Fabric cleaning tablets and methods

Abstract

A method for washing fabrics is disclosed, comprising the successive steps of: (i) performing at least two pre-wash cycles, each of which comprises washing the fabrics with room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% of the water volume; (ii) washing the fabrics with a solution comprising water and detergent at 35°C-90°C for 50-90 minutes; and (iii) performing at least three post-wash cycles without detergent, each of which comprises washing the fabrics immersed in room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% of the water volume.

Description

[Technical field]

[0001] The present invention, in some embodiments thereof, relates to cleaning fabrics, and more particularly to tablets and methods for cleaning fabrics. [Background technology]

[0002] Laundry detergent in tablet form is widely used in many homes these days. The first laundry tablets were introduced to the market in the mid-1960s. The original tablets could not be completely dissolved in water, so new tablets with improved solubility were developed.

[0003] Laundry tablets contain a mixture of active and inactive materials such as soluble solids, water softeners, surfactants, laundry bleaches, enzymes, fragrances, and pigments. Additional ingredients may include "anti-redeposition agents" such as carboxymethylcellulose, which are used to prevent fine soil particles from redepositing on products being washed, and color transfer inhibitors (e.g., polar water-soluble polymers such as polyvinylpyrrolidone to which dyes preferentially bind) that prevent dyes from one article from staining other items.

[0004] Commercially available washing machines use detergent in tablets or other forms during the first and sometimes second wash cycles. Wash cycles may be carried out for 20 minutes to several hours at temperatures ranging from room temperature up to 90° C. At the end of each wash cycle, the washing machine performs multiple rinses (usually at least two) to remove most of the detergent, and then optionally spins the laundry to squeeze out the water.

[0005] One of the most difficult fabrics to clean is a soiled cloth diaper, which leads parents to prefer disposable diapers that pose a major environmental risk. An estimated 27.4 billion disposable diapers are used in the United States each year, resulting in 3.4 million tons of used diapers potentially being added to landfills each year. Discarded disposable diapers take approximately 450 years to decompose. Domestic washing machines cannot adequately wash diapers, especially those worn by older infants.

[0006] Therefore, there is a need for a new cleaning method for cleaning stubborn stains such as excrement, and a tablet that can efficiently remove stubborn stains. Summary of the Invention

[0007] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods that are intended to be exemplary and illustrative, not limiting in scope.

[0008] In one embodiment, a method for washing fabrics is provided comprising the following steps in succession: (a) performing at least two pre-wash cycles, where each pre-wash cycle comprises washing the fabrics with room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% of the water volume; (b) washing the fabric in a solution containing water and detergent at 35°C to 90°C for 50 to 90 minutes; and (c) performing at least three detergent-free post-wash cycles, each post-wash cycle comprising washing the fabrics immersed in room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% of the water volume.

[0009] In some embodiments, the step of performing at least two pre-wash cycles is performed with water without detergent. In some embodiments, the step of performing at least one pre-wash cycle of the at least two pre-wash cycles is performed with water containing detergent. In some embodiments, step (a) includes performing at least three pre-wash cycles. In some embodiments, the detergent has a tablet including a first layer and a second layer, the first layer including, by weight, at least 20% sodium carbonate; at least 10% first nonionic surfactant; at least 10% first anionic surfactant; at least 20% enzyme, the enzyme being selected from the group consisting of protease, amylase, lipase, cellulase, mannanase, or any combination thereof, and the second layer including, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% second anionic surfactant, and at least 5% second nonionic surfactant.

[0010] In some embodiments, the first anionic surfactant is the same as the second anionic surfactant. In some embodiments, the first nonionic surfactant is the same as the second nonionic surfactant. In some embodiments, the second layer is sandwiched between two first layers. In some embodiments, the first layer, the second layer, or both, comprises at least 2% by weight magnesium stearate. In some embodiments, the first layer, the second layer, or both, comprises at least 2% by weight microcrystalline cellulose. In some embodiments, the first layer, the second layer, or both, comprises at least one water softener.

[0011] Some embodiments of the present invention are directed to a tablet comprising a first layer and a second layer, the first layer comprising, by weight, at least 20% sodium carbonate; at least 10% a first nonionic surfactant; at least 10% a first anionic surfactant; at least 20% an enzyme, the enzyme selected from the group consisting of a protease, an amylase, a lipase, a cellulase, a mannanase, or any combination thereof, and the second layer comprising, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% a second anionic surfactant, and at least 5% a second nonionic surfactant.

[0012] In some embodiments, the first anionic surfactant is the same as the second anionic surfactant. In some embodiments, the first nonionic surfactant is the same as the second nonionic surfactant. In some embodiments, the second layer is sandwiched between two first layers. In some embodiments, the first layer, the second layer, or both, comprises at least 2% by weight magnesium stearate. In some embodiments, the first layer, the second layer, or both, comprises at least 2% by weight microcrystalline cellulose.

[0013] In some embodiments, the first layer, the second layer, or both, comprises a fragrance. In some embodiments, the first layer, the second layer, or both, comprises a pigment. In some embodiments, the enzyme is subtilisin.

[0014] In some embodiments, the disinfectant is sodium dichloroisocyanurate dihydrate. In some embodiments, the first layer, the second layer, or both, include at least one water softener. In some embodiments, the first layer includes at least 2% by weight of a first water softener. In some embodiments, the first layer includes at least 2% by weight of a second water softener different from the first water softener. In some embodiments, the second layer includes between 2 and 15% by weight of an optical brightener.

[0015] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by study of the following detailed description. [Brief description of the drawings]

[0016] Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. Specific reference will now be made to the detailed drawings, it being stressed that the particulars shown are by way of example and are for the purpose of illustrative discussion of embodiments of the invention. In this regard, the description together with the drawings will make apparent to those skilled in the art how embodiments of the invention may be practiced.

[0017] [Figure 1] 1 is a flow chart of a method for cleaning fabrics according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention is directed to a novel cleaning method for cleaning tough soils such as feces and to a tablet that can effectively remove tough soils. The novel method includes an additional short pre-wash cycle to soften and facilitate removal of tough soils, a long wash cycle with detergent to wash the fabrics, and at least three additional post-wash cycles to remove detergent and soils.

[0019] In some embodiments, the detergent is a multi-layer tablet comprising at least two layers, where the first layer completely dissolves after at most 30 minutes and the second layer completely dissolves after at most 70 minutes at 40°C. Cleaning Method

[0020] Reference is now made to FIG. 1, which is a flow chart of a method for washing fabrics, according to some embodiments of the present invention. The method of FIG. 1 may be performed by any commercially available washing machine having a processor reprogrammed to perform the method. Thus, the method may be executed by the processor of the washing machine. In step 110, at least two pre-wash cycles (e.g., two, three, four, five cycles, etc.) are performed, where each wash cycle includes washing the fabrics soaked in water for 3-10 minutes, and draining the water for 2-10 minutes, thereby draining at least 30% (e.g., at least 40%, 50%, 60%, 70%, or more) of the water volume.

[0021] The term "fabric" as used herein may refer to any woven or nonwoven fabric made from natural fibers, synthetic fibers, or a combination of both. For example, the fabric may be a reusable diaper. In some embodiments, the fabric may be soiled with persistent stains, such as fecal matter, mud, dried blood, and the like.

[0022] In some embodiments, each pre-wash cycle may last 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or more.

[0023] In some embodiments, at least two pre-wash cycles in step 110 are performed with water that does not contain detergent. In some embodiments, at least one wash cycle of the at least two pre-wash cycles in step 110 is performed with water that includes detergent. In some embodiments, the water is at room temperature. In some embodiments, at least one drain step may include spin-drying. In some embodiments, all drain steps include spin-drying. Thus, the draining results in at least 80% of the water volume being drained, e.g., 85%, 90%, 93%, 95%, or more.

[0024] In some embodiments, all pre-wash cycles are substantially identical, have substantially the same duration, and use substantially the same amount of water. Alternatively, the pre-wash cycles differ in at least one of the duration of wash, the amount of water, the use of detergent, the amount of water drained, and the addition of a spin-dry. In some embodiments, each wash cycle may consume 2 to 30 liters of water. 5±2, 10±2, 15±2, 20±2, 25±2, 30±2, 35±2, 40±2, or more.

[0025] In step 120, the fabrics may be washed in a solution comprising water and detergent at 35° C.-60° C. for 50-90 minutes. For example, the washing may be performed using a detergent tablet according to some embodiments of the present invention, or any other suitable detergent. In some embodiments, the washing may last for 50 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, or more.

[0026] In some embodiments, the cleaning solution may be heated to 35° C. In some embodiments, the cleaning solution may be heated to 40° C. In some embodiments, the cleaning solution may be heated to 45° C. In some embodiments, the cleaning solution may be heated to 50° C. In some embodiments, the cleaning solution may be heated to 55° C. In some embodiments, the cleaning solution may be heated to 60° C. In some embodiments, the cleaning solution may be heated to 70° C. In some embodiments, the cleaning solution may be heated to 80° C. In some embodiments, the cleaning solution may be heated to 90° C.

[0027] In some embodiments, one type of detergent (mono-detergent) may be used. In such cases, a powder, solution, or pod containing more than one powder or solution may be added and dissolved at one time.

[0028] In some embodiments, two different detergents, each with a different dissolution time, may be added to the water. For example, the first detergent may contain an enzyme (in addition to other active materials) and the second detergent may contain a disinfectant (e.g., chlorinated in addition to other active materials). As will be appreciated by those skilled in the art, the disinfectant may destroy the enzyme when added together. Thus, for both the enzyme and the disinfectant to function properly to break down soils, the detergent containing the enzyme must dissolve completely while only a portion (e.g., less than 40% by weight) of the detergent containing the disinfectant dissolves to limit the amount of disinfectant that can affect the enzyme. Thus, the first detergent may dissolve in less than 30 minutes and the second detergent may dissolve in less than 90 minutes.

[0029] Disinfectants as used herein may include any substance or composition used to inactivate or destroy microorganisms on inanimate objects. Disinfectants according to embodiments of the present invention are configured to inactivate or destroy microorganisms such as bacteria, fungi, and viruses on fabrics.

[0030] In some embodiments, the first detergent comprises, by weight, at least 20% sodium carbonate; at least 10% first nonionic surfactant; at least 10% first anionic surfactant; and at least 20% enzyme, the enzyme being selected from the group consisting of protease, amylase, lipase, cellulase, mannanase, or any combination thereof. In some embodiments, the second detergent comprises, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% second anionic surfactant, and at least 5% second nonionic surfactant.

[0031] In step 130, at least three detergent-free post-wash cycles may be performed, each detergent-free post-wash cycle including washing fabrics soaked in room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% (e.g., at least 40%, 50%, 60%, 70%, or more) of the water volume.

[0032] In some embodiments, at least one drainage step may include centrifugal dewatering. In some embodiments, all drainage steps may include centrifugal dewatering. Thus, drainage removes at least 80%, e.g., 85%, 90%, 92%, 95%, or more, of the water volume. tablet

[0033] The tablet according to the embodiment of the present invention may include a first layer and a second layer. In some embodiments, the first layer may include an enzyme, and the second layer may include a disinfectant. As will be apparent to those skilled in the art, the inclusion of both an enzyme and a disinfectant (e.g., chlorinated) in a mono-detergent may result in the enzyme being destroyed by the disinfectant. Thus, each of the layers of the tablet according to the embodiment of the present invention may have a different dissolution time. In some embodiments, the first layer containing the enzyme may dissolve in less than 30 minutes, and the second layer containing the disinfectant may dissolve in less than 90 minutes. Thus, the layer containing the enzyme is completely dissolved when only a portion (e.g., less than 40% by weight) of the layer containing the disinfectant is dissolved. The amount of disinfectant that can affect the enzyme is limited.

[0034] In some embodiments, the tablet may include more than two layers, whereby the second layer is sandwiched between two first layers. In a non-limiting example, the size of the tablet may be 40×40×17 mm. In some embodiments, the weight ratio of the first layer to the second layer is between 2 and 0.3. For example, the weight ratio of the first layer to the second layer is 1.7, 1.6, 1.5, 1.2, 1.1, 1, 0.9, 0.8, 0.7, 0.6, and 0.5.

[0035] In some embodiments, the total weight of the tablet may be between 20 and 40 grams. For example, the total weight of the tablet may be 24 grams, 26 grams, 28 grams, 30 grams, 32 grams, 35 grams, and 38 grams. In some embodiments, the total weight of the tablet may be greater than 40 grams.

[0036] In some embodiments, the first layer is configured to completely dissolve in water after at most 30 minutes, e.g., at most 25 minutes, 20 minutes, 15 minutes, or less, hi some embodiments, the second layer is configured to completely dissolve in water after at most 70 minutes, e.g., at most 65 minutes, 60 minutes, 50 minutes, 45 minutes, 40 minutes, or less.

[0037] In some embodiments, the first layer comprises, by weight, at least 20% sodium carbonate; at least 10% first nonionic surfactant; at least 10% first anionic surfactant; and at least 20% enzyme, wherein the enzyme is selected from the group consisting of protease, amylase, lipase, cellulase, mannanase, or any combination thereof. In some embodiments, the second layer comprises, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% second anionic surfactant, and at least 5% second nonionic surfactant.

[0038] In some embodiments, the first anionic surfactant is the same as the second anionic surfactant. In some embodiments, the first nonionic surfactant is the same as the second nonionic surfactant.

[0039] In some embodiments, the first layer may comprise at least 5% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 7% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 8% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 10% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 12% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 13% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 14% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 15% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 17% by weight of the first anionic surfactant.

[0040] In some embodiments, the first layer may comprise at least 8% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 10% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 12% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 15% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 17% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 20% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 21% by weight of the first anionic surfactant. In some embodiments, the first layer may comprise at least 22% by weight of the first nonionic surfactant. In some embodiments, the first layer may comprise at least 25% by weight of the first non-ionic surfactant.

[0041] In some embodiments, the second layer may comprise at least 5% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 7% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 8% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 10% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 12% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 13% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 14% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 15% by weight of the second anionic surfactant. In some embodiments, the second layer may comprise at least 17% by weight of the second anionic surfactant.

[0042] In some embodiments, the second layer may comprise at least 5% by weight of the first non-ionic surfactant. In some embodiments, the second layer may comprise at least 10% by weight of the second non-ionic surfactant. In some embodiments, the second layer may comprise at least 12% by weight of the second non-ionic surfactant. In some embodiments, the second layer may comprise at least 15% by weight of the second non-ionic surfactant. In some embodiments, the second layer may comprise at least 17% by weight of the second non-ionic surfactant. In some embodiments, the second layer may comprise at least 20% by weight of the second non-ionic surfactant.

[0043] The term "anionic surfactant" refers to any surfactant that contains anionic functional groups, including sulfates, sulfonates, phosphates, and carboxylates.

[0044] In some embodiments, the anionic surfactant of the present invention is or includes alkyl benzene sulfonates, alcohol ether sulfates, secondary alkane sulfonates, and alkyl sulfates, as well as any combinations and / or any salts thereof.

[0045] In some embodiments, the anionic surfactant of the present invention is or includes alkyl benzene sulfonic acid (e.g., linear (C5-C20) alkyl benzene sulfonic acid such as sodium dodecyl benzene sulfonate), ammonium lauryl sulfate, sodium lauryl sulfate, or (sodium dodecyl sulfate, SDS), sodium laureth sulfate (sodium lauryl ether sulfate, or SLES), sodium myreth sulfate, dioctyl sodium sulfosuccinate (docusate), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid, alkyl-aryl ether phosphate, alkyl ether phosphate, sodium stearate, sodium lauryl sarcosinate, perfluorononanoic acid, and perfluorooctanoic acid (PFOA or PFO), as well as any salts thereof. In some embodiments, the anionic surfactant is SDS.

[0046] The term "nonionic surfactant" refers to any surfactant that has a covalently bonded oxygen-containing hydrophilic group attached to a hydrophobic philic structure.

[0047] In some embodiments, the surfactant of the present invention is or comprises a non-ionic surfactant. In some embodiments, the non-ionic surfactant of the present invention is or comprises an alkoxylated fatty acid, a glucosyl dialkyl ether, a polysorbate, a span, a tween, a polyether, a polyol, a polysaccharide, a polypeptide, a polyester, a polyvinyl acetate, a polyacrylamide, and a polyacrylate, as well as any mixture or copolymer thereof. Other non-ionic surfactants are well known in the art. In some embodiments, the non-ionic surfactant of the present invention comprises a polymeric surfactant (e.g., a dispersant). Many dispersants are well known in the art. In some embodiments, the alkoxylated fatty acid comprises an ethoxylated castor oil.

[0048] In some embodiments, nonionic surfactants of the present invention include polymeric surfactants including polyethers, polyols (e.g., polyvinyl alcohol or PVA), polysaccharides (e.g., cellulose, alkylated cellulose, or any other cellulose derivative), polypeptides, polyesters, polyvinyl acetates, polyacrylamides, and polyacrylates, as well as any mixtures or copolymers thereof.

[0049] Non-limiting examples of non-ionic surfactants include, but are not limited to, polysorbates (e.g., polysorbate 20, 40, 60, and 80), ethoxylated castor oil, narrow range ethoxylates, octaethylene glycol monododecyl ether, pentaethylene glycol monododecyl ether, nonoxynol, Triton X-100, polyethoxylated tallowamine, cocamide monoethanolamine, cocamide diethanolamine, poloxamers, glycerol monostearate, glycerol monolaurate, sorbitan monolaurate, sorbitan monostearate, sorbitan tristearate, decyl glucoside, lauryl glucoside, octyl glucoside, lauryl dimethylamine oxide, dimethyl sulfoxide, phosphine oxide, and others. In some embodiments, the non-ionic surfactant is polysorbate 20.

[0050] In some embodiments, the surfactants of the present invention include polyethers. In some embodiments, the polyethers include aliphatic polyglycols, also used herein as polyalkoxylates. In some embodiments, the polyethers include polyethylene glycols (PEGs), alkylated PEGs, polypropylene glycols (PPGs), alkylated PPGs, branched PEGs, branched PPGs, polytetramethylene ether glycols, amino-modified polypropylene glycols, and ester-modified polypropylene glycols, or any copolymers including PPG and PEG blocks. Other polyethers include modified C5-C18 fatty alcohol ethoxylates, C10-C18 oxoalcohol ethoxylates, Cl6-C18 unsaturated fatty alcohol ethoxylates, sorbitan ester ethoxylates, castor oil ethoxylates, or any combination thereof, among others. Exemplary polyalkoxylate-based surfactants are well known in the art and include Agnique®, Disponil®, Emulan®, Eumulgin®, Lutensol®, Synperonic®, among others.

[0051] In some embodiments, the surfactants of the present invention comprise a polyol. In some embodiments, the polyol comprises a polyalkyl backbone comprising a plurality of hydroxy groups and, optionally, carboxy groups and / or C1-C10 carboxylate groups attached thereto. In some embodiments, the polyol or polyalcohol is at least partially derived from a polysaccharide (e.g., by deesterification). In some embodiments, the polyol comprises an at least partially deesterified or hydrolyzed polysaccharide.

[0052] In some embodiments, the polyol is a polyester polyol selected from a polyester polyol composition such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, and azelaic acid; a polyol composition such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, tripropylene glycol, trimethylolpropane, and glycerol. and polylactone polyester polyols such as polycaprolactone polyols and (poly)p-methyl-α-valerolactone), polyolefin-based polyols (e.g., (poly)hydroxypolymers), polyol xylene resins, polybutadiene-based polyols (e.g., polyols comprised of homopolymers having a polybutadiene backbone (1,2-adducts and 1,4-adducts); polyols comprised of polybutadiene copolymers copolymerized with butadiene, and styrene, and acrylonitrile; and hydrogenated analogs thereof), polyether polyols, acrylic polyols, and castor oil derivatives (e.g., refined castor oil, dehydrated castor oil, polymerized dehydrated castor oil, and castor oil polyols).

[0053] In some embodiments, the surfactant of the present invention comprises PVA (e.g., a polymeric resin comprising water-soluble PVA, PVA, or any copolymer of PVA). In some embodiments, the surfactant of the present invention comprises PVA, where the PVA is derived from polyacetate. In some embodiments, the surfactant of the present invention comprises at least partially deesterified or hydrolyzed polyacetate. In some embodiments, the PVA of the present invention comprises between 70 and 90% by weight, between 70 and 75% by weight, between 75 and 80% by weight, between 80 and 85% by weight, between 85 and 90% by weight, between 90 and 95% by weight, between 95 and 99% by weight of deesterified or hydrolyzed polyvinyl acetate. Exemplary PVA polymeric surfactants include, but are not limited to, Poval 4-88 (registered trademark), Poval 5-88 (registered trademark), Poval 6-88 (registered trademark), Poval 8-88 (registered trademark), as well as any mixture thereof.

[0054] In some embodiments, the surfactant of the present invention is or includes a polymeric surfactant (e.g., PVA), where the weight average molecular weight of the polymeric surfactant is from 10,000 to 250,000, 10,000 to 250,000, 10,000 to 20,000, 20,000 to 30,000, 30,000 to 40,000, 40,000 to 50,000, 50,000 to 60,000, 60,000 to 70,000, 70,000 to 80,000, 80,000 to 90,000, 90,000 to 100,000, 100,000 to 150,000, 150,000 to 200,000, 200,000 to 250,000, as well as any range or value therebetween.

[0055] In some embodiments, the surfactant of the present invention is or includes a PVA derived from polyvinyl acetate having a polymeric surfactant weight average molecular weight of 10,000 to 250,000, as well as any range or value therebetween, in some embodiments, the surfactant of the present invention is or includes multiple PVA polymers having different molecular weights and / or degrees of deesterification (e.g., between 70 and 90%, as well as any range therebetween).

[0056] In a non-limiting example, the enzyme is subtilisin.

[0057] In a non-limiting example, the disinfectant may include a chlorine containing salt, such as sodium dichloroisocyanurate dihydrate. Additional optional chlorine containing salts may include sodium hypochlorite, trichloroisocyanuric acid.

[0058] In some embodiments, the first layer, the second layer, or both, comprise at least 2% magnesium stearate by weight of the total weight of the respective layer. For example, the second layer and / or the first layer may comprise 4% magnesium stearate, 5% magnesium stearate, 6% magnesium stearate, 7% magnesium stearate, 8% magnesium stearate, or more by weight.

[0059] In some embodiments, the first layer, the second layer, or both, comprise at least 2% by weight of microcrystalline cellulose based on the total weight of the respective layer. For example, the first layer may comprise 5% by weight of microcrystalline cellulose, 8% by weight of microcrystalline cellulose, 10% by weight of microcrystalline cellulose, 15% by weight of microcrystalline cellulose, 20% by weight of microcrystalline cellulose, 22% by weight of microcrystalline cellulose, 25% by weight of microcrystalline cellulose, 28% by weight of microcrystalline cellulose, 30% by weight of microcrystalline cellulose, and 32% by weight of microcrystalline cellulose.

[0060] In some embodiments, the first layer, the second layer, or both, include a fragrance. In some embodiments, the first layer, the second layer, or both, include a pigment.

[0061] In some embodiments, the second layer comprises between 2 and 15% by weight ethylenediaminetetraacetic acid.

[0062] In some embodiments, the first layer, the second layer, or both, include at least one water softener. In some embodiments, the first layer includes at least 2% by weight, e.g., 2.2%, 2.4%, 2.5%, 2.7%, 3%, 3.2%, 3.4%, 3.5%, 4% or more of the first water softener by weight. In some embodiments, the first layer further includes at least 2.5% by weight, e.g., 2.5%, 2.7%, 3%, 3.2%, 3.4%, 3.5%, 4% or more of a second water softener different from the first water softener by weight. In a non-limiting example, the first water softener is a polyphosphonic acid sodium salt. In another non-limiting example, the second water softener is a polyacrylic acid, sodium salt. Other possible water softeners may be selected from sodium tripolyphosphate, potassium diphosphate, diethyl ester dimethyl ammonium chloride, and the like.

[0063] In some embodiments, the first layer, the second layer, or both, include at least one anti-redeposition agent, such as carboxymethylcellulose. For example, each layer may include at least 2% by weight, such as 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3% by weight, or more, of carboxymethylcellulose.

[0064] In some embodiments, the second layer comprises between 0.1 and 0.5 wt % of an optical brightener. For example, the optical brightener may be benzenesulfonic acid 2,2'-([1,1'-biphenyl]-4,4'-diyldi-2,1-ethenediyl)bis-disodium salt.

[0065] In some embodiments, the tablet may be made using any known method. For example, the ingredients of a first layer may be mixed together to form a first mixture, and the ingredients of a second layer may be mixed together to form a second mixture. The first mixture may be poured into a mold and compressed, and the second mixture may be poured onto the first mixture in the mold and compressed. The tablet may be dried to add additional strength.

[0066] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples.

[0067] Table 1 includes the composition of tablets according to some embodiments of the present invention. The tablets include two layers, the first layer weighing 16 grams and the second layer weighing 12 grams.

[0068] Table 1 28g tablet [Table 1] [Table 2]

[0069] Table 2 includes the composition of another tablet according to some embodiments of the present invention. This tablet includes three layers, with the two outer first layers each weighing 7 grams and the center second layer weighing 14 grams. [Table 3] [Table 4]

[0070] While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

Claims

1. 1. A method for cleaning fabrics comprising the following successive steps: (d) performing at least two pre-wash cycles, where each pre-wash cycle comprises washing said fabrics with room temperature water for 3-10 minutes and draining said water for 2-10 minutes, thereby draining at least 30% of the water volume; (e) washing the fabric in a solution containing water and detergent for 50-90 minutes at 35°C to 90°C; and (f) performing at least three detergent-free post-wash cycles, each post-wash cycle comprising washing the fabrics immersed in room temperature water for 3-10 minutes and draining the water for 2-10 minutes, thereby draining at least 30% of the water volume; A method comprising:

2. The method of claim 1 , wherein the step of performing at least two pre-wash cycles is performed with detergent-free water.

3. The method of claim 1 , wherein the step of performing at least one pre-wash cycle of the at least two pre-wash cycles is performed with water containing a detergent.

4. 4. The method of claim 1, wherein step (a) comprises performing at least three pre-wash cycles.

5. The detergent comprises a tablet including a first layer and a second layer; the first layer comprises, by weight, at least 20% by weight of sodium carbonate; at least 10% by weight of a first nonionic surfactant; at least 10% by weight of a first anionic surfactant; at least 20% by weight of an enzyme, the enzyme being selected from the group consisting of a protease, an amylase, a lipase, a cellulase, a mannanase, or any combination thereof; 10. The method of claim 1, wherein the second layer comprises, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% second anionic surfactant, and at least 5% second nonionic surfactant.

6. The method of claim 5 , wherein the first anionic surfactant is the same as the second anionic surfactant.

7. The method of claim 5 , wherein the first non-ionic surfactant is the same as the second non-ionic surfactant.

8. The method of claim 5 , wherein the second layer is sandwiched between two first layers.

9. The method of claim 5 , wherein the first layer, the second layer, or both, comprise at least 2% by weight magnesium stearate.

10. The method of claim 5 , wherein the first layer, the second layer, or both, comprise at least 2% by weight microcrystalline cellulose.

11. 11. The method of any one of claims 5 to 10, wherein the first layer, the second layer, or both, comprise at least one water softener.

12. 1. A tablet comprising a first layer and a second layer, the first layer comprises, by weight, at least 20% by weight of sodium carbonate; at least 10% by weight of a first nonionic surfactant; at least 10% by weight of a first anionic surfactant; at least 20% by weight of an enzyme, the enzyme being selected from the group consisting of a protease, an amylase, a lipase, a cellulase, a mannanase, or any combination thereof; The tablet wherein the second layer comprises, by weight, at least 30% sodium carbonate, at least 15% disinfectant, at least 5% second anionic surfactant, and at least 5% second nonionic surfactant.

13. 13. The tablet of claim 12, wherein the first anionic surfactant is the same as the second anionic surfactant.

14. 13. The tablet of claim 12, wherein the first non-ionic surfactant is the same as the second non-ionic surfactant.

15. 13. The tablet of claim 12, wherein the second layer is sandwiched between two first layers.

16. 13. The tablet of claim 12, wherein the first layer, the second layer, or both, comprise at least 2% by weight of magnesium stearate.

17. 13. The tablet of claim 12, wherein the first layer, the second layer, or both, comprise at least 2% by weight of microcrystalline cellulose.

18. 13. The tablet of claim 12, wherein the first layer, the second layer, or both, comprise a flavoring.

19. 13. The tablet of claim 12, wherein the first layer, the second layer, or both, comprise a pigment.

20. 13. The tablet of claim 12, wherein the enzyme is subtilisin.

21. 13. The tablet of claim 12, wherein the disinfectant is sodium dichloroisocyanurate dihydrate.

22. 13. The tablet of claim 12, wherein the first layer, the second layer, or both, include at least one water softener.

23. 23. The tablet of claim 22, wherein the first layer comprises, by weight, at least 2% of a first water softening agent.

24. 24. The tablet of claim 23, wherein the first layer comprises at least 2% by weight of a second water softener different from the first water softener.

25. A tablet according to any one of claims 12 to 24, wherein the second layer comprises between 2 and 15% by weight of optical brightener.

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