ammonium salts.

The composition can contain at least one cohesion agent, lubricant, corrosion protecting agent, and emulsifier. These may be fatty acid ethoxylate as lubricant and emulsifier and ricinol ethoxylate as cohesion agent.

The hydrophilic spin finish treatment composition of the present invention is applied in quantities from 0.2-5.0% relative to nonwoven websheet weight, preferably in the range of 0.3- 2.0 by weight depending on the hydrophilicity required. Said applied weight is the dry matter remaining after application of aqueous spin finish treatment composition and subsequent drying. The aqueous emulsion or solid dispersion has an active content of upto 20% by weight, whereas to avoid high viscosity concentrations, less than 5% content is preferred. With the active content hydrophilicity contributing agents in the composition is meant.

The aqueous composition of the present invention is prepared by mixing of the components in water and homogenizing by a thorough stirring with subsequent diluting with water to form aqueous dispersion or emulsion of the composition. This composition is used for hydrophilic finishing of the nonwoven websheet.

Said spin finish composition may be applied by way of metering rods, calendaring, immersion baths, by spray drying or kiss rolls. In case of the nonwoven websheet of the present invention kiss roll method is preferred.

The spinfinish composition may be applied by contacting nonwoven websheet with the aqueous composition, thus imparting hydrophilic properties to hydrophobic nonwoven websheet. Obtained treated nonwoven websheet conveys water quickly into the pouch where the cleaning composition is found.

The obtained, with hydrophilic finishing treated nonwoven websheet is used to prepare a unit dose cleaning product by filling the nonwoven websheet with cleaning composition and welding the edges of the nonwoven websheet to form a pouch. Unit dose products obtained with this method are allowing water entry to the inside of the pouch in a fast manner contrary to the pouchs having nonwoven websheets which are not hydrophilic spin finish treated. The spinfinish treatment is achieved by application of spin finish composition onto the nonwoven websheet material with methods such as spraying, calendering, kiss roll among others, whereas kiss roll method is preferred.

With the present invention it has been found that a treatment with hydrophilic spin finish composition enhances the hydrophilicity of the hydrophobic nonwoven websheet.

The nonwoven unit dose cleaning product of the present invention may contain one or multiple compartments wherein these compartments can involve different ingredients which are poorly compatible or incompatible with each other. The ingredients contained within the compartment(s) can be solid particles which are in powder, granule, shaped form or mixtures thereof and/or can be liquid, gel, semi-solid, wax, paste form or mixtures thereof.

The nonwoven unit dose cleaning product of the present invention can be rectangular, square, triangle, oblong, circle, semicircle, spheres, ovoids and hexagonal, round, square, elliptical and other 3-dimensional shapes, preferably rectangular in shape. The shape and the volume of compartments of the unit dose product can be same and/or different from each other.

The nonwoven unit dose cleaning product of the present invention can be formed from single folded sheets which are sealed on two or three sides or from two sheets one on top of another which are sealed from four sides. As an alternative, the sheets can be folded like envelopes or pillows wherein the overlapping flaps are sealed along all its free edges to form the closed structure and also, the product may contain additional transverse or longitudinal seals as required. The sheet(s) can be sealed ultrasonically or by using heat-sealing or by using adhesives. The seals must be strong enough not to rupture during the washing process. Additionally, the nonwoven websheets used to form the unit dose cleaning product also must have sufficient wet strength to withstand disintegration during washing process in washing machine. The unit dose product of the present invention remains closed during washing process.

The nonwoven unit dose cleaning product of the present invention can be marked or tagged or comprise a texture on one or more of its surfaces. By this way, it can be easily recognized within the washed fabrics. The product of the present invention may be embossed with embossed pattern or may contain apertures arranged in a random or non-random, repeating pattern. After the use, the nonwoven unit dose product of the present invention can be discarded. The terms cleaning product and/or cleaning composition and/or detergent composition are used interchangeably and refers to an amount of a laundry detergent or dishwashing detergent which is sufficient for laundering, dishwashing, cleaning or washing operation implementing with automatic washing machines or dishwashers. The terms cleaning product and/or cleaning composition and/or detergent composition are used interchangeably and refers to an amount of a laundry detergent or dishwashing detergent which is sufficient for laundering, dishwashing, cleaning or washing operation implementing with automatic washing machines or dishwashers or refers to cleaning composition employed for body cleansing. The terms pouch and /or sachet and/or capsule and/or bag are used interchangeably and refer to unit dose cleaning product.

The term unit dose cleaning product of the present invention refers to the products containing single or multiple compartments, such as pouch, bag, sachet.

The term“web” is used to refer to a collection of formed fibers and/or filaments and/or a sheet formed by fibers and/or filaments wherein continuous filaments of any nature or origin associate one another. The term non-woven used to refer to a sheet of fibers and/or filaments of any nature or origin that are bonded together by any means formed into a web by any means with the exception of weaving or knitting as defined by European Disposables and Nonwovens Association (EDANA). The term water permeable is used to refer to the material which allows the intrusion of water under conditions of product used.

The following examples should serve for understanding the present invention and should not be limiting.

EXAMPLES

Example 1 : Preparation of Nonwoven Websheet of SSMMS Layer

A spunbond layer is provided by extrusion of isotactic polypropylene strands through orifices under air cooling giving strands having average diameter of 16 micron on a moving layer. An additional spunbond layer is provided as above and extruded above the first spunbond layer.

A meltblown layer is provided above the second spunbond layer by meltblowing the isotactic polypropylene strands with an average diameter of 1.6 micron through orifices under air cooling. An additional meltblown layer is provided as above and extruded above the first meltblown layer.

An additional spunbond layer is provided as above and extruded above the second meltblown layer.

Collected layers are heat pressed with a calender by a temperature close to polypropylene melting point, wherein the emboss cylinder is heated to 200°C around.

The emboss pattern were dots with 16 per cm2 and covering around 15% of the total nonwoven websheet surface.

Thereby a nonwoven websheet comprise of SSMMS layers is obtained with a weight per area of 50gsm; gram square meter, wherein meltblown layers have 10% by weight of the total weight of nonwoven websheet, remaining 90% are spunbond layers whereas each spunbond layer has similar weight ratio.

Example 2: Preparation of Spin Finish Treatment Composition:

A composition of 30% fatty acid polyethylene glycol ester methyl ether,

50% of quaternary ammonium compound derivatized with alkyl carboxylated, hydroxyl ethyl groups and cationically modified polydimethyl siloxane

10% fatty acid polyethylene glycol and 10% ethoxylated ricinol by weight is provided.

Said composition is diluted and homogenized to obtain a 5% aqueous composition of spin finish treatment composition.

Example 3: Preparation of Solid Particulate Cleaning Composition Labsa Na %18

Sodium Silicate %6

Carboxy Methyl Cellulose %1

Sodium Carbonate %10

Phosphonate %0.4 Sodium Sulfate %16 of the total weight of final composition are slurried in water and spray dried in tower to obtain granulated matter with a particle size distributed mainly in the range of 0.1 to 1 mm .

This granulate is further mixed with

Nonionic A7 %2 Zeolith %4

Sodium percarbonate %26

TAED %1.5

Enzyme %2

Texcare SRA %1.5 Further perfume, antifoaming agent, whitening agent, optics among other may be added. Example 4: Preparation of Nonwoven Websheet with Spin Finish Treatment According to the Present Invention.

A roll of nonwoven websheet with 50 gsm comprised of SSMMS layers as described in Example 1 is provided. This roll is conveyed to the kiss roll equipment wherein an embossed roller is sinked into a tank comprising an aqueous hydrophilic treatment composition with an active content of 5% prepared as described in Example 2

After passing kiss roller, the nonwoven websheet, wetted with aqueous spin finish treatment composition is passed through calender roll heated to around 200°C. Thus obtained 0.5% by weight finish treatment composition containing nonwoven websheet is enrolled to a coil.

Example 5: Preparation of Unit Dose Cleaning Product Prepared with Nonwoven Websheet with Spin Finish Treatment and Solid Particulate Cleaning Composition According to the Present Invention. In example 4 prepared spin finish treated nonwoven websheet is placed on a template of moulds and vacuum is applied to provide nonwoven websheet cavities.

Preweighed amounts of solid particulate cleaning composition prepared according to example 3 is poured into each moulds and another nonwoven websheet is placed thereupon.

After that each mould is heat sealed by heating close to polypropylene melting point temperatures at the edges and cut to obtain individual unit dose products.

Example 6: Preparation of Nonwoven Websheet Without Spin Finish Treatment and Unit Dose Cleaning Product Using the Same.

In the art of in example 1 prepared nonwoven websheet without spin finish treatment is placed on a template of moulds and vacuum is applied to provide nonwoven websheet cavities. Preweighed amounts of solid particulate cleaning composition prepared according to example 3 is poured into each moulds and another nonwoven websheet is placed thereupon. After that each mould is heat sealed by heating close to polypropylene melting point temperatures at the edges and cut to obtain individual unit dose products.

TESTS

1 : Strike Through Time Test A standard test method for nonwoven websheet liquid strike thorough time: WSP 70.3 is applied.

The time required for water to penetrate the nonwoven websheet and reach to filter paper situated on the other side of the nonwoven websheet is measured.

Whereby a known volume of liquid is applied to the surface of nonwoven websheet. A complete machine from Fritz Mezger Inc, Spartanburg is used for this purpose.

A 125mmX125mm dimensioned test nonwoven websheet is cut and set on reference blotter papers on the base plate,

Place the strike through plate on top of the nonwoven websheet and run 5 ml of liquid onto nonwoven websheet and measure the time the water reaches to the other side of nonwoven websheets with help of electrodes.

Results:

50 gsm spin finish treated nonwoven websheet of Example 4:

Front face strike through time: 2.74 sec Back face strike through time: 2.80 sec 50 gsm non spin finish treated nonwoven websheet of Example 1 : no liquid penetration observed

Front face means the face in contact with kiss roll by spin finish treatment application. The very similar strike through time indicates that by kiss roll method almost all surfaces of fibers are coated with spin finish treatment composition. This makes this method a preferred one due to its simplicity of appliance and effectiveness. 2: Water Penetration Test

Measured by the total exit of the cleaning composition by water entry into the pouch, subsequent dissolving and exit from the pouch.

Thereby the pouches are examined for the residual cleaning composition ingredients in the unit dose product of the present invention after the washing procedure.

The unit dose products of the present invention, which are with the spin finish treatment composition treated are showing the complete use of the cleaning composition by the washing performances applied in the test washings .

Whereas by test washings with unit dose products without spin finish treatment a residual cleaning composition is observed.

Test washings are washings in automated washing machines with 30 minutes washing program.