High-color-fastness dyeing and post-treatment cleaning method for spandex fabric
By optimizing the dyeing conditions and post-treatment steps of spandex fabrics, eliminating the oil removal steps and using high-temperature dyeing technology, the problem of insufficient color fastness in spandex fabrics in traditional processes is solved, and the effect of high color fastness and reducing production costs is achieved.
Patent Information
- Application Number
- CN202510039264.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-04-11
AI Technical Summary
In the traditional spandex fabric dyeing process, the oil removal step has a significant impact on the color fastness of spandex fabric, resulting in insufficient color fastness, especially in PVC color fastness tests, which can only reach levels 2-3.
By optimizing the dyeing conditions and post-treatment cleaning steps, the oil removal steps are eliminated, high-temperature dyeing technology is adopted, and various parameters in the dyeing and post-treatment process are accurately controlled, including bath ratio, additives and temperature control.
It achieves good dyeing effect and high color fastness without oil removal. The PVC color fastness of spandex fabric can reach 4-5 levels, significantly improving the dyeing effect and color fastness, while reducing production costs.
Smart Images
Figure CN119800629A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of textiles, and more particularly to a method for dyeing and post-processing a spandex fabric with high color fastness. Background Art
[0002] In the traditional dyeing process of spandex fabrics, the degreasing step is regarded as a key link in the pretreatment, but its effect on the color fastness of spandex fabrics is particularly significant. Specifically, if the spandex fabric is degreased before dyeing, it may lack the necessary protective layer on the surface of the fabric due to excessive cleaning, thus affecting the uniform penetration and firm adhesion of the dye during dyeing. This characteristic makes spandex fabrics prone to insufficient color fastness after dyeing. Even after carefully designed dyeing conditions and subsequent post-treatment cleaning steps, its PVC color fastness can usually only reach level 2-3; Compared with other fabrics, spandex fabric is more likely to suffer from decreased color fastness after degreasing. This is because the fiber structure of spandex fabric is relatively special, and it has a strong adsorption capacity for dyes and auxiliaries, but it is also more susceptible to chemical or physical damage during the processing process. Although the degreasing step can remove grease and impurities on the surface of the fabric, it may also destroy the microstructure of the fabric fiber, resulting in the inability of the dye to be effectively fixed inside the fiber, thereby affecting color fastness. Summary of the invention
[0003] In view of the technical problems such as the limitations of the color fastness of spandex caused by the degreasing step in the traditional spandex fabric dyeing process, the present invention provides a spandex fabric high color fastness dyeing and post-treatment cleaning method, aiming to achieve the goal of obtaining good dyeing effect and high color fastness without degreasing by optimizing the dyeing conditions and post-treatment cleaning steps.
[0004] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: The present invention provides a method for dyeing and post-processing and cleaning a spandex fabric with high color fastness, and the method comprises the following steps: a. Fabric dyeing: Place the spandex fabric in a dyeing tank, heat it to 125°C to 130°C, dye it, and keep the temperature for 30 to 50 minutes; b. Cooling treatment: After dyeing is completed, the temperature in the dyeing tank is cooled to 70℃ to 80℃ and maintained at this temperature for 20 to 40 minutes; c. First post-treatment: The cooled spandex fabric is immersed in water at a bath ratio of 1:8 to 1:15. For each liter of water at this ratio, 2 to 4 grams of hydrosulfite and an equal amount of soda ash are added, and then the temperature is raised to 80°C to 90°C and maintained at this temperature for 20 to 40 minutes; d. Second post-treatment: Add glacial acetic acid to the same aqueous solution after the first post-treatment in an amount of 0.5-1 g of glacial acetic acid per liter of water, and then keep warm at a temperature range of 40°C to 60°C for 20 to 30 minutes; e. Third post-treatment: Add a weak alkaline soaping agent to the same aqueous solution after the second post-treatment, wherein the pH value of the soaping agent is 7 to 8, and the amount added is 1 to 4 grams of soaping agent per liter of water, and the temperature is raised to 30°C to 80°C, and the temperature is maintained for 20 to 50 minutes; f. Washing: After the third post-treatment, cool the spandex fabric to 30°C to 40°C and wash it for 10 to 15 minutes until the fabric is clean.
[0005] As a preferred technical solution of the present invention, in the step c), the weight of the spandex fabric is 5-800kg.
[0006] As a preferred technical solution of the present invention, in the step c), the mixture is immersed in water at a bath ratio of 1:10.
[0007] As a preferred technical solution of the present invention, in the step c), 4 grams of sodium hypochlorite and an equal amount of soda ash are added to each liter of water at this ratio.
[0008] As a preferred technical solution of the present invention, in the step a), the heating rate is 1-2°C per minute.
[0009] As a preferred technical solution of the present invention, in the step b), the cooling rate is 1-2°C per minute.
[0010] The beneficial effects of the present invention are as follows: The present invention successfully solves the problem of insufficient color fastness of spandex fabrics in traditional dyeing processes by omitting the degreasing step, adopting high-temperature dyeing technology and accurately controlling various parameters in the dyeing and post-processing processes. It not only improves the dyeing effect and color fastness, but also reduces the production cost, bringing new technological breakthroughs and market opportunities to the dyeing and post-processing fields of spandex fabrics. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 1 is a schematic diagram of a test sample of color fastness of spandex fabric in Example 1; Figure 2 Schematic diagram of a test sample of color fastness of spandex fabric in Example 2; Figure 3 This is a schematic diagram of a test sample of color fastness of spandex fabric in comparative example 1; Figure 4 It is a schematic diagram of the test sample of the color fastness of the spandex fabric of comparative example 2. DETAILED DESCRIPTION
[0012] The present invention provides a method for dyeing and post-processing and cleaning a spandex fabric with high color fastness, and the method comprises the following steps: a. Fabric dyeing: Place the spandex fabric in a dyeing tank, heat it to 125°C to 130°C, dye it, and keep the temperature for 30 to 50 minutes; b. Cooling treatment: After dyeing is completed, the temperature in the dyeing tank is cooled to 70℃ to 80℃ and maintained at this temperature for 20 to 40 minutes; c. First post-treatment: The cooled spandex fabric is immersed in water at a bath ratio of 1:8 to 1:15. For each liter of water at this ratio, 2 to 4 grams of hydrosulfite and an equal amount of soda ash are added, and then the temperature is raised to 80°C to 90°C and maintained at this temperature for 20 to 40 minutes; d. Second post-treatment: Add glacial acetic acid to the same aqueous solution after the first post-treatment in an amount of 0.5-1 g of glacial acetic acid per liter of water, and then keep warm at a temperature range of 40°C to 60°C for 20 to 30 minutes; e. Third post-treatment: Add a weak alkaline soaping agent to the same aqueous solution after the second post-treatment, wherein the pH value of the soaping agent is 7 to 8, and the amount added is 1 to 4 grams of soaping agent per liter of water, and the temperature is raised to 30°C to 80°C, and the temperature is maintained for 20 to 50 minutes; f. Washing: After the third post-treatment, cool the spandex fabric to 30°C to 40°C and wash it for 10 to 15 minutes until the fabric is clean and ready to be washed; Wherein, in the step c), the weight of the spandex fabric is 5-800kg; Wherein, in the step c), the mixture is immersed in water at a bath ratio of 1:10; Wherein, in the step c), for every liter of water at this ratio, 4 grams of sodium hypochlorite and an equal amount of soda ash are added; Wherein, in step a), the heating rate is 1-2°C per minute; Wherein, in the step b), the cooling rate is 1-2°C per minute.
[0013] In the fabric dyeing stage, the present invention cleverly adopts high-temperature dyeing technology, placing the spandex fabric in a dyeing vat, heating it to a suitable temperature range of 125°C to 130°C, and maintaining this high temperature for 30 to 50 minutes. This step ensures that the dye can fully penetrate into the fiber to achieve uniform and full color. Subsequently, through cooling treatment, the present invention slowly adjusts the temperature in the dyeing vat to 70°C to 80°C and maintains it for a period of time, thereby consolidating the fixation state of the dye in the fiber and effectively preventing the dye from falling off in the subsequent process; In terms of the improvement of the degreasing step, the present invention omits the degreasing step in the traditional process, avoiding the destruction of the natural protective layer on the surface of the spandex fabric due to excessive cleaning. This improvement not only improves the utilization rate of the dye, but also significantly enhances the color fastness of the fabric, so that the dyed spandex fabric can easily achieve a higher level of performance in the PVC color fastness test, which can reach level 4-5, far exceeding the level 2-3 that can be achieved by the traditional process; In the first post-treatment stage, the present invention carefully selects the bath ratio, immerses the cooled spandex fabric in water at a ratio of 1:8 to 1:15, and adds an appropriate amount of hydrosulfite and an equal amount of soda ash to each liter of water at this ratio, and then heats up to 80°C to 90°C again and maintains it for a period of time, so as to improve the stability of the dye and ensure the durability and brightness of the fabric color. Next, in the second post-treatment stage, the present invention further adds glacial acetic acid to the same aqueous solution, and further stabilizes the binding state of the dye in the fiber by adjusting the pH value of the solution. In the third post-treatment stage, the present invention introduces a weak alkaline soaping agent, which not only helps to remove the active agent on the surface of the fabric, but also further consolidates the binding between the dye and the fabric, thereby improving the overall quality of the fabric. In addition, the innovative method of the present invention also significantly reduces production costs. Since the degreasing step is omitted, not only the amount of auxiliary agents used and the wastewater treatment cost are reduced, but also the production cycle is shortened and the production efficiency is improved. At the same time, due to the significant improvement in color fastness, the dyed spandex fabric is more durable in subsequent processing and use, reducing the return and rework caused by insufficient color fastness, and further reducing the overall cost. In summary, the present invention successfully solves the problem of insufficient color fastness of spandex fabrics in traditional dyeing processes by omitting the degreasing step, adopting high-temperature dyeing technology and accurately controlling various parameters in the dyeing and post-processing processes. It not only improves the dyeing effect and color fastness, but also reduces the production cost, bringing new technological breakthroughs and market opportunities to the dyeing and post-processing fields of spandex fabrics. Example 1
[0014] Fabric selection and preparation: Spandex fabric with a mass of 6 kg was selected as the experimental material; Dyeing: Place the spandex fabric in a dyeing tank, heat it up to 128°C at a rate of 1.5°C per minute, and maintain this temperature for 40 minutes for dyeing; Cooling treatment: After dyeing is completed, the temperature in the dyeing tank is lowered to 75°C at a cooling rate of 1.5°C per minute and maintained at this temperature for 30 minutes; First post-treatment: The cooled spandex fabric is immersed in water at a bath ratio of 1:12 (i.e., the ratio of fabric mass to water is 6kg:72L). For each liter of water at this ratio, 0.33 grams of hydrosulfite and an equal amount of soda ash are added (i.e., a total of 24 grams of hydrosulfite and 24 grams of soda ash are added), and then the temperature is raised to 85°C and maintained at this temperature for 30 minutes; • Second post-treatment: Add glacial acetic acid to the same aqueous solution after the first post-treatment, with the amount added being 0.042 g of glacial acetic acid per liter of water (i.e., a total of 3 g of glacial acetic acid), and then keep warm at 50°C for 25 minutes; • Third post-treatment: Add weak alkaline soaping agent (pH 7.5) to the same aqueous solution after the second post-treatment, with the amount added being 0.083 g of soaping agent per liter of water (i.e., a total of 6 g of soaping agent), raise the temperature to 50°C, and maintain the temperature for 35 minutes; Washing and discharging fabric: After the third post-treatment, cool the spandex fabric to 35°C and wash it for 12 minutes until the fabric is clean and discharged; Test standards and methods: Color fastness test: GB / T 3920-2008 "Textiles - Color fastness - Tests for color fastness to rubbing" standard is used for testing, and the color fastness can reach level 4.5; By visual inspection, such as Figure 1 As shown, the left side is a black spandex fabric sample, and the right side is a white fabric sample. After the two were rubbed against each other, it was observed that there was no obvious color contamination or change on the surface of the white fabric sample, indicating that the black spandex fabric sample has high color fastness. Example 2
[0015] Fabric selection and preparation: 8kg of spandex fabric was selected as the experimental material; Dyeing: Place the spandex fabric in a dyeing tank, heat it up to 130°C at a rate of 2°C per minute, and maintain this temperature for 50 minutes for dyeing; Cooling treatment: After dyeing is completed, the temperature in the dyeing tank is lowered to 80°C at a cooling rate of 2°C per minute and maintained at this temperature for 40 minutes; First post-treatment: The cooled spandex fabric is immersed in water at a bath ratio of 1:10 (i.e., the ratio of fabric mass to water is 8kg:80L). For each liter of water at this ratio, 0.5 grams of hydrosulfite and an equal amount of soda ash are added (i.e., a total of 40 grams of hydrosulfite and 40 grams of soda ash are added), and then the temperature is raised to 90°C and maintained at this temperature for 40 minutes; Second post-treatment: Add glacial acetic acid to the same aqueous solution after the first post-treatment, with the amount added being 0.0625 g of glacial acetic acid per liter of water (i.e., a total of 5 g of glacial acetic acid), and then keep warm at 60°C for 30 minutes; Third post-treatment: add weak alkaline soaping agent (pH 8) to the same aqueous solution after the second post-treatment, with the amount added being 0.125 g of soaping agent per liter of water (i.e., a total of 10 g of soaping agent), raise the temperature to 80°C, and maintain the temperature for 20 minutes; Washing and discharging fabric: After the third post-treatment, cool the spandex fabric to 40℃ and wash it for 15 minutes until the fabric is clean and discharged; Color fastness test: GB / T 3920-2008 "Textiles - Color fastness - Tests for color fastness to rubbing" standard is used for testing, and the color fastness can reach level 4; By visual inspection, such as Figure 2 As shown, the left side is a black spandex fabric sample, and the right side is a white fabric sample. After the two were rubbed against each other, it was observed that there was no obvious color contamination or change on the surface of the white fabric sample, indicating that the black spandex fabric sample has high color fastness.
[0016] Comparative Example 1 Experimental conditions and steps: Fabric selection and preparation: Use spandex fabric of the same mass (6 kg) as in Example 1; Degreasing step: Before dyeing, the fabric is subjected to conventional degreasing treatment; Dyeing: Raise the temperature to 125°C and keep it for 30 minutes for dyeing; Cooling treatment: cool to 70℃ and keep for 20 minutes; First post-treatment: bath ratio 1:12 (i.e. 6kg fabric: 72L water), add hydrosulfite and soda ash, add 0.33g per liter of water (24g in total), heat to 80℃, keep for 30 minutes; Second post-treatment: add glacial acetic acid, 0.042 g per liter of water (3 g in total), and keep warm for 20 minutes; Washing cloth: After completing the second post-treatment, wash the cloth directly; Color fastness test: GB / T 3920-2008 "Textiles - Color fastness - Tests for color fastness to rubbing" standard was used for testing, and the color fastness reached level 2.5; By visual inspection, such as Figure 3 As shown, the left side is a black spandex fabric sample, and the right side is a white fabric test product. After the two were rubbed against each other, it was observed that the surface of the white fabric test product had obvious color staining or changes, indicating that the color fastness of the black spandex fabric sample was low.
[0017] Comparative Example 2 Experimental conditions and steps: Fabric selection and preparation: Use spandex fabric of the same mass (8 kg) as in Example 2; Degreasing step: Before dyeing, the fabric is subjected to intensive degreasing treatment; Dyeing: Heat to 130°C and keep for 50 minutes for dyeing; Cooling treatment: cool to 80℃ and keep for 40 minutes; First post-treatment: bath ratio 1:10 (i.e. 8kg fabric: 80L water), add hydrosulfite and soda ash, add 0.5g per liter of water (40g in total), heat to 90℃, keep for 40 minutes; Second post-treatment: add glacial acetic acid, 0.0625 g per liter of water (5 g in total), and keep warm for 30 minutes; Washing cloth: After completing the second post-treatment, wash the cloth directly; Color fastness test: GB / T 3920-2008 "Textiles - Color fastness - Tests for color fastness to rubbing" standard was used for testing, and the color fastness reached level 2; By visual inspection, such as Figure 4 As shown, the left side is a black spandex fabric sample, and the right side is a white fabric test product. After the two were rubbed against each other, it was observed that the surface of the white fabric test product had obvious color staining or changes, indicating that the color fastness of the black spandex fabric sample was low.
[0018]
[0019] This experiment mainly discussed the effect of spandex fabric dyeing and post-treatment process on color fastness; by comparing the dyeing and post-treatment processes under different conditions, the following conclusions were drawn: Example 1 and Example 2: Without degreasing treatment, spandex fabrics showed higher color fastness grades (4.5 and 4 respectively) through specific dyeing and post-treatment processes (including the addition of weak alkaline soaping agent in the third post-treatment); Visual inspection results showed that there was no obvious color contamination or change on the surface of the white fabric after the friction test, further verifying the high level of color fastness; Comparative Example 1 and Comparative Example 2: In the case of degreasing treatment (conventional or enhanced) but lack of third post-treatment (soaping agent), the color fastness grade of spandex fabrics is significantly reduced (grade 2.5 and grade 2 respectively); Visual inspection results showed that after the friction test, the surface of the white fabric test product had obvious color staining or changes, indicating low color fastness; Key findings: The addition of weak alkaline soaping agent in the third post-treatment has a significant effect on improving the color fastness of spandex fabrics; Although degreasing treatment may help improve dyeing results in some cases, it was not found to have a direct effect on color fastness in this experiment. On the contrary, it may lead to a decrease in color fastness due to the lack of subsequent appropriate post-treatment; In summary, the color fastness of spandex fabrics can be significantly improved by optimizing the dyeing and post-treatment processes, especially the addition of soaping agent in the third post-treatment; this finding is of great significance for improving the quality and durability of textiles.
[0020] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.
[0021] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. A method for dyeing and post-treatment cleaning of spandex fabric with high color fastness, characterized in that: The method comprises the following steps: a. Fabric dyeing: Place the spandex fabric in a dyeing tank, heat it to 125°C to 130°C, dye it, and keep the temperature for 30 to 50 minutes; b. Cooling treatment: After dyeing is completed, the temperature in the dyeing tank is cooled to 70℃ to 80℃ and maintained at this temperature for 20 to 40 minutes; c. First post-treatment: The cooled fabric is immersed in water at a bath ratio of 1:8 to 1:
15. For every liter of water at this ratio, 2 to 4 grams of hydrosulfite and an equal amount of soda ash are added, and then the temperature is raised to 80°C to 90°C and maintained at this temperature for 20 to 40 minutes; d. Second post-treatment: Add glacial acetic acid to the same aqueous solution after the first post-treatment in an amount of 0.5-1 g of glacial acetic acid per liter of water, and then keep warm at a temperature range of 40°C to 60°C for 20 to 30 minutes; e. Third post-treatment: Add a weak alkaline soaping agent to the same aqueous solution after the second post-treatment, wherein the pH value of the soaping agent is 7 to 8, and the amount added is 1 to 4 grams of soaping agent per liter of water, and the temperature is raised to 30°C to 80°C, and the temperature is maintained for 20 to 50 minutes; f. Washing: After the third post-treatment, cool the spandex fabric to 30°C to 40°C and wash it for 10 to 15 minutes until the fabric is clean.
2. The method for dyeing and post-treatment cleaning of spandex fabric with high color fastness according to claim 1, characterized in that: In the step c), the weight of the spandex fabric is 5-800kg.
3. The method for dyeing and post-treatment cleaning of spandex fabric with high color fastness according to claim 1, characterized in that: In the step c), the mixture is immersed in water at a bath ratio of 1:
10.
4. The method for dyeing and post-processing and cleaning a spandex fabric with high color fastness according to claim 1, characterized in that: In the step c), 4 grams of sodium hydrosulfite and an equal amount of soda ash are added to each liter of water at this ratio.
5. The method for dyeing and post-treatment cleaning of spandex fabric with high color fastness according to claim 1, characterized in that: In the step a), the heating rate is 1-2°C per minute.
6. The method for high color fastness dyeing and post-treatment cleaning of spandex fabric according to claim 1, characterized in that: In the step b), the cooling rate is 1-2°C per minute.