Preparation method of lotus fiber persimmon-dyed textile based on lotus plants

Abstract

The invention relates to the technical field of persimmon dyeing, in particular to a preparation method of a lotus fiber persimmon-dyed textile based on lotus plants. The preparation method comprises the following steps: providing lotus stem fibers; carrying out enzymolysis pretreatment to obtain lotus stem fibers subjected to enzymolysis treatment; providing lotus leaves to obtain a lotus stem polyphenol concentrated solution; providing green persimmons to obtain a persimmon extracting solution; mixing the persimmon extracting solution with the lotus stem polyphenol concentrated solution to obtain a composite dyeing solution; then immersing the lotus stem fibers in the composite dye liquor, and obtaining a textile intermediate product after dipping; the intermediate product of the textile is subjected to microwave color fixation treatment and post-treatment, and the lotus fiber persimmon-dyed textile based on the lotus plants is obtained. The persimmon-dyed textile obtained by the invention has the advantages of bacteria resistance, oxidation resistance, color fastness and the like.

Description

Technical Field

[0001] This invention relates to the field of persimmon dyeing technology, specifically to a method for preparing lotus fiber persimmon-dyed textiles based on lotus plants. Background Technology

[0002] Natural dyeing is a broad category of dyeing and weaving methods, and persimmon dyeing is one of them. Persimmon dyeing has a long history in my country, but with the development and widespread use of chemical dyes, this ancient technique was gradually forgotten. In an era of diversified aesthetics and a return to nature, as dyeing techniques have matured, people have begun to enrich the color palette of natural dyes. In recent years, persimmon-dyed products have returned to the public eye as an environmentally friendly dye with unique characteristics. However, while persimmon-dyed products are environmentally friendly and natural, their antibacterial properties are insufficient, thus they are usually only decorative.

[0003] Lotus stems, a major waste product of lotus plants, are rich in cellulose and natural polyphenols, among which polyphenols possess certain antibacterial and antioxidant activities. Therefore, there is an urgent need for a preparation process that can combine lotus stem products with persimmon-dyed products to obtain a persimmon-dyed textile with antibacterial properties. Summary of the Invention

[0004] This disclosure provides a method for preparing lotus fiber-dyed textiles based on lotus plants, in order to address the shortcomings of related technologies.

[0005] According to a first aspect of the present disclosure, a method for preparing lotus fiber-dyed textiles based on lotus plants is provided, the method comprising the following steps: Step 1: Provide lotus stem fibers; pre-treat the lotus stem fibers with enzymatic hydrolysis to obtain enzymatically hydrolyzed lotus stem fibers; Step 2: Provide lotus leaves, and after crushing and reflux extraction, obtain lotus stem polyphenol concentrate; Step 3: Provide green persimmons, process the green persimmons to obtain persimmon extract; then mix the persimmon extract with the lotus stem polyphenol concentrate obtained in Step 2, and stir to obtain a composite dye solution; Step 4: Immerse the enzymatically hydrolyzed lotus stem fibers obtained in Step 1 in the composite dye solution obtained in Step 3, and obtain the intermediate textile product after immersion. Step 5: The intermediate textile product obtained in Step 4 is subjected to microwave color fixing treatment to obtain the color-fixed intermediate textile product. Step 6: The intermediate textile product after color fixing is post-processed to obtain the lotus fiber persimmon dyed textile based on lotus plants.

[0006] In one aspect of this disclosure, step 1 includes the following: Step 1-1: Provide lotus stem fiber; add the lotus stem fiber to cellulase solution, heat to 45℃-55℃, and enzymatically hydrolyze for 2-3 hours; Steps 1-2: After the enzymatic hydrolysis treatment is completed, the lotus stem fibers are taken out, washed and dried to obtain the enzymatically hydrolyzed lotus stem fibers. In step 1-1, the mass percentage of cellulase in the cellulase solution is selected from 0.5% to 1%; the mass ratio of lotus stalk fiber to the cellulase solution is selected from 1:(20-50).

[0007] In one aspect of this disclosure, step 2 includes the following: Step 2-1: Provide lotus leaves, crush the lotus leaves and pass them through a 20-50 mesh sieve to obtain lotus leaf powder; Step 2-2: Add the lotus leaf powder to a 65%-80% ethanol solution, heat to 65℃-85℃, and reflux for 1.5-3.5 hours; Steps 2-3: After reflux extraction, the filtrate is obtained by filtration, and then the volume of the filtrate is concentrated to 1 / 4 to 1 / 6 of the original volume to obtain the lotus stem polyphenol concentrate; In step 2-2, the mass ratio of the lotus leaf powder to the ethanol solution is selected from 1:(25-45).

[0008] In one aspect of this disclosure, step 3 includes the following: Step 3-1a: Provide fresh green persimmons, wash the green persimmons, remove the stems and seeds, juice them, filter them, and obtain persimmon extract; Step 3-2a: Mix the persimmon extract with the lotus stem polyphenol concentrate obtained in step 2, adjust the pH to 4.0-4.5, and stir at 45℃-55℃ for 30-60 min to obtain a composite dye solution; wherein, the mass ratio of the persimmon extract to the lotus stem polyphenol concentrate obtained in step 2 is selected from 10:(1-1.5).

[0009] In one aspect of this disclosure, step 3 includes the following: Step 3-1b: Provide fresh green persimmons, wash, remove stems and pits from the green persimmons, and cut them into fruit slices 3-10 mm thick; pre-freeze at -25℃ to -60℃ for 12-24 hours, then vacuum dry and pulverize through a 30-60 mesh sieve to obtain green persimmon powder; Step 3-2b: Add the green persimmon powder to water, heat to 45℃-55℃, and extract by ultrasonication for 1-2 hours; wherein the mass ratio of the green persimmon powder to water is selected from 1:(3-5); Step 3-3b: After ultrasonic extraction, the persimmon extract is obtained by filtration; then the persimmon extract is mixed with the lotus stem polyphenol concentrate obtained in step 2, the pH value is adjusted to 4.0-4.5, and the mixture is kept warm and stirred at 45℃-55℃ for 30-60 minutes to obtain a composite dye solution; wherein, the mass ratio of the persimmon extract to the lotus stem polyphenol concentrate obtained in step 2 is selected as 10:(1-2).

[0010] In one aspect of this disclosure, step 4 includes the following: Step 4-1: Immerse the enzymatically hydrolyzed lotus stem fibers obtained in Step 1 in the composite dye solution obtained in Step 3, with a bath ratio of 1:(20-35); keep the solution at 40℃-50℃ for 90-120 minutes, stirring once every 20 minutes during the process.

[0011] In one aspect of this disclosure, step 5 includes the following: Step 5-1: Place the intermediate textile product obtained in Step 4 into a microwave drying and color-fixing device, set the power to 300-400W, the temperature to 60℃-65℃, microwave for 5-10 minutes, and then let it cool naturally to room temperature to obtain the intermediate textile product after color fixing.

[0012] In one aspect of this disclosure, step 6 includes the following: Step 6-1: Wash and dry the intermediate textile product after color fixing; Step 6-2: Dissolve chitosan in a 1.5wt%-3wt% acetic acid solution, stir until the chitosan is completely dissolved, and then let it stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1-2%. Step 6-3: Add the dried and color-fixed intermediate textile product to the chitosan solution and soak for 10-25 minutes; then take it out, roll it with a rolling mill so that the roll-off rate falls to 60%-70%, and then dry it with hot air to obtain the lotus fiber persimmon dyed textile based on lotus plants.

[0013] In one aspect of this disclosure, the lotus stalk fiber is prepared by the following steps: Step 7-1: Provide lotus stalks as raw materials; cut the lotus stalks into small sections of 1.5-4cm, then add them to a 5-10g / L sodium hydroxide solution, heat to 90℃-95℃, and keep warm while stirring for 2-3 hours; Step 7-2: After the reaction is complete, the mixture is washed and added to a 1-2 g / L sodium chlorite solution, and bleached at 65℃-75℃ for 1-2 h; after bleaching, the lotus stem fibers are obtained after washing and drying.

[0014] In one aspect of this disclosure, in step 7-1, the sodium chlorite solution has a mass percentage content of 1.5 g / L.

[0015] In one aspect of this disclosure, in step 3-1a, a 100-120 mesh screen is used for filtration.

[0016] In one aspect of this disclosure, in step 3-3b, a 100-120 mesh screen is used for filtration.

[0017] In one aspect of the present disclosure, in step 5-1, the frequency of the microwave drying and color-fixing device is set to 2450MHz.

[0018] In one aspect of this disclosure, in step 5-1, the thickness of the intermediate textile product laid flat inside the microwave drying and color-fixing device does not exceed 5 mm.

[0019] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention uses only lotus stems and leaves as raw materials, and includes fiber preparation, polyphenol extraction and dyeing functions. It avoids relying on other high-value components such as lotus seeds and lotus pods, improves the utilization rate of raw materials, and conforms to the concept of circular economy. (2) Enzymatic pretreatment was used to improve the dyeing performance of lotus stem fiber. Combined with microwave-assisted color fixing technology, the dyeing efficiency was improved. Furthermore, persimmon tannin and lotus leaf polyphenols formed a synergistic effect, resulting in better antibacterial properties than traditional persimmon dye products. (3) The color fastness was further improved by combining the composite dyeing solution with the chitosan post-treatment; (4) The entire process of this disclosure uses water and ethanol as the main solvents and does not use any toxic chemical reagents. The energy consumption of microwave color fixing is reduced by 50% compared with traditional hot air color fixing, which meets the requirements of green production. Attached Figure Description

[0020] Figure 1 The present invention provides a process flow diagram for the preparation of lotus fiber-dyed textiles based on lotus plants. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0023] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0024] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0025] Examples and comparative examples:

[0026] Example 1: Example 1 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 1.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 7.8 parts by weight of lotus stalk fiber.

[0027] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0028] Weigh 15 parts by weight of lotus leaves, crush the lotus leaves and pass them through a 30-mesh sieve to obtain 11.5 parts by weight of lotus leaf powder; add the lotus leaf powder to 345 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain lotus stem polyphenol concentrate (about 80 parts by weight).

[0029] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of lotus stem polyphenol concentrate. The pH was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0030] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0031] After color fixing, the product was washed (washed with water until neutral) and dried at 60°C. Chitosan was dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan was completely dissolved. Then, the product was allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product was added to the chitosan solution and immersed for 12 minutes. Then, the product was taken out and rolled with a rolling mill to achieve a roll-off rate of about 60%. The product was then dried with hot air (105°C) to obtain the lotus fiber persimmon-dyed textile based on lotus plants as described in Example 1.

[0032] Example 2: Example 2 includes the following steps: 400 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and then added to a 3 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 8.1 parts by weight of lotus stalk fiber.

[0033] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0034] Weigh 15 parts by weight of lotus leaves, crush the lotus leaves and pass them through a 30-mesh sieve to obtain 11.5 parts by weight of lotus leaf powder; add the lotus leaf powder to 345 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain lotus stem polyphenol concentrate (about 80 parts by weight).

[0035] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of lotus stem polyphenol concentrate. The pH was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0036] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0037] After color fixing, the product is washed (washed with water until neutral) and dried at 60°C. Chitosan is dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan is completely dissolved. Then, it is allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product is added to the chitosan solution and soaked for 12 minutes. Then, it is taken out and rolled with a rolling mill to make the roll-off rate about 60%. Then, it is dried with hot air (105°C) to obtain the lotus fiber persimmon dyed textile based on lotus plants in Example 2.

[0038] The difference between Example 2 and Example 1 is that the sodium chlorite solution used in Example 2 has a higher concentration, resulting in a decrease in the yield of lotus stalk fiber (Example 1 yielded 7.8 parts by weight of product from 250 parts by weight of lotus stalk, while Example 2 yielded 8.1 parts by weight of product from 400 parts by weight of lotus stalk).

[0039] Example 3: Example 3 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 0.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 9.4 parts by weight of lotus stalk fiber.

[0040] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0041] Weigh 15 parts by weight of lotus leaves, crush the lotus leaves and pass them through a 30-mesh sieve to obtain 11.5 parts by weight of lotus leaf powder; add the lotus leaf powder to 345 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain lotus stem polyphenol concentrate (about 80 parts by weight).

[0042] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of lotus stem polyphenol concentrate. The pH was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0043] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0044] After color fixing, the product is washed (washed with water until neutral) and dried at 60°C. Chitosan is dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan is completely dissolved. Then, it is allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product is added to the chitosan solution and soaked for 12 minutes. Then, it is taken out and rolled with a rolling mill to make the roll-off rate about 60%. Then, it is dried with hot air (105°C) to obtain the lotus fiber persimmon dyed textile based on lotus plants in Example 3.

[0045] The difference between Example 3 and Example 1 is that the sodium chlorite solution used in Example 3 has a lower concentration, resulting in a decrease in the yield of lotus stem fibers.

[0046] Example 4: Example 4 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 1.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 7.8 parts by weight of lotus stalk fiber.

[0047] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0048] Weigh 15 parts by weight of lotus leaves, crush the lotus leaves and pass them through a 30-mesh sieve to obtain 11.5 parts by weight of lotus leaf powder; add the lotus leaf powder to 345 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain lotus stem polyphenol concentrate (about 80 parts by weight).

[0049] Fresh green persimmons were provided. The persimmons were washed, stemmed, and pitted, then sliced ​​into pieces approximately 4-6 mm thick. Pre-frozen at -30°C for 18 hours, then vacuum-dried and pulverized through a 40-mesh sieve to obtain green persimmon powder. The green persimmon powder was added to four times its weight of water, heated to 50°C, and ultrasonically extracted for 1.5 hours. After ultrasonic extraction, the extract was filtered through a 120-mesh sieve to obtain the persimmon extract. 200 parts by weight of the persimmon extract were mixed with 25 parts by weight of lotus stem polyphenol concentrate, and the pH was adjusted to 4.3 using citric acid. The mixture was stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0050] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0051] After color fixing, the product is washed (washed with water until neutral) and dried at 60°C. Chitosan is dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan is completely dissolved. Then, it is allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product is added to the chitosan solution and soaked for 12 minutes. Then, it is taken out and rolled with a rolling mill to make the roll-off rate about 60%. Then, it is dried with hot air (105°C) to obtain the lotus fiber persimmon dyed textile based on lotus plants in Example 4.

[0052] The difference between Example 4 and Example 1 is that the method for extracting persimmon extract in Example 4 is different.

[0053] Comparative Example 1: Comparative Example 1 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 1.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 7.8 parts by weight of lotus stalk fiber.

[0054] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0055] Weigh 10 parts by weight of perilla seeds, grind and pulverize them, and pass them through a 60-mesh sieve. Then, add petroleum ether to remove the fat. The mass ratio of petroleum ether to perilla seed powder is 2:1. After sealing and soaking for 24 hours, filter the mixture and dry the residue in an oven until constant weight. Then, add 1.5 wt% pectinase and heat to 45°C for enzymatic hydrolysis for 2 hours. After enzymatic hydrolysis, after enzyme inactivation and filtration, obtain the residue. Then, add 40% ethanol at a material-to-liquid ratio of 1:35 and perform ultrasonic treatment (50°C, 45 min, 432 W). Then, combine the filtrates and concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain perilla seed concentrate.

[0056] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of perilla seed concentrate. The pH was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a compound dye solution.

[0057] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0058] After color fixing, the product was washed (washed with water until neutral) and dried at 60°C. Chitosan was dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan was completely dissolved. Then, the product was allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product was added to the chitosan solution and immersed for 12 minutes. Then, the product was removed, rolled with a rolling mill to achieve a roll-off rate of about 60%, and then dried with hot air (105°C) to obtain the persimmon-dyed textile of Comparative Example 1.

[0059] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses perilla seed polyphenol concentrate instead of lotus stem polyphenol concentrate in Example 1.

[0060] Comparative Example 2: Comparative Example 2 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 1.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 7.8 parts by weight of lotus stalk fiber.

[0061] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0062] Weigh 15 parts by weight of tea leaves, crush the tea leaves and pass them through a 50-mesh sieve to obtain 12.7 parts by weight of tea powder; add the tea powder to 350 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain tea polyphenol concentrate (about 82 parts by weight).

[0063] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of tea polyphenol concentrate. The pH value was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0064] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0065] After color fixing, the product was washed (washed with water until neutral) and dried at 60°C. Chitosan was dissolved in a 1.5 wt% acetic acid solution and stirred until the chitosan was completely dissolved. Then, the product was allowed to stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1%. The color-fixed product was added to the chitosan solution and immersed for 12 minutes. Then, the product was taken out and rolled with a rolling mill to achieve a roll-off rate of about 60%. The product was then dried with hot air (105°C) to obtain the persimmon-dyed textile of Comparative Example 2.

[0066] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 uses tea polyphenol concentrate instead of lotus stem polyphenol concentrate in Example 1.

[0067] Comparative Example 3: The steps in Comparative Example 3 are the same as those in Example 1, except that Comparative Example 3 uses ramie fabric fibers of equal mass instead of the lotus stalk fibers used in Example 1.

[0068] Comparative Example 4: The steps in Comparative Example 4 are the same as those in Example 1, except that Comparative Example 3 uses cotton fibers of equal mass instead of the lotus stalk fibers used in Example 1.

[0069] Comparative Example 5: The steps in Comparative Example 5 were the same as in Example 1, except that Comparative Example 5 did not use lotus stem polyphenol concentrate, but directly used persimmon extract to impregnate the lotus stem fibers.

[0070] Comparative Example 6: Comparative Example 6 includes the following steps: 250 parts by weight of lotus stalks were weighed as raw material; the lotus stalks were cut into small sections of about 2.5 cm, and then added to a 5 g / L sodium hydroxide solution, heated to 90 °C, and stirred for 2 h; after the reaction was completed, the mixture was washed and added to a 1.5 g / L sodium chlorite solution, and bleached at 70 °C for 1 h; after bleaching, the mixture was washed (washed with water until neutral) and dried at 60 °C to obtain 7.8 parts by weight of lotus stalk fiber.

[0071] Weigh 7.5 parts by weight of lotus stem fiber; add the lotus stem fiber to 150 parts by weight of 0.5 wt% cellulase solution, heat to 45°C, and enzymatically hydrolyze for 2 hours; after the enzymatic hydrolysis is completed, take out the lotus stem fiber, wash (wash with water until neutral), and dry at 60°C to obtain the enzymatically hydrolyzed lotus stem fiber.

[0072] Weigh 15 parts by weight of lotus leaves, crush the lotus leaves and pass them through a 30-mesh sieve to obtain 11.5 parts by weight of lotus leaf powder; add the lotus leaf powder to 345 parts by weight of 60% ethanol solution, heat to 70℃, and reflux for 2 hours; after the reflux extraction is completed, filter to obtain filtrate, and then concentrate the volume of the filtrate to 1 / 5 of the original volume to obtain lotus stem polyphenol concentrate (about 80 parts by weight).

[0073] Fresh green persimmons were provided. The green persimmons were washed, stemmed, and pitted. Juice was extracted and filtered (through a 120-mesh sieve) to obtain 200 parts by weight of persimmon extract. The 200 parts by weight of persimmon extract were mixed with 25 parts by weight of lotus stem polyphenol concentrate. The pH was adjusted to 4.3 with citric acid and stirred at 50°C for 45 minutes to obtain a composite dye solution.

[0074] Lotus stalk fibers were immersed in a composite dyeing solution with a liquor ratio of 1:25; the solution was kept at 40°C for 100 minutes, and stirred every 20 minutes during the process; the product was then placed in a 2450MHz microwave drying and color-fixing device with a power of 300W and a temperature of 60°C for 5 minutes, and then naturally cooled to room temperature to obtain the color-fixed product.

[0075] After color fixing, the product was washed (washed with water until neutral) and dried at 60°C to obtain the lotus fiber persimmon-dyed textile of Comparative Example 6.

[0076] Antibacterial ability test: The antibacterial properties of the fiber samples were tested according to GB / T20944.3-2008 "Evaluation of Antibacterial Properties of Textiles - Part 3: Shaking Method". A working bacterial solution without fiber samples served as a control group. Three parallel samples were set up for each fiber sample, and the average value was taken. 10 mg of antibacterial fiber was placed in a bacterial culture bottle with an optical density (OD value) of 0.5, resulting in a bacterial concentration of 10... 5 -10 6 The concentration of CFU / mL was then increased, and the culture was placed in a ZHWY-100 constant temperature shaker (Shanghai Zhicheng Analytical Instruments Co., Ltd.) for 24 hours. The OD value of the bacterial culture was measured using a Lambda 950 UV-Vis spectrophotometer (PerkinElmer, Germany). The inhibition rate was calculated using the following formula: R = (O A -O B ) / O A *100%, where R is the antibacterial rate, and O A The OD value of the control group (i.e., pure bacterial culture without fiber) after 24 hours of incubation in a constant temperature shaker is shown below; OB is the OD value of the experimental group sample and bacterial culture after 24 hours of co-incubation in a constant temperature shaker. The antibacterial activity of the examples and comparative examples in the bacterial cultures of *Escherichia coli* and *Staphylococcus aureus* was tested respectively; the values ​​are shown in Table 1 below.

[0077]

[0078] Colorfastness test and antioxidant capacity test: The color fastness to washing of the examples and comparative examples was tested according to AATCC 61-2010 3A test method; the color fastness to rubbing of the examples and comparative examples was tested according to AATCC 8-2007 test method, and the values ​​are shown in Table 2 below.

[0079] The textiles of the examples and comparative examples were treated with a D65 light source for 18 hours, and the color difference ΔE before and after sun exposure was recorded. The values ​​are shown in Table 2 below (the smaller the color difference ΔE value before and after sun exposure, the better the antioxidant fastness).

[0080]

[0081] As can be seen from Tables 1 and 2, both lotus stem polyphenols and lotus stem fibers have good compatibility with persimmon dye extract. Lotus stem polyphenols have outstanding antioxidant protection ability for persimmon dye extract, and lotus stem fibers also have good adhesion to persimmon dye extract, both of which are better than comparative examples 1-4.

[0082] Furthermore, the performance of Example 4 is particularly significant because the freeze-drying-ultrasonic extraction method provided in Example 4 yields fine particles with a high tannin concentration per unit area, which can better penetrate the cell cavities and micropores of lotus stalk fibers, and then form hydrogen bonds with the cellulose hydroxyl groups through tannin. Moreover, sugar molecules form a viscous hydration layer with water, hindering the formation of hydrogen bonds between tannin and cellulose hydroxyl groups; freeze-drying can significantly reduce sugar content, thereby improving color fastness.

[0083] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A method for preparing lotus fiber-dyed textiles based on lotus plants, characterized in that, The preparation method includes the following steps: Step 1: Provide lotus stem fibers; pre-treat the lotus stem fibers with enzymatic hydrolysis to obtain enzymatically hydrolyzed lotus stem fibers; Step 2: Provide lotus leaves, and after crushing and reflux extraction, obtain lotus stem polyphenol concentrate; Step 3: Provide green persimmons, process the green persimmons to obtain persimmon extract; then mix the persimmon extract with the lotus stem polyphenol concentrate obtained in Step 2, and stir to obtain a composite dye solution; Step 4: Immerse the enzymatically hydrolyzed lotus stem fibers obtained in Step 1 in the composite dye solution obtained in Step 3, and obtain the intermediate textile product after immersion. Step 5: The intermediate textile product obtained in Step 4 is subjected to microwave color fixing treatment to obtain the color-fixed intermediate textile product. Step 6: The intermediate textile product after color fixing is post-processed to obtain the lotus fiber persimmon dyed textile based on lotus plants.

2. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 1 includes the following: Step 1-1: Provide lotus stem fiber; add the lotus stem fiber to cellulase solution, heat to 45℃-55℃, and enzymatically hydrolyze for 2-3 hours; Steps 1-2: After the enzymatic hydrolysis treatment is completed, the lotus stem fibers are taken out, washed and dried to obtain the enzymatically hydrolyzed lotus stem fibers. In step 1-1, the mass percentage of cellulase in the cellulase solution is selected from 0.5% to 1%; the mass ratio of lotus stalk fiber to cellulase solution is selected from 1:(20-50).

3. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 2 includes the following: Step 2-1: Provide lotus leaves, crush the lotus leaves and pass them through a 20-50 mesh sieve to obtain lotus leaf powder; Step 2-2: Add the lotus leaf powder to a 65%-80% ethanol solution, heat to 65℃-85℃, and reflux for 1.5-3.5 hours; Steps 2-3: After reflux extraction, the filtrate is obtained by filtration, and then the volume of the filtrate is concentrated to 1 / 4 to 1 / 6 of the original volume to obtain the lotus stem polyphenol concentrate; In step 2-2, the mass ratio of the lotus leaf powder to the ethanol solution is selected from 1:(25-45).

4. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 3 includes the following: Step 3-1a: Provide fresh green persimmons, wash the green persimmons, remove the stems and seeds, juice them, filter them, and obtain persimmon extract; Step 3-2a: Mix the persimmon extract with the lotus stem polyphenol concentrate obtained in step 2, adjust the pH to 4.0-4.5, and stir at 45℃-55℃ for 30-60 min to obtain a composite dye solution; wherein, the mass ratio of the persimmon extract to the lotus stem polyphenol concentrate obtained in step 2 is selected from 10:(1-1.5).

5. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 3 includes the following: Step 3-1b: Provide fresh green persimmons, wash, remove stems and pits from the green persimmons, and cut them into fruit slices 3-10 mm thick; pre-freeze at -25℃ to -60℃ for 12-24 hours, then vacuum dry and pulverize through a 30-60 mesh sieve to obtain green persimmon powder; Step 3-2b: Add the green persimmon powder to water, heat to 45℃-55℃, and extract by ultrasonication for 1-2 hours; wherein the mass ratio of the green persimmon powder to water is selected from 1:(3-5); Step 3-3b: After ultrasonic extraction, the persimmon extract is obtained by filtration; then the persimmon extract is mixed with the lotus stem polyphenol concentrate obtained in step 2, the pH value is adjusted to 4.0-4.5, and the mixture is kept warm and stirred at 45℃-55℃ for 30-60 minutes to obtain a composite dye solution; wherein, the mass ratio of the persimmon extract to the lotus stem polyphenol concentrate obtained in step 2 is selected as 10:(1-2).

6. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 4 includes the following: Step 4-1: Immerse the enzymatically hydrolyzed lotus stem fibers obtained in Step 1 in the composite dye solution obtained in Step 3, with a bath ratio of 1:(20-35); keep the solution at 40℃-50℃ for 90-120 minutes, stirring once every 20 minutes during the process.

7. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 5 includes the following: Step 5-1: Place the intermediate textile product obtained in Step 4 into a microwave drying and color-fixing device, set the power to 300-400W, the temperature to 60℃-65℃, microwave for 5-10 minutes, and then let it cool naturally to room temperature to obtain the intermediate textile product after color fixing.

8. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, Step 6 includes the following: Step 6-1: Wash and dry the intermediate textile product after color fixing; Step 6-2: Dissolve chitosan in a 1.5wt%-3wt% acetic acid solution, stir until the chitosan is completely dissolved, and then let it stand to remove bubbles to obtain a chitosan solution with a mass percentage of 1-2%. Step 6-3: Add the dried and color-fixed intermediate textile product to the chitosan solution and soak for 10-25 minutes; then take it out, roll it with a rolling mill so that the roll-off rate falls to 60%-70%, and then dry it with hot air to obtain the lotus fiber persimmon dyed textile based on lotus plants.

9. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1 or 2, characterized in that, The lotus stalk fiber is prepared by the following steps: Step 7-1: Provide lotus stalks as raw materials; cut the lotus stalks into small sections of 1.5-4cm, then add them to a 5-10g / L sodium hydroxide solution, heat to 90℃-95℃, and keep warm while stirring for 2-3 hours; Step 7-2: After the reaction is complete, the mixture is washed and added to a 1-2 g / L sodium chlorite solution, and bleached at 65℃-75℃ for 1-2 h; after bleaching, the lotus stem fibers are obtained after washing and drying.

10. The method for preparing lotus fiber-dyed textiles based on lotus plants according to claim 1, characterized in that, The preparation method satisfies at least one of the following conditions: (1) In step 3-1a, filter using a 100-120 mesh screen; (2) In step 3-3b, filter using a 100-120 mesh screen; (3) In step 5-1, the frequency of the microwave drying and color fixing device is set to 2450MHz; (4) In step 5-1, the thickness of the intermediate textile product laid flat inside the microwave drying and color fixing device does not exceed 5 mm.

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