Antibacterial mildew-proof self-cleaning curtain pulley and preparation method thereof

Abstract

The invention relates to the technical field of curtain pulleys, in particular to an antibacterial mildew-proof self-cleaning curtain pulley and a preparation method thereof, and the antibacterial mildew-proof self-cleaning curtain pulley comprises the following components in parts by weight: 80-90 parts of high density polyethylene (HDPE); 0.5 to 2.0 parts of nano silver; 0.3 to 1.5 parts of isothiazolinone; 3-8 parts of titanium dioxide; 1 to 3 parts of polytetrafluoroethylene (PTFE) micro powder; 5 to 10 parts of ethylene-vinyl acetate copolymer (EVA); 0.2 to 1.0 part of sodium dodecyl benzene sulfonate; through the synergistic effect of the nano-silver and the isothiazolinone, the antibacterial rate close to 100% is achieved, and high efficiency is still kept after long-term use; the photocatalytic effect of titanium dioxide is combined with the super-hydrophilic surface, pollutants can be actively decomposed, passive cleaning can be achieved during water washing, and continuous self-cleaning circulation is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of curtain pulleys, and particularly to an antibacterial, mildew-proof and self-cleaning curtain pulley and a preparation method thereof. Background Art

[0002] With the improvement of people's living standards and the enhancement of health awareness, the requirements for the home environment are also increasing day by day. As an important part of indoor decoration, curtains not only play a role in regulating light and protecting privacy, but also play an important role in beautifying the indoor space. However, traditional curtain pulleys often face many problems during long-term use, such as bacterial growth, mold growth, dirt accumulation, etc., which not only affect the appearance, but also may pose a potential threat to the health of residents.

[0003] At present, common curtain pulleys on the market are mostly made of ordinary plastic materials. Although they meet the use requirements in basic functions, they have obvious deficiencies in antibacterial, mildew-proof and self-cleaning aspects. Some improved curtain pulleys improve antibacterial performance by adding antibacterial agents or coating antibacterial coatings, but these methods often have problems such as poor persistence and easy shedding. Some other products use self-cleaning coatings, but their wear resistance and long-term stability still need to be improved. In addition, the antibacterial, mildew-proof and self-cleaning functions in the existing technology are often realized separately, lacking effective synergistic effects and being difficult to meet the growing multi-functional requirements. Summary of the Invention

[0004] The antibacterial, mildew-proof and self-cleaning curtain pulley of the present invention and its preparation method aim to solve multiple problems existing in the prior art.

[0005] The purpose of the present invention is to provide an antibacterial, mildew-proof and self-cleaning curtain pulley, which comprises the following components in parts by weight: 80 - 90 parts of high-density polyethylene HDPE; 0.5 - 2.0 parts of nano silver; 0.3 - 1.5 parts of isothiazolinone; 3 - 8 parts of titanium dioxide; 1 - 3 parts of polytetrafluoroethylene PTFE micropowder; 5 - 10 parts of ethylene-vinyl acetate copolymer EVA; 0.2 - 1.0 part of sodium dodecylbenzenesulfonate; 0.5 - 2.0 parts of silane coupling agent KH-550.

[0006] Preferably, the particle size of the nano silver is 10 - 50 nm.

[0007] Preferably, the titanium dioxide is a mixture of anatase type and rutile type, and the weight ratio of anatase type to rutile type is 3:1 to 1:1.

[0008] Preferably, the average particle size of the polytetrafluoroethylene (PTFE) micro powder is 1 - 5 μm.

[0009] For the antibacterial, mildew-proof and self-cleaning curtain pulley described above, the surface of the curtain pulley has a silk-screen coating, and this coating consists of the following components: Titanium dioxide: 2 - 5 parts by weight; Nano silver: 0.2 - 0.5 parts by weight; Isothiazolinone: 0.1 - 0.3 parts by weight; Organic solvent: 95 - 97.7 parts by weight, wherein the organic solvent is a mixture of ethanol and isopropanol, and the volume ratio of ethanol to isopropanol is 3:1.

[0010] Preferably, it includes the following steps: (1) Pretreatment step: First, vacuum dry HDPE, EVA and PTFE micro powder at 60 - 70 °C for 4 - 6 hours; Second, vacuum dry nano silver, isothiazolinone and titanium dioxide at 40 - 50 °C for 2 - 3 hours; (2) Composite material preparation step: Then, successively add the pretreated components into a twin-screw extruder for mixing and extrusion, wherein the temperature of the extruder is 180 - 200 °C and the screw speed is 100 - 150 rpm; (3) Pulley forming step: Next, dry the prepared composite material pellets until the water content is less than 0.05%, and obtain the curtain pulley by injection molding, wherein the injection molding temperature is 190 - 210 °C, the mold temperature is 40 - 60 °C, the injection pressure is 80 - 120 MPa, and the holding pressure time is 10 - 15 seconds; (4) Surface treatment step: Again, perform plasma treatment on the formed pulley, with the treatment power of 50 - 100 W and the time of 2 - 5 minutes; (5) Coating preparation step: Finally, use the screen printing method to coat the antibacterial, mildew-proof and self-cleaning coating on the surface of the pulley, and dry it at 60 - 80 °C for 10 - 15 minutes.

[0011] Preferably, in the composite material preparation step, the adding order of the components is: First, add HDPE and EVA to the feed inlet of the extruder; Second, add PTFE micro powder and sodium dodecylbenzenesulfonate at the first side feed inlet; Then, successively add nano silver, isothiazolinone and titanium dioxide at the second side feed inlet; Finally, add silane coupling agent KH-550 into the third side feed port.

[0012] Preferably, in the surface treatment step, oxygen plasma is used for plasma treatment.

[0013] Preferably, in the coating preparation step, the screen mesh count used for screen printing is 300 - 400 meshes.

[0014] Preferably, it further includes a performance testing step: Test the antibacterial performance, mildew-proof performance, self-cleaning performance and mechanical performance of the curtain pulley, where: The antibacterial performance is tested according to the standard of GB / T 21866-2008, and the antibacterial rate should be ≥99%; The mildew-proof performance is tested according to the standard of GB / T 24346-2009, and the mildew-proof grade should reach level 0; The self-cleaning performance adopts the contact angle test method, and the water contact angle should be <10°; The mechanical performance tests the tensile strength according to the standard of GB / T 1040.1-2006, and it should be ≥25 MPa.

[0015] The innovation of the present invention lies in that for the first time, functional components such as nano silver, isothiazolinone, and titanium dioxide are organically combined with the polymer matrix material, and through the carefully designed formula and preparation process, the synergistic effect of antibacterial, mildew-proof and self-cleaning functions is achieved. Compared with the prior art, the present invention has the following remarkable characteristics and advantages: 1. Multiple antibacterial mechanisms: Nano silver acts by destroying the bacterial cell membrane, while isothiazolinone kills bacteria by inhibiting bacterial metabolism. This double-hit mechanism not only greatly improves the antibacterial efficiency but also effectively reduces the possibility of bacteria developing drug resistance. At the molecular level, the Ag+ ions of nano silver can form strong interactions with the sulfhydryl groups (-SH) on the bacterial cell membrane, destroying the integrity of the cell membrane; the N-S bond in isothiazolinone can react with the enzyme molecules in bacteria, inhibiting their metabolic processes.

[0016] 2. Photocatalytic self-cleaning: Titanium dioxide can generate strongly oxidizing hydroxyl radicals (·OH) and superoxide anion radicals (O2·-) under ultraviolet light irradiation. These active radicals can effectively decompose organic pollutants to achieve the self-cleaning effect. At the same time, the photocatalytic effect of titanium dioxide can also enhance the antibacterial effect, forming a synergistic effect with nano silver and isothiazolinone.

[0017] 3. Superhydrophilic surface: The micro-nano composite structure formed by titanium dioxide nanoparticles and polymer matrix significantly increases the surface roughness. According to the Wenzel equation, this micro-nano structure can amplify the hydrophilicity of the material itself, thus achieving a superhydrophilic effect. The superhydrophilic surface not only facilitates the flushing of pollutants but also forms a water film to prevent the attachment of bacteria and molds.

[0018] 4. Balance of mechanical properties and functionality: By adding PTFE micro powder and EVA, the present invention not only provides excellent functionality but also achieves excellent mechanical properties and durability. The introduction of PTFE micro powder significantly reduces the surface energy of the material and improves wear resistance; the addition of EVA enhances the toughness of the material through its flexible molecular chains, especially its performance in low-temperature environments.

[0019] 5. Long-term stability: Sodium dodecylbenzenesulfonate, as a dispersant, has a long-chain alkyl group compatible with the polymer matrix, while the hydrophilic sulfonic acid group interacts with inorganic fillers, effectively improving the dispersibility of functional components. The silane coupling agent KH-550 forms a chemical bond with inorganic fillers at one end through its unique molecular structure and is entangled with the polymer matrix at the other end, significantly enhancing the bonding force at the organic-inorganic interface. This strong interface interaction not only improves the mechanical properties of the material but also creates a stable microenvironment for functional components, which is the key to achieving long-term performance stability.

[0020] Through the above innovative design, the present invention has successfully solved the problems of bacterial growth, mold growth, and dirt accumulation existing in traditional curtain pulleys, and at the same time overcome the defects of single function, poor durability, and easy detachment in existing improved products. More importantly, the present invention realizes the synergistic effect of multiple functions, optimizes the material structure and performance at the molecular and microscale, and creates a new type of curtain pulley material with persistent antibacterial, antifungal, self-cleaning functions, and excellent mechanical properties and durability at the same time.

[0021] The beneficial effects of the present invention are mainly reflected in the following aspects: 1. Persistent and highly efficient antibacterial and antifungal properties: Through the synergistic effect of nano silver and isothiazolinone, an antibacterial rate close to 100% is achieved and remains highly efficient after long-term use.

[0022] 2. Self-repairing and self-cleaning effect: The combination of the photocatalytic effect of titanium dioxide and the superhydrophilic surface can not only actively decompose pollutants but also achieve passive cleaning during water flushing, forming a continuous self-cleaning cycle.

[0023] 3. Excellent comprehensive mechanical properties: While maintaining high compressive strength, it also has good wear resistance and low-temperature toughness, meeting various requirements in actual use.

[0024] 4. Excellent long-term performance stability: After accelerated aging tests, all functional and mechanical properties remain at a very high level, demonstrating excellent anti-aging characteristics.

[0025] 5. Environmentally friendly: All the functional components used in this invention are non-toxic and harmless materials. While providing excellent performance, they will not have a negative impact on the environment and human health.

[0026] In summary, through the collaborative design of multi-components and innovative preparation processes, this invention realizes functional integration and performance optimization at the molecular level. It not only solves multiple problems existing in traditional curtain pulleys but also provides new ideas and methods for the design of functional polymer composites, having important theoretical significance and broad application prospects. Detailed implementation manners

[0027] Example 1 This example provides an antibacterial, mildew-proof and self-cleaning curtain pulley, and its components and parts by weight are as follows: 80 parts of HDPE, 0.5 part of nano-silver, 0.3 part of isothiazolinone, 3 parts of titanium dioxide, 1 part of PTFE micro-powder, 5 parts of EVA, 0.2 part of sodium dodecylbenzenesulfonate, 0.5 part of silane coupling agent KH-550.

[0028] Its preparation method includes the following steps: (1) Pretreatment step: First, vacuum-dry HDPE, EVA and PTFE micro-powder at 60 °C for 4 hours; second, vacuum-dry nano-silver, isothiazolinone and titanium dioxide at 40 °C for 2 hours.

[0029] (2) Composite material preparation step: Then, sequentially add the pretreated components into a twin-screw extruder for mixing and extrusion. Among them, the temperature of the extruder is set at 180 °C and the screw speed is 100 rpm. The adding order of the components is: First, add HDPE and EVA to the feed inlet of the extruder; second, add PTFE micro-powder and sodium dodecylbenzenesulfonate at the first side feed inlet; then, sequentially add nano-silver, isothiazolinone and titanium dioxide at the second side feed inlet; finally, add silane coupling agent KH-550 at the third side feed inlet.

[0030] (3) Pulley forming step: Next, dry the prepared composite material pellets to a water content lower than 0.05% and obtain curtain pulleys by injection molding. The injection temperature is 190 °C, the mold temperature is 40 °C, the injection pressure is 80 MPa, and the holding pressure time is 10 seconds.

[0031] (4) Surface treatment step: Again, perform plasma treatment on the formed pulleys. Use oxygen plasma, the treatment power is 50 W, and the time is 2 minutes.

[0032] (5) Coating preparation step: Finally, an antibacterial, mildew-proof and self-cleaning coating is applied to the surface of the pulley by screen printing, and the screen mesh count is 300 meshes. The coating components are: 2 parts by weight of titanium dioxide, 0.2 parts by weight of nano silver, 0.1 parts by weight of isothiazolinone, and 97.7 parts by weight of organic solvent (the volume ratio of ethanol to isopropanol is 3:1). After coating, it is dried at 60 °C for 10 minutes.

[0033] In this embodiment, HDPE as the matrix material provides good mechanical strength and chemical resistance; the particle size of nano silver is 10 nm, with excellent antibacterial properties; isothiazolinone enhances the antibacterial effect by inhibiting bacterial metabolism and forms a synergistic effect with nano silver; titanium dioxide is a mixture of anatase and rutile with a ratio of 3:1, which produces a photocatalytic effect under ultraviolet light irradiation to decompose organic pollutants and improve the self-cleaning effect; the average particle size of PTFE micro powder is 1 μm, which improves the wear resistance and lubricity of the material; EVA increases the toughness of the material and balances the rigidity of HDPE; sodium dodecyl benzene sulfonate as a dispersant improves the dispersibility of each component; silane coupling agent KH-550 improves the compatibility between organic and inorganic components.

[0034] Example 2 This embodiment provides another antibacterial, mildew-proof and self-cleaning curtain pulley, and its components and parts by weight are as follows: 85 parts of HDPE, 1.25 parts of nano silver, 0.9 parts of isothiazolinone, 5.5 parts of titanium dioxide, 2 parts of PTFE micro powder, 7.5 parts of EVA, 0.6 parts of sodium dodecyl benzene sulfonate, and 1.25 parts of silane coupling agent KH-550.

[0035] Its preparation method includes the following steps: (1) Pretreatment step: First, HDPE, EVA and PTFE micro powder are vacuum dried at 65 °C for 5 hours; second, nano silver, isothiazolinone and titanium dioxide are vacuum dried at 45 °C for 2.5 hours.

[0036] (2) Composite material preparation step: Then, the pretreated components are sequentially added into a twin-screw extruder for mixing and extrusion. Among them, the temperature of the extruder is set at 190 °C, and the screw speed is 125 rpm. The addition order of the components is the same as that in Example 1.

[0037] (3) Pulley molding step: Then, the prepared composite material pellets are dried until the water content is lower than 0.05%, and curtain pulleys are obtained by injection molding. The injection temperature is 200 °C, the mold temperature is 50 °C, the injection pressure is 100 MPa, and the holding pressure time is 12.5 seconds.

[0038] (4) Surface treatment step: Again, the formed pulley is subjected to plasma treatment using oxygen plasma with a treatment power of 75 W and a time of 3.5 minutes.

[0039] (5) Coating preparation step: Finally, an antibacterial, mildew-proof and self-cleaning coating is applied to the surface of the pulley by screen printing with a screen mesh count of 350 meshes. The coating components are: 3.5 parts by weight of titanium dioxide, 0.35 parts by weight of nano silver, 0.2 parts by weight of isothiazolinone, and 95.95 parts by weight of organic solvent (the volume ratio of ethanol to isopropanol is 3:1). After coating, it is dried at 70 °C for 12.5 minutes.

[0040] Preferably, in this embodiment, the particle size of nano silver is increased to 30 nm, improving its dispersibility in the matrix; the ratio of anatase type to rutile type of titanium dioxide is adjusted to 2:1, further enhancing the photocatalytic effect; the average particle size of PTFE micro powder is increased to 3 μm, increasing the lubricity and also enhancing the bonding force with the matrix. These adjustments enable this embodiment to further improve the self-cleaning effect and mechanical properties while maintaining good antibacterial and mildew-proof performance.

[0041] Example 3 This embodiment provides a third type of antibacterial, mildew-proof and self-cleaning curtain pulley, and its components and parts by weight are as follows: 90 parts of HDPE, 2.0 parts of nano silver, 1.5 parts of isothiazolinone, 8 parts of titanium dioxide, 3 parts of PTFE micro powder, 10 parts of EVA, 1.0 part of sodium dodecylbenzenesulfonate, and 2.0 parts of silane coupling agent KH-550.

[0042] Its preparation method includes the following steps: (1) Pretreatment step: First, HDPE, EVA and PTFE micro powder are vacuum dried at 70 °C for 6 hours; second, nano silver, isothiazolinone and titanium dioxide are vacuum dried at 50 °C for 3 hours.

[0043] (2) Composite material preparation step: Then, the pretreated components are sequentially added into a twin-screw extruder for mixing and extrusion. Among them, the temperature of the extruder is set at 200 °C and the screw rotation speed is 150 rpm. The addition order of the components is the same as that in Example 1.

[0044] (3) Pulley forming step: Next, the prepared composite material pellets are dried to a water content of less than 0.05% and formed into curtain pulleys by injection molding. The injection temperature is 210 °C, the mold temperature is 60 °C, the injection pressure is 120 MPa, and the holding pressure time is 15 seconds.

[0045] (4) Surface treatment step: Again, the formed pulley is subjected to plasma treatment using oxygen plasma with a treatment power of 100 W and a time of 5 minutes.

[0046] (5) Coating preparation step: Finally, an antibacterial, mildew-proof and self-cleaning coating is applied to the surface of the pulley by screen printing method, and the mesh number of the screen plate is 400 meshes. The coating components are: 5 parts by weight of titanium dioxide, 0.5 parts by weight of nano silver, 0.3 parts by weight of isothiazolinone, and 94.2 parts by weight of organic solvent (the volume ratio of ethanol to isopropanol is 3:1). After coating, it is dried at 80 °C for 15 minutes.

[0047] In this embodiment, by increasing the content of each functional component, the antibacterial, mildew-proof and self-cleaning performance of the curtain pulley is further improved. In particular, the particle size of nano silver is increased to 50 nm, which improves its stability in the matrix while maintaining good antibacterial properties; the ratio of anatase type to rutile type of titanium dioxide is adjusted to 1:1, which enhances the photocatalytic effect and also improves the wear resistance; the average particle size of PTFE micropowder is increased to 5 μm, further improving the lubrication performance of the pulley. In addition, by increasing the content of EVA, the toughness and elasticity of the material are significantly improved, so that the pulley has better impact resistance while maintaining high strength.

[0048] Example 4 This embodiment provides a fourth kind of antibacterial, mildew-proof and self-cleaning curtain pulley, and its components and parts by weight are as follows: 87.5 parts of HDPE, 1.75 parts of nano silver, 1.2 parts of isothiazolinone, 6.5 parts of titanium dioxide, 2.5 parts of PTFE micropowder, 8.75 parts of EVA, 0.8 part of sodium dodecylbenzenesulfonate, and 1.75 parts of silane coupling agent KH-550.

[0049] Its preparation method includes the following steps: (1) Pretreatment step: First, HDPE, EVA and PTFE micropowder are vacuum dried at 67.5 °C for 5.5 hours; second, nano silver, isothiazolinone and titanium dioxide are vacuum dried at 47.5 °C for 2.75 hours.

[0050] (2) Composite material preparation step: Then, the pretreated components are sequentially added into a twin-screw extruder for mixing and extrusion. Among them, the temperature of the extruder is set at 195 °C, and the screw speed is 137.5 rpm. The addition order of the components is the same as that in Example 1.

[0051] (3) Pulley molding step: Then, the prepared composite material pellets are dried to a water content of less than 0.05%, and curtain pulleys are obtained by injection molding. The injection temperature is 205 °C, the mold temperature is 55 °C, the injection pressure is 110 MPa, and the holding pressure time is 13.75 seconds.

[0052] (4) Surface treatment step: Again, the formed pulley is subjected to plasma treatment using oxygen plasma with a treatment power of 87.5 W and a treatment time of 4.25 minutes.

[0053] (5) Coating preparation step: Finally, an antibacterial, mildew-proof and self-cleaning coating is applied to the surface of the pulley by screen printing with a screen mesh count of 375 meshes. The coating components are: 4.25 parts by weight of titanium dioxide, 0.425 parts by weight of nano silver, 0.25 parts by weight of isothiazolinone, and 95.075 parts by weight of organic solvent (the volume ratio of ethanol to isopropanol is 3:1). After coating, it is dried at 75 °C for 13.75 minutes.

[0054] In this embodiment, through optimizing the ratios of each component and the preparation parameters, a comprehensive balance of performance is achieved. In particular, the particle size of nano silver is set to 40 nm, taking into account the dispersibility and stability while maintaining good antibacterial properties; the ratio of anatase type to rutile type of titanium dioxide is adjusted to 1.5:1, improving the wear resistance and shielding property while maintaining the photocatalytic effect; the average particle size of PTFE micropowder is set to 4 μm, ensuring good bonding with the matrix while improving the lubricity. In addition, by precisely controlling the preparation parameters such as the pretreatment temperature and time, the extrusion temperature and speed, and the injection molding parameters, etc., the distribution and interaction of each component in the matrix are further optimized, thus achieving the best balance of antibacterial, mildew-proof, self-cleaning and mechanical properties.

[0055] Comparative Example 1: This comparative example aims to verify the synergistic antibacterial effect of nano silver, corresponding to Example 1. Its components and parts by weight are as follows: 80.5 parts of HDPE, 0.3 parts of isothiazolinone, 3 parts of titanium dioxide, 1 part of PTFE micropowder, 5 parts of EVA, 0.2 parts of sodium dodecylbenzenesulfonate, and 0.5 parts of silane coupling agent KH-550.

[0056] The preparation method is basically the same as that of Example 1, except that the addition of nano silver is omitted in the composite material preparation step.

[0057] In this comparative example, due to the lack of nano silver, although isothiazolinone can still provide a certain antibacterial effect, the synergistic effect between nano silver and isothiazolinone cannot be achieved. By comparing with Example 1, it is found that the antibacterial performance of this comparative example is significantly reduced, and the antibacterial rate is only 85%, far lower than 99% of Example 1. This fully proves the key role of nano silver in the present invention. It not only plays a role through its own antibacterial mechanism, but also forms a synergistic effect with isothiazolinone, significantly improving the overall antibacterial performance.

[0058] Comparative Example 2: This comparative example aims to verify the self-cleaning effect of titanium dioxide, corresponding to Example 2. Its components and parts by weight are as follows: 90.5 parts of HDPE, 1.25 parts of nano silver, 0.9 parts of isothiazolinone, 2 parts of PTFE micro powder, 7.5 parts of EVA, 0.6 parts of sodium dodecylbenzenesulfonate, 1.25 parts of silane coupling agent KH-550.

[0059] The preparation method is basically the same as that of Example 2, except that the addition of titanium dioxide is omitted in the composite material preparation step, and the content of HDPE is adjusted accordingly.

[0060] In this comparative example, due to the lack of titanium dioxide, the photocatalytic self-cleaning function of the pulley surface is lost. Through contact angle measurement, it is found that the water contact angle of this comparative example is 65°, much higher than 8° of Example 2. This indicates that without the presence of titanium dioxide, the pulley surface cannot effectively decompose organic pollutants, resulting in a significant decline in self-cleaning performance. In addition, it is also observed that during the long-term use test, the pulley surface of this comparative example is more likely to accumulate stains and bacteria, further confirming the importance of titanium dioxide in maintaining the long-term performance of the pulley.

[0061] Comparative Example 3: This comparative example aims to verify the lubricating effect of PTFE micro powder, corresponding to Example 3. Its components and parts by weight are as follows: 93 parts of HDPE, 2.0 parts of nano silver, 1.5 parts of isothiazolinone, 8 parts of titanium dioxide, 10 parts of EVA, 1.0 parts of sodium dodecylbenzenesulfonate, 2.0 parts of silane coupling agent KH-550.

[0062] The preparation method is basically the same as that of Example 3, except that the addition of PTFE micro powder is omitted in the composite material preparation step, and the content of HDPE is increased accordingly.

[0063] In this comparative example, due to the lack of PTFE micro powder, the friction coefficient of the pulley increases significantly. Through friction and wear test, it is found that the friction coefficient of the pulley in this comparative example is 0.35, while the friction coefficient of Example 3 is only 0.12. This results in a large resistance during the use of the pulley, which not only affects the smooth opening and closing of the curtain, but also accelerates the wear of the pulley. The long-term durability test shows that the pulley in this comparative example shows obvious wear after 100,000 opening and closing cycles, while the pulley of Example 3 still remains in good condition. This fully proves the key role of PTFE micro powder in improving the lubricity and wear resistance of the pulley.

[0064] Comparative Example 4: This comparative example aims to verify the toughening effect of EVA, corresponding to Example 4. Its components and parts by weight are as follows: 96.25 parts of HDPE, 1.75 parts of nano silver, 1.2 parts of isothiazolinone, 6.5 parts of titanium dioxide, 2.5 parts of PTFE micropowder, 0.8 part of sodium dodecylbenzenesulfonate, 1.75 parts of silane coupling agent KH-550.

[0065] The preparation method is basically the same as that of Example 4, except that the addition of EVA is omitted in the composite material preparation step, and the content of HDPE is increased accordingly.

[0066] In this comparative example, due to the lack of EVA, the toughness of the pulley is significantly reduced. Through the impact strength test, it is found that the impact strength of the pulley in this comparative example is only 2.5 kJ / m², while the impact strength of Example 4 reaches 7.8 kJ / m². In the drop test carried out at a low temperature environment (-20 °C), obvious cracks appear in the pulley of this comparative example, while the pulley of Example 4 remains intact. This fully proves the important role of EVA in balancing the rigidity of HDPE, improving the toughness and low temperature resistance of the pulley.

[0067] Comparative Example 5: This comparative example aims to verify the dispersion effect of sodium dodecylbenzenesulfonate, corresponding to Example 1. Its components and parts by weight are as follows: 80.2 parts of HDPE, 0.5 part of nano silver, 0.3 part of isothiazolinone, 3 parts of titanium dioxide, 1 part of PTFE micropowder, 5 parts of EVA, 0.5 part of silane coupling agent KH-550.

[0068] The preparation method is basically the same as that of Example 1, except that the addition of sodium dodecylbenzenesulfonate is omitted in the composite material preparation step, and the content of HDPE is slightly increased.

[0069] In this comparative example, due to the lack of sodium dodecylbenzenesulfonate as a dispersant, the dispersibility of each functional component in the HDPE matrix is significantly reduced. Through scanning electron microscopy observation, it is found that obvious agglomeration phenomena of nano silver and titanium dioxide appear in this comparative example, and the particle size distribution is uneven. This leads to the instability of antibacterial performance and self-cleaning effect, showing large fluctuations in repeated tests. In contrast, the components in Example 1 are evenly dispersed and the performance is stable. This fully proves the key role of sodium dodecylbenzenesulfonate in improving the uniformity and performance stability of the composite material.

[0070] Comparative Example 6: This comparative example aims to verify the interfacial modification effect of silane coupling agent KH-550, corresponding to Example 2. Its components and parts by weight are as follows: 86.25 parts of HDPE, 1.25 parts of nano silver, 0.9 part of isothiazolinone, 5.5 parts of titanium dioxide, 2 parts of PTFE micropowder, 7.5 parts of EVA, 0.6 part of sodium dodecylbenzenesulfonate.

[0071] The preparation method is basically the same as that of Example 2, except that the addition of silane coupling agent KH-550 is omitted in the composite material preparation step, and at the same time, the content of HDPE is slightly increased.

[0072] In this comparative example, due to the lack of silane coupling agent KH-550, the interfacial bonding force between the organic matrix and the inorganic filler is significantly reduced. Through dynamic thermomechanical analysis (DMA) testing, it is found that there is an obvious loss peak near the glass transition temperature of the composite material in this comparative example, indicating poor interfacial bonding. In addition, after cyclic thermal shock testing (-40°C to 80°C, 1000 cycles), microcracks appear on the surface of the pulley in this comparative example, while the pulley of Example 2 remains intact. This fully demonstrates the key role of silane coupling agent KH-550 in improving the organic-inorganic interfacial bonding, enhancing the overall performance and durability of the composite material.

[0073] Through the design and testing of the above 6 comparative examples, the synergistic action mechanism of each key component in the present invention is comprehensively verified. It also specifically shows the contribution of each component to the performance of the final product. The results show that the antibacterial, mildew-proof and self-cleaning curtain pulley of the present invention is superior to the comparative examples in all performance indicators, fully demonstrating the creativity and superiority of the present invention. This formula design with multi-component synergistic action successfully realizes the organic unity of multiple performances such as antibacterial, mildew-proof, self-cleaning, wear-resistant and toughness, providing new ideas and methods for the functional design of curtain pulleys.

[0074] To comprehensively evaluate the performance and its action mechanism of the antibacterial, mildew-proof and self-cleaning curtain pulley of the present invention, a series of scientific and rigorous test experiments are designed. These experiments aim to verify the core innovation points of the present invention and deeply explore the synergistic action mechanism among the components.

[0075] 1. Antibacterial performance test Experimental conditions: The test is carried out with reference to the standard of GB / T 21866-2008.

[0076] Experimental method: First, inoculate the test strains (Escherichia coli and Staphylococcus aureus) on the surface of the pulley and culture at 37°C for 24 hours. Then, calculate the survival rate of bacteria by the plate counting method.

[0077] Experimental results: Table 1. Antibacterial performance test results

[0078] Result analysis: Examples 1 - 4 all exhibited excellent antibacterial properties, with the antibacterial rate exceeding 99%. In particular, for Example 3, its antibacterial rate was close to 100%, demonstrating the best antibacterial effect. In contrast, for Comparative Example 1, due to the absence of silver nanoparticles, the antibacterial performance was significantly reduced. This fully proves the synergistic antibacterial mechanism of silver nanoparticles and isothiazolinone. The combination of the two not only broadens the antibacterial spectrum but also achieves synergistic enhancement through different mechanisms of action (silver nanoparticles damage the bacterial cell membrane, and isothiazolinone inhibits bacterial metabolism).

[0079] 2. Self - cleaning performance test Experimental conditions: A method combining contact angle measurement and photocatalytic degradation experiment was adopted.

[0080] Experimental method: First, a contact angle measuring instrument was used to measure the contact angle of water droplets on the surface of the pulley. Then, methylene blue solution was coated on the surface of the pulley, and the degradation situation was observed under ultraviolet light irradiation (365 nm, intensity 2 mW / cm²).

[0081] Experimental results: Table 2. Self - cleaning performance test results

[0082] Result analysis: Examples 1 - 4 all exhibited excellent self - cleaning performance, with the water contact angle less than 10°, showing superhydrophilicity. In particular, for Example 3, its water contact angle was the smallest and the methylene blue degradation rate was the highest, demonstrating the best self - cleaning effect. For Comparative Example 2, due to the absence of titanium dioxide, the self - cleaning performance was significantly reduced. This verifies the key role of titanium dioxide in the present invention: it not only provides the photocatalytic self - cleaning function but also enhances the hydrophilicity of the material through its unique surface structure, thus achieving the "dual self - cleaning" effect.

[0083] 3. Mechanical properties and durability test Experimental conditions: Comprehensively evaluate the compressive strength, wear resistance, and low - temperature toughness of the pulley.

[0084] Experimental method: a) Compressive strength: Use a universal material testing machine with a loading rate of 5 mm / min.

[0085] b) Wear resistance: pin - on - disk method, load 5 N, rotation speed 500 rpm, test for 100,000 cycles.

[0086] c) Low - temperature toughness: Conduct a cantilever beam impact test at - 20°C.

[0087] Experimental results: Table 3. Mechanical properties and durability test results

[0088] Result analysis: Examples 1 - 4 all exhibited excellent comprehensive mechanical properties. In particular, Example 3 showed the best wear resistance and good low-temperature toughness while maintaining high compressive strength. In Comparative Example 3, due to the lack of PTFE micro-powder, although the compressive strength was slightly higher, the wear resistance decreased significantly. In Comparative Example 4, the lack of EVA led to a substantial decrease in low-temperature toughness. This fully demonstrated the synergistic effect of PTFE micro-powder and EVA in the present invention: PTFE micro-powder significantly improved the wear resistance of the material, while EVA effectively enhanced the toughness of the material, especially its performance in low-temperature environments.

[0089] 4. Long-term performance stability test Experimental conditions: Simulate the actual use environment and conduct an accelerated aging test.

[0090] Experimental method: Place the samples in a QUV accelerated aging chamber and cycle through ultraviolet light irradiation (8 h, 60 °C) and condensation (4 h, 50 °C) for a total duration of 1000 h. Regularly take samples to test antibacterial properties, self-cleaning properties, and mechanical properties.

[0091] Experimental results: Table 4. Long-term performance stability test results (after 1000 h)

[0092] Result analysis: Examples 1 - 4 still maintained excellent comprehensive performance after long-term aging tests, and Example 3 performed the best. In Comparative Examples 5 and 6, due to the lack of dispersant and coupling agent respectively, the performance stability was poor. This verified the key role of sodium dodecylbenzenesulfonate and silane coupling agent KH-550 in maintaining long-term performance stability: the former ensured the uniform dispersion of functional components, and the latter enhanced the bonding force at the organic-inorganic interface, jointly improving the aging resistance of the composite material.

[0093] Based on the above test results, the following conclusions can be drawn: 1. Optimal example: Considering all performance indicators, Example 3 performed the best and can be regarded as the optimal example of the present invention.

[0094] 2. Unexpected technical effects: a) Ultra-long-lasting antibacterial: The synergistic effect of nano-silver and isothiazolinone not only provided an antibacterial rate close to 100%, but more importantly, it still maintained high efficiency after long-term aging tests, showing unexpected long-lasting antibacterial performance.

[0095] b) Self - healing and self - cleaning: The combination of the photocatalytic effect of titanium dioxide and the super - hydrophilic surface achieves a "self - healing" self - cleaning effect. Even when some pollutants are not completely degraded, the super - hydrophilic surface can wash away the residual pollutants when coming into contact with water next time, thus continuously maintaining cleanliness.

[0096] c) Perfect balance between mechanical properties and functionality: Through a carefully designed multi - component system, the present invention not only provides excellent functionality (antibacterial, mildew - proof, self - cleaning), but also achieves excellent mechanical properties and durability. Such a balance is usually difficult to achieve in a single material.

[0097] 3. In - depth mechanism explanation: The excellent performance of the present invention stems from the synergistic effect among multi - components: a) Nano - silver and isothiazolinone form a "double - strike" antibacterial system. The former destroys the bacterial cell membrane, and the latter inhibits metabolism, greatly reducing the possibility of bacteria developing drug resistance.

[0098] b) Titanium dioxide not only provides photocatalytic self - cleaning, but its nano - structure also enhances the surface roughness, forming a micro - nano composite structure with the HDPE matrix and achieving super - hydrophilicity.

[0099] c) The addition of PTFE micro - powder and EVA not only improves wear resistance and toughness, but also enhances the repulsive effect on hydrophobic components (such as bacteria and organic pollutants) by changing the surface energy distribution of the material, indirectly enhancing the antibacterial and self - cleaning effects.

[0100] d) The synergistic effect of sodium dodecylbenzenesulfonate and silane coupling agent KH - 550 not only ensures the uniform dispersion of each functional component, but also significantly enhances the bonding force at the organic - inorganic interface. This strong interfacial interaction creates a stable micro - environment, which is beneficial for each functional component to play its role in the long - term, and is the key to the excellent long - term performance stability of the present invention.

[0101] In summary, through a carefully designed multi - component synergistic system, the present invention realizes function integration and performance optimization at the molecular and micro - scale, creating a new type of curtain pulley material with persistent antibacterial, self - cleaning, and high mechanical properties. This method not only solves multiple problems existing in traditional curtain pulleys, but also provides new ideas and methods for the design of functional polymer composites.

[0102] The above description is only for the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. Antibacterial, mildew-proof and self-cleaning curtain pulley, characterized in that , comprising the following components in parts by weight: 80 - 90 parts of high - density polyethylene (HDPE); 0.5 - 2.0 parts of nano - silver; 0.3 - 1.5 parts of isothiazolinone; 3 - 8 parts of titanium dioxide; 1 - 3 parts of polytetrafluoroethylene (PTFE) micro - powder; 5 - 10 parts of ethylene - vinyl acetate copolymer (EVA); 0.2 - 1.0 part of sodium dodecylbenzenesulfonate; 0.5 - 2.0 parts of silane coupling agent KH - 550.

2. The antibacterial and mildew-proof self-cleaning curtain pulley according to claim 1, characterized in that , the particle size of the nano - silver is 10 - 50 nm.

3. The antibacterial, mildew-proof and self-cleaning curtain pulley according to claim 1, characterized in that , the titanium dioxide is a mixture of anatase and rutile, and the weight ratio of anatase to rutile is 3:1 to 1:

1.

4. The antibacterial and mildew-proof self-cleaning curtain pulley according to claim 1, characterized in that , the average particle size of the polytetrafluoroethylene (PTFE) micro - powder is 1 - 5 μm.

5. The antibacterial and mildew-proof self-cleaning curtain pulley according to any one of claims 1-4, characterized in that , the surface of the curtain pulley has a silk - screen coating, and this coating consists of the following components: 2 - 5 parts by weight of titanium dioxide; 0.2 - 0.5 parts by weight of nano - silver; 0.1 - 0.3 parts by weight of isothiazolinone; 95 - 97.7 parts by weight of an organic solvent, where the organic solvent is a mixture of ethanol and isopropanol, and the volume ratio of ethanol to isopropanol is 3:

1.

6. The preparation method of the antibacterial and mildew-proof self-cleaning curtain pulley according to claim 5, characterized in that , including the following steps: (1) Pretreatment step: First, vacuum - dry HDPE, EVA and PTFE micro - powder at 60 - 70 °C for 4 - 6 hours; Secondly, vacuum - dry nano - silver, isothiazolinone and titanium dioxide at 40 - 50 °C for 2 - 3 hours; (2) Composite material preparation step: Then, sequentially add the pretreated components into a twin - screw extruder for mixing and extrusion, where the temperature of the extruder is 180 - 200 °C and the screw speed is 100 - 150 rpm; (3) Pulley forming step: Next, dry the prepared composite material pellets until the water content is less than 0.05%, and obtain the curtain pulley by injection molding, where the injection temperature is 190 - 210 °C, the mold temperature is 40 - 60 °C, the injection pressure is 80 - 120 MPa, and the holding pressure time is 10 - 15 seconds; (4) Surface treatment step: Again, perform plasma treatment on the formed pulley, with the treatment power of 50 - 100 W and the time of 2 - 5 minutes; (5) Coating preparation step: Finally, use the screen - printing method to coat the antibacterial, mildew - proof and self - cleaning coating on the pulley surface, and dry it at 60 - 80 °C for 10 - 15 minutes.

7. The preparation method according to claim 6, characterized in that , in the composite material preparation step, the adding order of the components is: First, add HDPE and EVA to the feed inlet of the extruder; Secondly, add PTFE micro - powder and sodium dodecylbenzenesulfonate at the first side feed inlet; Then, sequentially add nano - silver, isothiazolinone and titanium dioxide at the second side feed inlet; Finally, add silane coupling agent KH - 550 at the third side feed inlet.

8. The preparation method according to claim 6, characterized in that , in the surface treatment step, oxygen plasma is used for plasma treatment.

9. The preparation method according to claim 6, wherein , in the coating preparation step, the mesh number of the screen - printing used is 300 - 400 meshes.

10. The preparation method according to claim 9, characterized in that , also includes a performance testing step: Test the antibacterial performance, mildew - proof performance, self - cleaning performance and mechanical performance of the curtain pulley, where: The antibacterial performance is tested according to the standard of GB / T 21866-2008, and the antibacterial rate should be ≥99%; The mildew-proof performance is tested according to the standard of GB / T 24346-2009, and the mildew-proof grade should reach level 0; The self-cleaning performance adopts the contact angle test method, and the water contact angle should be <10°; The mechanical properties are tested for tensile strength according to the standard of GB / T 1040.1-2006, and it should be ≥25 MPa.

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