Preparation process of fluffy soft fabric

Abstract

The invention relates to the technical field of textile treatment, in particular to a preparation process of a fluffy soft fabric. The technical problem that the mechanical property and the durability of the traditional biological treatment fabric are difficult to consider at the same time is solved. According to the invention, rhamnolipid and modified bacterial cellulose are utilized to pretreat the fabric, and yarns are undestructively opened through physical steric hindrance; adding a composite biological enzyme to carry out gradient temperature control synergistic micro-etching; then introducing modified chitosan and glutamine transaminase, and carrying out an in-situ enzymatic cross-linking reaction; and finally, carrying out high-temperature inactivation curing to obtain a finished product. A three-dimensional bionic network is constructed in the fabric through a one-bath method, the modified bacterial cellulose is used for providing rigid framework support, the covalent cross-linked modified chitosan is used for providing flexible lubrication, mechanical damage is completely avoided, the strength of the fabric is protected, and meanwhile the excellent and washable durable effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of textile processing technology, specifically to a process for preparing a fluffy and soft fabric. Background Technology

[0002] As people's demands for clothing comfort continue to rise, the demand for fluffy and soft fabrics is increasing in areas such as underwear, children's clothing, and high-end home textiles. Traditional fabric softening and fluffing treatments mainly rely on mechanical napping, liquid ammonia treatment, or the extensive use of silicone-based chemical softeners in the finishing stage. Although these conventional methods can give fabrics a certain smooth and supple feel in a short time, chemical auxiliaries often only remain on the surface of the fabric and cannot penetrate into the fiber to change its structure, resulting in a significant reduction in the fabric's breathability and moisture absorption.

[0003] In recent years, although the industry has introduced traditional biological treatment technologies such as enzyme washing to improve the feel and remove surface fuzz, it still faces two major technical problems: First, poor mechanical properties. Excessive or uncontrollable degradation by a single enzyme can severely damage the amorphous and even crystalline regions of the fiber, leading to a sharp drop in fabric strength and making it extremely prone to tearing. Second, poor durability. Conventional softeners and treated fibers are mostly physically attached or have weak intermolecular forces, making them extremely susceptible to washing. Furthermore, the fluffiness brought by a single biological treatment will disappear after several washes due to the re-adhesion of cellulose, causing the fabric to become stiff and shrunken again. How to solve the problem of traditional biologically treated fabrics failing to balance mechanical properties and durability is a pressing issue that needs to be addressed.

[0004] To address this, a process for preparing fluffy and soft fabrics was proposed. Summary of the Invention

[0005] The purpose of this invention is to design a process for preparing a fluffy and soft fabric. This invention utilizes rhamnose glycolipids and modified bacterial cellulose to pretreat the fabric, using physical steric hindrance to non-destructively expand the yarns; then, a composite bio-enzyme is added for gradient temperature-controlled synergistic micro-etching; subsequently, modified chitosan and transglutaminase are introduced to carry out an in-situ enzymatic cross-linking reaction; finally, high-temperature inactivation and curing yields the finished product. This invention constructs a three-dimensional biomimetic network within the fabric using a one-bath method, with modified bacterial cellulose providing rigid skeletal support and covalently cross-linked modified chitosan providing flexible lubrication. This achieves excellent and wash-resistant durability while completely avoiding mechanical damage and protecting the fabric's strength.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a process for preparing a fluffy and soft fabric, comprising the following steps: The fabric is pretreated by rhamnolipid and modified bacterial cellulose to obtain pretreated fabric; compound biological enzymes are added to the pretreated fabric for synergistic biological treatment to obtain biological treated fabric; modified chitosan and transglutaminase are added to the biological treated fabric for in-situ enzymatic crosslinking to obtain retreated fabric; finally, the fabric is obtained by inactivation and curing treatment to obtain fluffy and soft fabric. Modified bacterial cellulose was obtained by modifying bacterial cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride; modified chitosan was obtained by modifying chitosan with wheat protein peptides.

[0007] Preferably, the fabric is cotton.

[0008] Preferably, the specific pretreatment process is as follows: 100 parts of fabric are immersed in a dyeing vat containing 1000 parts of deionized water, 0.1-0.3 parts of rhamnolipin and 0.5-2.0 parts of modified bacterial cellulose are added, the pH value of the bath solution is adjusted to 6.5, ultrasonic assistance is turned on (frequency 40kHz, power 200W), and the temperature is controlled at 30℃ for 20 minutes to obtain the pretreated fabric.

[0009] The preferred preparation process of modified bacterial cellulose is as follows: 10 parts of pulverized bacterial cellulose are slowly added to 200 parts of 60% sulfuric acid solution, mechanical stirring is started (300 rpm), the temperature is precisely controlled at 45℃, and the reaction is carried out at a constant temperature for 2 hours; the reaction is terminated by adding 10 times the volume of ice water for rapid cooling; then the mixture is washed several times by centrifugation at 10000 rpm, and placed in a dialysis bag (molecular weight cutoff 8000-14000) for dialyzing with deionized water until neutral. After ultrasonic dispersion, a suspension is obtained. (Solid content is 1.5%); Take 8-12 parts of the suspension, slowly add 2 parts of NaOH solution (mass fraction of 20%), activate at 65℃ for 30 min, then slowly add 6-8 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride solution (65% aqueous solution), and continuously stir magnetically at 65℃ for 4 h; After the reaction is completed, neutralize with dilute hydrochloric acid to pH=7, dialyze again for 3 days to remove unreacted reagents and salts, and finally freeze dry to obtain modified bacterial cellulose.

[0010] Preferably, the specific process of synergistic biological treatment is as follows: 0.1-0.5 parts of compound biological enzyme (cellulase + neutral protease, mass ratio 2:1, cellulase activity of 50000U / g, protease activity of 100000U / g) are added to the original bath, the bath temperature is increased to 45℃ at a heating rate of 1.5℃ / min, and the temperature is kept constant for 20-40min to obtain the biologically treated fabric.

[0011] The preferred in-situ enzymatic crosslinking process is as follows: the temperature of the bath solution is slightly reduced to 40°C, followed by the addition of 1.5-3.0 parts of modified chitosan and 0.3-0.8 parts of transglutaminase (enzyme activity of 100-500 U / g), maintaining the pH between 6.0 and 6.5 (using 0.1 mol / L phosphate buffer), and the reaction is continued for 35-45 minutes to obtain the retreated fabric.

[0012] Preferably, the preparation process of modified chitosan is as follows: 4 parts of wheat protein peptide (Mw=1000~3000Da) are dissolved in 100 parts of MES buffer (pH 5.5, 0.1M), 1.5 parts of carbodiimide hydrochloride (specifically 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and 1 part of N-hydroxysuccinimide are added, and the mixture is magnetically stirred for 1 hour at room temperature (25℃) in the dark to obtain an activated solution; 8-12 One part of chitosan (degree of deacetylation >90%, molecular weight approximately 10-30 kDa) was dissolved in 400 parts of MES buffer, and then an activation solution was slowly added dropwise. The reaction was carried out at room temperature (25°C) with continuous stirring for 16-20 hours. After the reaction was completed, the solution was placed in a dialysis bag (molecular weight cutoff 3500 Da) and dialyzed in deionized water for 48 hours, with the water changed every 8 hours to completely remove unreacted substances. The dialysate was then freeze-dried to obtain modified chitosan.

[0013] Preferably, the specific process of inactivation and curing treatment is as follows: the temperature of the bath liquid is rapidly increased to 85°C at a rate of 3°C / min, and kept at this temperature for 10-20 minutes; then the liquid is drained, the fabric is rinsed once with clean water, and finally dried and shaped at 100°C for 3 minutes to obtain a fluffy and soft fabric.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves non-destructive physical expansion of fabrics by introducing positively charged modified bacterial cellulose, combined with ultrasound and rhamnolipids, fundamentally solving the problem of significant degradation in fabric mechanical properties caused by traditional mechanical napping. During the pretreatment stage, the highly rigid and positively charged modified bacterial cellulose, through the cavitation effect of ultrasound and the penetrating power of rhamnolipids, targets and enters the fabric yarn. Utilizing the electrostatic repulsion of like charges and the steric hindrance of the nanorod structure, the modified bacterial cellulose physically expands the tightly packed yarn from the inside. This active support mechanism completely avoids the cutting or tearing of the fabric's main fibers caused by traditional mechanical napping, giving the fabric a lasting structural fluffiness and preserving its original properties to the maximum extent.

[0015] This invention employs a composite bio-enzyme combined with a stepped temperature-controlled micro-etching technology to achieve targeted and gentle treatment of the yarn interior, effectively overcoming the excessive hydrolysis and strong damage to fibers that are easily caused by traditional free single-enzyme treatments. At a controlled temperature of 45℃, because the yarn has been pre-expanded by modified bacterial cellulose, the composite bio-enzyme, composed of cellulase and protease, can smoothly penetrate deep into the fiber micro-gap for slight etching. This synergistic effect of the material and the process creates abundant active rough surfaces deep within the yarn, providing anchoring points for subsequent polymer cross-linking, while avoiding deep damage to the outer backbone and core crystalline regions of the fiber, further ensuring the fabric's excellent mechanical properties.

[0016] This invention constructs a bio-flexible lubricating layer through an in-situ enzymatic cross-linking reaction between wheat protein peptide-modified chitosan and transglutaminase. During the enzymatic cross-linking stage at a temperature slightly reduced to 40°C, transglutaminase specifically recognizes the wheat protein peptide sequences on the end groups of the modified chitosan, constructing a dense three-dimensional encapsulation network on the surface of the fabric fibers and within the yarns after micro-etching. This flexible polymer network replaces the pseudo-softness of traditional silicone oil, which is easily detached, enabling it to withstand repeated harsh household washes and giving the fabric a long-lasting, non-diminishing soft feel.

[0017] The overall preparation process of this invention constructs a three-dimensional biomimetic network structure within the fabric, achieving a balance between protecting the fabric's mechanical properties and providing long-lasting, durable softness. Rigid modified bacterial cellulose serves as a skeletal support within the fabric to address the issue of flatness and dryness, while covalently cross-linked modified chitosan acts as flexible hinges at the fiber interlacing points, providing lubrication. The subsequent rapid heating and curing process at 85°C not only instantly inactivates all biological enzymes to halt hydrolysis and lock in mechanical strength, but also utilizes thermal energy to promote hydrogen bond bonding between the flexible polysaccharide network and the rigid cellulose skeleton. This system-level synergistic innovation successfully overcomes the industry challenge of the often mutually restrictive relationship between fabric softness and mechanical strength.

[0018] This invention employs a one-bath stepped temperature-controlled synergistic process, possessing both high industrial feasibility and significant environmental benefits. This process integrates complex pretreatment, micro-etching, cross-linking, and inactivation curing into a single dyeing vat, proceeding in an orderly manner according to a temperature gradient (30℃→45℃→40℃→85℃), avoiding interference between different biological reactions. The entire process eliminates traditional, recalcitrant chemical auxiliaries such as amino silicone oil, using pure bio-based materials (bacterial cellulose, chitosan, wheat protein peptides) and biological enzymes. Simultaneously, the one-bath method significantly reduces water consumption and wastewater discharge associated with traditional multi-stage washing processes, providing a green and sustainable fabric production solution. Attached Figure Description

[0019] Figure 1 The images show the fracture strength diagrams after 50 washes in Examples 1-5 and Comparative Examples 7-8 of this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a process for preparing a fluffy and soft fabric, the technical solution of which is as follows: Example 1

[0022] Ten parts of pulverized bacterial cellulose were slowly added to 200 parts of 60% sulfuric acid solution, and mechanical stirring was started (300 rpm). The temperature was precisely controlled at 45℃, and the reaction was carried out at a constant temperature for 2 hours. The reaction was terminated by adding 10 times the volume of ice water for rapid cooling. The mixture was then centrifuged and washed several times at 10,000 rpm and placed in a dialysis bag (molecular weight cutoff 8,000-14,000) and dialyzed against deionized water until neutral. After ultrasonic dispersion, a suspension (solid content of 1.5%) was obtained. Ten parts of the suspension were taken, and two parts of NaOH solution (mass fraction of 20%) were slowly added dropwise. The mixture was activated at 65℃ for 30 minutes. Then, seven parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride solution (65% aqueous solution) were slowly added dropwise. The mixture was continuously magnetically stirred at 65℃ for 4 hours. After the reaction was completed, the mixture was neutralized to pH=7 with dilute hydrochloric acid and dialyzed again for 3 days to remove unreacted reagents and salts. Finally, the mixture was freeze-dried to obtain modified bacterial cellulose.

[0023] Four parts of wheat protein peptides were dissolved in 100 parts of MES buffer, and 1.5 parts of carbodiimide hydrochloride and 1 part of N-hydroxysuccinimide were added. The mixture was magnetically stirred for 1 hour at room temperature in the dark to obtain an activated solution. Ten parts of chitosan were dissolved in 400 parts of MES buffer, and then the activated solution was slowly added dropwise. The mixture was stirred continuously at room temperature for 18 hours. After the reaction was completed, the solution was placed in a dialysis bag (molecular weight cutoff 3500 Da) and dialyzed in deionized water for 48 hours, with the water changed every 8 hours to completely remove unreacted substances. The dialysate was then freeze-dried to obtain modified chitosan.

[0024] 100 parts of fabric were immersed in a dyeing vat containing 1000 parts of deionized water. 0.2 parts of rhamnolipin and 1.5 parts of modified bacterial cellulose were added, and the pH of the bath was adjusted to 6.5. Ultrasonic assistance (frequency 40kHz, power 200W) was applied, and the temperature was controlled at 30℃ for 20 minutes to obtain the pretreated fabric. 0.3 parts of a compound biological enzyme (cellulase + protease, mass ratio 2:1) were added to the original bath, and the bath temperature was increased to 4℃ at a rate of 1.5℃ / min. The biotreated fabric was obtained by treating the solution at 5℃ for 30 minutes. The temperature of the bath was then slightly reduced to 40℃, followed by the addition of 2 parts modified chitosan and 0.5 parts transglutaminase. The pH was maintained between 6.0 and 6.5, and the reaction was continued for 40 minutes to obtain the retreated fabric. The temperature of the bath was then rapidly increased to 85℃ at a rate of 3℃ / min and kept at that temperature for 15 minutes. The solution was then drained, the fabric was rinsed once with clean water, and finally dried and set at 100℃ for 3 minutes to obtain a fluffy and soft fabric.

[0025] Examples 2-5 refer to the parameter conditions in Example 1, with specific differences shown in Table 1.

[0026] Table 1 Parameters and conditions for Examples 1-5 Comparative Example 1 follows the same parameters and conditions as in Example 1, except that modified bacterial cellulose is not added.

[0027] Comparative Example 2 follows the same parameters and conditions as in Example 1, except that the bacterial cellulose is not modified.

[0028] Comparative Example 3 follows the same parameters and conditions as in Example 1, except that no ultrasonic-assisted treatment is performed during the pretreatment process.

[0029] Comparative Example 4 follows the same parameters and conditions as in Example 1, except that the synergistic biological treatment step is omitted, while the rest of the steps are the same.

[0030] Comparative Example 5 follows the same parameters and conditions as in Example 1, except that cellulase is used instead of the complex biological enzyme.

[0031] Comparative Example 6 follows the same parameters and conditions as in Example 1, except that a protease is used instead of a complex biological enzyme.

[0032] Comparative Example 7 follows the same parameters and conditions as in Example 1, except that modified chitosan is not added.

[0033] Comparative Example 8 follows the same parameters and conditions as in Example 1, except that chitosan is not modified.

[0034] Comparative Example 9 followed the same parameters and conditions as in Example 1, except that no transglutaminase was added.

[0035] Comparative Example 10 followed the parameters and conditions in Example 1, except that instead of using a stepwise temperature control of 30℃→45℃→40℃→85℃, all enzyme preparations and adjuvants were added at once and mixed at a constant temperature of 45℃ for 105 min.

[0036] Experimental Example 1: Mechanical Properties, Softness, and Loft Tests The fracture strength of Examples 1-5 and Comparative Examples 1-10 was tested according to GB / T 3923.1-2013 standard.

[0037] The cotton fabric to be tested was equilibrated for 24 hours at a temperature of 21±1℃ and a relative humidity of 65±2%, and a 100cm² area was cut off. 2 Circular samples were tested using a PhabrOmeter fabric style tester. A pressure block was added based on the sample's thickness and mass, and the test settings were adjusted according to the fabric's thickness and areal density to determine the fabric's softness and smoothness.

[0038] The bulkiness was tested using the compression-rebound method, measured with a professional bulkiness tester. During the test, a pressure of 500 Pa was applied to the sample, held for 30 seconds, and then released. The initial thickness, compressed thickness, and rebound thickness of the sample were recorded. The ambient temperature was maintained at 20±2℃, and the relative humidity was controlled at 65±5% during the test.

[0039] The results are shown in Table 2. Table 2 Mechanical properties, softness, and loft of Examples 1-5 and Comparative Examples 1-10 Table 2 shows that Comparative Example 1, without the addition of modified bacterial cellulose, resulted in a significant decrease in fabric bulk. This, conversely, demonstrates that modified bacterial cellulose plays a crucial role in providing rigid nano-support within the system. Without this nanomaterial providing physical steric hindrance within the yarn, the yarn naturally shrinks and becomes tightly bound during water treatment and subsequent drying, failing to achieve structural expansion from the inside out. Simultaneously, the lack of internal skeletal support increases inter-fiber friction, leading to a consequent decrease in softness and smoothness. Comparative Example 2, using unmodified bacterial cellulose, exhibited significantly lower bulk than the examples. Since ordinary bacterial cellulose is non-positively charged, it cannot generate strong electrostatic targeting adsorption with naturally occurring, slightly negatively charged cotton fibers. This causes the bacterial cellulose to easily aggregate in the bath solution, failing to penetrate deep into the yarn and merely adhering to the fabric surface. Without the electrostatic repulsion between like positive charges, the cellulose nanocrystals cannot exert their physical expansion effect. Comparative Example 3, which omitted the ultrasonic-assisted treatment, resulted in a decrease in all overall indicators, especially softness and fluffiness. This indicates that without the micro-jet generated by ultrasonic cavitation, the high-density cotton yarn constitutes a strong physical mass transfer barrier. With only conventional soaking, modified bacterial cellulose and subsequent polymer materials struggle to overcome liquid film resistance and enter the yarn core. The materials remain only on the fabric surface, failing to expand the yarn and causing surface additive accumulation, resulting in a stiff and rough fabric feel. Comparative Example 4 omitted the synergistic bio-enzyme treatment step. Without enzyme etching, the initial fiber structure remained unaffected, resulting in the highest breaking strength. However, its softness and smoothness were significantly lower than the examples. This is because the surface of the cotton fibers without bio-micro-etching is too smooth, lacking micro-rough structures and reaction binding sites. The subsequently added modified chitosan and cross-linking enzymes cannot find sufficient anchoring points on the fiber surface for covalent bonding, leading to an ineffective construction of the flexible lubricating layer and a lack of fundamental improvement in the fabric feel. Comparative Example 5 used only a single cellulase for etching, resulting in a severe decrease in breaking strength. Cellulase has a very strong specific hydrolytic effect on cotton fibers; in the absence of protease synergistic passivation and competitive adsorption, a single cellulase is prone to runaway reaction, resulting in excessive hydrolysis and severely damaging the amorphous and even crystalline regions of the cotton fibers. Comparative Example 6 used only protease treatment. For cotton fabrics, protease cannot effectively hydrolyze and etch the cellulose backbone (mainly targeting impurities or protein fibers such as wool). Therefore, the data performance of this group is similar to that of Comparative Example 4. However, due to the failure to effectively open the active sites on the fiber surface, the subsequent cross-linking reaction efficiency was extremely low, and the softness and smoothness of the fabric were at extremely poor levels.

[0040] Comparative Example 7 did not include modified chitosan in the in-situ enzymatic crosslinking step, resulting in a significant decrease in the softness and smoothness of the fabric. This demonstrates that modified chitosan plays a crucial role as a flexible hinge and lubricant in the system. Although the rigid support of modified bacterial cellulose in the system allowed the fabric to retain good bulk, the lack of flexible polymer encapsulation and crosslinking on the fiber surface resulted in the fiber surface being directly exposed after micro-etching, increasing the coefficient of friction and causing the fabric to feel extremely dry and stiff, failing to achieve an overall performance improvement. Comparative Example 8 used ordinary chitosan that had not been modified with wheat protein peptides. Because ordinary chitosan molecular chains lack polypeptide sequences rich in glutamine residues, glutamine transaminase cannot specifically recognize and catalyze it. Therefore, chitosan can only physically adhere to the fabric surface through weak intermolecular forces and cannot form a dense covalently crosslinked hydrogel network. Its initial softness and smoothness were significantly lower than those of Example 1. Comparative Example 9 did not add transglutaminase during the treatment process, resulting in test results similar to Comparative Example 8. This indirectly confirms the irreplaceable nature of cross-linking enzymes: even if modified chitosan grafted with active substrates is present in the system, the acyl transfer reaction cannot be triggered without the biocatalysis of transglutaminase; the modified chitosan cannot form strong covalent bonds with the micro-etched fiber surface, and fails to construct a three-dimensional flexible polymer network, resulting in the fabric's softness and smoothness failing to meet the standards of the examples. Comparative Example 10 abandoned the stepped temperature control, adding all reagents at once and treating them at a constant temperature of 45°C for an extended period, resulting in a complete collapse of all performance indicators, especially a sharp drop in breaking strength. This demonstrates that the time and temperature axis design of the process in this invention has extremely strong process synergy: without stepped temperature control, on the one hand, the cellulase in the composite bio-enzyme acts uncontrollably at 45°C for an extended period, leading to excessive hydrolysis of the amorphous and even crystalline regions of the cotton fibers, severely damaging the fabric strength; on the other hand, the etching reaction and the enzymatic cross-linking reaction proceed simultaneously and interfere with each other, disrupting the orderly mechanism of first creating rough anchor points and then cross-linking to form a film in situ, ultimately reducing the softness and fluffiness.

[0041] Experiment Example 2: Durability Test A Wascator standard shrinkage tester was used, along with AATCC 1993 standard detergent (WOB, free of fluorescent whitening agents). The washing program was set to 4N (normal washing, water temperature 40±3℃), with each cycle including a main wash, rinse, and spin-dry. The liquor ratio was set to 1:10. The number of cycles was set to 50 consecutive washes. Drying and conditioning: After the specified number of washes, the fabric was hung to dry. It was then equilibrated for 24 hours under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±5%). Performance retesting: The mechanical properties, softness, and bulkiness of the washed fabric were retested. The results are shown in Table 3. The breaking strength of Examples 1-5 and Comparative Examples 7-8 after 50 washes is shown in Table 3. Figure 1As shown.

[0042] Table 3 Durability of Examples 1-5 and Comparative Examples 7-10 From Table 3 and Figure 1 It can be observed that after 50 washes, the softness and smoothness of the fabric in Comparative Example 7 were severely reduced, completely exposing the defects of a dry and stiff feel. Due to the complete absence of the flexible polymer network constructed by modified chitosan in the system, the surface of the fabric fibers was exposed and rough after undergoing micro-etching by composite bio-enzymes. During the mechanical tumbling and friction of the washing machine for up to 50 times, the fiber surface, lacking the protection of a flexible lubricating layer, was subjected to further physical wear, which not only caused the remaining soft touch to disappear completely, but also resulted in a slightly lower breaking strength than the example protected by the flexible network. Comparative Example 8 demonstrates the absolute necessity of peptide modification for durability. Although this group possessed a certain degree of softness initially, its softness and smoothness plummeted after 50 standard washes. This is because ordinary chitosan without wheat protein peptide grafts cannot be recognized and catalyzed by transglutaminase. It can only rely on weak hydrogen bonds and van der Waals forces for physical adsorption onto the fiber surface. Faced with the strong peeling of surfactants in detergents and the mechanical scouring of water, this physically adsorbed layer is easily detached, completely losing its long-term lubricating function. The data from Comparative Example 9 are similar to those of Comparative Example 8, further confirming the source of durability from an enzyme catalysis perspective: even if the correct wheat protein peptide-modified chitosan is used in the material, without transglutaminase catalysis, the peptide end groups cannot undergo acyl transfer reactions with the substrate. Without covalent bond locking, the macromolecular chains can only remain at the physical adhesion level, and are ultimately largely washed away after 50 washes. Comparative Example 10, after 50 washes, not only did its hand feel index drop significantly, but its breaking strength also decreased dramatically. Because step temperature control was not used during preparation, various enzyme preparations interfered with each other at 45°C, which led to excessive hydrolysis of cotton fibers by cellulase and hindered the effective construction of a dense cross-linked network by transglutaminase. Incomplete polymer deposits easily fell off during the washing process, and the already damaged and fragile cotton fibers underwent more severe secondary breakage under the mechanical pulling of the washing process.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a fluffy and soft fabric, characterized in that, Includes the following steps: The fabric is pretreated by rhamnolipid and modified bacterial cellulose to obtain pretreated fabric; compound biological enzymes are added to the pretreated fabric for synergistic biological treatment to obtain biological treated fabric; modified chitosan and transglutaminase are added to the biological treated fabric for in-situ enzymatic crosslinking to obtain retreated fabric; finally, the fabric is obtained by inactivation and curing treatment to obtain fluffy and soft fabric. The composite bioenzyme is obtained by mixing cellulase and protease; the modified bacterial cellulose is obtained by modifying bacterial cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride; and the modified chitosan is obtained by modifying chitosan with wheat protein peptides.

2. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The specific process of the pretreatment is as follows: the fabric is immersed in a dyeing vat of deionized water, the rhamnose glycolipid and the modified bacterial cellulose are added, the pH value of the bath is adjusted, and ultrasonic assistance is turned on. The pretreated fabric is obtained after treatment.

3. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The preparation process of the modified bacterial cellulose is as follows: the pulverized bacterial cellulose is added to a sulfuric acid solution and stirred at a constant temperature for reaction; The reaction was terminated by adding ice water for rapid cooling; then centrifugation and washing were performed, and the mixture was placed in a dialysis bag and dialyzed until neutral. The suspension was obtained by ultrasonic dispersion. Take the suspension and add NaOH solution dropwise. After activation, add 3-chloro-2-hydroxypropyltrimethylammonium chloride solution dropwise. After stirring the reaction, neutralize to neutral, dialyze to remove impurities, and freeze-dry to obtain the modified bacterial cellulose.

4. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The specific process of the synergistic biological treatment is as follows: the compound biological enzyme is added to the original bath, the bath temperature is raised to 45°C, and the temperature is kept constant for 20-40 minutes to obtain the biologically treated fabric.

5. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The specific process of the in-situ enzymatic crosslinking is as follows: the temperature of the bath solution is lowered to 40°C, and then the modified chitosan and the transglutaminase are added, and the reaction is continued for 35-45 minutes to obtain the retreated fabric.

6. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The preparation process of the modified chitosan is as follows: the wheat protein peptide is dissolved in MES buffer, carbodiimide hydrochloride and N-hydroxysuccinimide are added, and the reaction is stirred to obtain an activated solution; the chitosan is dissolved in MES buffer, and then the activated solution is added dropwise, and the reaction is continuously stirred at room temperature; after the reaction is completed, the solution is placed in a dialysis bag, dialyzed to remove unreacted substances, and then freeze-dried to obtain the modified chitosan.

7. The preparation process of a fluffy and soft fabric according to claim 1, characterized in that, The specific process of the inactivation and curing treatment is as follows: the temperature of the bath liquid is raised to 85°C and kept at that temperature for 10-20 minutes; then the liquid is drained, the fabric is rinsed with clean water, and finally dried and shaped to obtain the fluffy and soft fabric.

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