US20040144065A1

US20040144065A1 - Pouch manufacture and uses

Info

Publication number: US20040144065A1
Application number: US10/683,044
Authority: US
Inventors: David Smith; Rhys Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-09
Filing date: 2003-10-08
Publication date: 2004-07-29
Also published as: CA2501204C; WO2004033301A1; JP4197321B2; MXPA05003776A; AU2003267295A1; JP2006501111A; EP1551712A1; CA2501204A1

Abstract

A vacuum-assisted process for making a fluid-containing water-soluble pouch. The pouches obtained according to the process of the invention have a reduce air content. The use of the pouches containing detergent composition for laundry and dishwashing is also disclosed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S. provisional patent application serial No. 60/417,100 filed Oct. 9, 2002.[0001]

TECHNICAL FIELD

The present invention is in the field of pouch manufacture, in particular it relates to fluid-containing water-soluble pouches and their use for detergency applications.

BACKGROUND OF THE INVENTION

The use of water-soluble pouches for different applications, especially for cleaning applications, has become increasingly popular. Among many other advantages pouches avoid the contact of the user with the cleaning composition which may contain bleach and/or other irritant substances.

Often the geometry and size of the pouch is determined by its application, for example in the case of pouches for use in automatic dishwashing machines, the geometry and size of the pouch may be determined among other things by the shape of the detergent dispenser compartment.

One of the most efficient ways of producing pouches is using a horizontal-forming process. One of the drawbacks of pouches made according to this process, especially fluid-containing pouches, is that the pouch inevitably contains certain amount of air. This air takes part of the space that otherwise would be occupied by active fluid. The problem is more acute in the case of shallow pouches, i.e., pouches with large base to height ratio and in the case of pouches sealed by heat sealing. In view of this discussion, there is the need of minimizing the amount of air entrained in horizontal-formed fluid-containing pouches, especially in shallow heat sealed pouches.

The heat-sealing process requires maintenance of the sealing area in a dry condition. Contamination of the sealing area can translate into a weak sealing. Therefore, a requirement during the sealing process is to maintain the fluid level in the open pouch at a certain distance below the sealing area of the pouch. This requirement gives rise to pouches having a considerable volume occupied by air as compared with the volume occupied by active fluid. As discussed above, this phenomenon is more acute in case of shallow pouches.

SUMMARY OF THE INVENTION

Applicants have now found that the volume of air contained in a fluid-containing pouch of a given shape can be reduced by making the pouch by means of a vacuum-assisted process in a mould comprising a cavity and flange, wherein the effective fluid surface area during the pouch making process is smaller than the area of the region defined by the sealing lines during the pouch making process. The desired final shape of the pouch can be achieved by controlling the size of the area created by the sealing lines and the strechability of the film material.

Thus according to the first aspect of the invention, there is provided a vacuum-assisted process for making a fluid-containing water-soluble pouch comprising the steps of:

a) placing a first sheet of elastic film material over a horizontal mould comprising a cavity and a flange;

b) drawing the film material into the cavity with vacuum assistance while maintaining the film under tension to form an open pouch;

c) filling the open pouch with a volume of fluid to define an effective fluid surface area A _f;

d) closing and sealing the open pouch with a second sheet of film material along one or more sealing lines, the region bounded by the sealing lines having an area A _s; and

e) releasing the vacuum applied to the pouch;

and wherein the volume of fluid relative to that of the cavity and the position of the sealing lines relative to the flange are such that A _fand A_sare in a ratio of from about 1:1.2 to about 1:5, preferably from about 1:1.6 to about 1:4 and more preferably from about 1:1.8 to about 1:3.

The process of the invention requires the assistance of vacuum for drawing the film into the mould and stretching the film. The drawing of the film can be additionally helped by heating of the film, either outside or inside the mould. Heating seems to reduce the formation of wrinkles in the film.

The flange of the mould is considered to be the peripheral horizontal region surrounding the cavity in the region of its rim. The “effective fluid surface area, A _f” is the calculated area of the surface of the fluid in the open pouch under static conditions. The area of the region defined by the sealing lines A_sis considered to be the area of an imaginary plane resting horizontally on the mould flange wherein the sealing lines delimit the perimeter of the plane.

In preferred embodiments the first sheet of film material is subjected to a deformation of from about 20% to about 55%, preferably from about 30% to about 40% in at least one direction during steps b) to d) of the process. Preferably, the first and second sheets of film material are similar in size (e.g., their dimensions do not differ more than 10%, preferably 5%) under static conditions, e.g., when they are not under tension. When the pouch is being formed, the first sheet is stretched but preferably the second one is not or is deformed to a lesser extent. Therefore, after the pouch is formed and the vacuum released, the elastic forces acting on the first sheet are balanced between the sheets and equilibrium is established. This process gives rise to pouches having different geometry to that of the cavity in which they are formed. The final shape of the pouch is mainly determined by the deformation of the first sheet during the pouch making process, the shape of the mould cavity and the shape of the sealing lines.

The deformation being defined herein as: (x _i/x_f)×100; wherein x_iis the length of the film between two opposing points of the sealing lines before the film has been subjected to the vacuum and x_fis the length of the film between the same two opposing points of the sealing lines after the film has been subjected to the vacuum and before the vacuum has been released.

The deformation of the first sheet of film material under vacuum can be determined by for example, drawing a grid on the sheet, subjecting the sheet to the vacuum conditions of the process and then heating and cooling the sheet. The heating step is such as to transform the elastic deformation into plastic deformation and after cooling the sheet will maintain the structure. Thus, the deformation of the sheet can be measured by comparing the size of the initial grid with that of the final grid.

In order to achieve a robust sealing, especially in the cases in which the sealing is performed by means of heat sealing, contamination of the sealing area by the fluid should be avoided. On the other hand, the level of the fluid below the flange of the mould should be as small as possible in order to reduce the volume of air entrapped into the pouch. It has been found that an optimum sealing robustness/volume of entrapped air is reached when the open pouch is filled to a height of about 3 mm, preferably about 2 mm and more preferably about 1 mm below the flange of the mould.

In a preferred embodiment the mould cavity has cylindrical geometry and the region defined by the sealing lines has a parallelepiped geometry, preferably the footprint (when the pouch is placed into the dispenser) of the resulting pouch is substantially rectangular or square. The majority of dishwashing dispensers have a rectangular or square geometry, therefore pouches having those shapes are better suited for dispenser fit.

In a preferred embodiment the pouch includes a plurality of sealing lines and sealing of the pouch is intermittently performed, preferably by means of heat sealing, by for example sealing firstly two opposite sides of the pouch-to-be followed by sealing two other opposite sides. The second sheet is usually bowed to a certain extent during the sealing step. Preferably an anti-bowing step takes place during the sealing, this further reduces the amount of air entrained in the pouch. The anti-bowing can be performed by for example, air means, i.e., a current of air blowing downwards towards the pouch, or by weight means, e.g., a bar pushing the second sheet downwards. This bar should have an appropriate shape, usually matching the shape of the aperture of the cavity but slightly smaller, in order to maximize the amount of air evacuated from the pouch without establishing contact between the fluid and the film. Alternatively, the sealing can be carried out by means of solvent sealing.

The fluid contained in the pouches made according to the process of the invention can be in the form of a liquid, gel or paste. The fluid can also comprises a solid or a multitude of solid inserts, such as for example micro-beads, noodles or one or more pearlized balls.

According to a second aspect of the invention, there are provided pouches made by the process of the invention. In a preferred embodiment there is provided a horizontally-formed fluid-containing water-soluble pouch having a first and a second sheet sealed together (preferably by means of heat sealing) and a base length to height ratio of from about 50:1 to about 2:1, preferably from about 20:1 to about 3:1 and more preferably from about 10:1 to about 4:1 characterised in that both sheets are stretched and under tension and the volume of fluid and the volume of air contained in the pouch are in a ratio of from about 1.7:1 to about 8:1, preferably from about 2:1 to about 6:1. These pouches are characterised by having a volume of entrapped air smaller than that of traditional horizontal formed pouches while presenting a very robust sealing.

The height of the pouch is defined as the maximum longitudinal dimension, perpendicular to one of the pouch bases, when the pouch is lying on one of the bases which has the maximum footprint under a static load of about 2 Kg. The base length is defined as the maximum width of the pouch in a plane perpendicular to the longitudinal direction under the same conditions.

In another aspect of the invention, there is also provided a horizontally-formed fluid-containing water-soluble pouch having a first and a second sheet sealed together and a base length to height ratio of from about 50:1 to about 2: 1, preferably from about 20:1 to about 3:1 and more preferably from about 10:1 to about 4:1 characterised in that the pouch is formed by a process including the step of subjecting the second sheet to an anti-bowing step during the sealing of the pouch for purposes of reducing air entrainment and the volume of fluid and the volume of air contained in the pouch are in a ratio of from about 1.7:1 to about 8:1, preferably from about 2:1 to about 6:1.

The pouches of the invention are also suitable for making multi-compartment pouches, either fluid/fluid or solid/fluid multi-compartment pouches. The process of the invention can be used to make only one compartment or alternatively it can be used for making the whole multi-compartment pouch. Multi-compartment pouches are preferably made by forming and filling a first open pouch and closing this open pouch with a second pre-formed pouch. This process is described in WO 02/42408. Especially suitable for use in dishwashing are powder/liquid pouches.

There are also provided methods for using the pouches of the invention for laundry and dishwashing. The pouches can be placed either in the detergent dispenser or in the interior of the machine. In the case of dishwashing, the pouches are preferably placed into the dispenser.

DETAILED DESCRIPTION OF THE INVENTION

The present invention envisages a horizontal process for making fluid-containing water-soluble pouches. The pouches produced according to the process of the invention contain an air volume lower than that contained in pouches made according to traditional processes. This is especially advantageous in pouches having a high base length to height ratio, i.e., shallow pouches. The present invention also envisages the use of these pouches for dishwashing and laundry.

The pouches of the invention can comprise any liquid composition compatible with the pouch material. These pouches are especially useful in the field of detergency.

The pouch is preferably made of a material which is soluble or dispersible in water, and has a water-solubility of at least 50%, preferably at least 75% or even at least 95%, as measured by the method set out here after using a glass-filter with a maximum pore size of 20 microns.

50 grams ±0.1 gram of capsule or pouch material is added in a pre-weighed 400 ml beaker and 245 ml ±1 ml of distilled water is added. This is stirred vigorously on a magnetic stirrer set at 600 rpm, for 30 minutes. Then, the mixture is filtered through a qualitative sintered-glass filter with a pore size as defined above (max. 20 micron). The water is dried off from the collected filtrate by any conventional method, and the weight of the remaining material is determined (which is the dissolved or dispersed fraction). Then, the % solubility or dispersability can be calculated.

Preferred pouch materials are polymeric materials, preferably polymers which are formed into a film or sheet. The pouch material can, for example, be obtained by casting, blow-moulding, extrusion or blown extrusion of the polymeric material, as known in the art.

Preferred polymers, copolymers or derivatives thereof suitable for use as pouch material are selected from polyvinyl alcohols, polyvinyl pyrrolidone, polyalkylene oxides, acrylamide, acrylic acid, cellulose, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetates, polycarboxylic acids and salts, polyaminoacids or peptides, polyamides, polyacrylamide, copolymers of maleic/acrylic acids, polysaccharides including starch and gelatine, natural gums such as xanthum and carragum. More preferred polymers are selected from polyacrylates and water-soluble acrylate copolymers, methylcellulose, carboxymethylcellulose sodium, dextrin, ethylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, maltodextrin, polymethacrylates, and most preferably selected from polyvinyl alcohols, polyvinyl alcohol copolymers and hydroxypropyl methyl cellulose (HPMC), and combinations thereof. Preferably, the level of polymer in the pouch material, for example a PVA polymer, is at least 60%.

Mixtures of polymers can also be used. This may in particular be beneficial to control the mechanical and/or dissolution properties of the compartment or pouch, depending on the application thereof and the required needs. For example, it may be preferred that a mixture of polymers is present in the material of the compartment, whereby one polymer material has a higher water-solubility than another polymer material, and/or one polymer material has a higher mechanical strength than another polymer material. It may be preferred that a mixture of polymers is used, having different weight average molecular weights, for example a mixture of PVA or a copolymer thereof of a weight average molecular weight of 10,000-40,000, preferably around 20,000, and of PVA or copolymer thereof, with a weight average molecular weight of about 100,000 to 300,000, preferably around 150,000.

Also useful are polymer blend compositions, for example comprising hydrolytically degradable and water-soluble polymer blend such as polylactide and polyvinyl alcohol, achieved by the mixing of polylactide and polyvinyl alcohol, typically comprising 1-35% by weight polylactide and approximately from 65% to 99% by weight polyvinyl alcohol, if the material is to be water-dispersible, or water-soluble. It may be preferred that the PVA present in the film is from 60-98% hydrolysed, preferably 80% to 90%, to improve the dissolution of the material.

Most preferred pouch and wrap materials are PVA films known under the trade reference Monosol M8630, as sold by Chris-Craft Industrial Products of Gary, Ind., US, and PVA films of corresponding solubility and deformability characteristics. Other films suitable for use herein include films known under the trade reference PT film or the K-series of films supplied by Aicello, or VF-HP film supplied by Kuraray.

The water-soluble film herein may comprise other additive ingredients than the polymer or polymer material. For example, it may be beneficial to add plasticisers, for example glycerol, ethylene glycol, diethyleneglycol, propylene glycol, sorbitol and mixtures thereof, additional water, disintegrating aids. It may be useful that the pouch or water-soluble film itself comprises a detergent additive to be delivered to the wash water, for example organic polymeric soil release agents, dispersants, dye transfer inhibitors.

The pouches of the invention preferably comprise detergent auxiliaries or compositions. These detergent auxiliaries or compositions can comprise traditional detergency components and can also comprise organic solvents having a cleaning function and organic solvents having a carrier or diluent function or some other specialised function. The compositions will generally be built and comprise one or more detergent active components which may be selected from bleaching agents, surfactants, alkalinity sources, enzymes, thickeners (in the case of liquid, paste, cream or gel compositions) and anti-corrosion agents (e.g. sodium silicate). Highly preferred detergent components include a builder compound, an alkalinity source, a surfactant, an enzyme and a bleaching agent.

The organic solvents should be selected so as to be compatible with the tableware/cookware as well as with the different parts of an automatic dishwashing machine. Furthermore, the solvent system should be effective and safe to use having a volatile organic content above 1 mm Hg (and preferably above 0.1 mm Hg) of less than about 50%, preferably less than about 30%, more preferably less than about 10% by weight of the solvent system. Also they should have very mild pleasant odours. The individual organic solvents used herein generally have a boiling point above about 150° C., flash point above about 100° C. and vapor pressure below about 1 mm Hg, preferably below 0.1 mm Hg at 25° C. and atmospheric pressure.

Solvents that can be used herein include: i) alcohols, such as benzyl alcohol, 1,4-cyclohexanedimethanol, 2-ethyl-1-hexanol, furfuryl alcohol, 1,2-hexanediol and other similar materials; ii) amines, such as alkanolamines (e.g. primary alkanolamines: monoethanolamine, monoisopropanolamine, diethylethanolamine, ethyl diethanolamine; secondary alkanolamines: diethanolamine, diisopropanolamine, 2-(methylamino)ethanol; ternary alkanolamines: triethanolamine, triisopropanolamine); alkylamines (e.g. primary alkylamines: monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, cyclohexylamine), secondary alkylamines: (dimethylamine), alkylene amines (primary alkylene amines: ethylenediamine, propylenediamine) and other similar materials; iii) esters, such as ethyl lactate, methyl ester, ethyl acetoacetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate and other similar materials; iv) glycol ethers, such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol butyl ether and other similar materials; v) glycols, such as propylene glycol, diethylene glycol, hexylene glycol (2-methyl-2, 4 pentanediol), triethylene glycol, composition and dipropylene glycol and other similar materials; and mixtures thereof.

Surfactant

Surfactants suitable herein include anionic surfactants such as alkyl sulfates, alkyl ether sulfates, alkyl benzene sulfonates, alkyl glyceryl sulfonates, alkyl and alkenyl sulphonates, alkyl ethoxy carboxylates, N-acyl sarcosinates, N-acyl taurates and alkyl succinates and sulfosuccinates, wherein the alkyl, alkenyl or acyl moiety is C ₅-C₂₀, preferably C₁₀-C₁₈linear or branched; cationic surfactants such as chlorine esters (U.S. Pat. No. 4,228,042, U.S. Pat. No. 4,239,660 and U.S. Pat. No. 4,260,529) and mono C₆-C₁₆N-alkyl or alkenyl ammonium surfactants wherein the remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups; low and high cloud point nonionic surfactants and mixtures thereof including nonionic alkoxylated surfactants (especially ethoxylates derived from C₆-C₁₈primary alcohols), ethoxylated-propoxylated alcohols (e.g., BASF Poly-Tergent® SLF18), epoxy-capped poly(oxyalkylated) alcohols (e.g., BASF Poly-Tergent® SLF18B—see WO-A-94/22800), ether-capped poly(oxyalkylated) alcohol surfactants, and block polyoxyethylene-polyoxypropylene polymeric compounds such as PLURONIC®, REVERSED PLURONIC®, and TETRONIC® by the BASF-Wyandotte Corp., Wyandotte, Mich.; amphoteric surfactants such as the C₁₂-C₂₀alkyl amine oxides (preferred amine oxides for use herein include C₁₂lauryldimethyl amine oxide, C₁₄and C₁₆hexadecyl dimethyl amine oxide), and alkyl amphocarboxylic surfactants such as Miranol™ C2M; and zwitterionic surfactants such as the betaines and sultaines; and mixtures thereof. Surfactants suitable herein are disclosed, for example, in U.S. Pat. No. 3,929,678 , U.S. Pat. No. 4,259,217, EP-A-0414 549, WO-A-93/08876 and WO-A-93/08874. Surfactants are typically present at a level of from about 0.2% to about 30% by weight, more preferably from about 0.5% to about 10% by weight, most preferably from about 1% to about 5% by weight of composition. Preferred surfactant for use herein are low foaming and include low cloud point nonionic surfactants and mixtures of higher foaming surfactants with low cloud point nonionic surfactants which act as suds suppresser therefor.

Builder

Builders suitable for use herein include water-soluble builders such as citrates, carbonates and polyphosphates e.g. sodium tripolyphosphate and sodium tripolyphosphate hexahydrate, potassium tripolyphosphate and mixed sodium and potassium tripolyphosphate salts; and partially water-soluble or insoluble builders such as crystalline layered silicates (EP-A-0164514 and EP-A-0293640) and aluminosilicates inclusive of Zeolites A, B, P, X, HS and MAP. The builder is typically present at a level of from about 1% to about 80% by weight, preferably from about 10% to about 70% by weight, most preferably from about 20% to about 60% by weight of composition.

Amorphous sodium silicates having an SiO ₂:Na₂O ratio of from 1.8 to 3.0, preferably from 1.8 to 2.4, most preferably 2.0 can also be used herein although highly preferred from the viewpoint of long term storage stability are compositions containing less than about 22%, preferably less than about 15% total (amorphous and crystalline) silicate.

Enzyme

Enzymes suitable herein include bacterial and fungal cellulases such as Carezyme and Celluzyme (Novo Nordisk A/S); peroxidases; lipases such as Amano-P (Amano Pharmaceutical Co.), M1 Lipase® and Lipomax® (Gist-Brocades) and Lipolase® and Lipolase Ultra® (Novo); cutinases; proteases such as Esperase®, Alcalase®, Durazym® and Savinase® (Novo) and Maxatase®, Maxacal®, Properase® and Maxapem® (Gist-Brocades); α and β amylases such as Purafect Ox Am® (Genencor) and Termamyl®, Ban®, Fungamyl®, Duramyl®, and Natalase® (Novo); pectinases; and mixtures thereof. Enzymes are preferably added herein as prills, granulates, or cogranulates at levels typically in the range from about 0.0001 % to about 2% pure enzyme by weight of composition.

Bleaching Agent

Bleaching agents suitable herein include chlorine and oxygen bleaches, especially inorganic perhydrate salts such as sodium perborate mono-and tetrahydrates and sodium percarbonate optionally coated to provide controlled rate of release (see, for example, GB-A-1466799 on sulfate/carbonate coatings), preformed organic peroxyacids and mixtures thereof with organic peroxyacid bleach precursors and/or transition metal-containing bleach catalysts (especially manganese or cobalt). Inorganic perhydrate salts are typically incorporated at levels in the range from about 1% to about 40% by weight, preferably from about 2% to about 30% by weight and more preferably from abut 5% to about 25% by weight of composition. Peroxyacid bleach precursors preferred for use herein include precursors of perbenzoic acid and substituted perbenzoic acid; cationic peroxyacid precursors; peracetic acid precursors such as TAED, sodium acetoxybenzene sulfonate and pentaacetylglucose; pernonanoic acid precursors such as sodium 3,5,5-trimethylhexanoyloxybenzene sulfonate (iso-NOBS) and sodium nonanoyloxybenzene sulfonate (NOBS); amide substituted alkyl peroxyacid precursors (EP-A-0170386); and benzoxazin peroxyacid precursors (EP-A-0332294 and EP-A-0482807). Bleach precursors are typically incorporated at levels in the range from about 0.5% to about 25%, preferably from about 1% to about 10% by weight of composition while the preformed organic peroxyacids themselves are typically incorporated at levels in the range from 0.5% to 25% by weight, more preferably from 1% to 10% by weight of composition. Bleach catalysts preferred for use herein include the manganese triazacyclononane and related complexes (U.S. Pat. No. 4,246,612, U.S. Pat. No. 5,227,084); Co, Cu, Mn and Fe bispyridylamine and related complexes (U.S. Pat. No. 5,114,611); and pentamine acetate cobalt(III) and related complexes(U.S. Pat. No. 4,810,410).

Low Cloud Point Non-Ionic Surfactants and Suds Suppressers

The suds suppressers suitable for use herein include nonionic surfactants having a low cloud point. “Cloud point”, as used herein, is a well known property of nonionic surfactants which is the result of the surfactant becoming less soluble with increasing temperature, the temperature at which the appearance of a second phase is observable is referred to as the “cloud point” (See Kirk Othmer, pp. 360-362). As used herein, a “low cloud point” nonionic surfactant is defined as a nonionic surfactant system ingredient having a cloud point of less than 30° C., preferably less than about 20° C., and even more preferably less than about 10° C., and most preferably less than about 7.5° C. Typical low cloud point nonionic surfactants include nonionic alkoxylated surfactants, especially ethoxylates derived from primary alcohol, and polyoxypropylene/polyoxyethylene/polyoxypropylene (PO/EO/PO) reverse block polymers. Also, such low cloud point nonionic surfactants include, for example, ethoxylated-propoxylated alcohol (e.g., BASF Poly-Tergent® SLF18) and epoxy-capped poly(oxyalkylated) alcohols (e.g., BASF Poly-Tergent® SLF18B series of nonionics, as described, for example, in U.S. Pat. No. 5,576,281).

Preferred low cloud point surfactants are the ether-capped poly(oxyalkylated) suds suppresser having the formula:

wherein R ¹is a linear, alkyl hydrocarbon having an average of from about 7 to about 12 carbon atoms, R²is a linear, alkyl hydrocarbon of about 1 to about 4 carbon atoms, R³is a linear, alkyl hydrocarbon of about 1 to about 4 carbon atoms, x is an integer of about 1 to about 6, y is an integer of about 4 to about 15, and z is an integer of about 4 to about 25.

Other low cloud point nonionic surfactants are the ether-capped poly(oxyalkylated) having the formula:

R_IO(R_IIO)_nCH(CH₃)OR_III

wherein, R ₁is selected from the group consisting of linear or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic or aromatic hydrocarbon radicals having from about 7 to about 12 carbon atoms; R_IImay be the same or different, and is independently selected from the group consisting of branched or linear C₂to C₇alkylene in any given molecule; n is a number from 1 to about 30; and R_IIIis selected from the group consisting of:

(i) a 4 to 8 membered substituted, or unsubstituted heterocyclic ring containing from 1 to 3 hetero atoms; and

(ii) linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, aliphatic or aromatic hydrocarbon radicals having from about 1 to about 30 carbon atoms;

(b) provided that when R ²is (ii) then either: (A) at least one of R¹is other than C₂to C₃alkylene; or (B) R²has from 6 to 30 carbon atoms, and with the further proviso that when R²has from 8 to 18 carbon atoms, R is other than C₁to C₅alkyl.

Other suitable components herein include organic polymers having dispersant, anti-redeposition, soil release or other detergency properties invention in levels of from about 0.1% to about 30%, preferably from about 0.5% to about 15%, most preferably from about 1% to about 10% by weight of composition. Preferred anti-redeposition polymers herein include acrylic acid containing polymers such as Sokalan PA30, PA20, PA15, PA10 and Sokalan CP10 (BASF GmbH), Acusol 45N, 480N, 460N (Rohm and Haas), acrylic acid/maleic acid copolymers such as Sokalan CP5 and acrylic/methacrylic copolymers. Preferred soil release polymers herein include alkyl and hydroxyalkyl celluloses (U.S. Pat. No. 4,000,093), polyoxyethylenes, polyoxypropylenes and copolymers thereof, and nonionic and anionic polymers based on terephthalate esters of ethylene glycol, propylene glycol and mixtures thereof.

Heavy metal sequestrants and crystal growth inhibitors are suitable for use herein in levels generally from about 0.005% to about 20%, preferably from about 0.1% to about 10%, more preferably from about 0.25% to about 7.5% and most preferably from about 0.5% to about 5% by weight of composition, for example diethylenetriamine penta (methylene phosphonate), ethylenediamine tetra(methylene phosphonate) hexamethylenediamine tetra(methylene phosphonate), ethylene diphosphonate, hydroxy-ethylene-1,1-diphosphonate, nitrilotriacetate, ethylenediaminotetracetate, ethylenediamine-N,N′-disuccinate in their salt and free acid forms.

The compositions herein can contain a corrosion inhibitor such as organic silver coating agents in levels of from about 0.05% to about 10%, preferably from about 0.1% to about 5% by weight of composition (especially paraffins such as Winog 70 sold by Wintershall, Salzbergen, Germany), nitrogen-containing corrosion inhibitor compounds (for example benzotriazole and benzimadazole—see GB-A-1137741) and Mn(II) compounds, particularly Mn(II) salts of organic ligands in levels of from about 0.005% to about 5%, preferably from about 0.01% to about 1%, more preferably from about 0.02% to about 0.4% by weight of the composition.

Other suitable components herein include colorants, water-soluble bismuth compounds such as bismuth acetate and bismuth citrate at levels of from about 0.01% to about 5%, enzyme stabilizers such as calcium ion, boric acid, propylene glycol and chlorine bleach scavengers at levels of from about 0.01% to about 6%, lime soap dispersants (see WO-A-93/08877), suds suppressors (see WO-93/08876 and EP-A-0705324), polymeric dye transfer inhibiting agents, optical brighteners, perfumes, fillers and clay.

Liquid detergent compositions suitable for use in the pouches of the invention can also containe low quantities of low molecular weight primary or secondary alcohols such as methanol, ethanol, propanol and isopropanol. Other suitable carrier solvents used in low quantities includes glycerol, propylene glycol, ethylene glycol, 1,2-propanediol, sorbitol and mixtures thereof.

EXAMPLE 1

Monosol M8630 (76 μm thick), PVA film, supplied by Chris Craft Inc, Gary, Ind., USA, is used for making the pouch. The film is delivered to the mould and anchored by means of a belt. The mould comprises a hemi-spherical cavity cut with a spherical drill of 14.27 mm radius to a depth of 8.89 mm (as shown in FIG. 1). The film is drawn into the mould by means of vacuum. The vacuum is applied to the film in two stages. Initially a high vacuum of approximately 800 mbar is applied to the film to form the open pouch followed by the application of a low vacuum of approximately 300 mbar to hold the film in the cavity. The deformation of the film under these conditions is 28%. 1.9 ml of detergent product is dosed into the open pouch leaving 0.9 ml of head space. A second sheet is placed over the open pouch and sealed in two steps by means of two parallel seal bars (2 mm wide). The first step is performed by seal bars having a centre-to-centre pitch of 38 mm and the second step is performed by seal bars perpendicular to the bars of the first step and having a centre-to-centre pitch of 34 mm. [0065]

EXAMPLE 2

Example 1 is repeated with the addition of an anti-bowing step during the second sealing step. During this step a finger located between the seal bars pushes out some of the air in the head space before closing the pouch. This contributes to a further reduction of the volume of air entrapped into the pouch.[0066]

Claims

What is claimed is:

1. A vacuum-assisted process for making a fluid-containing water-soluble pouch comprising the steps of:

f) filling the open pouch with a volume of fluid to define an effective fluid surface area A_f;

g) closing and sealing the open pouch with a second sheet of film material along one or more sealing lines, the region bounded by the sealing lines having an area A_s; and

h) releasing the vacuum applied to the pouch;

wherein the volume of fluid relative to that of said cavity and the position of said sealing lines relative to said flange are such that A_fand A_sare in a ratio of from about 1:1.2: to about 1:5.

2. A process according to claim 1 wherein when said first sheet of said film material is maintained under tension according to step (b), said first sheet is subjected to a deformation of from about 20% to about 55%.

3. A process according to claim 1 wherein the dimensions of said first and said second sheet of said film material under static conditions differ less than about 10%.

4. A process according to claim 1 wherein said open pouch is filled to a height of about 2 mm below said flange of said mould.

5. A process according to claim 1 wherein said mould cavity has cylindrical geometry; and wherein the region defined by said sealing lines has a parallelepiped geometry.

6. A process according to claim 1 wherein the footprint of the resulting pouch is rectangular or square.

7. A process according to claim 1 wherein said pouch comprises a plurality of sealing lines; and wherein the sealing is performed by means of intermittent sealing.

8. A process according to claim 1 wherein said second sheet is subject to an anti-bowing step during the sealing of said pouch for purposes of reducing air entrainment.

9. A process according to claim 8 wherein said anti-bowing step is performed by one or more of the following means: air means or weight means.

10. A process according to claim 1 wherein said fluid is selected from the group consisting of a liquid, gel, paste, and combinations thereof.

11. A fluid-containing water-soluble pouch made according to claim 1.

12. A pouch according to claim 11 further comprising one of the following: a solid insert or a multitude of solid inserts.

13. A method of cleaning articles using a pouch made according to claim 11, wherein said method comprises the steps of:

a) providing said pouch; and

b) delivering said pouch to wash water.

14. A method according to claim 13, wherein said pouch is a multi-compartment pouch.

15. A method according to claim 13, wherein said wash water is from dishwashing processes.

16. A method according to claim 13, wherein after step (a) said method further comprises the step of placing said pouch in one or more of the following: the detergent dispenser or in the interior of an automatic dishwashing machine.

17. A method according to claim 13, wherein said wash water is from laundry processes.

18. A method according to claim 13, wherein after step (a) said method further comprises the step of placing said pouch in one or more of the following: the detergent dispenser or in the interior of a washing machine.

19. A horizontally-formed fluid-containing water-soluble pouch comprising a first and a second sheet sealed together and a base length to height ratio of from about 10:1 to about 2:1; wherein both sheets of said pouch are under tension; and wherein the volume of fluid and the volume of air contained in said pouch are in a ratio of from about 1.7:1 to about 8:1.

20. A horizontally-formed fluid-containing water-soluble pouch comprising a first and a second sheet sealed together and a base length to height ratio of from about 10:1 to about 2:1; wherein said pouch is formed by a process comprising the step of subjecting said second sheet to an anti-bowing step during the sealing of said pouch for purposes of reducing air entrainment; and wherein the volume of fluid and the volume of air contained in said pouch are in a ratio of from about 1.7:1 to about 8:1.