Subject of the Invention and Technical Field

The invention relates to a new enzyme mixture content and a denim washing method using this enzyme mixture. The invention especially relates to an enzyme mixture which can be applied both without stone washing and without water, instead of bleaching with pumice stone, in the denim sector and which allows for more sustainable and environmentally friendly enzyme washing.

State of the Art

Today, it is seen that almost all denim products do not have color integrity, and there are differences in color, texture and surface. The finishing processes for denim create the final appearance of the denim. One step of the mentioned finishing processes is the denim washing process. The differences in the final product are realized by various washing processes available in the state of the art. In the denim sector, the washing processes or bleaching processes can be performed with various applications using sodium hypochlorite, hydrogen peroxide, and pumice stone. These applications cause the environmental pollution by increasing the use of chemicals and also increase the energy and water consumption during the denim washing.

A traditional technology of the production is to obtain a stone-washed appearance in the denim washing. In this process, known as stone washing or abrasion, the denim fabrics are washed in the industrial washing machines in short liquor ratios in the presence of pumice stone in order to give the desired abrasion and aging effect. Then, as a result of the processes such as sodium hypochlorite and neutralization, the products are bleached and given the desired appearance. This process causes the significant costs and environmental pollution. As the pumice stone abrades the denim surface like a sandpaper, it creates a faded or worn appearance and removes some dye particles from the surfaces of the yarn. The effects obtained in the enzyme washing, in which chemicals are used, are more spot-based, more vivid and bright. Especially, the materials such as tablets, sponges and styrofoam with the enzymes are preferred, instead of stones, in washing the slim fabrics. This is because the stone can break up the slim fabrics. On the other hand, if the amount and duration of the use of the enzymes are not adjusted, the product may wear out and lose strength. In the products with light colors and many effects, the enzyme can be used together with materials such as stone, etc., depending on the structure of the fabric, so that the desired color and effect can be achieved.

On the other hand, the cellulase enzymes are used together with the stone or alone in the abrasion of the denim products in washing with enzymes. The cellulase enzymes hydrolyze the cellulose molecule. As a result, the fabric surface becomes smooth with the loss of the surface fibers and its texture softens. Based on the weight loss, there is also a loss of strength. The enzyme washing is performed to achieve the desired color effect but in turn less worn denim garments. Thus, the service life of the denim product is increased compared to the ones washed with stones.

In the state of the art, the article titled “Laccase: production by Trametes versicolor and application to denim washing” by Nurdan Ka§ikara et al., 2005, describes the production of laccase with Trames Versicolor and the application examples in denim washing. The cellulase and laccase enzymes can partially reduce or completely eliminate the use of pumice stone, which has an abrasive effect on the denim fabric surface. The indigo-dyed denim fabrics can be bleached to the lighter shades.

In the state of the art, the article titled “The effects of cellulase enzymes on cellulosic fabrics” by Kerim Duran et al., 2007, examines the changes in viscose and cotton fabrics caused, without mechanical effect, by the cellulase residues which remain undeactivated after biopolishing. The mentioned article gives information on the use of the cellulase enzyme in the textile processes. It is mentioned that the pumice stone is used during washing to bleach the denim fabrics and give them a different appearance, and the problems caused by the use of stones are listed. The use of the cellulase enzymes has partially or completely eliminated these problems by reducing the amount of the stones or completely omitting them. The desired abrasion effect can be achieved by adjusting the machine type, liquor ratio, fabric amount, stone amount and enzyme amount. The treatment time can be reduced by using more cellulase, but the high concentration of the cellulases reduces the fabric strength. In the state of the art, the acidic cellulases are more preferably used in the biopolishing (enzymatic hair removal) process while the neutral cellulase enzymes are preferred in the enzymatic stone washing process applied to the products made of denim fabric or in the washing processes performed only with the enzymes without the use of stones. Therefore, the pH value of the bath to be used for washing is very important. If the pH of the bath is above 7, it should be balanced with the formic acid which is an organic acid found in nature. The working principles of enzymes are based on the lock and key relationship. Therefore, a suitable working environment should be provided for the developed enzyme. In general, the enzymes are very sensitive to heat. The optimum temperature required for the correct functioning of enzymes is in the range of 40-60°C.

The first step in washing is removing the sizing material transferred to the fabric from the product to allow the weaving to function with the maximum efficiency during the production of the denim fabric. In the desizing process, the amylase enzyme reacts with the sizing agent and helps to remove it from the fabric. In the next steps, the fabric is rinsed to completely remove these substances therefrom. It is prevented with the dispersant supplied with the enzyme that the powdered enzyme is dispersed homogeneously in the water and the dissolved dye binds again to the fabric. Then, the dye and other chemicals separated from the fabric during the rinsing step are removed and the fabric is dried.

In the state of the art, there have also been the patents related thereto. One of them is the Turkish Patent no. 1998/01300 and titled “Fabric treated with cellulase and oxidoreductase”. Said patent relates to a process for giving an abraded appearance to the dyed fabric with the reduced strength loss. Accordingly, the fabric dyed in a diluted medium is contacted with cellulase at a concentration corresponding to 0.01-250 pg of enzyme protein per gram of fabric. The specified fabric is treated, simultaneously or later, with a phenol oxidizing enzyme system and an enzyme-enhancing active ingredient.

The Turkish Patent no. 2002/01647 and titled “Process for removal of excess dispersed dye from printed or dyed textile material” describes a process for removal of excess dispersed dye from the printed or dyed textile material, comprising a treatment with a rinsing liquid which consists of at least one enzyme selected from the group consisting of the enzymes with peroxidase activity or laccase activity, an oxidizing agent, and at least one intermediate.

The Turkish Patent no. 2012/06248 and titled “New laccase enzymes and the use thereof” describes the new laccase enzymes obtainable from the species belonging to the family Thielavia or the species belonging to the family Chaetomium. It also describes methods of producing enzymes in the recombinant hosts with the nucleic acid sequences encoding enzymes and with the recombinant hosts into which the nucleic acid sequences are inserted. In said patent, it is described that the enzymes of the invention can be used in various applications such as treating the jeans and removing the stains, etc.

The American Patent no. US5474577A and titled “Methods and compositions for treating denim fabric and the fabric produced thereby” relates to the methods and contents for changing the color of the denim fabrics and said content includes cellulase enzyme, detergent, salt, buffer, and dyestuffs.

The American Patent no. US2004010856A1 and titled “Method for customizing an aged appearance in denim garments” describes the treating methods and compositions for giving an aged appearance to the denim products. Said method comprises spot treating the denim products with the enzyme components and agitating them in a domestic laundry environment. The patent describes a treatment with a cellulase enzyme solution.

The Chinese Patent no. CN101563500A and titled “Laccase mediators and methods of use” describes a new laccase system with the enhanced stability and superior bleaching performance.

The International Patent no. WO2012054485A1 and titled “Local color modification of dyed fabrics using a laccase system” describes a textile treatment system which provides a local color change by contacting a dyed textile piece with a laccase enzyme system under the adequate conditions and for a specified period of time.

Accordingly, there are the improvements for the denim bleaching systems in the state of the art. The enzymes will play a major role in the sustainable systems which will become the technology of today and the future. The compounds such as gallic acid, ferulic acid, xylidin, guaiacol, syringaldazine and veratryl alcohol are widely used to increase the activity of the enzymes. Considering the industrial importance of the enzymes, the new studies are needed to improve the production capabilities and working activities of the laccases and cellulases.

In order to better understand the denim washing method of the invention, the following figure will be referred.

Description of the Figures

Fig. 1 is a flow chart showing the work-flow in the denim washing method of the invention.

Process Flow Chart that Helps Explain the Invention

100 - Pre-washing step 200 - First rinsing step 300 - Enzyme washing step 400 - Second rinsing step

Technical Problems to Be Solved by the Invention

The object of the invention is to provide a more sustainable and environmentally friendly enzyme washing method which can be applied without stone washing and without water in the denim sector and applied with a new enzyme mixture content comprising the components such as organic peracids, carbonic acid salts, fillers, peracid activators, organic acids, dispersants, enzymes, detergents, and enzyme activators.

The most important advantage of the denim washing method of the invention is that the enzyme mixture is used with stone powder instead of pumice stone. Thus, the damages caused by the pumice stone to the fabric and the washing machine are prevented. An advantage of the denim washing method of the invention is that it allows the washing machine to be cleaned more easily. Thus, it saves labor and time.

Another advantage of the denim washing method of the invention is that less chemicals are needed. This makes the method of the invention more sustainable and environmentally friendly.

Another advantage of the denim washing method of the invention is that it consumes less water and energy. This brings along the advantages in terms of cost.

Detailed Description of the Invention

With the denim washing method of the invention, a more sustainable and environmentally friendly enzyme washing is intended, which can be applied both without stone washing and without water, instead of bleaching with pumice stone in the state of the art. Based on this main object, a new enzyme mixture content is used in the method of the invention, which comprises the components such as organic peracids, carbonic acid salts, fillers, peracid activators, organic acids, dispersants, enzymes, detergents, and enzyme activators. Although the method of the invention is referred to as the denim washing method, it also includes the non-denim textile groups. The method of the invention can be performed without stone washing and/or without water, based on the desired effect.

In the denim washing method of the invention, the product is generally subjected to a pre-washing process and rinsed, then subjected to the enzyme washing process with the specially developed enzyme mixture. At the end of the enzyme washing process, the application is completed with the second rinsing process. The flow chart showing the work-flow in the denim washing method of the invention is given in Fig. 1. Accordingly, the denim washing method of the invention comprises the following steps:

Pre-washing step (100)

First rinsing step (200)

Enzyme washing step (300)

Second rinsing step (400) The detailed descriptions of the above mentioned steps are given below.

Pre-washing step (100): The pre-washing process in this step is performed with at least one of the wetting agent, dispersant, and anti-breaking agent preferably in the range of 1 : 1-1 :7 liquor ratio and preferably at a temperature in the range of 15-65 °C. The anti-breaking agent in this step is used to prevent the mechanical damages in the fabrics. The present anti-breaking agents in the state of the art can be selected in the desired amounts. Said dispersant is any one of polymeric dispersant, polymer based dispersant, and modified dispersant, or the multiple combinations thereof.

First rinsing step (200): After the pre-washing step (100), the product in the first rinsing step (200) is subjected to the process of washing with water preferably in the range of 1:1 to 1:5 liquor ratio.

Enzyme washing step (300): After the first rinsing step (200), the enzyme mixture is applied to the product preferably in the range of 1:0.5 to 1:5 liquor ratio and preferably at a temperature in the range of 15-65 °C. In this step, at least one of the materials causing the mechanical friction, such as the pumice stone, synthetic stone, and stone powder, are used as an additive together with the enzyme mixture based on the desired effect.

Second rinsing step (400): After the enzyme washing step (300), the process of washing with water is performed preferably in the range of 1:1 to 1:5 liquor ratio and preferably at a temperature in the range of 15-65°C. This step can be repeated more than once in the process. In other words, after the enzyme washing step (300), the product may be rinsed more than once.

The liquor ratio used in the descriptions above shows the amount of the bath to be used for the product. For example, the liquor ratio of 1:15 indicates that 15 mL of the bath will be used for 1 gram of the product. Based on the amount of product, the amount of the bath to be used can be calculated according to this ratio. The details of the content of the new enzyme mixture used in the enzyme washing step (300) of the denim washing method of the invention are given in the table below. This table includes the components constituting the enzyme mixture and their percentages by weight. The sum of the lower limit values and the upper limit values in the given ratios does not equal 100. The values in the specified ranges are selected to add up to 100 in total. For example, 10% of organic peracid, 45% of carbonic acid salt, 3% of filler, 2% of peracid activator, 10% of organic acid, 11% of dispersant, 16% of enzyme, 2% of detergent, 1% of enzyme activator.

The content of the enzyme mixture of the invention comprises at least one organic peracid in the range of 5-20% by weight, at least one carbonic acid salt in the range of 35-60% by weight, at least one filler in the range of 0.5-5% by weight, at least one peracid activator in the range of 0.5-5% by weight, at least one organic acid in the range of 2.5-15% by weight, at least one dispersant in the range of 5-20% by weight, at least one enzyme in the range of 5-20% by weight, at least one detergent in the range of 1-2% by weight, and at least one enzyme activator in the range of 0.5-5% by weight. In the content of the enzyme mixture of the invention, the organic peracid acts as a bleaching agent and any one of the chemicals such as anionic peracid salts, cationic peracid salts, metal salts, calcium percarbonate, magnesium percarbonate, sodium perborate, sodium perphosphate, sodium persulfate, and sodium percarbonate, or the multiple combinations thereof can be used.

In the content of the enzyme mixture of the invention, the carbonic acid salt acts as a bleaching agent and any one of the chemicals such as sodium carbonate, sodium bicarbonate, potassium carbonate, calcium carbonate, magnesium carbonate, ammonium carbonate, calcite, gaspeite, magnesite, smithsonite, ankerite(kutnahorite), malachite, aragonite, azurite, otavite, rhodochrosite, dolomite, cerussite, trona, siderite, natrite, monohydrocalcite, and ikaite, or the multiple combinations thereof can be selected as the carbonic acid salt.

In the content of the enzyme mixture of the invention, the filler acts as a binder. Said filler can be any one of the chemicals such as alkaline and alkaline-earth-metal salts of sulfates and chlorides, sodium silicate, silicic acid salts, inorganic salts, sodium metasilicate, alumina, sodium sulfate, sodium tripolyphosphate, and sodium pyrophosphate, or the multiple combinations thereof.

In the content of the enzyme mixture of the invention, the peracid activator is used as an oxygen activator. Said peracid activator can be any one of the chemicals such as nonanoyloxybenzenesulfonate (NOBS), tetraacetylethylenediamine (TAED), lauroyloxybenzenesulfonate sodium (LOBS), decanoyloxybenzoic acid (DOBA), ethylenediamine tetraacetic acid (EDTA), diethylene triamine penta acetic acid (DTPA), trans- 1,2-cyclohexane diamine tetra acetic acid (CDTA), ethylenediamine tetra methylene phosphonic acid (EDTMP), diethylene triamine penta methylene phosphonic acid (DTPMP), cationic bleaching activators, N-[4-(trimethyl ammonium ethyl) benzol] caprolactam chloride (TBCC), and N-diethylammonium chloride diethylam (CPDC), or the multiple combinations thereof.

In the content of the enzyme mixture of the invention, the organic acids act as pH regulator and can be any one of adipic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, oxalic acid, lactic acid, malic acid, citric acid, benzoic acid, carbonic acid, uric acid, aminomethylphosphonic acid, capronic acid, stearic acid, malonic acid, tartaric acid, sorbic acid, fumaric acid and benzoic acid, or the multiple combinations thereof.

In the content of the enzyme mixture of the invention, the dispersant acts as a dispersing agent. Dispersion means that any substance disperses in another substance homogeneously and in the form of the small particles. Said dispersant is any one of polymeric dispersant, polymer based dispersant, and modified dispersant, or the multiple combinations thereof. In the content of the enzyme mixture of the invention, the enzyme acts as a chemical reaction promoter and said enzyme can be any one of the enzymes such as cellulase, laccase, catalase, and hemicellulase, or the multiple combinations thereof.

In the content of the enzyme mixture of the invention, the detergent acts as a surfactant. The surfactants are the chemicals which affect (often reduce) the surface tension when dissolved in water or an aqueous solution. Said detergent can be selected from any one of the substances such as linear alkyl benzene sulfonic acid (LAPSA), alkanesulfonates (SAS), olefinsulfonates (AOS), dimethyl esters (SES), fatty alcohol sulfates (FAS), alkylether sulfates (FES), and sodium lauryl ether sulfate (SLES), or the multiple combinations thereof.

In the content of the enzyme mixture of the invention, the enzyme activator can be any one of the chemicals such as methyl syringate, ABTS (2,2-Azinobis(3- Ethylbenzothiazoline-6-Sulfonic Acid)), 4-(N-methylcarboxamido)-2,6-dimethoxyphenol, 4-carboxamido-2,6-dimethoxyphenol, 2,6-dimethoxyphenol, 2, 2,6,6-

Tetramethylpiperidin-1-yl)-0xyl (TEMPO), Phthalimide N-Oxyl (PINO), benzoylperoxide, tert-butyl hydroperoxide, 10- methylphenothiazine, 4- carboxyphenoxyazine-10-propionic acid, gallic acid, ferulic acid, syringaldazine, 2,2'- azinebis diammonium salt, 2,6-dipoxyphenol, 2-thiosacil, sodium dimethyldithio carbonate hydrate, sulfanilic acid, salicylic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, adipic acid, and 1-hydroxybenzotriazole, or the multiple combinations thereof.

In the denim washing method of the invention, the enzyme mixture described in detail above will preferably be used in the range of 0.5-2 kg. In the method of the invention, the cellulase enzyme in the range of 0.1-1 kg, laccase enzyme in the range of 0.1-2 kg, dispersant in the range of 0.1-0.5 kg, and stone powder in the range of 30-100 kg are preferably used together with the enzyme mixture in the range of 0.5-2 kg. These components can be used in the form a mixture as well as they can be processed separately in the desired order.

Industrial Application of the Invention

The content of the enzyme mixture of the invention can inventively provide the processes of abrading, patterning, and aging of denim, linen, canvas products, etc. The enzyme mixture of the invention can be used in the textile washing systems, especially in the denim washing systems. The method of the invention can be performed without stone washing and/or without water, depending on the desired effect. The process parameters are essential in the steps of the method of the invention, and the details about the place where these processes will be performed and the equipment thereof are not given.