How to wash fabrics

Abstract

The present invention relates to a method of laundering fabrics, the method comprising the steps of: (a) calculating a final amount of water to be added to a final wash bath; (b) calculating the amount of energy required to heat the final amount of water to a desired final temperature; (c) contacting an amount of water less than the final amount with fabrics to form an intermediate wash bath, wherein a detergent composition contacts the fabrics during or prior to the formation of the intermediate wash bath; (d) heating the water that contacts the fabrics during step (c) with the energy calculated in step (b) so that the intermediate wash bath has a temperature above the desired final temperature; (e) washing the fabrics in the intermediate wash bath for at least 3 minutes; (f) contacting the remaining amount of water with the intermediate wash bath to form a final wash bath having the desired final temperature; (g) washing the fabrics in the final wash bath for at least 5 minutes; and (h) rinsing the fabrics.

Description

[Technical Field]

[0001] The present invention provides a method for laundering fabrics that improves the efficiency of the laundering process and is particularly useful for laundering processes designed for economical wash cycles. [Background technology]

[0002] The trend in fabric washing is moving towards shorter cycles and cooler cycles to reduce energy use and deliver improved fabric care. The present invention provides a method for washing fabrics that improves cleaning performance when compared to existing cycles that use the same water and energy sources. The present invention is particularly useful for improving performance in economical wash cycles, such as those with wash temperatures below 30°C, where cleaning performance of solid fatty soils and other temperature-sensitive soils with melting points above 30°C is lagging.

[0003] In the present invention, the intermediate wash step in the main wash subjects fabrics to an initial reduced amount of water, so that the same amount of chemicals and heat energy delivered in a standard cycle can be concentrated in this intermediate wash step, resulting in higher concentrations of chemicals and higher temperatures, e.g., wash temperatures above the melting points of solid greasy soils.

[0004] Most washing machines feature an outer tub that contains water and an inner rotating drum where fabrics are washed. There is typically a space between the inner rotating drum and the outer tub to allow for suspended motion of the rotating drum. Washers often incorporate cold water intake and a water heater located within the outer tub below the rotating inner drum, resulting in no direct contact between the heating element and the fabrics. An initial charge of 2 to 5 kg of water typically covers the heating element so that heating begins as quickly as possible. The space between the outer tub and the bottom of the rotating inner drum is called the sump, and the mass of water in that space is called the sump water mass. Other washing machines have both cold and hot water inlets, allowing temperature control via the mixing of the two water inlets. A standard washing machine cycle typically follows these steps: (i) Water begins filling the washer, first filling the sump water volume and then immersing the fabrics; (ii) the detergent is dispensed either from a drawer by filling with water, or from a dosing device in an internal drum, or in soluble unit doses; (iii) rotating the drum to ensure that the fabric absorbs the added water; (iv) Water holds the fill until the fabric is saturated with water, and there is some additional free water on top of the water sump mass and water absorbed on the fabric (this additional free water is often measured via a pressure sensor); (v) The filling process can be in several stages: water stops, the drum rotates for water absorption, water fills again, etc. until the required free water is measured. Summary of the Invention [Means for solving the problem]

[0005] The present invention provides a method for laundering fabrics, comprising: (a) calculating the final amount of water to be added to the final cleaning bath; (b) calculating the amount of energy required to heat this final volume of water to the desired final temperature; (c) contacting a volume of water less than the final volume with fabrics to form an intermediate wash bath, wherein the detergent composition contacts the fabrics during or prior to forming the intermediate wash bath; (d) heating the water that contacts the fabrics during step (c) with the energy calculated in step (b) so that the intermediate wash bath has a temperature above the desired final temperature; (e) washing the fabric in the intermediate wash bath for at least 3 minutes; (f) contacting the remaining amount of water with the intermediate cleaning bath to form a final cleaning bath having a desired final temperature; (g) washing the fabric in a final wash bath for at least 5 minutes; (h) rinsing the fabric. DETAILED DESCRIPTION OF THE INVENTION

[0006] How to wash fabrics. How to wash fabrics. (a) calculating the final amount of water to be added to the final cleaning bath; (b) calculating the amount of energy required to heat this final volume of water to the desired final temperature; (c) A volume of water (m) less than the final volume to form an intermediate cleaning bath. Water,int ) with fabrics, wherein the detergent composition contacts the fabrics during or prior to the formation of an intermediate wash bath; (d) The temperature at which the intermediate cleaning bath exceeds the desired final temperature (T int heating the water that contacts the fabric during step (c) with the energy calculated in step (b) so as to have (e) washing the fabric in the intermediate wash bath for at least 3 minutes; (f) contacting the remaining amount of water with the intermediate cleaning bath to form a final cleaning bath having a desired final temperature; (g) washing the fabric in a final wash bath for at least 5 minutes; (h) rinsing the fabric.

[0007] Preferably, the ratio of the washing time in step (e) to the washing time in step (g) is within the range of 1:2 to 1:20.

[0008] Preferably, the temperature profile of the method is such that the desired final temperature is at or below 30° C., with intermediate wash bath temperatures above 37° C. Typical fats, and their melting points, are: extracorporeal sebum (T Melting =33~36℃), butter (T Melting =32~35℃), lard (T Melting = 34-41°C). At a temperature of 30°C, standard wash cycle operation results in low removal of all these fats. However, above 37°C, most of these fats melt and accelerate the removal process via surfactants and mechanical action.

[0009] The method of the present invention is also suitable for sequential release of chemicals. For example, chemicals that are incompatible or that benefit from high temperature and concentration (e.g., surfactants and kinetic technologies such as enzymes and bleaches) can be administered sequentially, for example, one chemical in the middle wash bath and another chemical in the final wash bath. In this manner, the method of the present invention can allow the incorporation of incompatible chemicals into the detergent composition.

[0010] An example of a useful sequential dosing profile is when bleach contacts the fabrics after step (e), such that the intermediate wash baths do not contain bleach, but the final wash bath contains bleach. This sequential dosing profile may allow for the incorporation of ingredients that are immiscible with bleach into the intermediate wash bath. Such ingredients that are immiscible with bleach may include enzymes.

[0011] Typically, the concentration of detergent chemicals present in the intermediate wash bath is higher than the concentration of detergent chemicals present in the final wash bath. However, some detergent ingredients can be added later in the process so that they are not present in the intermediate wash bath. In this extreme case, the concentration of detergent chemicals present in the intermediate wash bath may be the same as or lower than the concentration of detergent chemicals present in the final wash bath.

[0012] Typically, the method is carried out in an automatic washing machine. The water can be heated in the sump of the automatic washing machine, at the water inlet of the automatic washing machine, or external to the automatic washing machine.

[0013] Step (a) Calculate the final volume of water to be added to the final wash bath. Step (a) calculates the final volume of water to be added to the final wash bath.

[0014] Typically, during step (a), the weight of the fabrics to be washed during the method is determined and this fabric weight is used when calculating the final amount of water to be added to the final wash bath. Typically, step (a) can be calculated by:

[0015]

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[0016] Step (b) calculates the amount of energy required to heat this final volume of water to the desired final temperature. Step (b) calculates the amount of energy required to heat this final volume of water to the desired final temperature. Typically, step (b) can be calculated by:

[0017]

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[0018] Step (c) Forming an intermediate cleaning bath. Step (c) is to form an intermediate cleaning bath by adding a water amount m less than the final water amount. Water,int is contacted with the fabrics, and the detergent composition is contacted with the fabrics during or prior to the formation of the intermediate wash bath.

[0019] The amount of water is typically controlled to ensure adequate water absorption of the fabric during the intermediate wash step. Typically, the amount of water that contacts the fabric in step (c) to form the intermediate wash liquor is that amount that provides a moisture content of 0.5 kg to 3.5 kg of water per kg of fabric.

[0020] It may be preferable to determine the type of fabric to be washed during the method and take this fabric type into consideration when determining the amount of water to contact the fabric in step (c). In this manner, it may be preferable to form the intermediate wash so that (a) when the fabric type is primarily cotton, the water content is 0.7 kg to 3.5 kg of water per kilogram of fabric, preferably 1 kg to 3 kg of water per kilogram of fabric, and most preferably 1.5 kg to 2.5 kg of water per kilogram of fabric; and (b) when the fabric type is primarily polyester, the water content is 0.5 kg to 2.5 kg of water per kilogram of fabric, preferably 0.8 kg to 2 kg of water per kilogram of fabric, and most preferably 1.1 kg to 1.75 kg of water per kilogram of fabric. The fabric type can be determined by the wash cycle programmed by the automatic washing machine.

[0021] Typically, the amount of water that contacts the fabrics in step (c) to form the intermediate wash bath is in the range of 5 v / v% to 70 v / v% of the total amount of water calculated in step (a), depending on the type of washing machine. In front-loading automatic washing machines, when water is added directly to the fabrics or to an outer tub of the washing machine and then recycled onto the fabrics, it is in the range of 25 v / v% to 50 v / v% of the total amount of water calculated in step (a), or in the range of 40 v / v% to 70 v / v% of the total amount of water calculated in step (a) when water is added to an outer tub. In top-loading automatic washing machines, this amount of water is typically in the range of m Water,int is still calculated using the previous method, while the total water volume is much less than what could rise to a maximum of 60-70 liters. Therefore, the water volume is typically within the range of 5 v / v% to 30 v / v% of the total water volume calculated in step (a) when water is added directly onto the fabrics or added to the outer tub of the washing machine and then recycled onto the fabrics, or within the range of 10 v / v% to 40 v / v% of the total water volume calculated in step (a) when water is added to the outer tub.

[0022] Step (d) heating the intermediate cleaning bath. Step (d) is performed by heating the intermediate cleaning bath to a temperature T above the desired final temperature. int The water that contacts the fabric during step (c) is heated with the energy calculated in step (b) so as to have:

[0023]

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[0024] Step (e) Intermediate Wash Step: Step (e) involves washing the fabric in an intermediate wash bath for at least 3 minutes. Typically, no additional water is added during this step.

[0025] Typically, the intermediate washing step (e) is carried out under agitation conditions.

[0026] Step (f) Forming a Final Wash Bath Step (f) involves contacting the remaining amount of water with the intermediate wash bath to form a final wash bath having a desired final temperature.

[0027] Step (g) Washing Step: Step (g) involves washing the fabric in a final wash bath for at least 5 minutes.

[0028] Step (h) Rinse Step: In step (h), the fabric is rinsed.

[0029] Intermediate cleaning bath. Typically, the intermediate cleaning bath contains a detersive surfactant having a total concentration of 500 ppm to 4000 ppm, more preferably 1000 ppm to 3000 ppm, an amylase enzyme having a concentration of 0.1 ppm to 0.8 ppm, more preferably 0.2 to 0.6 ppm, a protease enzyme having a concentration of 1 ppm to 7 ppm, more preferably 2 to 5 ppm, a lipase enzyme having a concentration of 0.2 ppm to 2 ppm, more preferably 0.4 ppm to 1.2 ppm, and a chelating agent having a concentration of 15 ppm to 100 ppm, more preferably 25 ppm to 70 ppm.

[0030] The intermediate washing bath typically contains all of the detergent components present in the detergent composition.However, this method is also suitable for sequential dosing of detergent components.In this way, if desired, it is possible to ensure that the intermediate washing bath does not contain certain detergent components.An example of this is when the intermediate washing bath does not contain bleach.

[0031] Final Wash Bath: The final wash bath typically contains all of the detergent components of the detergent composition. The final wash bath may contain bleach.

[0032] Detergent compositions may typically contain one or more detersive surfactants, including, but not limited to, anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, and combinations thereof.

[0033] Useful anionic surfactants can themselves be of several different types. For example, water-soluble salts of higher fatty acids, i.e., "soaps," are useful anionic surfactants. These include alkali metal soaps, such as the sodium, potassium, ammonium, and alkylammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, preferably from about 12 to about 18 carbon atoms. Soaps can be made by direct saponification of fats and oils or by neutralization of free fatty acids. Particularly useful are the sodium and potassium salts of mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap. Additional non-soap anionic surfactants suitable for use herein include the water-soluble salts, preferably alkali metal and ammonium salts, of organosulfur reaction products having an alkyl group (the term "alkyl" includes the alkyl portion of an acyl group) containing from about 10 to about 20 carbon atoms in its molecular structure and a sulfonic acid or sulfate ester group. Examples of this group of synthetic anionic surfactants include, but are not limited to, a) sodium, potassium, and ammonium alkyl sulfates with either straight or branched carbon chains, especially alkyl sulfates of higher alcohols (C), such as those produced by reducing glycerides of tallow or coconut oil; 10 ~C 20carbon atoms), b) sodium, potassium and ammonium alkylethoxysulfates, particularly those in which the alkyl group contains from about 10 to about 20, preferably from about 12 to about 18, carbon atoms, and the ethoxylated chain has an average degree of ethoxylation ranging from about 0.1 to about 5, preferably from about 0.3 to about 4, more preferably from about 0.5 to about 3; c) sodium and potassium alkylethoxysulfates, particularly those in which the alkyl group contains from about 10 to about 20 carbon atoms in either a linear or branched carbon chain structure, preferably a linear carbon chain structure. benzenesulfonate, d) sodium, potassium, and ammonium alkyl sulfonates, in which the alkyl group contains from about 10 to about 20 carbon atoms in either a linear or branched configuration, e) sodium, potassium, and ammonium alkyl phosphates or phosphonates, in which the alkyl group contains from about 10 to about 20 carbon atoms in either a linear or branched configuration, and f) sodium, potassium, and ammonium alkyl carboxylates, in which the alkyl group contains from about 10 to about 20 carbon atoms in either a linear or branched configuration, and combinations thereof. Particularly preferred for the practice of the present invention are C 10 ~C 20 Linear alkyl benzene sulphonate (LAS) and C 10 ~C 20 Surfactant systems containing linear or branched non-alkoxylated alkyl sulfates (AS). Preferred for the practice of the present invention are LAS surfactants, as described above.

[0034] The composition may comprise one or more C ethoxylates having an average degree of ethoxylation ranging from about 0.1 to about 5, preferably from about 0.3 to about 4, and more preferably from about 0.5 to about 3. 10 ~C 20A linear or branched alkylalkoxylated sulfate (AAS) may also be included. Such AAS surfactants may be present in the final cleaning bath in an amount ranging from about 0 ppm to about 1000 ppm, preferably from about 0 ppm to about 500 ppm, and more preferably from about 0 ppm to about 300 ppm.

[0035] Additionally, the composition may comprise a non-ionic surfactant. Preferred non-ionic surfactants are those of formula R 1 (OC2H4) n OH, wherein R 1 is C 10 ~C 20 alkyl or alkylphenyl group, n being from about 1 to about 80. Particularly preferred are C 10 ~C 20 It is an alkylalkoxylated alcohol (AA).

[0036] Other surfactants useful herein include amphoteric surfactants and cationic surfactants, which are well known for use in laundry detergents.

[0037] The compositions may also contain one or more adjunct ingredients commonly used to formulate laundry detergent compositions, such as detersive surfactants, such as anionic detersive surfactants, nonionic detersive surfactants, cationic detersive surfactants, zwitterionic detersive surfactants, and amphoteric detersive surfactants. The detergent ingredients include polymers such as carboxylate polymers, soil release polymers, anti-redeposition polymers, cellulosic polymers, and care polymers; bleaching agents such as hydrogen peroxide sources, bleach activators, bleach catalysts, and pre-formed peracids; photobleaches such as zinc and / or aluminum sulfonated phthalocyanines; enzymes such as proteases, amylases, cellulases, lipases; zeolite builders; phosphate builders; co-builders such as citric acid and citrates; carbonates such as sodium carbonate and sodium bicarbonate; sulfates such as sodium sulfate; silicates such as sodium silicate; chlorides such as sodium chloride; brighteners; chelating agents; hueing agents; dye transfer inhibitors; dye fixing agents; fragrances; silicones; fabric softeners such as clays; flocculating agents such as polyethylene oxide; suds suppressors; and any combination thereof.

[0038] Test Method Measurement of stain removal. The degree of stain removal performance achieved by any wash cycle is calculated as the color difference in L, a, b color space between the stain and the fabric background before and after washing. The initial color difference is the initial visibility (IN i , Equation 1), while the final visibility (FN i , Equation 2) refers to the color difference between the stain after washing and the initial background of the fabric. The stain removal index (SRI) for a given stain i is i ) is calculated as shown in Equation 3.

[0039]

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[0040] Method for measuring fabric absorbency. Fabric absorbency refers to the maximum amount of water retained per mass of dry fabric. To measure fabric absorbency of a particular fabric type, the following steps are required: (i) selecting three items of the same fabric type having a mass of at least 20 g; (ii) Weigh each dry fabric to determine its dry mass (m 乾燥 ) determining (iii) immersing the fabrics in a bucket of water so that there is significantly more water than is absorbed by the fabric, removing each fabric, stretching it, and allowing it to drip for 20 seconds; (iv) Wet fabric (m 湿潤 ) and calculating the mass of water per mass of dry fabric:

[0041]

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[0042] Dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm." [Example]

[0043] Example 1: Comparison of stain removal performance of fabric treatment processes for wash cycles with intermediate and final wash baths All experiments are carried out in a medium-scale, high-throughput instrument operated on the Peerless System platform. This consists of ten 1 L vessels equipped with three-blade post-agitators similar to those used by Ganguli and Eenderbug (1980) running in parallel. The instrument is automated so that vessel filling, cleaning, draining, and rinsing are performed automatically by the system.

[0044] Before starting the washing process, the vessels were cleaned by adding 0.25 L of 30°C tap water to each vessel. The water was left in the vessels for 2 minutes under constant agitation at 1800°C / s. After draining the water used in the cleaning stage, the vessels were ready for use. All experiments were carried out using a total ballast load of 60 g, including a 50 g knitted cotton swatch (5 cm x 5 cm) and a test item (10 g of a 7 cm x 7 cm knitted cotton swatch) containing the stain to be analyzed. The water absorption of the ballast load used was 3 kg of water / kg of dry fabric. Table 2 lists the detergent formulations used for the reference and comparative washing processes.

[0045] In the reference wash process (Experiment A), after draining the water used in the cleaning stage, 0.4 L of tap water at the target wash temperature (30°C) is added to the vessel. Next, the required dose of detergent formulation (2.38 g) pre-dissolved in the required volume of tap water at the target temperature (30°C) to reach 1 L of total aqueous solution is added to the vessel and mixed for 1 minute under constant agitation at 300 rpm. A ballast load containing knitted cotton swatches and test items is then added to the vessel before starting the wash process. The main wash is carried out for 30 minutes under constant agitation at 300 rpm, followed by a 15-minute rinse at 30°C.

[0046] In other washing processes (Experiments B-C), the required dosage of liquid detergent formulation (2.38 g) was pre-dissolved in the required volume of tap water at the target temperature listed in Table 1 for the intermediate wash bath to achieve the same detergent concentration obtained in a Front Loading Washing Machine (FLWM) when considering a ballast load of 3 kg with a water absorbency of 3 kg water / kg dry fabric, and a volume of water equal to the total water absorbency of 70% of the ballast load (6.3 kg total water).

[0047] After dissolving the detergent formulation, a portion of the solution is added to the vessel, corresponding to a volume equal to 70% of the water absorbency of the ballast load used in the experiment (60 g at 3 kg water / kg dry fabric absorbency), resulting in a total of 0.126 kg of water. The ballast load containing the knitted cotton swatches and test items is then added to the vessel. The detergent solution remains in contact with the ballast for 5 minutes at the target temperature for the intermediate wash bath and under constant agitation as described in Table 1. At this point, the remaining detergent solution previously prepared is also added to the vessel, along with an excess volume of tap water at the target temperature for the main wash (see Table 1) required to reach 1 L of total wash solution in each vessel. At this point, the main wash begins. In all cases, the main wash is carried out for 30 minutes under constant agitation at 300 rpm, followed by a 15-minute rinse at 30°C.

[0048] [Table 1]

[0049] In all cases, after the wash cycle is completed, the ballast load and stain are removed from the container and placed in separate drying bags (reference and comparative wash processes). The fabrics are then dried at low temperature for 30 minutes in an Electrolux T3290 gas dryer. The degree of stain removal is calculated as the color difference between the stain and the fabric background before and after washing, as described in Equations 1 to 3.

[0050] Table 3 shows the stain removal performance results obtained for each experiment. The Stain Removal Index (SRI) is calculated via image analysis under D65 standard illuminant conditions. The results presented are the average of two internal replicates and four external replicates for each experimental condition.

[0051] [Table 2]

[0052] [Table 3]

[0053] Table 3 shows that Comparative Wash Process B shows improved stain removal for some stains (i.e., ASTM sebum, red wine, espresso coffee), while Experiment C exhibits the best performance across all stains. The stains can be observed to belong to beverage categories (e.g., red wine and coffee), enzymes (e.g., chocolate soy milk, BBQ and gravy), and grease stains (e.g., ASTM sebum, dyed bacon fat, and cooked beef).

Claims

1. 1. A method of laundering fabrics, comprising: (a) calculating the final amount of water to be added to the final cleaning bath; (b) calculating the amount of energy required to heat this final volume of water to the desired final temperature; (c) contacting an amount of water less than the final water volume with fabrics to form an intermediate wash bath, wherein a detergent composition is contacted with the fabrics during or prior to forming the intermediate wash bath, the intermediate wash bath comprising a detersive surfactant having a total concentration of 1000 ppm to 4000 ppm; (d) heating the water that contacts the fabrics during step (c) with the energy calculated in step (b) so that the intermediate wash bath has a temperature above a desired final temperature; (e) washing the fabrics in the intermediate wash bath for at least 3 minutes, and optionally up to 10 minutes; (f) contacting the remaining amount of water with the intermediate cleaning bath to form the final cleaning bath having a desired final temperature; (g) washing the fabrics in the final wash bath for at least 5 minutes; (h) rinsing the fabric; A method wherein the desired final temperature is at or below 30°C and the temperature of said intermediate wash bath is above 37°C.

2. 10. The method of claim 1, wherein during step (a), the weight of fabrics to be laundered during the method is determined and this fabric weight is used when calculating the final amount of water to be added to the final wash bath.

3. 3. The method according to claim 1 or 2, wherein the amount of water contacting the fabric in step (c) to form the intermediate wash bath is in the range of 5 v / v % to 70 v / v % of the final water amount calculated in step (a).

4. The amount of water that contacts the fabric in step (c) to form the intermediate wash bath is (a) within the range of 25% v / v to 70% v / v of the final water volume calculated in step (a), and the process is carried out in a front-loader automatic washing machine; or 4. The method of claim 1, wherein (b) the final water volume calculated in step (a) is in the range of 5% to 40% v / v of the final water volume calculated in step (a), and the process is carried out in a top loader automatic washing machine.

5. 5. The method of any one of claims 1 to 4, wherein the washing time of step (e) to the washing time of step (g) is in the range of 1:2 to 1:

20.

6. The method according to any one of claims 1 to 5, wherein the intermediate washing step (e) is carried out under stirring conditions.

7. The method of any one of claims 1 to 6, wherein the intermediate cleaning bath comprises a detersive surfactant, an enzyme, and a chelating agent.

8. 8. The method of any one of claims 1 to 7, wherein bleaching agent is contacted with the fabrics after step (e) such that the intermediate wash bath does not contain bleaching agent, but the final wash bath does contain bleaching agent.

9. A method according to any one of claims 1 to 8, wherein the concentration of detergent chemicals present in the intermediate wash bath is higher than the concentration of detergent chemicals present in the final wash bath.

10. The method according to any one of claims 1 to 9, wherein the method is carried out in an automatic washing machine.

11. 10. The method of claim 9, wherein the water can be heated in the sump of the automatic washing machine, at the water inlet of the automatic washing machine, or external to the automatic washing machine.

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