Mildew-proof antibacterial composite material and preparation method thereof

Abstract

The invention relates to the technical field of automotive trim processing, and particularly discloses a mildew-proof and antibacterial composite material and a preparation method thereof. The mildewproof and antibacterial composite material comprises a non-woven fabric, a dipping film, a blend fiber felt and a dipping film which are compounded in sequence, wherein the blend fiber felt comprises the following raw materials in percentage by mass: 40-60% of sisal fibers and 40-60% of modified polypropylene fibers; the dipping film is a mildew-proof antibacterial agent modified polypropylene dipping film; in addition, the preparation method disclosed by the invention has the advantage of improving the mildew-proof and antibacterial properties of the automotive interior material.

Description

Technical Field

[0001] The present application relates to the technical field of automobile interior processing, and more specifically, to an anti-mildew and anti-bacterial composite material and a preparation method thereof. Background Art

[0002] With increasingly stringent environmental regulations and consumers' urgent demand for healthy and sustainable materials, automotive interior materials are gradually transforming towards biodegradable and renewable materials. Although traditional polyurethane-based composite materials have excellent mechanical strength and wear resistance, they are non-biodegradable and difficult to recycle.

[0003] In recent years, natural fibers, such as hemp fiber, bamboo fiber, coconut shell fiber, etc., have been introduced into the automotive interior field due to their low carbon emission and renewable characteristics. However, a single natural fiber cannot meet the comprehensive performance requirements of automotive interior materials, and the compatibility between natural fibers and polymers is poor. The obtained composite fiber is prone to drainage difficulties due to the hygroscopicity of natural fibers and the hydrophobicity of polymers. Mold is prone to occur inside the material and at the composite interface, which is not conducive to the use of the material. Summary of the invention

[0004] In order to improve the mildew and antibacterial properties of automobile interior materials, the present application provides a mildew and antibacterial composite material and a preparation method thereof.

[0005] In a first aspect, the present application provides an anti-mildew and antibacterial composite material, which adopts the following technical solution: A mildew-proof and antibacterial composite material comprises a non-woven fabric, an impregnated membrane, a blended fiber felt and an impregnated membrane which are compounded in sequence. The blended fiber felt comprises the following raw materials in percentage by mass: 40-60% sisal fiber and 40-60% modified polypropylene fiber; the impregnated membrane is a mildew-proof and antibacterial agent modified polypropylene impregnated membrane.

[0006] By adopting the above technical scheme, natural fibers and modified polypropylene fibers are mixed to obtain fiber felt, which effectively reduces the water absorption of the blended fiber felt and reduces the moisture content of the composite material during use, thereby improving the mildew resistance of the mixed material. At the same time, the modified polypropylene fiber can improve the bonding strength between the blended fiber felt and the impregnated membrane. The impregnated membrane is a polypropylene impregnated membrane modified by an anti-mildew and antibacterial agent, which has high mildew resistance and antibacterial properties. The impregnated membrane has high antibacterial properties and hydrophobicity, thereby achieving the improvement of the mildew resistance and antibacterial properties of the composite material.

[0007] Preferably, the preparation method of the modified polypropylene fiber comprises the following steps: mixing the antibacterial particles with the polypropylene chips, and then performing melt spinning, with a spinneret diameter of 0.5-0.6 mm, a spinning rate of 110-120 m / min, a spinning temperature of 190-230°C, a stretching temperature of 80°C, a stretching multiple of 4-6, and a heat setting temperature of 100°C.

[0008] By adopting the above technical scheme, the antibacterial particles have good antibacterial properties and thermal stability, and can be mixed with polypropylene chips and then spun. The modified polypropylene fibers obtained by melt spinning have good strength and antibacterial properties, and are also hydrophobic. After being mixed with natural fibers, the mixed fiber felt has good antibacterial properties.

[0009] Preferably, the added amount of the antibacterial particles is 1.37-2.18wt% of the polypropylene slices, and the antibacterial particles are titanium dioxide microspheres loaded with nano zinc oxide.

[0010] By adopting the above technical scheme, both titanium dioxide and zinc oxide have good antibacterial properties, can interfere with the growth activities of microorganisms or bacteria under light or no light conditions, and improve the antibacterial properties of modified polypropylene fibers. At the same time, as inorganic particles, they have good thermal stability and can exist relatively stably in the preparation process of modified polypropylene fibers.

[0011] Preferably, the preparation method of the antibacterial particles comprises the following steps: mixing 85-90 mL of isopropanol with 22-25 mL of acetone, adding dropwise 2.2-2.5 mL of titanium chloride ultrasonically dispersed with nano-zinc oxide while stirring, magnetically stirring for 30 minutes, ultrasonicating for 5 minutes, performing a hydrothermal reaction at 200-220° C. for 12 hours, naturally cooling, precipitating, washing, drying, and heat treating at 550-560° C. for 2 hours to obtain the antibacterial particles.

[0012] By adopting the above technical scheme, nano-titanium dioxide microspheres with better shape and moderate size are obtained by hydrothermal method. Nano-zinc oxide is dispersed in titanium chloride. In the process of forming microspheres by hydrothermal reaction, nano-zinc oxide is fixed in the antibacterial particles along with titanium dioxide, thereby realizing the loading of nano-zinc oxide.

[0013] Preferably, the added amount of the nano zinc oxide is 15.26-20.68wt% of the titanium chloride.

[0014] By adopting the above technical scheme, the addition amount of nano zinc oxide is controlled so that the nano zinc oxide can be evenly dispersed in titanium chloride and finally evenly loaded in titanium dioxide microspheres. At the same time, zinc oxide can synergistically exert antibacterial properties with titanium dioxide, thereby improving the antibacterial properties of modified polypropylene fibers.

[0015] Preferably, the preparation method of the impregnated membrane comprises the following steps: immersing a polypropylene membrane in an acetone solution of maleic anhydride, irradiating the membrane with ultraviolet light to obtain a polypropylene membrane with surface photografting, and then immersing the membrane in a silver nitrate solution for 50 seconds, rinsing the membrane with water for 40 seconds, and then immersing the membrane in a sodium chloride solution for 50 seconds, repeating the immersion operation for 8-10 times, and obtaining the impregnated membrane after natural drying.

[0016] By adopting the above technical scheme, maleic anhydride is grafted on the polypropylene film through ultraviolet light irradiation, and the maleic anhydride grafting can effectively improve the adhesion of the polypropylene film, thereby providing good deposition and adsorption conditions for silver chloride precipitation in the subsequent impregnation process, and promoting the smooth and perfect deposition of the silver chloride layer on the surface of the polypropylene film. After the impregnated film is compounded with the blended fiber felt, the silver in the impregnated film cooperates with the zinc oxide and titanium dioxide in the modified polypropylene fiber, so that the interface between the blended fiber felt and the impregnated film, which is prone to mold and bacteria, has higher antibacterial properties, thereby improving the overall anti-mildew and antibacterial properties of the composite material.

[0017] Preferably, the ultraviolet light irradiation time is 160-180s, the wavelength is 254nm, and the intensity is 8500-9000μW / cm 2 .

[0018] By adopting the above technical solution, the irradiation time, wavelength and intensity of ultraviolet light are controlled, thereby ensuring the grafting effect and grafting amount of maleic anhydride, making the polypropylene film have better adhesion, thereby ensuring the antibacterial performance of the impregnated film.

[0019] In a second aspect, the present application provides a method for preparing a mildew-proof and antibacterial composite material, which adopts the following technical solution: A method for preparing an anti-mildew and antibacterial composite material comprises the following steps: sisal fiber and modified polypropylene fiber are combed, mixed, laid and needled to obtain a blended fiber felt; a non-woven fabric, an impregnated membrane, the blended fiber felt and the impregnated membrane are stacked in sequence; and a plate is made by a rolling process at 150°C to obtain the anti-mildew and antibacterial composite material.

[0020] By adopting the above technical scheme, sisal fiber and modified polypropylene fiber are mixed to prepare a blended fiber felt, which reduces the water absorption of the blended fiber felt, thereby reducing the amount of water absorbed by the composite material during use, thereby improving its mildew resistance. The addition of modified polypropylene fiber can increase the bonding strength between the blended fiber felt and the impregnated membrane during board making.

[0021] In summary, this application has the following beneficial effects: 1. Since the present application mixes natural fibers with modified polypropylene fibers to prepare fiber felt, the water absorption of the blended fiber felt is effectively reduced, and the moisture content of the composite material during use is reduced, thereby improving the mildew resistance of the mixed material. At the same time, the modified polypropylene fiber can improve the bonding strength between the blended fiber felt and the impregnated membrane. The impregnated membrane is a polypropylene impregnated membrane modified with an anti-mildew and antibacterial agent, which has high mildew resistance and antibacterial properties. The impregnated membrane has high antibacterial properties and hydrophobicity, thereby achieving the improvement of the mildew resistance and antibacterial properties of the composite material.

[0022] 2. The antibacterial particles in the present application have good antibacterial properties and thermal stability, and can be mixed with polypropylene chips and spun. The modified polypropylene fibers obtained by melt spinning have good strength and antibacterial properties, and are also hydrophobic. After being mixed with natural fibers, the mixed fiber felt has good antibacterial properties.

[0023] 3. In the present application, maleic anhydride is grafted onto the polypropylene film by ultraviolet light irradiation. Maleic anhydride grafting can effectively improve the adhesion of the polypropylene film, thereby providing good deposition and adsorption conditions for silver chloride precipitation in the subsequent impregnation process, and promoting the smooth and perfect deposition of the silver chloride layer on the surface of the polypropylene film. After the impregnated film is compounded with the blended fiber felt, the silver in the impregnated film cooperates with the zinc oxide and titanium dioxide in the modified polypropylene fiber, so that the interface between the blended fiber felt and the impregnated film, which is prone to mold and bacteria growth, has higher antibacterial properties, thereby improving the overall antibacterial and mildew-proof properties of the composite material. DETAILED DESCRIPTION

[0024] The present application is further described in detail below with reference to the embodiments. Preparation Example 1-5 of Antibacterial Particles

[0025] Preparation Example 1 The preparation method of antibacterial particles comprises the following steps: mixing 85 mL of isopropanol with 22 mL of acetone, adding dropwise 2.2 mL of titanium chloride in which nano zinc oxide is ultrasonically dispersed while stirring, wherein the amount of nano zinc oxide added is 20.68 wt % of the titanium chloride, magnetically stirring for 30 minutes and ultrasonicating for 5 minutes, performing a hydrothermal reaction at 200° C. for 12 hours, naturally cooling, precipitating, washing, and drying, and heat treating at 550° C. for 2 hours to obtain the antibacterial particles.

[0026] Preparation Example 2 The preparation method of antibacterial particles comprises the following steps: mixing 90 mL of isopropanol with 25 mL of acetone, adding dropwise 2.5 mL of titanium chloride in which nano zinc oxide is ultrasonically dispersed while stirring, wherein the amount of nano zinc oxide added is 15.26 wt % of the titanium chloride, magnetically stirring for 30 minutes and ultrasonicating for 5 minutes, performing a hydrothermal reaction at 220° C. for 12 hours, naturally cooling, precipitating, washing, and drying, and heat treating at 560° C. for 2 hours to obtain the antibacterial particles.

[0027] Preparation Example 3 The difference between Preparation Example 3 and Preparation Example 1 is that in Preparation Example 3, the added amount of nano zinc oxide is 5.95 wt % of titanium chloride.

[0028] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that in Preparation Example 4, the added amount of nano zinc oxide is 30.25 wt % of titanium chloride.

[0029] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 1 is that in Preparation Example 5, nano zinc oxide is not added to the titanium chloride.

[0030] Preparation Example 6-13 of Modified Polypropylene Fiber Preparation Example 6 The preparation method of modified polypropylene fiber comprises the following steps: mixing antibacterial particles with polypropylene chips, wherein the addition amount of the antibacterial particles is 1.37wt% of the polypropylene chips, and melt spinning is performed with a spinneret diameter of 0.5mm, a spinning rate of 110m / min, a spinning temperature of 190°C, a stretching temperature of 80°C, a stretching multiple of 4, and a heat setting temperature of 100°C. The antibacterial particles are the antibacterial particles prepared in Preparation Example 1.

[0031] Preparation Example 7 The preparation method of modified polypropylene fiber comprises the following steps: mixing antibacterial particles with polypropylene chips, wherein the addition amount of the antibacterial particles is 2.18wt% of the polypropylene chips, and melt spinning is performed with a spinneret diameter of 0.6mm, a spinning rate of 120m / min, a spinning temperature of 230°C, a stretching temperature of 80°C, a stretching multiple of 6, and a heat setting temperature of 100°C. The antibacterial particles are the antibacterial particles prepared in Preparation Example 2.

[0032] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 6 is that in Preparation Example 8, the antibacterial particles are the antibacterial particles prepared in Preparation Example 3.

[0033] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 6 is that in Preparation Example 9, the antibacterial particles are the antibacterial particles prepared in Preparation Example 4.

[0034] Preparation Example 10 The difference between Preparation Example 10 and Preparation Example 6 is that in Preparation Example 10, the antibacterial particles are the antibacterial particles prepared in Preparation Example 5.

[0035] Preparation Example 11 The difference between Preparation Example 11 and Preparation Example 6 is that in Preparation Example 11, the added amount of antibacterial particles is 0.52wt% of the polypropylene slice.

[0036] Preparation Example 12 The difference between Preparation Example 12 and Preparation Example 6 is that in Preparation Example 12, the added amount of antibacterial particles is 4.95wt% of the polypropylene slice.

[0037] Preparation Example 13 The difference between Preparation Example 13 and Preparation Example 6 is that in Preparation Example 13, no antibacterial particles are added. Preparation Example 14-15 of Impregnated Membrane

[0038] Preparation Example 14 The preparation method of the impregnated film comprises the following steps: immersing the polypropylene film in an acetone solution of maleic anhydride, and irradiating the film with ultraviolet light to obtain a polypropylene film after surface photografting, wherein the ultraviolet light irradiation time is 160s, the wavelength is 254nm, and the intensity is 9000μW / cm 2 , and then immersed in a silver nitrate solution for 50 seconds, rinsed with clean water for 40 seconds, and then immersed in a sodium chloride solution for 50 seconds. The immersion operation was repeated 8 times, and the impregnated membrane was obtained after natural drying.

[0039] Preparation Example 15 The preparation method of the impregnated film comprises the following steps: immersing the polypropylene film in an acetone solution of maleic anhydride, and irradiating the film with ultraviolet light to obtain a polypropylene film after surface photografting, wherein the ultraviolet light irradiation time is 180s, the wavelength is 254nm, and the intensity is 8500μW / cm 2 , and then immersed in a silver nitrate solution for 50 seconds, rinsed with clean water for 40 seconds, and then immersed in a sodium chloride solution for 50 seconds. The immersion operation was repeated 10 times, and the impregnated membrane was obtained after natural drying. Example

[0040] Example 1 A mildew-proof and antibacterial composite material comprises a non-woven fabric, an impregnated membrane, a blended fiber felt and an impregnated membrane which are compounded in sequence, the blended fiber felt comprises the following raw materials in percentage by mass: 40% sisal fiber and 60% modified polypropylene fiber, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 6; the impregnated membrane is a mildew-proof and antibacterial agent modified polypropylene impregnated membrane, the impregnated membrane is the impregnated membrane prepared in Preparation Example 14.

[0041] The preparation method of the above-mentioned mildew-proof and antibacterial composite material includes the following steps: sisal fiber and modified polypropylene fiber are combed, mixed, laid and needled to obtain a blended fiber felt, non-woven fabric, impregnated membrane, blended fiber felt and impregnated membrane are stacked in sequence, and then a plate is made by a rolling process at 150°C to obtain a mildew-proof and antibacterial composite material.

[0042] Example 2 A mildew-proof and antibacterial composite material comprises a non-woven fabric, an impregnated membrane, a blended fiber felt and an impregnated membrane which are compounded in sequence, the blended fiber felt comprises the following raw materials in percentage by mass: 60% sisal fiber and 40% modified polypropylene fiber, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 7; the impregnated membrane is a mildew-proof and antibacterial agent modified polypropylene impregnated membrane, the impregnated membrane is the impregnated membrane prepared in Preparation Example 15.

[0043] The preparation method of the above-mentioned mildew-proof and antibacterial composite material includes the following steps: sisal fiber and modified polypropylene fiber are combed, mixed, laid and needled to obtain a blended fiber felt, non-woven fabric, impregnated membrane, blended fiber felt and impregnated membrane are stacked in sequence, and then a plate is made by a rolling process at 150°C to obtain a mildew-proof and antibacterial composite material.

[0044] Example 3 The difference between Example 3 and Example 1 is that in Example 3, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 8.

[0045] Example 4 The difference between Example 4 and Example 1 is that in Example 4, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 9.

[0046] Example 5 The difference between Example 5 and Example 1 is that in Example 5, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 10.

[0047] Example 6 The difference between Example 6 and Example 1 is that in Example 6, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 11.

[0048] Example 7 The difference between Example 7 and Example 1 is that in Example 7, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 12.

[0049] Example 8 The difference between Example 8 and Example 1 is that in Example 8, the modified polypropylene fiber is the modified polypropylene fiber prepared in Preparation Example 13. Comparative Example

[0050] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, a polypropylene film is used instead of the impregnated film.

[0051] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the mass percentage of sisal fiber in the blended fiber felt is 20%.

[0052] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, the mass percentage of sisal fiber in the blended fiber felt is 80%. Performance testing

[0053] According to the raw materials and preparation methods of Examples 1-8 and Comparative Examples 1-3, a mildew-proof and antibacterial composite material was prepared. The sample area was 100 mm×100 mm, and the sample was hung in a closed test box. 200 mL of clean water was placed at the bottom of the closed test box, and the distance between the sample and the clean water surface was 15 cm. The temperature of the closed test box was 40±5°C, and the humidity was 90±5%. The sample testing time was 14 days. After the test, the closed test box was opened, and the test box was smelled for moldy odor, and then the surface of the non-woven fabric was observed for mold growth, and the interface between the blended fiber felt and the impregnated membrane and the blended fiber felt were observed for mold growth. The observation results are recorded in Table 1.

[0054] Table 1 Anti-mildew and antibacterial performance test project Musty Surface mold Interface mold Fiber felt mold Example 1 no no no no Example 2 no no no no Example 3 yes no yes yes Example 4 yes no yes yes Example 5 yes no yes yes Example 6 yes no yes yes Example 7 yes no yes yes Example 8 yes no yes yes Comparative Example 1 yes no yes no Comparative Example 2 yes no yes yes Comparative Example 3 yes no no yes According to Table 1, Examples 1-2 and Comparative Examples 1-3, it can be seen that the sample surfaces, blended fiber felts and interfaces of Examples 1-2 were not moldy, and there was no moldy smell inside the test box, indicating that the composite materials prepared in Examples 1-2 have high anti-mold and antibacterial properties, while mold appeared at the interface of Comparative Example 1, mold appeared at the blended fiber felt and interface of Comparative Example 2, and mold appeared on the blended fiber felt of Comparative Example 3. In Comparative Example 1, a polypropylene film was used instead of an impregnated film, and the polypropylene film was not treated with silver chloride precipitation coating, which reduced the anti-mold and antibacterial properties of the composite material. At the same time, there were only antibacterial particles at the interface, and no silver chloride, zinc oxide, or disulfide was present. Titanium oxide performs synergistic antibacterial effects, thereby reducing the antibacterial performance at the interface compared with Examples 1-2, and mold grows at the interface. Comparative Examples 2-3 change the mass percentage of sisal fiber and modified polypropylene fiber. In Comparative Example 2, the sisal fiber content is too high, and the modified polypropylene fiber content is reduced, the composite strength of the blended fiber felt and the impregnated membrane is reduced, the bonding degree at the interface is reduced, and the water absorption is better. During the experiment, the blended fiber felt absorbs and retains too much water, which is easy to breed mold. In Comparative Example 3, the sisal fiber content is reduced, and the modified polypropylene fiber content is increased, the water absorption of the blended fiber felt is reduced, local water is retained inside, water is difficult to lose, and mold occurs.

[0055] In Examples 1-2, antibacterial particles are added to the modified polypropylene fiber. The zinc oxide and titanium dioxide in the antibacterial particles have good antibacterial properties, which can inhibit the growth and reproduction of mold and bacteria in the material, thereby achieving an antibacterial and mildew-proof effect. At the same time, at the interface between the blended fiber felt and the impregnated membrane, the antibacterial particles can cooperate with the silver chloride layer coated on the surface of the impregnated membrane to achieve antibacterial and mildew-proof properties, further improving the antibacterial and mildew-proof properties at the interface. At the same time, the modified polypropylene fiber improves the bonding strength between the blended fiber felt and the impregnated membrane, improves the compatibility and bonding tightness at the interface, reduces water storage at the interface, and thus improves the antibacterial and mildew-proof properties of the composite material.

[0056] Compared with Example 1, in Example 3-4, the amount of nano-zinc oxide added was changed during the preparation of the antibacterial particles of Example 3-4, and mold appeared at the interface and the mixed fiber felt. The amount of nano-zinc oxide added affected the dispersibility of nano-zinc oxide in titanium chloride. If the amount added was too much, the nano-zinc oxide was easily dispersed unevenly, thereby reducing the loading of nano-zinc oxide on titanium dioxide microspheres and reducing the nano-zinc oxide content in the antibacterial particles, affecting the antibacterial properties of the antibacterial particles. If the amount added was too little, the synergistic antibacterial properties of nano-zinc oxide, titanium dioxide and silver chloride were reduced, thereby reducing the mildew and antibacterial properties of the composite material.

[0057] Compared with Example 1, Example 5 does not add nano zinc oxide during the preparation of the antibacterial particles of Example 5, that is, the antibacterial particles are titanium dioxide microspheres. Mold occurs at the interface and blended fiber felt of Example 5, indicating that the addition of nano zinc oxide can effectively improve the antibacterial and mildew-proof properties of the composite material. The absence of nano zinc oxide reduces the antibacterial and mildew-proof properties of the antibacterial particles and weakens the synergistic effect between the antibacterial particles and the impregnated membrane, thereby reducing the antibacterial and mildew-proof properties at the interface and causing mold.

[0058] Compared with Example 1, the modified polypropylene fibers of Examples 6-7 were prepared by changing the amount of antibacterial particles added. The polypropylene fibers used in Example 8 did not contain antibacterial particles. Mildew occurred at the interfaces and blended fiber felts of Examples 6-8, indicating that the amount of antibacterial particles added affected the antibacterial properties of the composite materials. When the amount of antibacterial particles added was reduced or not added, the mildew and antibacterial properties of the blended fiber felt decreased. When the amount of antibacterial particles added was increased, the antibacterial particles were easily unevenly dispersed in the modified polypropylene fibers, affecting the spinning performance of the modified polypropylene fibers, and at the same time affecting the mildew and antibacterial properties of the modified polypropylene fibers.

[0059] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A mildew and antibacterial composite material, characterized in that: It comprises a non-woven fabric, an impregnated membrane, a blended fiber felt and an impregnated membrane which are compounded in sequence. The blended fiber felt comprises the following raw materials in percentage by mass: 40-60% sisal fiber and 40-60% modified polypropylene fiber. The impregnated membrane is a mildew and antibacterial agent modified polypropylene impregnated membrane.

2. The mildew-proof and antibacterial composite material according to claim 1, characterized in that: The preparation method of the modified polypropylene fiber comprises the following steps: mixing the antibacterial particles with the polypropylene slices, and then performing melt spinning, with a spinneret diameter of 0.5-0.6 mm, a spinning rate of 110-120 m / min, a spinning temperature of 190-230° C., a stretching temperature of 80° C., a stretching multiple of 4-6, and a heat setting temperature of 100° C.

3. The mildew-proof and antibacterial composite material according to claim 2, characterized in that: The added amount of the antibacterial particles is 1.37-2.18wt% of the polypropylene slices, and the antibacterial particles are titanium dioxide microspheres loaded with nano zinc oxide.

4. The mildew-proof and antibacterial composite material according to claim 3, characterized in that: The preparation method of the antibacterial particles comprises the following steps: mixing 85-90 mL of isopropanol with 22-25 mL of acetone, adding dropwise 2.2-2.5 mL of titanium chloride with nano zinc oxide ultrasonically dispersed therein while stirring, magnetically stirring for 30 minutes, ultrasonicating for 5 minutes, performing a hydrothermal reaction at 200-220° C. for 12 hours, naturally cooling, precipitating, washing, drying, and heat-treating at 550-560° C. for 2 hours to obtain the antibacterial particles.

5. The mildew-proof and antibacterial composite material according to claim 4, characterized in that: The added amount of the nano zinc oxide is 15.26-20.68wt% of the titanium chloride.

6. The mildew-proof and antibacterial composite material according to claim 1, characterized in that: The preparation method of the impregnated membrane comprises the following steps: immersing a polypropylene membrane in an acetone solution of maleic anhydride, irradiating with ultraviolet light to obtain a polypropylene membrane with surface photografting, then immersing in a silver nitrate solution for 50 seconds, rinsing with clean water for 40 seconds, and then immersing in a sodium chloride solution for 50 seconds, repeating the immersion operation for 8-10 times, and obtaining an impregnated membrane after natural drying.

7. The mildew-proof and antibacterial composite material according to claim 6, characterized in that: The ultraviolet light irradiation time is 160-180s, the wavelength is 254nm, and the intensity is 8500-9000μW / cm 2 .

8. The method for preparing a mildew-proof and antibacterial composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Sisal fiber and modified polypropylene fiber are combed, mixed, laid and needle-punched to obtain a blended fiber felt. The non-woven fabric, impregnated membrane, blended fiber felt and impregnated membrane are stacked in sequence and then made into a board by a rolling process at 150°C to obtain an anti-mildew and antibacterial composite material.