Preparation method of low-moisture-regaining cotton fiber, washable anti-hardening flocculus and application

Abstract

The invention relates to the technical field of modified fibers, in particular to a preparation method of low-moisture-regaining cotton fibers, which comprises the following steps: dispersing cotton fibers, putting the cotton fibers into constant-temperature alkali liquor for activation, and washing the cotton fibers until the cotton fibers are neutral after activation; a nanoscale hydrophobic material is added into the cotton fibers, and the cotton fibers and the nanoscale hydrophobic material are subjected to a full grafting reaction; dehydrating and drying to obtain low-moisture-regaining cotton fibers; the washable anti-hardening flocculus can be obtained by mixing the low-moisture-regaining cotton fibers with common cotton fibers according to different proportions. Hydrophobic groups are introduced into the fibers and are subjected to a full grafting reaction with hydroxyl groups in cotton fibers, so that the hydroxyl groups can be closed and inactivated and cannot form hydrogen bonds with water molecules to lock water, reduce moisture regaining and improve quick-drying performance; the nanoscale hydrophobic material can change the surface chemical composition of the fiber, reduce the surface energy of the fiber, reduce the shrinkage capacity of cotton washing and increase the dimensional stability, and has an anti-hardening function.

Description

Technical Field

[0001] This invention relates to the field of modified fiber technology, and in particular to a method for preparing low moisture regain cotton fiber, a washable anti-caking sheet, and its application. Background Technology

[0002] Cotton fiber, as a natural cellulose fiber, possesses excellent moisture absorption, breathability, biodegradability, and comfort. Therefore, non-woven cotton wadding made from cotton fiber has significant demand in the home textile industry. However, ordinary non-woven cotton wadding has a moisture regain of 8.5%. Due to the presence of numerous hydrophilic hydroxyl groups in its molecular structure, these hydroxyl groups form hydrogen bonds with water molecules upon contact with water, locking the water molecules within the cotton fiber. This causes irreversible shrinkage of the fiber, making it difficult for the moisture inside the fiber to evaporate. Consequently, ordinary non-woven cotton wadding has poor quick-drying properties. During washing, it easily forms a hard, dense block that loses its elasticity and is difficult to recover, resulting in poor dimensional stability and making it unwashable. In humid environments, it is highly susceptible to mold growth, leading to yellowing, odor, and even fiber degradation. These shortcomings of ordinary cotton fiber prevent the preparation of non-woven cotton wadding and its applications from meeting consumer needs.

[0003] Chemical grafting modification is an effective solution to the problems existing in ordinary cotton fibers and non-woven cotton fiber wadding. By introducing hydrophobic groups into the fiber interior and allowing them to fully graft with the hydroxyl groups in the cotton fiber, the hydroxyl groups can be blocked and deactivated, preventing them from forming hydrogen bonds with water molecules, thus reducing moisture regain and improving quick-drying properties. Furthermore, it can alter the surface chemical composition of the fiber, reducing its surface energy, decreasing the shrinkage of cotton after washing, increasing dimensional stability, and providing anti-caking properties. The resulting low-moisture-gain cotton fibers and washable anti-caking wadding have a wide range of applications in daily life, meeting diverse needs and providing excellent comfort. Summary of the Invention

[0004] To address the above problems, this invention provides a method for preparing low-moisture-regain cotton fibers, comprising the following steps: 1) After dispersing the cotton fibers, they are placed in a constant-temperature alkaline solution for activation. The alkaline solution is one or a mixture of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution, or trisodium phosphate solution with a concentration of 0.1~40 g / L; the activation temperature of the alkaline solution is 10~90℃; and the activation time is 10~90 min. Alkaline treatment can increase the amorphous region of the cotton fibers, improve the activity of the fibers, expose more cellulose hydroxyl groups, provide more reaction sites for nanoscale hydrophobic materials, enhance the binding ability with nanoscale hydrophobic materials, make it easier for nanoscale hydrophobic materials to enter the fiber interior, and promote graft copolymerization. After activation treatment, the fibers are washed with deionized water until neutral to remove residual sodium hydroxide solution and avoid interfering with subsequent reactions.

[0005] 2) Add nanoscale hydrophobic materials to the cotton fibers from step 1). The nanoscale hydrophobic materials are one or a mixture of organosilane compounds, paraffinic auxiliaries, acrylates, fatty acids, and their derivatives. The organosilane compounds are hexadecyltrimethoxysilane, polydimethylsiloxane, n-octyltrimethoxysilane, and hexamethyldisiloxane; the paraffinic auxiliaries are polyethylene wax emulsion, oxidized paraffin emulsion, and Fischer-Tropsch wax emulsion; the acrylates are dodecyl methacrylate, octadecyl acrylate, and hexadecyl acrylate; and the fatty acids and their derivatives are stearic acid, palmitic acid, methyl stearate, and fatty acid amides. The concentration of the nanoscale hydrophobic materials is 0.1%–10%; the grafting reaction time is 1–5 hours; and the grafting reaction temperature is 20–90°C. By grafting cotton fibers with nanoscale hydrophobic materials, the hydrophobic groups can be introduced into the fiber interior, opening up the fiber's cavity structure and enhancing its anti-caking ability. Furthermore, the nanoscale hydrophobic materials can alter the fiber's surface chemical composition, reducing its surface energy and further improving its hydrophobic function. The core principle is to chemically modify the fiber surface to construct a hydrophobic layer, mimicking the natural "lotus effect" and endowing the cotton fiber with excellent low moisture regain, anti-caking, and quick-drying properties. By optimizing the type and amount of nanoscale hydrophobic materials, the needs of different application scenarios can be met.

[0006] 3) Dehydrate the cotton fibers treated in step 2), and then dry them at a temperature of 80~110℃ to obtain low-moisture cotton fibers.

[0007] The low-moisture regain cotton fiber and ordinary cotton fiber or functional chemical fiber obtained by this invention are used to prepare a washable anti-caking wadding using a non-woven fabric wadding equipment. The proportion of each fiber in the wadding is as follows: the proportion of low-moisture regain cotton fiber is 20wt%~100wt%.

[0008] This invention introduces hydrophobic groups into the fiber interior, which fully graft with the hydroxyl groups in the cotton fiber. This can block and deactivate the hydroxyl groups, preventing them from forming hydrogen bonds with water molecules and locking in water, thus reducing moisture regain and improving quick-drying properties. The nanoscale hydrophobic material can change the surface chemical composition of the fiber, reduce the surface energy of the fiber, reduce the shrinkage of cotton after washing, increase dimensional stability, and provide anti-caking function.

[0009] This invention also provides an application of the above-mentioned washable anti-caking quilting sheet in comforters, sleeping mats, seat cushions, mattress pads, and cotton clothing. In comforter applications, the washable anti-caking quilting sheet, with its low moisture regain, anti-caking, and quick-drying properties, keeps the comforter dry, preventing caking and odor problems caused by dampness, creating a comfortable sleeping environment for the user. Even if the comforter accidentally gets damp, it dries quickly, reducing the possibility of bacterial growth. In sleeping mats, its excellent anti-caking properties ensure that the sleeping mat remains flat even after long-term use, without localized dents or lumps, making the mat's support stable and long-lasting. Furthermore, its quick-drying performance helps regulate moisture generated during sleep, improving sleep comfort. For seat cushions, this quilting sheet effectively solves the problem of moisture accumulation caused by prolonged sitting, keeping the cushion surface dry and comfortable. Its anti-caking characteristics keep the cushion soft and fluffy, enhancing the user's sitting experience, making it suitable for both home and office use. When this wadding is used on mattresses, its moisture-proof effect is significant, effectively resisting ground moisture and protecting the user's health. Furthermore, it quickly returns to its original shape after washing, and its performance is not affected by repeated washing, extending the mattress's lifespan. In cotton clothing, the washable anti-caking wadding provides excellent breathability and quick-drying properties. When the wearer sweats, the clothing quickly wicks away moisture, keeping the body dry and preventing the cold and discomfort caused by damp clothing. At the same time, its anti-caking properties ensure that the clothing remains fluffy, warm, and aesthetically pleasing even after multiple washes and wears. Attached Figure Description

[0010] Figure 1 The moisture content-time curves of the cotton fiber wadding sheets from Examples 4-6 and Comparative Examples 2-4 after being dried in the sun are shown.

[0011] Figure 2 The moisture content-time curves of cotton fiber wadding sheets from Examples 4-6 and Comparative Examples 2-4 after being air-dried indoors are shown. Detailed Implementation

[0012] The present invention will be described below with reference to examples. These examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Example

[0013] A method for preparing low-moisture-regain cotton fiber includes the following steps: 1) After dispersing the cotton fibers, place them in a sodium hydroxide solution for activation treatment. The activation concentration is 2g / L, the activation temperature is 60℃, and the activation time is 60min. After treatment, wash with deionized water until neutral and set aside.

[0014] 2) Add the cotton fibers from step 1) to an aqueous solution of dodecyl methacrylate at a concentration of 5% and a bath ratio of 1:10. Circulate the solution continuously and stably using a circulating pump to ensure a full grafting reaction. The reaction time is 1 hour and the reaction temperature is 60°C.

[0015] 3) Dehydrate the cotton fibers processed in step 2), and then dry them at a temperature of 90°C to obtain low-moisture cotton fibers. Example

[0016] A method for preparing low-moisture-regain cotton fiber includes the following steps: 1) After dispersing the cotton fibers, place them in a sodium hydroxide solution for activation treatment. The activation concentration is 2g / L, the activation temperature is 60℃, and the activation time is 60min. After treatment, wash with deionized water until neutral and set aside.

[0017] 2) Add nano-grade hexaalkyltrimethoxysilane and polydimethylsiloxane to the cotton fibers from step 1) at a concentration of 2.5% and a bath ratio of 1:10. Circulate the mixture continuously and stably using a circulating pump to ensure a full grafting reaction. The reaction time is 5 hours and the reaction temperature is 40°C.

[0018] 3) Dehydrate the cotton fibers processed in step 2), and then dry them at 100℃ to obtain low-moisture cotton fibers. Example

[0019] A method for preparing low-moisture-regain cotton fiber includes the following steps: 1) After dispersing the cotton fibers, place them in a sodium hydroxide solution for activation treatment. The activation concentration is 2g / L, the activation temperature is 60℃, and the activation time is 60min. After treatment, wash with deionized water until neutral and set aside.

[0020] 2) Add nano-sized n-octyltrimethoxysilane and hexamethyldisiloxane to the cotton fibers from step 1) at a concentration of 7.5% and a bath ratio of 1:10. Circulate the mixture continuously and stably using a circulating pump to ensure a full grafting reaction. The reaction time is 3 hours and the reaction temperature is 70°C.

[0021] 3) Dehydrate the cotton fibers processed in step 2), and then dry them at a temperature of 105℃ to obtain low-moisture cotton fibers.

[0022] Comparative Example 1 Untreated ordinary cotton fibers.

[0023] The cotton fibers from Examples 1-3 and Comparative Example 1 were subjected to the following relevant performance tests.

[0024] 1. Cotton fiber moisture regain test: Refer to GB / T 6102.1-2006 "Test Method for Moisture Regain of Raw Cotton - Oven Method". Weigh a certain amount of test sample and place it in an oven at a certain temperature to evaporate the moisture in the test sample until the test sample reaches a constant weight. Calculate the moisture regain of the raw cotton from the difference between the original mass and the dried mass, and the dried mass.

[0025] 2. Cotton fiber resistivity test: Refer to GB / T 14342-2015 "Test Method for Resistivity of Short Chemical Fibers", and use the formula ρ=R for volume resistivity. The resistivity of fibers with a certain density under a certain geometric shape is measured, and then converted into a specific resistivity value based on the fiber filling degree.

[0026] Table 1. Test results of cotton fiber properties in Examples 1-3 and Comparative Example 1 performance Moisture regain / % Specific resistivity / (Ω·cm) Key Indicators Moisture regain index Volume resistivity Testing standards GB / T6102.1-2006 GB / T 14342-2015 Example 1 4.0 <![CDATA[8.9×10 9 ]]> Example 2 4.2 <![CDATA[8.4×10 9 <!-- 3 -->]]> Example 3 4.4 <![CDATA[8.1×10 9 ]]> Comparative Example 1 12.5 <![CDATA[9.6×10 8 ]]> As shown in Table 1, the low-moisture-regain cotton fibers prepared in Examples 1-3 of this invention have a moisture regain of 4%-5%, which is about twice that of Comparative Example 1, and a resistivity of 8×10⁻⁶. 9 ~9×10 9 The Ω·cm value increased by less than 10 times compared to Comparative Example 1, and will not have a significant impact on subsequent flocculation processing.

[0027] Example 4 A method for preparing a washable anti-caking flocculant sheet includes the following steps: The low-moisture regain cotton fiber prepared in Example 1, with a low-moisture regain cotton fiber content of 100%, was used to prepare a washable anti-caking wadding using a nonwoven fabric wadding equipment. The wadding weight was 200 g / m². 2 .

[0028] Example 5 A method for preparing a washable anti-caking flocculant sheet includes the following steps: The low-moisture regain cotton fiber prepared in Example 1 was uniformly mixed with ordinary cotton fiber and then processed into a washable, anti-caking wadding using a nonwoven fabric wadding equipment. The wadding had a basis weight of 300 g / m². 2 Of which, low-moisture cotton fiber accounts for 50% and ordinary cotton fiber accounts for 50%.

[0029] Example 6 The low-moisture regain cotton fiber prepared in Example 1 and the three-dimensional crimped hollow polyester fiber were used to prepare a sandwich-structured, washable, anti-caking wadding sheet using a nonwoven fabric wadding equipment. The wadding sheet had a basis weight of 400 g / m². 2 The upper and lower layers of the wadding are made of low-moisture-regain cotton fibers, and the middle layer is made of three-dimensional crimped hollow polyester fibers; the fiber ratio is 50% low-moisture-regain cotton fibers and 50% three-dimensional crimped hollow polyester fibers.

[0030] Comparative Example 2 The difference between this comparative example and Example 4 is that 100% ordinary cotton fiber was used to prepare the wadding using a nonwoven fabric wadding machine, and the basis weight of the wadding was 200 g / m². 2 .

[0031] Comparative Example 3 The difference between this comparative example and Example 5 is that 100% ordinary cotton fiber was used to prepare the wadding using a nonwoven fabric wadding machine, and the basis weight of the wadding was 300 g / m². 2 .

[0032] Comparative Example 4 The difference between this comparative example and Example 6 is that the top and bottom layers are made of ordinary cotton fiber, and the middle layer is made of three-dimensional crimped hollow polyester. The fiber is fabricated into a sandwich structure using a nonwoven fabric wadding machine, and the wadding weight is 400 g / m². 2 The fiber ratio is 50% ordinary cotton fiber and 50% three-dimensional crimped hollow polyester fiber.

[0033] The flocs from Examples 4-6 and Comparative Examples 2-4 were subjected to the following related performance tests.

[0034] 1. Fluffiness test of wadding: Referring to FZ / T08005-2024 "Washable pure cotton wadding", after the sample is subjected to a specified pressure for a certain period of time, the height of the sample after the load is removed is measured, and the ratio of the measured volume to the mass of the sample is calculated to characterize the fluffiness of the sample.

[0035] 2. Compression and recovery rate test of wadding: Referring to FZ / T08005-2024 "Washable pure cotton wadding", after the sample is subjected to a specified pressure for a certain period of time, its height is compressed by the pressure. After the load is removed, its height recovers due to elasticity. The height value at different pressures is measured, and the compression rate and recovery rate of the sample are calculated.

[0036] 3. Fluff washing and quick-drying test: After the flocculation is washed with water, it is placed under sunlight and indoors under certain temperature and humidity conditions, and the time taken for the sample to become completely dry in the water-containing state is recorded.

[0037] Table 2. Results of floc performance tests in Examples 4-6 and Comparative Examples 2-4 As can be seen from Table 2, the fluffiness of the washable anti-caking sheet prepared in Example 6 of the present invention is 120 cm. 3 / g, compression rate 47%, recovery rate 91%, washable anti-caking flocculent flakes with a bulkiness of 114cm after washing. 3 / g, compression rate 44%, recovery rate 89%, the washable anti-caking sheet retains excellent performance after washing, the drying time in the sun is 100min and the drying time in the shade is 170min, which is shorter than the drying time of untreated cotton fiber sheets, indicating that the washable anti-caking sheet prepared in Example 6 has good bulkiness, compression resilience and quick-drying properties.

[0038] Figure 1 The graphs show the moisture content-time curves of the cotton fiber sheets from Examples 4-6 and Comparative Examples 2-4 after sun drying. Figure 2 The graphs show the moisture content-time of the cotton fiber sheets from Examples 4-6 and Comparative Examples 2-4 after indoor air drying. Figure 1 and Figure 2 It can be seen that the cotton fiber wadding in Examples 4-6, whether dried in the sun or in the shade indoors, exhibited a significantly faster rate of moisture content reduction over time compared to the cotton fiber wadding in Comparative Examples 2-4. This further demonstrates intuitively that the wadding made from the low-moisture-regain cotton fiber prepared using this invention has significantly improved quick-drying performance.

[0039] In practical applications, this quick-drying performance is of great significance. Taking comforters as an example, in humid environments, ordinary cotton comforters are prone to dampness, which not only affects sleep comfort but may also breed bacteria and mold, harming human health. Comforters made using the washable, anti-caking wadding prepared by this invention can dry quickly even when slightly damp in humid weather, maintaining dryness and comfort. Similarly, in the application of cotton clothing, when encountering rain or sweating, the clothing dries quickly, preventing hypothermia caused by prolonged dampness and providing better warmth and health protection for the wearer. Furthermore, the low-moisture-regain cotton fiber and the wadding made from it also have excellent environmental performance. Due to its fast drying speed, energy consumption is reduced during the washing and drying process, meeting the modern society's demand for energy-saving and environmentally friendly products. At the same time, its anti-caking properties allow the wadding to maintain good structure and performance even after multiple washes, extending product lifespan, reducing waste generation, and playing a positive role in environmental protection. This invention relates to a washable anti-flocculent sheet, which, based on its weight, width, and other specifications, combined with the final product application scenario and appropriate sewing technology, can be used in quilts, sleeping mats, cushions, mattress pads, and cotton clothing.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing low-moisture-regain cotton fiber, characterized in that, Includes the following steps: 1) After dispersing the cotton fibers, place them in a constant-temperature alkaline solution. After the fibers are activated by the alkali, wash them with deionized water until neutral and set aside. 2) Add nanoscale hydrophobic materials to the cotton fibers from step 1), introduce low surface energy groups on the surface of the cotton fibers, and allow the cotton fibers to fully graft with the nanoscale hydrophobic materials. 3) Dehydrate the cotton fibers obtained in step 2), and then dry them to obtain low moisture regain cotton fibers.

2. The method according to claim 1, characterized in that, In step 1), the alkaline solution is one or a mixture of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution or trisodium phosphate solution with a concentration of 0.1~40g / L; the activation temperature of the alkaline solution is 10~90℃ and the activation time is 10~90min.

3. The method according to claim 1, characterized in that, In step 2), the nanoscale hydrophobic material is one or more of organosilane compounds, paraffinic additives, acrylates, fatty acids and their derivatives; the organosilane compound is hexadecyltrimethoxysilane, polydimethylsiloxane, n-octyltrimethoxysilane or hexamethyldisiloxane; the paraffinic additive is polyethylene wax emulsion, oxidized paraffin emulsion or Fischer-Tropsch wax emulsion; the acrylate is dodecyl methacrylate, octadecyl acrylate or hexadecyl acrylate; and the fatty acid and its derivative is stearic acid, palmitic acid, methyl stearate or fatty acid amide.

4. The method according to claim 3, characterized in that, The concentration of the nanoscale hydrophobic material is 0.1%~10%, the grafting reaction time is 1~5h, and the grafting reaction temperature is 20~90℃.

5. A washable anti-caking sheet, characterized in that, The low-moisture regain cotton fiber and ordinary cotton fiber or functional chemical fiber prepared by the method according to any one of claims 1 to 4 are prepared by non-woven fabric wadding equipment, wherein the proportion of the low-moisture regain cotton fiber in the washable anti-caking wadding is 20wt% to 100wt%.

6. The use of the washable anti-caking sheet as described in claim 5 in quilt cores, sleeping mats, seat cushions, mattress pads, and cotton clothing.

Images