Cellulose fabric ozone washing method

Abstract

The invention relates to a cellulose fabric ozone water washing method. The method comprises the following steps: 1) feeding cloth and washing with cold water; 2) ozone water washing; 3) atomizing, spraying and washing; and 4) drying and discharging the cloth. According to the method, the strong oxidizing property of ozone is utilized, color development and auxochrome groups in unreacted dye molecules are efficiently destroyed, a better flooding removal effect is achieved, and the cleanliness and color fastness of the fabric are improved. Compared with a conventional water washing method, the water and electricity energy consumption can be greatly saved, and the use of chemical auxiliaries is remarkably reduced; and flooding dye molecules are degraded into colorless small molecules, so that the wastewater treatment difficulty is reduced, the treatment effect is improved, and remarkable environmental benefits are achieved.

Description

Technical Field

[0001] This invention belongs to the field of textile printing and dyeing washing technology, and specifically relates to an ozone washing method for cellulose fabrics. Background Technology

[0002] Cellulose fibers are a class of fibers whose basic chemical composition is the high-molecular-weight polysaccharide "cellulose." They include two main categories: natural cellulose fibers and regenerated cellulose fibers, and are generally dyed using reactive dyes. Under certain conditions, the reactive groups of the dye can form strong covalent bonds with the fiber. However, not all dyes can completely bind to the fiber during the dyeing process. Because reactive dyes have good water solubility, the traditional treatment method is to remove these unbound dyes by washing. This involves rinsing with large amounts of cold and hot water, sometimes with the addition of a certain amount of chemical soaping agent, using physical, mechanical, or chemical treatments to promote the dissolution, exchange, and removal of the dyes. This prevents them from fading or contaminating other fabrics during subsequent use or washing. However, the entire washing process not only consumes a large amount of water, but the chemical auxiliaries used also place a significant burden on the environment and increase production costs. With increasing environmental awareness and technological innovation, the industry is seeking more environmentally friendly and efficient washing methods to reduce environmental impact and improve production efficiency.

[0003] Ozone is a strong oxidant that can destroy the chromophores and auxochromes of dyes, oxidizing and decomposing the conjugated π-electron system of the dye. Common basic components in dyes are o-hydroxyazo pigments. When these compounds react with ozone, ozone performs an electrophilic attack on the hydrazine support, cleaving the pigment skeleton and achieving a decolorization effect. When its free radicals (OH-) react with dyes or impurities, they break the unsaturated bonds in the chromophores of the dye, generating small-molecule, colorless organic acids, aldehydes, and other intermediate products. These intermediate products are difficult to completely decompose by ozone, but can be further degraded by microorganisms. Therefore, ozonation treatment improves the biodegradability of wastewater.

[0004] Therefore, ozone has been used in the textile industry for pretreatment bleaching and decolorization of colored wastewater during treatment, and directly for washing fabrics after dyeing or printing with reactive dyes, but no related research or reports have been found.

[0005] This invention proposes an ozone washing method for cellulose fabrics. It combines ozone treatment with a water washing process to efficiently remove unreacted dyes, residual chemical auxiliaries, and impurities from the fabric, effectively improving its cleanliness and colorfastness. Compared to traditional water washing processes, this method not only saves a significant amount of water resources but also significantly reduces the amount of chemical auxiliaries used, minimizing the environmental impact of wastewater. Summary of the Invention

[0006] This invention provides a method for ozone washing of cellulose fabrics, the steps of which include:

[0007] 3) Put the fabric in and wash it with cold water;

[0008] 4) Ozone water washing;

[0009] 3) Atomized spray water washing;

[0010] 4) Dry and unload the fabric;

[0011] In step 1), the fabric enters a washing tank filled with cold water via a fabric feeder, ensuring the fabric is fully wetted and impregnated. Neutralizing acid and a penetrating agent are added to the water simultaneously, enhancing the wetting and penetrating effect of the water while neutralizing any residual alkali from the dyeing process. The fabric feed speed is 40-80 m / min. The penetrating agent is an isomeric alcohol polyoxyethylene ether nonionic surfactant with the general formula RO(CH2CH2O)nH, where R is C 10 -C 13 The isomeric aliphatic hydrocarbon group has an n value ranging from 3 to 10 and a concentration of 0.3 to 1 g / L; the neutralizing acid is one or two of glacial acetic acid, citric acid, oxalic acid, and sulfuric acid, with a concentration of 0.1 to 1 g / L; the water washing temperature is 15 to 25°C; the number of water tanks is 4 to 6, and the water washing time is 1 to 1.5 min.

[0012] In step 2), ozone is continuously and evenly added to the ozone washing tank through the gas distribution pipe at the top of the sealed washing tank. The minimum water level at the bottom of the washing tank should be above the guide roller. The ozone concentration is maintained at 0.5-3.5 mg / L, the vehicle speed is 40-80 m / min, the temperature is 15℃-25℃, and the ozone washing time is 1.5-3 min.

[0013] In step 3), the spray angle of the atomizing nozzle is 80°-110°, the water flow of a single nozzle is 2-20L / min, the nozzle spacing is 5-12cm, and the angle between the nozzle and the fabric surface is 75°±5°.

[0014] Spray washing consists of two steps: hot water and cold water. Hot water spray washing: spray head pressure: 1-3 bar, vehicle speed: 40-80 m / min, temperature: 90℃±10℃, number of spray channels: 6-8, washing time: 1.5-2 min.

[0015] Cold water spray washing: Add 0.1-0.5 g / L of ozone quencher to the water. The ozone quencher is one of sodium thiosulfate, sodium sulfite, or sodium bisulfite. Spray head pressure: 2-2.5 bar; vehicle speed: 40-80 m / min; temperature: 20℃-40℃; number of spray channels: 6-8; washing time: 1.5-2 min; water volume: 1.5-3 m³ / min. 3 / h.

[0016] The drying method in step 4) is drum drying, and the drum temperature is set to 85℃.

[0017] The technical principle of this invention is:

[0018] Although ozone possesses strong oxidizing properties and can effectively destroy the chromophores and auxochromes of dyes, the oxidation rate of ozone differs significantly between dye molecules dissolved or hydrolyzed in water and those reacting with fibers. Reactive dyes that react with cellulose fibers through nucleophilic substitution or addition form stable covalent bonds, anchoring the chromophores to the fiber backbone. This creates physical shielding and steric hindrance, reducing the probability of ozone molecules attacking the chromophores. Simultaneously, the synergistic effect between cellulose molecules and the dye chromophores through covalent bonds reduces the electron cloud density of the chromophores, enhancing their antioxidant properties. Therefore, these dyes are difficult for ozone to destroy. Consequently, reactive dyes that have already reacted and become fixed are difficult to decolorize with ozone molecules under suitable time and concentration conditions. However, ozone can rapidly oxidize and decompose dye molecules dissolved or hydrolyzed in water into colorless small molecules.

[0019] After ozone treatment, both ozone decomposition products and fabric residues need to be removed through washing, including residual ozone. If residual ozone is not effectively removed, the fabric's color will slowly decompose during subsequent storage and use, eventually causing localized discoloration and rendering the fabric unusable. This invention employs a highly efficient high-pressure atomized spray washing method. High pressure is used to propel water through nozzles at a specific pressure and angle, forming a high-pressure water mist that powerfully impacts and cleans the fabric surface. During hot water spray washing, the high-pressure water stream can penetrate deep into the tiny crevices of the surface, quickly removing colorless small molecules, chemical auxiliaries, sizing agents, and other impurities formed after ozone treatment. Simultaneously, most of the residual ozone decomposes into oxygen at 80-100℃. During cold water spray washing, the high-pressure water mist carries ozone quenchers such as sodium thiosulfate, sodium sulfite, and sodium bisulfite, which quickly and evenly contact and react with the minimal amount of residual ozone, achieving the goal of cleaning residual pollutants and completely eliminating residual ozone.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The ozone washing method for cellulose fabrics proposed in this invention utilizes the strong oxidizing properties of ozone to efficiently destroy the chromophores and auxochromes in unreacted dye molecules, achieving better removal of floating dye and improving the cleanliness and colorfastness of the fabric. Compared with conventional washing methods, it can significantly save water and electricity consumption and also significantly reduce the use of chemical auxiliaries; it degrades floating dye molecules into colorless small molecules, reducing the difficulty of wastewater treatment and improving the treatment effect, thus having significant environmental benefits. Detailed Implementation

[0022] The present invention will now be described in detail. Before proceeding with the description, it should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the invention, based on the principle that the inventors are allowed to appropriately define the terms for the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention. It should be understood that other equivalents or modifications can be obtained from it without departing from the spirit and scope of the invention.

[0023] The following embodiments are merely examples illustrating implementations of the present invention and do not constitute any limitation on the present invention. Those skilled in the art will understand that modifications made without departing from the spirit and concept of the present invention fall within the protection scope of the present invention. Unless otherwise specified, the reagents and instruments used in the following embodiments are commercially available products.

[0024] Before proceeding with the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather should be interpreted based on the principle of allowing the inventors to define the terminology appropriately for the best interpretation, and based on its meaning and concept corresponding to the technical level of the invention. Therefore, the description herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention. Consequently, it should be understood that other equivalent implementations and modifications can be made without departing from the spirit and scope of the invention.

[0025] In this document, the terms “comprising,” “including,” “having,” “containing,” or any similar terms are open-ended transitional phrases intended to encompass non-exclusive inclusions. For example, a composition or article containing a plural element is not limited to the elements listed herein, but may also include other elements not explicitly listed but typically inherent to the composition or article. Furthermore, unless explicitly stated otherwise, the term “or” is inclusive, not exclusive. For example, the condition “A or B” is satisfied in any of the following cases: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); A and B are both true (or exist). Moreover, in this document, the terms “comprising,” “including,” “having,” and “containing” should be interpreted as specifically disclosed and simultaneously encompassing closed or semi-closed transitional phrases such as “composed of” and “substantially composed of.”

[0026] In this document, all features or conditions defined in the form of numerical ranges or percentage ranges are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible secondary ranges and individual values ​​within those ranges, particularly integer values. For example, a range description of "1 to 8" should be considered as specifically disclosing all secondary ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., particularly secondary ranges defined by all integer values, and should be considered as specifically disclosing individual values ​​within those ranges such as 1, 2, 3, 4, 5, 6, 7, 8, etc. Unless otherwise specified, the foregoing interpretation applies to all content throughout this invention, regardless of its scope.

[0027] If a quantity or other numerical value or parameter is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that this document has specifically disclosed all ranges consisting of any upper or preferred value of that range and the lower or preferred value of that range, regardless of whether such ranges are separately disclosed. Furthermore, when a range of numerical values ​​is mentioned herein, unless otherwise stated, the range shall include its endpoints and all integers and fractions within the range.

[0028] In this document, numerical values ​​are to be understood as having a precision with significant digits, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover a range from 39.50 to 40.49.

[0029] Process steps of Examples 1-4:

[0030] 1) Put the fabric in and wash it with cold water.

[0031] 2) Ozone water washing.

[0032] 3) High-pressure atomized spray water washing.

[0033] 4) Dry and unload the fabric.

[0034] Fabric feeding → Cold water wash (20℃±5℃, penetrant 0.3-1g / L, neutralizing acid 0.1-1g / L) → Ozone wash (20℃±5℃, ozone 0.5-3.5mg / L) → Hot water spray wash (90℃±10℃) → Cold water spray wash (30℃±10℃, quencher 0.1-0.5g / L) → Drying (85℃±5℃)

[0035] Fabric feeding speed: 40-80m / min; the concentration of the penetrant is 0.2-2g / L; the neutralizing acid is one or two of glacial acetic acid, citric acid, oxalic acid, and sulfuric acid: concentration 0.1-1g / L; water washing temperature: 20-40℃; number of water tanks: 4-6; water washing time: 1-1.5min.

[0036] Ozone concentration: 0.5-3.5 mg / L, vehicle speed: 40-80 m / min, temperature: 15℃-25℃, ozone water washing time: 1.5-3 min.

[0037] The penetrant used is the nonionic penetrant DT-ST, manufactured by Shandong Yellow River Delta Textile Technology Research Institute Co., Ltd.

[0038] Process steps for Comparative Examples 1-4:

[0039] Traditional washing: Fabric feed → Cold water wash (30℃±10℃) → Hot water wash (90℃±5℃) → Soap wash (95℃±5℃, soaping agent ZX-01 1-3g / L) → Hot water wash (90℃±5℃) → Cold water wash to adjust pH value (30℃±10℃, neutralize acid 0.2-1g / L) → Drying (85℃±5℃)

[0040] The soap detergent used is ZX-01, manufactured by Shandong Yellow River Delta Textile Technology Research Institute Co., Ltd.

[0041] Process formulations of Examples 1-4 and Comparative Examples 1-4

[0042]

[0043]

[0044]

[0045]

[0046]

[0047] The examples and comparative samples were tested according to the following criteria:

[0048] 1) Color fastness to washing with soap: Refer to GB / T3921—2008 "Textiles - Tests for color fastness to washing with soap".

[0049] 2) Color fastness to rubbing: Refer to GB / T3920—2008 "Textiles - Tests for color fastness to rubbing".

[0050] 3) Colorfastness to sunlight: Refer to GB / T5713—2013 "Textiles - Tests for colorfastness - Water fastness". The experimental data and test results for Examples 1 to 4 and Comparative Examples 1 to 4 are as follows.

[0051]

[0052]

[0053] Comparison of chemical auxiliaries and energy consumption per 100 meters of fabric between Examples 1 to 4 and Comparative Examples 1 to 4

[0054]

[0055] Compared to traditional washing processes, ozone washing technology offers numerous advantages in fabric treatment. Fabrics washed with ozone can achieve an appearance identical to those washed with traditional methods. While maintaining the fabric's good texture, it generally outperforms traditional washing in terms of colorfastness, a key indicator. Specifically, ozone-treated fabrics achieve wet rubbing colorfastness of 2-3 or even 3, while dry rubbing colorfastness reaches 3-4 or higher. This indicates that ozone-washed fabrics are thoroughly washed, preventing dye fading and staining. Furthermore, ozone-treated fabrics achieve soaping staining colorfastness and water fastness of 4 or higher, demonstrating that the color remains stable and does not easily fade after soaping or washing.

[0056] Ozone washing technology not only maintains the same effect as traditional washing but also significantly improves the cleaning efficiency of fabrics. Compared to traditional washing, ozone washing technology drastically reduces the amount of auxiliaries used, saving 70%-80%; water consumption is reduced by 45%-50%; and steam consumption is also reduced by 35-38%. This effectively reduces the economic costs of dyeing and printing production, improves fabric washing efficiency, and successfully demonstrates the high efficiency, feasibility, and environmental friendliness of the ozone washing method.

[0057] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for ozone washing of cellulose fabrics, characterized in that, Includes the following steps: 1) Put the fabric in and wash it with cold water; 2) Ozone water washing; 3) Atomized spray water washing; 4) Dry and unload the fabric.

2. The ozone washing method for cellulose fabrics according to claim 1, characterized in that, In step 1), the fabric enters the washing tank with cold water through the fabric feeding frame, so that the fabric is fully wetted and impregnated. Neutralizing acid and penetrating agent are added to the water at the same time. The fabric feeding speed is 40-80m / min.

3. The ozone washing method for cellulose fabrics according to claim 1, characterized in that, In step 1), the penetrant is an isomeric alcohol polyoxyethylene ether nonionic surfactant with the general formula RO(CH2CH2O)nH, where R is C 10 -C 13 The isomeric aliphatic hydrocarbon group has an n value ranging from 3 to 10 and a concentration of 0.3 to 1 g / L; the neutralizing acid is one or two of glacial acetic acid, citric acid, oxalic acid, and sulfuric acid, with a concentration of 0.1 to 1 g / L; the water washing temperature is 15 to 25°C; the number of water tanks is 4 to 6, and the water washing time is 1 to 1.5 min.

4. The ozone washing method for cellulose fabrics according to claim 1, characterized in that, In step 2), ozone is continuously and evenly added to the ozone washing tank through the gas distribution pipe at the top of the sealed washing tank. The lowest water level at the bottom of the washing tank is above the guide roller. The ozone concentration is maintained at 0.5-3.5 mg / L, the vehicle speed at 40-80 m / min, the temperature at 15℃-25℃, and the ozone washing time at 1.5-3 min.

5. The ozone washing method for cellulose fabrics according to claim 1, characterized in that, In step 3), the spray angle of the atomizing nozzle is 80°-110°, the water flow rate of a single nozzle is 2-20L / min, the nozzle spacing is 5-12cm, and the angle between the nozzle and the fabric surface is 75°±5°.

6. The ozone washing method for cellulose fabrics according to claim 5, characterized in that, The spray washing process consists of two steps: hot water and cold water. Hot water spray washing: spray head pressure: 1-3 bar, vehicle speed: 40-80 m / min, temperature: 90℃±10℃, number of spray channels: 6-8, washing time: 1.5-2 min.

7. The ozone washing method for cellulose fabrics according to claim 6, characterized in that, Cold water spray washing: Add 0.1-0.5 g / L of ozone quencher to the water. The quencher is one of sodium thiosulfate, sodium sulfite, or sodium bisulfite. Spray head pressure: 2-2.5 bar; vehicle speed: 40-80 m / min; temperature: 20℃-40℃; number of spray channels: 6-8; washing time: 1.5-2 min; water volume: 1.5-3 m³ / min. 3 / h.

8. The ozone washing method for cellulose fabrics according to claim 1, characterized in that, The drying method in step 4) is drum drying, and the drum temperature is set to 85℃.

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