A fabric based on protein fiber combined with natural fiber and a preparation method thereof

Abstract

The application relates to the technical field of fabrics, in particular to a fabric based on protein fiber combined with natural fiber and a preparation method thereof, which is prepared by wet core-sheath composite spinning of a down protein sheath layer and a natural cellulose core layer; the core layer is natural cellulose fiber, and the total mass of the functional fabric is 70-90%; the balance is the sheath layer formed by cross-linking and solidification of a down protein solution; and the sheath layer is loaded with nano titanium dioxide; the introduced natural cellulose core layer is the main skeleton component of the fabric, selects natural fibers such as bamboo pulp cellulose and cotton linter pulp, and provides basic mechanical support for the fabric. The abandoned down resource is used to prepare protein fiber, which is combined with natural cellulose fiber to construct a composite fiber with a functional sheath layer and a mechanical core layer. The technical scheme solves the problems of insufficient sun protection, insufficient antibacterial performance and single mechanical performance of traditional natural fiber fabrics.

Description

Technical Field

[0001] This invention relates to the field of fabric technology, specifically to a fabric based on protein fibers combined with natural fibers and its preparation method. Background Technology

[0002] In the field of textile materials, the development of functional fabrics has always been a research hotspot. With consumers' increasing demands for health and comfort, fabrics with multiple functions such as sun protection and antibacterial properties are becoming increasingly popular. Traditional natural fiber fabrics, such as those made from cotton, linen, and bamboo pulp, while possessing good breathability and comfort, have significant shortcomings in terms of functional characteristics: First, natural fibers themselves do not have sun protection capabilities and cannot effectively block ultraviolet rays from harming the human body, potentially leading to skin damage with prolonged use; second, natural fiber fabrics are prone to bacterial growth in humid environments, producing odors and exhibiting insufficient antibacterial properties, affecting hygiene and comfort; third, the mechanical properties of natural fibers are relatively limited, making it difficult to meet the application requirements of high-end functional fabrics in terms of strength and toughness, especially after repeated washing or external forces, easily leading to breakage and deformation.

[0003] To address the aforementioned issues, this invention proposes a method for fabricating functional fabrics by combining down protein fibers and natural cellulose fibers through a wet core-sheath composite spinning technique. Down protein fibers possess a unique molecular structure and biocompatibility, while natural cellulose fibers provide a robust mechanical support framework. Through the design of the core-sheath composite structure, the down protein sheath is loaded with nano-titanium dioxide, endowing the fabric with excellent sun protection and antibacterial properties. Simultaneously, the natural cellulose core layer enhances the overall mechanical properties of the fabric, effectively avoiding the functional and performance shortcomings of traditional natural fiber fabrics and providing a new solution for the preparation of multifunctional textile materials. Summary of the Invention

[0004] The purpose of this invention is to provide a fabric based on protein fibers combined with natural fibers and a method for preparing the same.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A functional fabric based on down protein fiber composite natural fiber is made by wet core-sheath composite spinning of down protein sheath and natural cellulose core. The core is natural cellulose fiber, accounting for 70-90% of the total mass of the functional fabric, and the remainder is the sheath formed by cross-linking and curing of down protein solution; the sheath is loaded with nano-titanium dioxide.

[0007] As a further technical solution, the natural cellulose includes at least one of bamboo pulp cellulose, cotton linter pulp, and straw pulp cellulose.

[0008] As a further technical solution, the natural cellulose fiber has an average length of 3-5 cm and a linear density of 1.2-1.8 dtex.

[0009] The preparation method of functional fabric based on down protein fiber composite natural fiber includes the following steps:

[0010] a. Down protein extraction: Waste down is subjected to reduction-hydrolysis treatment to extract a spinnable protein solution;

[0011] b. Functionalization treatment: Add nano-titanium dioxide and crosslinking agent to the spinnable protein solution;

[0012] c. Composite spinning: Natural cellulose is made into a core spinning solution, with the core spinning solution as the core layer and the functionalized protein solution as the sheath layer, and then formed by wet spinning.

[0013] d. Crosslinking and curing: Glutaraldehyde vapor is used for crosslinking and curing of the sheath structure.

[0014] As a further technical solution, the extraction of down protein in step a includes:

[0015] Pretreatment: The waste down feathers are soaked in an alkaline solution with pH 9-11 containing 2-3% sodium bisulfite at 80°C for 1 hour to break the disulfide bonds.

[0016] Enzymatic hydrolysis: Keratinase is used for enzymatic hydrolysis. The amount of keratinase added is 1.0-1.5% of the weight of waste down. Enzymatic hydrolysis is carried out for 3-4 hours at a pH of 7-9 and a temperature of 50℃.

[0017] Purification: Small molecule peptides with a molecular weight of less than 3kDa are removed by ultrafiltration to obtain a spinnable protein solution.

[0018] As a further technical solution, the functionalization treatment in step b includes: adding 1-1.3% by mass of nano-titanium dioxide, 0.5-0.8% by mass of crosslinking agent, and 0.3-0.5% by mass of dispersant to 100 parts by mass of the spinnable protein solution.

[0019] As a further technical solution, the crosslinking agent is glyoxal; the dispersant is sodium alginate.

[0020] As a further technical solution, the wet spinning in step c specifically refers to:

[0021] Core spinning solution preparation: Natural cellulose is dissolved in a -10℃ low temperature solution containing 8wt% NaOH and 15wt% urea at a mass ratio of 1:5-6.

[0022] Sheath injection: The core spinning solution and the sheath solution are co-extruded into the coagulation bath through a composite spinneret with a core pore size of 80 μm and an outer diameter of 120 μm.

[0023] The coagulation bath consists of sodium sulfate with a concentration of 50 g / L and sulfuric acid with a concentration of 20 g / L, and is held at a temperature of 15°C.

[0024] As a further technical solution, a multi-stage drawing process is also included: the solidified fiber is first subjected to wet heat drawing at a bath temperature of 60-64℃ and a drawing ratio of 1:3-4; then it is subjected to dry heat drawing at a temperature of 150-155℃ and a drawing ratio of 1:1.5-1.8.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The natural cellulose core layer introduced in this invention serves as the main skeletal component of the fabric. It utilizes natural fibers such as bamboo pulp cellulose and cotton linter pulp to provide fundamental mechanical support for the fabric. The crystalline structure of the cellulose molecular chains endows it with high tensile strength and rigidity, ensuring that the fabric maintains its shape and is not easily broken during weaving and use.

[0027] The down protein sheath layer introduced in this invention is formed by cross-linking and solidifying a protein solution extracted from waste down, serving as a functional carrier layer. The nano-titanium dioxide loaded in the sheath layer is the key component for achieving sun protection and antibacterial functions: nano-titanium dioxide absorbs and scatters ultraviolet rays, giving the fabric excellent UV protection; simultaneously, the photocatalytic effect of nano-titanium dioxide under light can destroy bacterial cell membranes, achieving an antibacterial rate of over 99%. The skin-friendly and flexible nature of down protein itself can improve the stiffness of natural cellulose, enhancing fabric comfort.

[0028] The crosslinking agent and dispersant introduced in this invention are as follows: glyoxal is used as a crosslinking agent, which reacts with the amino groups in the down protein molecules to form covalent bonds, solidify the sheath structure, and enhance the wash resistance and dimensional stability of the fiber; sodium alginate is used as a dispersant, which can improve the dispersion uniformity of nano-titanium dioxide in protein solution, avoid agglomeration, and ensure the effective performance of functional components.

[0029] This invention achieves multifunctional integration through the synergistic effect of a core-sheath composite structure: the natural cellulose core layer exists as a rigid skeleton, bearing the main mechanical load; its crystalline network structure formed by the low-temperature dissolution-spinning process significantly improves the warp breaking strength; the down protein sheath layer wraps around the core layer as a functional outer layer, forming a three-dimensional network structure through glutaraldehyde vapor crosslinking, firmly anchoring nano-titanium dioxide within the sheath layer. When irradiated with ultraviolet light, the wide bandgap semiconductor properties of nano-titanium dioxide cause it to absorb ultraviolet light and generate electron-hole pairs, thereby generating hydroxyl radicals and superoxide anion radicals, which destroy ultraviolet energy and inhibit bacterial activity; while the core-sheath interface is bound together by physical entanglement and intermolecular forces, forming a composite system that retains the breathability and moisture absorption of natural fibers, while compensating for their performance shortcomings through functional modification of the protein sheath layer.

[0030] This invention utilizes waste down to prepare protein fibers, which are then combined with natural cellulose fibers to construct a composite fiber that integrates a functional sheath layer and a mechanical core layer. This invention not only solves the problems of insufficient sun protection and antibacterial properties, as well as the limited mechanical properties of traditional natural fiber fabrics, but also achieves the following advantages:

[0031] Highly efficient functions integrated: It offers excellent sun protection and antibacterial properties while maintaining good wearing comfort;

[0032] Resource recycling: Transforming waste down into high-value-added textile raw materials aligns with the concept of green environmental protection;

[0033] High process compatibility: The wet spinning process is compatible with existing textile equipment and is suitable for large-scale industrial production;

[0034] Stable and durable performance: The cross-linking curing process allows the fabric to retain its function after multiple washes, extending the product's lifespan. Attached Figure Description

[0035] Figure 1 This is a flowchart of a fabric manufacturing process based on protein fibers combined with natural fibers. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention provides a functional fabric based on down protein fiber composite natural fiber, which is made by wet core-sheath composite spinning of down protein sheath layer and natural cellulose core layer. The core layer is natural cellulose fiber, accounting for 70-90% of the total mass of the functional fabric, and the remainder is the sheath layer formed by cross-linking and curing of down protein solution; the sheath layer is loaded with nano titanium dioxide.

[0038] Fabric composition and raw material sources

[0039] Natural cellulose fibers: including at least one of bamboo pulp cellulose, cotton linter pulp, and straw pulp cellulose, with an average length of 3-5 cm and a linear density of 1.2-1.8 dtex.

[0040] Down protein solution: obtained by extraction from waste down through reduction-hydrolysis treatment.

[0041] Nano-titanium dioxide: used for sheath loading.

[0042] Crosslinking agent: glyoxal, used for sheath curing.

[0043] Dispersant: Sodium alginate, used for dispersing nano-titanium dioxide.

[0044] Detailed steps of preparation method

[0045] a. Down protein extraction

[0046] Pretreatment: The waste down feathers are soaked in an alkaline solution with pH 9-11 containing 2-3% sodium bisulfite at 80°C for 1 hour to break the disulfide bonds.

[0047] Enzymatic hydrolysis: Keratinase is used for enzymatic hydrolysis. The amount of keratinase added is 1.0-1.5% of the weight of waste down. Enzymatic hydrolysis is carried out for 3-4 hours at a pH of 7-9 and a temperature of 50℃.

[0048] Purification: Small molecule peptides with a molecular weight of less than 3kDa are removed by ultrafiltration to obtain a spinnable protein solution.

[0049] b. Functionalization

[0050] To 100 parts by weight of the spinnable protein solution, add 1-1.3% by weight of nano-titanium dioxide, 0.5-0.8% by weight of glyoxal as a crosslinking agent, and 0.3-0.5% by weight of sodium alginate as a dispersant.

[0051] c. Composite spinning

[0052] Core spinning solution preparation: Natural cellulose is dissolved in a -10℃ low temperature solution containing 8wt% NaOH and 15wt% urea at a mass ratio of 1:5-6.

[0053] Sheath injection: The core spinning solution and the sheath solution are co-extruded into a coagulation bath through a composite spinneret with a core pore size of 80 μm and an outer diameter of 120 μm. The coagulation bath consists of sodium sulfate with a concentration of 50 g / L and sulfuric acid with a concentration of 20 g / L, and the temperature is 15 °C.

[0054] Multi-stage drawing: The solidified fiber is first subjected to wet heat drawing at a bath temperature of 60-64℃ and a drawing ratio of 1:3-4; then it is subjected to dry heat drawing at a temperature of 150-155℃ and a drawing ratio of 1:1.5-1.8.

[0055] d. Cross-linking curing

[0056] The sheath structure is cured by glutaraldehyde vapor crosslinking, wherein the mass concentration of glutaraldehyde vapor is 15-18%, the crosslinking temperature is controlled at 60-70℃, and the crosslinking time is 16-20min; the crosslinking process is carried out in a closed container, and the humidity inside the container is maintained within the range of 60-80%RH.

[0057] e. Textiles

[0058] The cross-linked and cured fibers are spun into yarn with a linear density of 16-20 tex and a twist coefficient controlled at 300-400. The yarn is then woven on a loom using a plain or twill weave structure at a speed of 300-350 r / min, with a warp tension of 20-30 N and a weft tension of 15-20 N, thereby obtaining the functional fabric.

[0059] The functional fabric provided by this invention achieves the resource utilization of down protein through a specific core-sheath composite structure and preparation process, while endowing the fabric with excellent functional properties (such as antibacterial and sun protection), and the fabric has good mechanical properties. The preparation process is highly operable and suitable for industrial production.

[0060] To further illustrate the present invention, the following examples provide a detailed description. The waste down used in the following examples of the present invention is commercially available washed down waste. The natural cellulose fiber is bamboo pulp cellulose (average length 4 cm, linear density 1.5 dtex). The nano-titanium dioxide is a commercially available product modified with silane coupling agent KH-550. The crosslinking agent glyoxal and the dispersant sodium alginate are both analytical grade and purchased from Sinopharm Group.

[0061] Example 1

[0062] Preparation steps

[0063] Down protein extraction: Waste down was soaked in an alkaline solution containing 2.5% sodium bisulfite at pH 10 for 1 hour at 80°C; keratinase (added at 1.2% of the mass of waste down) was used for enzymatic hydrolysis at pH 8 and 50°C for 3.5 hours; ultrafiltration was used to purify the solution to obtain spinnable protein.

[0064] Functionalization treatment: Add 1.1g nano titanium dioxide, 0.6g glyoxal, and 0.4g sodium alginate to 100g spinnable protein solution and stir until homogeneous.

[0065] Composite spinning: Bamboo pulp cellulose is dissolved in an 8wt% NaOH / 15wt% urea solution at -10℃ at a mass ratio of 1:5.5, and co-extruded through a spinneret with a core layer pore size of 80μm and a sheath layer outer diameter of 120μm into a 15℃ coagulation bath (50g / L sodium sulfate + 20g / L sulfuric acid); after coagulation, it is first subjected to wet heat stretching at 62℃ (stretching ratio 1:3.5), and then to dry heat stretching at 152℃ (stretching ratio 1:1.6).

[0066] Crosslinking curing: glutaraldehyde vapor mass concentration 16.5%, crosslinking at 65℃ for 18 min, humidity 70%RH.

[0067] Textile: 18tex yarn is spun with a twist coefficient of 350. Plain weave is used with a weaving speed of 320 r / min, warp tension of 25 N, and weft tension of 18 N.

[0068] Fabric composition

[0069] The core layer accounts for 80% of the mass, the sheath layer accounts for 20%, and the nano-titanium dioxide loading in the sheath layer is 5.5% of the sheath layer mass.

[0070] Example 2

[0071] Preparation steps

[0072] Down protein extraction: Waste down was soaked in an alkaline solution containing 2.5% sodium bisulfite at pH 10 for 1 hour at 80°C; keratinase (added at 1.2% of the mass of waste down) was used for enzymatic hydrolysis at pH 8 and 50°C for 3.5 hours; ultrafiltration was used to purify the solution to obtain spinnable protein.

[0073] Functionalization treatment: Add 1.3g of nano titanium dioxide, 0.8g of glyoxal, and 0.4g of sodium alginate to 100g of spinnable protein solution, and stir until homogeneous.

[0074] Composite spinning: Bamboo pulp cellulose is dissolved in an 8wt% NaOH / 15wt% urea solution at -10℃ at a mass ratio of 1:5.5, and co-extruded through a spinneret with a core layer pore size of 80μm and a sheath layer outer diameter of 120μm into a 15℃ coagulation bath (50g / L sodium sulfate + 20g / L sulfuric acid); after coagulation, it is first subjected to wet heat stretching at 62℃ (stretching ratio 1:3.5), and then to dry heat stretching at 152℃ (stretching ratio 1:1.6).

[0075] Crosslinking curing: 18% glutaraldehyde vapor mass concentration, crosslinking at 70℃ for 16 min, humidity 60%RH.

[0076] Textile: 18tex yarn is spun with a twist coefficient of 350. Plain weave is used with a weaving speed of 320 r / min, warp tension of 25 N, and weft tension of 18 N.

[0077] Fabric composition

[0078] The core layer accounts for 70% of the mass, the sheath layer accounts for 30%, and the nano-titanium dioxide loading in the sheath layer is 4.3% of the sheath layer mass.

[0079] Example 3

[0080] Preparation steps

[0081] Down protein extraction: Waste down was soaked in an alkaline solution containing 2.5% sodium bisulfite at pH 10 for 1 hour at 80°C; keratinase (added at 1.2% of the mass of waste down) was used for enzymatic hydrolysis at pH 8 and 50°C for 3.5 hours; ultrafiltration was used to purify the solution to obtain spinnable protein.

[0082] Functionalization treatment: Add 1.1g nano titanium dioxide, 0.6g glyoxal, and 0.4g sodium alginate to 100g spinnable protein solution and stir until homogeneous.

[0083] Composite spinning: Cotton lint pulp is dissolved in an 8wt% NaOH / 15wt% urea solution at -10℃ at a mass ratio of 1:5.5, and co-extruded through a spinneret with a core layer pore size of 80μm and a sheath layer outer diameter of 120μm into a 15℃ coagulation bath (50g / L sodium sulfate + 20g / L sulfuric acid); after coagulation, it is first subjected to 60℃ wet heat drawing (drawing ratio 1:3), and then to 150℃ dry heat drawing (drawing ratio 1:1.5).

[0084] Crosslinking curing: glutaraldehyde vapor mass concentration 16.5%, crosslinking at 65℃ for 18 min, humidity 70%RH.

[0085] Textile: 18tex yarn is spun with a twist coefficient of 350. Plain weave is used with a weaving speed of 320 r / min, warp tension of 25 N, and weft tension of 18 N.

[0086] Fabric composition

[0087] The core layer accounts for 90% of the mass, the sheath layer accounts for 10%, and the nano-titanium dioxide loading in the sheath layer is 11% of the sheath layer mass.

[0088] Example 4

[0089] Preparation steps

[0090] Down protein extraction: Waste down was soaked in an alkaline solution containing 2.5% sodium bisulfite at pH 10 for 1 hour at 80°C; keratinase (added at 1.2% of the mass of waste down) was used for enzymatic hydrolysis at pH 8 and 50°C for 3.5 hours; ultrafiltration was used to purify the solution to obtain spinnable protein.

[0091] Functionalization treatment: Add 1.0g nano titanium dioxide, 0.5g glyoxal, and 0.4g sodium alginate to 100g spinnable protein solution and stir until homogeneous.

[0092] Composite spinning: Bamboo pulp cellulose is dissolved in an 8wt% NaOH / 15wt% urea solution at -10℃ at a mass ratio of 1:5.5, and co-extruded through a spinneret with a core layer pore size of 80μm and a sheath layer outer diameter of 120μm into a 15℃ coagulation bath (50g / L sodium sulfate + 20g / L sulfuric acid); after coagulation, it is first subjected to wet heat stretching at 62℃ (stretching ratio 1:3.5), and then to dry heat stretching at 152℃ (stretching ratio 1:1.6).

[0093] Crosslinking curing: glutaraldehyde vapor mass concentration 16.5%, crosslinking at 65℃ for 18 min, humidity 70%RH.

[0094] Textile: 18tex yarn is spun with a twist coefficient of 350. It is woven in a twill weave at a speed of 300 r / min. The warp tension is 30 N and the weft tension is 18 N.

[0095] Fabric composition

[0096] The core layer accounts for 80% of the mass, the sheath layer accounts for 20%, and the nano-titanium dioxide loading in the sheath layer is 5% of the sheath layer mass.

[0097] Example 5

[0098] Preparation steps

[0099] Down protein extraction: Waste down was soaked in an alkaline solution containing 2.5% sodium bisulfite at pH 10 for 1 hour at 80°C; keratinase (added at 1.5% of the mass of waste down) was used for enzymatic hydrolysis at pH 8 and 50°C for 4 hours; ultrafiltration was used to purify the solution and obtain a spinnable protein solution.

[0100] Functionalization treatment: Add 1.1g nano titanium dioxide, 0.6g glyoxal, and 0.4g sodium alginate to 100g spinnable protein solution and stir until homogeneous.

[0101] Composite spinning: Bamboo pulp cellulose is dissolved in an 8wt% NaOH / 15wt% urea solution at -10℃ at a mass ratio of 1:5.5, and co-extruded through a spinneret with a core layer pore size of 80μm and a sheath layer outer diameter of 120μm into a 15℃ coagulation bath (50g / L sodium sulfate + 20g / L sulfuric acid); after coagulation, it is first subjected to wet heat stretching at 64℃ (stretching ratio 1:4), and then to dry heat stretching at 155℃ (stretching ratio 1:1.8).

[0102] Crosslinking curing: 15% glutaraldehyde vapor mass concentration, crosslinking at 60℃ for 20 min, humidity 80%RH.

[0103] Textile: 20tex yarn is spun with a twist coefficient of 400. Plain weave is used with a weaving speed of 320 r / min, warp tension of 25 N, and weft tension of 20 N.

[0104] Fabric composition

[0105] The core layer accounts for 80% of the mass, the sheath layer accounts for 20%, and the nano-titanium dioxide loading in the sheath layer is 5.5% of the sheath layer mass.

[0106] Comparative Example 1

[0107] The preparation method of Example 1 is used, with the difference being:

[0108] Functionalization: No nano titanium dioxide was added; only glyoxal and sodium alginate were added.

[0109] Fabric composition: core layer accounts for 80%, sheath layer accounts for 20%, and the sheath layer has no nano-titanium dioxide loading.

[0110] Comparative Example 2

[0111] The preparation method of Example 1 is used, with the difference being:

[0112] Composite spinning: without multi-stage drawing steps, it is directly solidified and then cross-linked and cured.

[0113] Fabric properties: Low fiber orientation leads to decreased mechanical properties.

[0114] Experimental verification section

[0115] Sunscreen performance test

[0116] Referring to GB / T18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles", the ultraviolet protection factor (UPF), UVA transmittance, and UVB transmittance of the fabric were tested. Using a UV-Vis spectrophotometer, the transmittance of the fabric was measured in the wavelength range of 280-400 nm, and the UPF value was calculated. The results are as follows:

[0117] Table 1

[0118]

[0119] As shown in Table 1, the UPF values ​​of Examples 1-5 all reached above 50, with low UVA and UVB transmittance, indicating that the fabric has excellent sun protection performance. This is because the nano-titanium dioxide loaded in the sheath layer has the effect of absorbing and scattering ultraviolet rays, and the core-sheath composite structure forms a physical shield.

[0120] Comparative Example 1, without the addition of nano titanium dioxide, had a UPF value of only 25, indicating a significant decrease in sun protection performance. This demonstrates that nano titanium dioxide is the key ingredient that gives the fabric its sun protection function.

[0121] Comparative Example 2 was not stretched, resulting in a loose fiber structure, which led to an increase in UV transmittance and a decrease in UPF value. This demonstrates that the specific stretching process of this invention is crucial for improving the fabric's density and sun protection performance.

[0122] Antibacterial performance test

[0123] Referring to GB / T20944.3-2008 "Evaluation of Antimicrobial Properties of Textiles - Part 3: Shaking Method", the antimicrobial rate of the fabric against Escherichia coli and Staphylococcus aureus was tested. The fabric sample was shaken and contacted with the bacterial solution at 37℃ for 24 hours, the number of viable bacteria was determined, and the antimicrobial rate was calculated. The results are as follows;

[0124] Table 2

[0125]

[0126] As shown in Table 2, Examples 1-5 all exhibited antibacterial rates exceeding 99% against both types of bacteria, demonstrating potent antibacterial properties. This is because the nano-titanium dioxide loaded in the down protein sheath has a photocatalytic antibacterial effect, while the protein matrix itself also has a certain inhibitory effect on bacteria.

[0127] Comparative Example 1 showed a significant decrease in antibacterial rate due to the lack of nano-titanium dioxide, indicating that nano-titanium dioxide plays a dominant role in antibacterial function.

[0128] Although Comparative Example 2 was not stretched, it still had a good antibacterial rate because the nano-titanium dioxide in the sheath was still present. However, insufficient stretching resulted in an insufficiently compact fiber structure, uneven distribution of antibacterial components, and a reduced antibacterial effect.

[0129] Fracture strength test

[0130] Referring to GB / T3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break - Strip Method", the warp and weft breaking strengths of the fabric were tested. A strip 5 cm wide and 20 cm long was prepared from the fabric and stretched at 100 mm / min on a universal testing machine. The breaking strength was recorded, and the results are as follows;

[0131] Table 3

[0132]

[0133] As shown in Table 3, Examples 1-5 exhibit high warp and weft breaking strengths, indicating that the fabrics possess excellent mechanical properties. This is attributed to the skeletal support provided by the natural cellulose core layer and the composite reinforcement structure formed by the cross-linking and curing of the down protein sheath layer. The multi-stage drafting process further enhances the fiber orientation and crystallinity.

[0134] The fracture strength of Comparative Example 1 is lower than that of the Example, possibly because the lack of nano-titanium dioxide in the sheath layer leads to a slight decrease in the strength and toughness of the protein sheath layer, while the bonding force at the core-sheath interface is also affected to some extent.

[0135] Comparative Example 2, which was not stretched, showed low fiber molecular chain orientation, loose structure, and significantly reduced breaking strength. This indicates that a specific stretching process is crucial for improving the mechanical properties of the fabric and can effectively enhance the fiber's strength and breaking strength.

[0136] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a fabric based on protein fibers combined with natural fibers, characterized in that, It is made by wet spinning of a down protein sheath layer and a natural cellulose core layer. The core layer is natural cellulose fiber, accounting for 70-90% of the total mass of the functional fabric, and the remainder is the sheath layer, which is formed by cross-linking and curing of a down protein solution. The sheath layer is loaded with nano-titanium dioxide. Specifically, the following steps are included: a. Down protein extraction: Waste down is subjected to reduction-hydrolysis treatment to extract a spinnable protein solution; b. Functionalization treatment: Add nano-titanium dioxide, crosslinking agent, and dispersant to the spinnable protein solution; The crosslinking agent is glyoxal; the dispersant is sodium alginate; c. Composite spinning: Natural cellulose is made into a core spinning solution, with the core spinning solution as the core layer and the protein solution after functionalization in step b as the sheath layer, and then formed by wet spinning. It also includes a multi-stage drawing process: the solidified fiber is first subjected to wet heat drawing at a bath temperature of 60-64℃ and a drawing ratio of 1:3-4; then it is subjected to dry heat drawing at a temperature of 150-155℃ and a drawing ratio of 1:1.5-1.

8. d. Crosslinking and curing: Glutaraldehyde vapor is used for crosslinking and curing of the sheath structure. The mass concentration of glutaraldehyde vapor is 15-18%, the crosslinking temperature is controlled at 60-70℃, and the crosslinking time is 16-20min. The crosslinking process is carried out in a closed container, and a certain humidity is maintained inside the container, with a humidity range of 60-80%RH. e. Textile: The cross-linked and cured fibers are spun into yarn with a linear density of 16-20 tex and a twist coefficient controlled at 300-400; then plain or twill weave is used to weave on a loom at a speed of 300-350 r / min, with warp tension of 20-30 N and weft tension of 15-20 N, thereby obtaining the functional fabric.

2. The preparation method according to claim 1, characterized in that, The extraction of down protein in step a includes: Pretreatment: The waste down feathers are soaked in an alkaline solution with pH 9-11 containing 2-3% sodium bisulfite at 80°C for 1 hour to break the disulfide bonds. Enzymatic hydrolysis: Keratinase is used for enzymatic hydrolysis. The amount of keratinase added is 1.0-1.5% of the weight of waste down. Enzymatic hydrolysis is carried out for 3-4 hours at a pH of 7-9 and a temperature of 50℃. Purification: Small molecule peptides with a molecular weight of less than 3kDa are removed by ultrafiltration to obtain a spinnable protein solution.

3. The preparation method according to claim 1, characterized in that, The functionalization process in step b includes adding 1-1.3% by mass of nano-titanium dioxide, 0.5-0.8% by mass of crosslinking agent, and 0.3-0.5% by mass of dispersant to 100 parts by mass of the spinnable protein solution.

4. The preparation method according to claim 1, characterized in that, The wet spinning process described in step c specifically refers to: Core spinning solution preparation: Natural cellulose is dissolved in a -10℃ low temperature solution containing 8wt% NaOH and 15wt% urea at a mass ratio of 1:5-6. Sheath injection: The core spinning solution and the sheath solution are co-extruded into the coagulation bath through a composite spinneret with a core pore size of 80 μm and an outer diameter of 120 μm. The coagulation bath consists of sodium sulfate with a concentration of 50 g / L and sulfuric acid with a concentration of 20 g / L, and is held at a temperature of 15°C.

5. The preparation method according to claim 1, characterized in that, The natural cellulose mentioned in step c includes at least one of bamboo pulp cellulose and cotton linter pulp.

6. The preparation method according to any one of claims 1-5 yields a fabric based on protein fibers combined with natural fibers.

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