Environment-friendly gambiered canton gauze silk dyeing method based on chitosan modification

Abstract

The invention discloses an environment-friendly gambiered canton gauze silk dyeing method based on chitosan modification and special modified slurry. The method comprises the steps that white body silk is cleaned and pretreated, and modified slurry (containing oxidized starch, glycerin and the like) containing food-grade chitosan with the deacetylation degree larger than 80% is adopted for sizing and drying; crushing dioscorea cirrhosa, soaking the dioscorea cirrhosa in common water to prepare juice, spraying silk, drying at the temperature below 70 DEG C, and circulating for 8-10 times; padding with a 3% laccase solution at the temperature of 30-35 DEG C, standing for 20 hours, drying at the temperature of 100 DEG C, and finally washing with water and desizing to finish dyeing. Chitosan is used for replacing a metal ion mordant, the problem that heavy metal exceeds the standard is thoroughly solved, the silk is endowed with the antibacterial function, the process is simplified, pollution is reduced, non-abandoned gambiered canton gauze environment-friendly and scientific development is achieved, and the modern textile standard is met.

Description

Technical Field

[0001] This invention relates to the field of silk dyeing technology, specifically to an environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification. Background Technology

[0002] As the world's only intangible cultural heritage technique for plant dyeing, Xiangyun yarn's traditional dyeing process has gradually revealed numerous flaws in its compatibility with modern environmental protection requirements and product quality standards over its long-term application. In the traditional Xiangyun yarn dyeing process, to effectively combine yam juice with silk fibers and enhance the dyeing effect, metal ions from the soil are typically used as a mordant. This involves either crushing the yam with the soil or soaking the yam in mineral-rich water to obtain the juice. This process, relying on metal ions from natural soil, makes the final dyed Xiangyun yarn products highly susceptible to heavy metal contamination, failing to meet the stringent heavy metal limits in modern textile safety standards. This severely restricts the promotion and application of Xiangyun yarn products in high-end markets both domestically and internationally.

[0003] Meanwhile, to achieve ideal dyeing depth and colorfastness, traditional processes often require repeated soaking and dyeing of silk. This repeated soaking and dyeing process further increases the accumulation of metal ions on the silk fabric, exacerbating the problem of excessive metal ion levels. Furthermore, the soaking and sun-drying stages and the mud-crossing stages in traditional Xiangyun yarn dyeing processes lack effective environmental control measures. This not only easily causes environmental pollution but also fails to fundamentally solve the inherent problems of poor colorfastness, unstable plant colors, and susceptibility to discoloration at high temperatures in plant dyeing. These defects collectively lead to fading and discoloration of traditional Xiangyun yarn products during use, affecting their lifespan and appearance stability, making it difficult to meet modern consumers' demands for high-quality and high-stability textiles. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems by providing an environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification, and also relates to a modified sizing agent for the dyeing method.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is: an environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification, comprising the following steps: Silk pretreatment steps: Clean the raw silk to remove oil and impurities from its surface; Sizing step: The pretreated silk is sized with a modified sizing agent containing chitosan, and then the sized silk is dried. Dioscorea cirrhosa juice preparation steps: crush Dioscorea cirrhosa and soak it in water to obtain Dioscorea cirrhosa juice; Dyeing steps: The yam juice is applied to the sized and dried silk, and then dried. This application and drying process is repeated multiple times. Enzyme treatment step: The silk that has undergone the dyeing step is impregnated with laccase solution and left to stand at 30-35°C for a period of time, followed by high-temperature drying; Post-processing steps: The enzyme-treated silk is washed with water and desized to obtain the dyed silk product.

[0006] Furthermore, the modified slurry used in the sizing step, based on the total weight of the modified slurry, includes the following components: Food-grade chitosan with a degree of deacetylation greater than 80% contains 3% or more. Oxidized starch 8%, 10% glycerin Citric acid 3%, 1% gelatin 5% urea Thickener 1%, The remainder is deionized water.

[0007] Furthermore, the preparation process of the modified slurry includes: mixing and stirring the components at a water temperature of 40-50℃ for 2 hours; The sizing step is completed using a digital printing sizing machine.

[0008] Furthermore, in the dyeing step, the yam juice is applied to the silk by spraying; the drying temperature is controlled below 70°C; and the application and drying are repeated 8 to 10 times.

[0009] Furthermore, in the enzyme treatment step, the concentration of the laccase solution is 3%; the standing time is 20 hours; and the high-temperature drying temperature is 100°C.

[0010] A modified sizing agent for an environmentally friendly dyeing method of Xiangyun yarn based on chitosan modification, comprising the following components based on the total weight of the modified sizing agent: Food-grade chitosan with a degree of deacetylation greater than 80% contains 3% or more. Oxidized starch 8%, 10% glycerin Citric acid 3%, 1% gelatin 5% urea Thickener 1%, The remainder is deionized water.

[0011] The advantages of this invention compared to existing technologies are as follows: It uses food-grade chitosan to replace the metal ion mordant in traditional processes, completely solving the problem of excessive metal ions caused by repeated soaking and dyeing in traditional Xiangyun yarn dyeing, thus ensuring the product meets modern environmental and safety standards; chitosan imparts natural antibacterial properties to the fabric, increasing its added value; it eliminates the reliance on soil-based metal ions in traditional processes, simplifying the process and reducing pollution; although it does not completely solve problems such as colorfastness, through laccase treatment and multiple spraying and drying processes, it improves the dyeing effect to a certain extent while remaining environmentally friendly, achieving the modernization and scientific development of intangible cultural heritage Xiangyun yarn, and reflecting the scientific progress of human civilization in the inheritance of traditional techniques. Detailed Implementation

[0012] I. Working principle of the invention: In the silk pretreatment stage, targeted cleaning treatment is carried out on the raw silk to remove oil, impurities and residual acid and alkali substances from the silk surface, so that the silk fiber surface is kept clean and uniform. This creates good conditions for the full bonding of modified sizing agent with silk fiber in the subsequent sizing step, and avoids the surface impurities affecting the adhesion of sizing agent and the uniformity of subsequent dyeing.

[0013] The sizing step, as one of the core innovative aspects of this invention, involves using a modified sizing agent containing food-grade chitosan with a deacetylation degree greater than 80% to sizing the pretreated silk. Chitosan molecules contain a large number of active groups such as amino and hydroxyl groups. These active groups can form hydrogen bonds and chemical bonds with the hydroxyl and amino groups on the surface of the silk fibers, thereby achieving a firm adhesion of the modified sizing agent to the silk fiber surface. Meanwhile, the oxidized starch in the modified slurry acts as a film-forming agent, forming a uniform film on the surface of silk fibers, providing a stable carrier for chitosan and other components; glycerol, as a plasticizer, enhances the flexibility of the slurry film, preventing silk from breaking due to slurry embrittlement during subsequent processing; citric acid adjusts the pH of the slurry, providing a suitable chemical environment for the dissolution of chitosan and the activation of active groups, and can also undergo cross-linking reactions with silk fibers and chitosan, further enhancing the bonding force between the slurry and silk; gelatin and thickener respectively improve the rheology and stability of the slurry; urea improves the solubility and dispersibility of each component in the slurry, ensuring uniform mixing of all components; and deionized water is used as a solvent to ensure that all components form a stable and uniform slurry system after stirring for 2 hours at a water temperature of 40-50℃. Using a digital printing sizing machine for sizing operations can achieve precise and uniform coating of sizing material on the silk surface. Subsequently, through drying treatment, the modified sizing material forms a strong functional film on the surface of the silk fibers. The chitosan in this film can not only replace metal ions in the traditional process as a mordant, but also has natural antibacterial properties, giving the dyed silk an antibacterial function.

[0014] In the preparation of yam juice, the traditional method of crushing yam with soil is abandoned. Instead, the washed yam is crushed and soaked in ordinary water to obtain yam juice. This eliminates the interference of metal ions in the soil on the dyeing process from the source, avoids the introduction and accumulation of metal ions on silk fabrics, and fundamentally solves the problem of excessive metal ions in traditional processes.

[0015] The dyeing process involves spraying yam juice onto the sized and dried silk surface. This spraying method ensures the juice is evenly distributed on the modified sizing film. The silk is then slowly dried at a temperature below 70°C. During this process, the pigment molecules in the yam juice are firmly fixed to the modified sizing film by chitosan through electrostatic adsorption and hydrogen bonding. Simultaneously, the active groups in the modified sizing chemically bind with the pigment molecules, enhancing the pigment's adhesion stability on the silk. Through 8-10 spraying and drying cycles, the pigment accumulation on the silk surface is gradually increased, achieving the desired dyeing depth while avoiding the problem of metal ion accumulation encountered in traditional repeated soaking and dyeing processes.

[0016] In the enzyme treatment step, a 3% laccase solution is used to paddle the silk that has undergone multiple spraying and drying processes. Laccase, as a redox enzyme, catalyzes the oxidative polymerization reaction of pigment molecules in yam juice, converting small-molecule pigments into large-molecule polymers. This further enhances the binding force between the pigments and chitosan and silk fibers, improving the color fastness after dyeing. Standing at 30-35℃ for 20 hours ensures that the laccase fully exerts its catalytic effect. Subsequently, drying at 100℃ stabilizes the enzyme-catalyzed reaction products on the silk fibers, further consolidating the dyeing effect.

[0017] The post-processing step involves professional water washing to desizing the enzyme-treated silk, removing unbound sizing components and impurities from the silk surface, restoring the soft feel of the dyed silk, and ensuring that there are no excess chemical residues in the final product, thus guaranteeing the product's environmental friendliness and safety.

[0018] 4. Implementation method: 2.1 Example 1 Raw materials and equipment Raw silk (S1): 14 momme raw silk, 1m x 1m; Modified slurry (total weight basis): chitosan (A1, degree of deacetylation 85%) 3%, oxidized starch (B1) 8%, glycerol (C1) 10%, citric acid (D1) 3%, gelatin (E1) 1%, urea (G1) 5%, thickener (F1) 1%, deionized water (H1) 69%; Other: 1 kg of fresh yam (W1), 3% laccase solution (N1); Equipment: mixing tank (U1), digital printing sizing machine (I1), dryer (V1 / AB1 / AE1), etc.

[0019] Process steps Pretreatment: S1 was soaked in a weak alkaline solution with pH=8 at 30°C for 30 minutes, rinsed until neutral, and dried at 60°C until the moisture content was 7%; Sizing: Heat H1 in U1 to 45℃, add B1-C1-D1-E1-G1-F1 to dissolve, then add A1 and stir for 2 hours; apply sizing to I1 (15g / m²) and dry at 80℃ for 10 minutes; Dioscorea cirrhosa juice: W1 is crushed (1-2mm), soaked in deionized water at a ratio of 1:5 for 24 hours (stirring once every 6 hours), and filtered to obtain J1; Dyeing: Spray J1 (8g / m²), dry at 65℃ for 8 minutes, repeat 10 times; Enzyme treatment: Immerse in 3% N1 (0.2MPa), stand at 32℃ for 20 hours, and dry at 100℃ for 15 minutes; Post-treatment: Wash with water at 40℃ for 20 minutes, then dry at 70℃ until the moisture content is 10%.

[0020] 2.2 Example 2 Slurry adjustment: chitosan (A2) 4%, deionized water (H2) 68%, the rest is the same as in Example 1; Process adjustments: Heat H2 to 42℃, apply 16g / m² of sizing (dry for 11 minutes); spray J2 (9g / m²), dry at 63℃ for 9 minutes (repeat 9 times); enzyme immersion pressure 0.22MPa (stand at 33℃), wash with water for 22 minutes, and dry to a moisture content of 9.5%.

[0021] 2.3, Example 3 Slurry preparation: Chitosan (A3) 3.5%, deionized water (H3) 68.5%, laccase solution (N3) 4%; Process adjustments: H3 is heated to 48℃, sizing is applied at 14g / m² (drying for 9 minutes); J3 is sprayed (7g / m²), dried at 67℃ for 7 minutes (repeated 8 times); enzyme immersion pressure is 0.18MPa (standing at 31℃), water washing is performed for 18 minutes, and drying is carried out until the moisture content is 10.2%.

[0022] 2.4 Comparative Example (Traditional Process) Raw materials and processes Raw materials: S4 (same as in Example 1), W4 1kg, river mud (M4, containing metal ions) 500g, mineral water (Wt4); Process: S4 is washed with clean water and then dried; W4 and M4 are crushed together, and WT4 is added and soaked for 24 hours to obtain J4; S4 is soaked in J4 for 2 hours and then exposed to the sun for 4 hours (repeated 10 times); it is soaked in river mud for 12 hours, dried, and then washed with water.

[0023] The present invention and its embodiments have been described above. This description is not restrictive. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. An environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification, characterized in that: Includes the following steps: Silk pretreatment steps: Clean the raw silk to remove oil and impurities from its surface; Sizing step: The pretreated silk is sized with a modified sizing agent containing chitosan, and then the sized silk is dried. Dioscorea cirrhosa juice preparation steps: crush Dioscorea cirrhosa and soak it in water to obtain Dioscorea cirrhosa juice; Dyeing steps: The yam juice is applied to the sized and dried silk, and then dried. This application and drying process is repeated multiple times. Enzyme treatment step: The silk that has undergone the dyeing step is impregnated with laccase solution and left to stand at 30-35°C for a period of time, followed by high-temperature drying; Post-processing steps: The enzyme-treated silk is washed with water and desized to obtain the dyed silk product.

2. The environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification according to claim 1, characterized in that: The modified slurry used in the sizing step, based on the total weight of the modified slurry, includes the following components: Food-grade chitosan with a degree of deacetylation greater than 80% contains 3% or more. Oxidized starch 8%, 10% glycerin Citric acid 3%, 1% gelatin 5% urea Thickener 1%, The remainder is deionized water.

3. The environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification according to claim 1, characterized in that: The preparation process of the modified slurry includes: mixing and stirring the components at a water temperature of 40-50℃ for 2 hours; The sizing step is completed using a digital printing sizing machine.

4. The environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification according to claim 1, characterized in that: In the dyeing step, the yam juice is applied to the silk by spraying; the drying temperature is controlled below 70°C; and the application and drying are repeated 8 to 10 times.

5. The environmentally friendly dyeing method for Xiangyun yarn based on chitosan modification according to claim 1, characterized in that: In the enzyme treatment step, the concentration of the laccase solution is 3%; the standing time is 20 hours; and the high-temperature drying temperature is 100°C.

6. A modified sizing agent for the environmentally friendly chitosan-modified Xiangyun yarn silk dyeing method according to any one of claims 1 to 5, characterized in that, Based on the total weight of the modified slurry, it is formulated from the following components: Food-grade chitosan with a degree of deacetylation greater than 80% contains 3% or more. Oxidized starch 8%, 10% glycerin Citric acid 3%, 1% gelatin 5% urea Thickener 1%, The remainder is deionized water.