Pure-cotton odor-removing sanitary towel and preparation method thereof

Abstract

The invention discloses a pure cotton odor-removing sanitary napkin which comprises a surface layer, an absorbing core body and an odor-removing layer, the surface layer is made of pure cotton materials and is loaded with nanoscale photocatalyst materials or bio-enzyme preparations, the absorbing core body is formed by mixing fluff pulp and super absorbent resin, and the nanoscale photocatalyst materials are loaded on the surface of the absorbing core body. The invention further discloses a preparation method of the pure-cotton odor-removing sanitary towel. The preparation method comprises the following steps of S1, surface layer treatment, S2, absorption core body preparation, S3, odor-removing layer preparation and S4, assembling. The photocatalyst, bio-enzyme catalysis, nano adsorption and ion exchange technologies are creatively fused, the excellent odor removal effect is achieved, the nanoscale titanium dioxide photocatalyst generates strong oxidizing free radicals under the illumination condition and can rapidly decompose odor molecules, the bio-enzyme can accurately catalyze and decompose organic components in menstrual blood, and the odor removal effect is good. The generation of peculiar smell is fundamentally inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of nursing products, and particularly relates to a pure cotton deodorant sanitary napkin and a preparation method thereof. Background Art

[0002] As an essential product for women during their menstrual periods, sanitary napkins play an important role in daily life. It mainly consists of a surface layer, an absorption core, a bottom layer, etc. The surface layer directly contacts the skin and needs to have the characteristics of softness and skin-friendliness; the absorption core undertakes the key function of absorbing and storing menstrual blood.

[0003] Traditional pure cotton sanitary napkins, with their natural material properties, have excellent skin-friendliness and can bring relatively comfortable experiences to users. However, they have significant defects in odor treatment. During menstruation, menstrual blood is rich in various organic substances such as proteins and blood, creating a breeding ground for bacteria. In a suitable environment, bacteria multiply rapidly, decomposing the components in menstrual blood and thus generating unpleasant odors. Ordinary pure cotton sanitary napkins rely solely on their own absorption ability and are difficult to fundamentally solve the odor problem. The odor will gradually emit during use, bringing many troubles to users. Currently, the deodorization technologies on the market are uneven. Some sanitary napkin products choose to add fragrances to cover up the odor, but this method is just like burying one's head in the sand. The fragrance only masks the odor through its own smell and does not really decompose the molecules that produce the odor. More seriously, some fragrances may cause allergic reactions, resulting in discomfort symptoms such as itching and redness on the user's skin, and instead pose a potential threat to the user's health. Summary of the Invention

[0004] The purpose of the present invention is to solve the defects existing in the prior art, and to propose a pure cotton deodorant sanitary napkin and a preparation method thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A pure cotton deodorant sanitary napkin and a preparation method thereof, including a surface layer, an absorption core, and a deodorization layer. The surface layer is made of pure cotton and is loaded with a nano-level photocatalyst material or a bioenzyme preparation. The absorption core is composed of a mixture of fluff pulp and a superabsorbent resin, and its surface is loaded with a nano-level photocatalyst material. The deodorization layer contains active ingredients such as a nano-porous adsorbent, an ion-exchange functional particle, or a plant extract.

[0007] Preferably, the nano-level photocatalyst material is nano-level titanium dioxide, with a particle size of 6 - 8 nm, a purity of not less than 99.9%, and an anatase crystal structure.

[0008] Preferably, the bio-enzyme preparation includes lipase and protease, the lipase activity is 50,000 - 60,000 U / g, and the protease activity is 30,000 - 40,000 U / g.

[0009] Preferably, the mass ratio of fluff pulp to superabsorbent resin in the absorbent core is 7:3, the superabsorbent resin is sodium polyacrylate, and the water absorption ratio is 45 times.

[0010] Preferably, the nanoporous adsorbent in the odor-removing layer is mesoporous silica, the specific surface area is 1500 m 2 / g, and the mesoporous pore diameter is 2.5 nm; the ion-exchange functional microparticles are quaternary ammonium salt ion-exchange resins, and the ion-exchange capacity is 2.0 mmol / g.

[0011] Preferably, the surface layer is long-staple cotton non-woven fabric with a gram weight of 35 g / m 2 ; or the surface layer is ordinary pure cotton non-woven fabric, and the specific surface area increases by 2.5 times after plasma treatment.

[0012] The preparation method of the above-mentioned pure cotton odor-removing sanitary napkin includes the following steps:

[0013] Surface layer treatment step: Prepare a dispersion liquid by mixing a nano-level photocatalyst material and a dispersant, load it on pure cotton non-woven fabric, and dry it; if a bio-enzyme preparation is loaded, prepare a solution by mixing the bio-enzyme preparation and a buffer solution, spray-coat it on the non-woven fabric loaded with the photocatalyst material, or directly spray-coat it on pure cotton non-woven fabric without photocatalyst treatment, and then dry it;

[0014] Absorbent core preparation: Mix fluff pulp and superabsorbent resin evenly to form a core prototype, and then spray the dispersion liquid containing photocatalyst on the surface of the core; if microcapsules containing bio-enzyme are used, mix the microcapsules into the core material;

[0015] Odor-removing layer preparation: Mix the nanoporous adsorbent and the ion-exchange functional microparticles, hot-press them into a composite film, and then composite it with the non-woven fabric containing active ingredients; or prepare a non-woven fabric containing active ingredients such as plant extracts for subsequent assembly;

[0016] Assembly: Assemble the treated surface layer, absorbent core, and odor-removing layer by hot-pressing or ultrasonic welding, etc.

[0017] Preferably, in the surface layer treatment step, when loading the photocatalyst material, the dispersion liquid concentration is 0.5%, and the loading amount is 0.2 g / m 2 ; when loading the bio-enzyme preparation, the solution concentration is 1%, and the loading amount is 0.12 - 0.15 g / m 2In the preparation of the absorbent core, the concentration of the dispersion containing the photocatalyst is 0.3-0.25%, the coating thickness is about 0.05 mm, and in the preparation of the deodorizing layer, the mixing time of the nanoporous adsorbent and the ion exchange functional particles is 1 hour, the hot pressing temperature is 150°C, the pressure is 5 MPa, the holding time is 10 minutes, and the adhesive coating amount is 0.05 g / m 2 In the assembly, the hot pressing temperature is 120-130° C. and the pressure is 0.3-0.4 MPa; the ultrasonic welding power is 1000-1500 W and the welding speed is 0.3-0.5 m / min.

[0018] The present invention has the following beneficial effects:

[0019] 1. The present invention innovatively integrates photocatalyst, bio-enzyme catalysis, nano-adsorption and ion exchange technology to achieve excellent deodorization effect. Nano-scale titanium dioxide photocatalyst produces strong oxidizing free radicals under light conditions, which can quickly decompose odor molecules. Bio-enzymes can accurately catalyze and decompose organic components in menstrual blood, inhibiting the generation of odor from the source. Nano-adsorption materials can efficiently capture odor molecules with their unique porous structure. Ion exchange technology further converts odor molecules into harmless substances. Multiple technologies work synergistically to ensure that odor is always effectively controlled during the entire menstrual period.

[0020] 2. The present invention is ingenious in creating the absorbent core, carefully selecting high-quality materials and optimizing the preparation process. Finely processed fluff pulp is selected, which has moderate fiber length and good fluffiness, and is mixed with SAP with a water absorption rate of up to 45 times in a precise ratio of 7:3. During the preparation process, key parameters such as stirring uniformity and core thickness are strictly controlled. This makes the absorbent core have a strong absorption capacity, can quickly absorb menstrual blood and lock it firmly, has a fast absorption speed and is not easy to reverse osmosis, always keeps the surface dry, effectively avoids side leakage problems, and provides women with all-round and reliable menstrual protection.

[0021] 3. In terms of processing technology, the combing process effectively removes short fibers and impurities by precisely controlling the combing speed at 30m / min, further optimizing the arrangement of fibers, and making it easier for the fibers to form an ordered structure in the subsequent processing. The web laying process is carried out at a speed of 0.5m / min to ensure the uniform distribution of fibers on the plane, providing a good foundation for subsequent acupuncture reinforcement. The acupuncture process is carried out at a frequency of 200 times / min. Through the physical action of acupuncture, the fibers are tightly interwoven together, which not only enhances the overall strength of the non-woven fabric, but also makes the surface of the non-woven fabric smoother and flatter. From the microscopic structure, acupuncture makes the fibers entangled and interlaced with each other, forming a stable three-dimensional structure, reducing the unevenness of the surface, thereby effectively reducing the friction coefficient when in contact with the skin, making the final non-woven fabric soft and smooth to the touch, bringing a highly comfortable experience to the user.

[0022] 4. The present invention innovatively integrates technologies such as photocatalyst, biocatalytic enzyme, nano-adsorption, and ion exchange, realizing the synergistic effect of multiple functions. The nano-sized titanium dioxide photocatalyst generates strongly oxidizing free radicals under light irradiation, which can not only decompose odor molecules but also kill microorganisms. The biocatalytic enzyme preparation can catalytically decompose the organic components in menstrual blood, inhibiting odor at the source. The nano-adsorption and ion exchange composite membrane can efficiently capture and transform odor molecules. These technologies cooperate with each other, significantly improving the odor removal effect of sanitary napkins. Brief Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of a pure cotton odor-removing sanitary napkin and its preparation method proposed by the present invention; Detailed Embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0025] Embodiment 1: Photocatalyst-dominated pure cotton odor-removing sanitary napkin

[0026] Material preparation: Surface layer: Select high-quality long-staple cotton from Xinjiang as raw material, comb it by a carding machine at a carding speed of 30 m / min, remove short fibers and impurities, then lay the web by a lapping machine at 0.5 m / min, and finally reinforce it by a needling machine at 200 times / min to make a non-woven fabric with a grammage of 35 g / m 2 The nano-sized titanium dioxide photocatalyst has a particle size of 8 nm, a purity of 99.9%, and an anatase crystal structure, with high photocatalytic activity.

[0027] Absorbent core: The fluff pulp is made by beating selected wood pulp by a beater at 2000 revolutions / min, controlling the beating degree at 30 - 35°SR. After impurity removal, the fluff fibers are 1 - 2 mm long and have good fluffiness. The water absorption ratio of polyacrylate SAP is 45 times, and it can absorb 30 times its own weight of liquid within 1 minute. It is mixed with the fluff pulp at a mass ratio of 7:3. The photocatalyst dispersion liquid uses deionized water as a solvent, adds 0.3% polyvinylpyrrolidone (PVP) as a dispersant, stirs for 3 hours to ensure the uniform dispersion of nano-titanium dioxide, and there is no obvious agglomeration within 6 months

[0028] Preparation method:

[0029] Surface treatment: Under the environment of constant temperature of 25°C and constant humidity of 50%, nano-titanium dioxide and PVP are added to deionized water in proportion, and stirred with a magnetic stirrer at 300 revolutions per minute for 2 hours to prepare a 0.5% dispersion liquid. An automatic dip-coating device is used, and the precision of the high-precision metering pump of this device can reach ±0.01 mL. The dispersion liquid is evenly coated on the surface layer of long-staple cotton non-woven fabric. Through real-time monitoring with an electronic balance, the loading amount is stably controlled at 0.2 g / m 2 , and the deviation is controlled within ±0.01 g / m 2 . Subsequently, it is sent into a hot air circulation oven. Five temperature sensors in the oven ensure that the temperature uniformity error is within ±1°C, and it is dried at 60°C for 30 minutes to make the photocatalyst firmly adhere to the fiber surface. Before each batch of production, the metering pump of the dip-coating device is calibrated, and the oven is calibrated for temperature to ensure the accuracy of the equipment.

[0030] Preparation of the absorption core: Using a planetary stirring device, fluff pulp and SAP are stirred at 300 revolutions per minute for 30 minutes, and the stirring uniformity is monitored through a torque sensor. It is pressed into the core prototype by a flat vulcanizing machine with a mold with an accuracy of ±0.1 mm. The surface roughness Ra of the mold is ≤0.8 μm, the thickness is controlled at 5 mm, and the deviation is controlled within ±0.2 mm. A spraying device equipped with a high-pressure airless spray gun is used. The pressure of the spray gun is 0.3 - 0.5 MPa, and the pressure fluctuation is controlled within ±0.02 MPa. The dispersion liquid containing 0.3% photocatalyst is evenly sprayed on the surface of the core. The coating thickness is monitored in real time by a non-contact laser thickness gauge and controlled at about 0.05 mm, and the deviation is controlled within ±0.01 mm. Every 1000 cores are produced, the mold is inspected and maintained to ensure accuracy; the spray gun pressure is calibrated regularly.

[0031] Assembly: A hot pressing and composite device is used. The temperature control accuracy of the device is ±1°C, the temperature uniformity error is within ±2°C, the accuracy of the pressure sensor is ±0.01 MPa, and the pressure uniformity error is within ±0.02 MPa. The treated surface layer and the absorption core are aligned and placed. The hot pressing temperature is 120°C, the pressure is 0.3 MPa, and the hot pressing time is 5 seconds. At the same time, the conveyor belt speed is adjusted to 0.5 m / min, and the speed fluctuation is controlled within ±0.05 m / min to ensure tight composite and no damage to the material. The edge neatness error of the finished product is controlled within ±1 mm. Before each shift of production, the temperature and pressure systems of the hot pressing and composite device are calibrated, and the operation status of the conveyor belt is checked.

[0032] Example 2: Pure cotton sanitary napkin mainly based on biocatalytic self-cleaning

[0033] Material preparation: Surface layer: Ordinary pure cotton non-woven fabric is processed by a plasma treatment device. At a power of 100W and a treatment time of 5 minutes, the gas flow rate inside the device is controlled at 5L / min, and a large number of micro-nano pores are formed on the fiber surface, increasing the specific surface area by 2.5 times. The lipase is produced by Novozymes, with an enzyme activity of 50000U / g, and the protease enzyme activity is 30000U / g. The catalytic activities of the two enzymes are optimal in an environment with a pH value of 6 - 8 and a temperature of 30 - 40°C.

[0034] Odor-removing layer: The gram weight is 25g / m 2 Contains activated carbon fiber non-woven fabric. The activated carbon fiber is activated at 900°C for 2 hours under the protection of inert gas, and the specific surface area reaches 1200m 2 / g, with rich micropores. Plant extracts such as tea polyphenols and eucalyptus oil are purified by supercritical carbon dioxide extraction technology. The extraction pressure is 30MPa, the extraction temperature is 40°C, and the purity is above 98%.

[0035] Preparation method: Loading of bioenzymes on the surface layer: In a clean workshop with a temperature of 25°C and a humidity of 50%, lipase, protease and a pH 7.0 phosphate buffer solution are prepared into a 1% solution in proportion, weighed with a high-precision electronic balance with an accuracy of up to ±0.001g, and the flow rate is controlled by a high-precision peristaltic pump with an accuracy of up to ±0.01mL / min. It is evenly spray-coated on the pure cotton non-woven fabric surface layer through a nozzle with a pore diameter of 0.1mm, and the loading amount is accurately controlled at 0.15g / m 2 The deviation is controlled within ±0.01g / m 2 After coating, it is placed in a vacuum freeze dryer. First, it is pre-frozen at -40°C for 2 hours, and the pre-freezing rate is controlled at 1 / min°C. Then, it is dried at 20°C and a vacuum degree of 10Pa, and is monitored in real time by a high-precision humidity sensor with a humidity measurement accuracy of ±2%RH to ensure the stability of bioenzyme activity. Before preparing the solution for each batch, calibrate the electronic balance and peristaltic pump; regularly maintain the vacuum freeze dryer.

[0036] Preparation of the odor-removing layer: Immerse the activated carbon fiber non-woven fabric in a solution containing plant extracts. The solution concentration is accurately measured by a high-performance liquid chromatography instrument with an accuracy of ±0.01mg / mL. Stir in a stirring tank at 50 revolutions per minute for 2 hours, and the special design of the stirring paddle ensures uniform stirring of the solution. After taking it out, it is placed in a forced-air drying oven and dried at 50°C for 4 hours. The temperature uniformity error in the oven is controlled within ±2°C to ensure the firm attachment of the active ingredients. Regularly calibrate the high-performance liquid chromatography instrument and calibrate the temperature of the forced-air drying oven.

[0037] Assembly: Use a hot melt adhesive composite device, select EVA hot melt adhesive, melt it at 120°C, and control the melting time within 10 - 15 minutes. The hot melt adhesive is applied at 0.2g / m through a precision coating device 2The coating amount is evenly coated on the bonding surface between the surface layer and the absorbent core, and the deviation of the coating amount is controlled within ±0.02 g / m 2 After lamination, it is sent to an ultrasonic welding device. The power of the device is set at 1000 - 2000 W, and the power fluctuation is controlled within ±50 W. The odor-removing layer is welded to the bottom of the absorbent core at a welding speed of 0.3 m / min, and the speed fluctuation is controlled within ±0.05 m / min to ensure that the weld is firm and sealed, and the weld width is controlled within 3 - 5 mm. Before production in each shift, check and calibrate the temperature of the hot melt adhesive lamination device and the coating device, and debug the power and welding speed of the ultrasonic welding device.

[0038] Example 3: Nano-adsorption and ion-exchange synergistic pure cotton sanitary napkin

[0039] Material preparation: Odor-removing layer: Mesoporous silica is prepared by the sol-gel method. Using tetraethyl orthosilicate as the precursor, under the action of an acidic catalyst, the hydrolysis and polycondensation reaction temperature is controlled at 60 °C, and the reaction time is 4 hours to form a structure with a specific surface area of 1500 m 2 / g, a mesoporous pore diameter of 2.5 nm, and a narrow pore size distribution. Quaternary ammonium salt ion exchange resin Dowex550AHCR with an ion exchange capacity of 2.0 mmol / g.

[0040] Surface layer and absorbent core: The average diameter of the pure cotton non-woven fabric fibers in the surface layer is 18 μm, with high uniformity. The fluff pulp fibers in the absorbent core are 1.5 mm long, screened by a 100-mesh vibrating screen, and the impurity content is less than 0.5%. The SAP water absorption ratio is 45 times, and the gel strength after liquid absorption is high.

[0041] Preparation method: Preparation of the odor-removing layer: Using a double planetary mixer, mix mesoporous silica and ion exchange resin at 200 revolutions per minute for 1 hour, and monitor the mixing uniformity through an online particle size analyzer. After mixing evenly, pass through a hot pressing and forming device, keep the pressure at 150 °C and 5 MPa for 10 minutes. The temperature uniformity error of the hot pressing device is controlled within ±3 °C, and the pressure uniformity error is controlled within ±0.1 MPa to make a composite film with a thickness of 0.2 mm, and the thickness deviation is controlled within ±0.02 mm. Use a precision coater to coat polyurethane adhesive on the bonding surface between the composite film and 15 g / m 2 coating amount, and the coating amount deviation is controlled within ±0.005 g / m 2 on the pure cotton non-woven fabric bonding surface, and after lamination, let it stand for 24 hours to fully cure the adhesive. Regularly calibrate the rotation speed of the double planetary mixer, maintain and calibrate the temperature and pressure systems of the hot pressing and forming device, and calibrate the coating amount of the precision coater. 2 Product assembly: Use a hot melt adhesive lamination device. The polyester hot melt adhesive melts at 160 °C, and the melting time is controlled within 15 - 20 minutes. Use a coating roller to apply the hot melt adhesive at 0.1 g / m

[0042] ​2 The coating amount is evenly coated on the bonding surfaces of the surface layer, the absorbent core, and the odor-removing layer, and the deviation of the coating amount is controlled within ±0.01 g / m 2 , the pressure of the equipment's pressure roller is 0.2 MPa, the pressure fluctuation is controlled within ±0.02 MPa, the conveyor belt speed is 0.4 m / min, and the speed fluctuation is controlled within ±0.04 m / min to ensure tight bonding of each layer. Before each shift of production, the temperature, pressure roller pressure, and conveyor belt speed of the hot melt adhesive bonding equipment are debugged and calibrated.

[0043] Example 4: High-end pure cotton sanitary napkin with triple composite technology

[0044] Material preparation:

[0045] Surface layer: The nano-sized titanium dioxide photocatalyst has a particle size of 6 nm, a purity of 99.95%, and a photocatalytic activity 20% higher than that of the 8-nm particle size product. The lipase enzyme activity is 60000 U / g, and the protease enzyme activity is 40000 U / g, both of which are food-grade enzyme preparations.

[0046] Absorbent core: The photocatalyst dispersion liquid is prepared by mixing nano-titanium dioxide and a dispersant in an optimized ratio, with good dispersion stability. After a 3-month stability test at 40 °C, there is no obvious precipitation. The microcapsules are prepared by the complex coacervation method of gelatin - arabic gum, reacting at pH 4 - 4.5 and 30 °C for 1 hour to form microcapsules with a particle size of 5 - 10 μm, an encapsulation efficiency of 92%, and accounting for 0.5% of the core mass.

[0047] Odor-removing layer: The same nano-adsorption and ion-exchange composite membrane as in Example 3, a non-woven fabric containing active ingredients such as vanillin and menthol purified by molecular distillation, with a molecular distillation temperature of 120 °C, a vacuum degree of 0.1 Pa, and an active ingredient content of 0.8%.

[0048] Preparation method: Surface layer treatment: In a cleanroom of Class 1000, first use a dip-coating device to load the nano-titanium dioxide photocatalyst on pure cotton non-woven fabric, with a loading amount of 0.18 g / m 2 , the dip-coating time is 5 minutes, the speed of the dip-coating device is controlled at 0.2 m / min, and the deviation of the loading amount is controlled within ±0.01 g / m 2 . After drying, use a spray-coating device to evenly spray and coat the biological enzyme solution at a pressure of 0.2 MPa, with a loading amount of 0.12 g / m 2 , the flow rate of the spray device is controlled at 5 - 8 mL / min, and the deviation of the loading amount is controlled within ±0.01 g / m 2 . Regularly maintain and calibrate the dip-coating device and the spray-coating device.

[0049] Absorbent core preparation: Through a high-voltage electrostatic spraying device, a dispersion liquid containing 0.25% photocatalyst is sprayed on the surface of the core at a voltage of 20 kV. The distance between the spray gun and the core is controlled within 10 - 15 cm, and the voltage fluctuation is controlled within ±1 kV. Use a high-speed stirring device to stir the bio-enzyme microcapsules at 500 revolutions per minute for 20 minutes, and ensure the uniform dispersion of the microcapsules in the core material through an online monitoring system. Regularly calibrate the voltage of the high-voltage electrostatic spraying device and maintain the high-speed stirring device.

[0050] Odor-removing layer preparation: Using a hot-pressing composite device, keep the pressure at 3 MPa for 8 minutes at 130 °C. The temperature uniformity error of the hot-pressing device is controlled within ±3 °C, and the pressure uniformity error is controlled within ±0.1 MPa. Composite the nano-adsorption and ion-exchange composite membrane with the non-woven fabric containing active ingredients. Regularly maintain and calibrate the hot-pressing composite device.

[0051] Assembly: Use a hot-pressing and ultrasonic welding composite device. The hot-pressing temperature is 120 °C, the pressure is 0.4 MPa. The temperature uniformity error of the hot-pressing device is controlled within ±2 °C, and the pressure uniformity error is controlled within ±0.05 MPa. The ultrasonic welding power is 1500 W, and the power fluctuation is controlled within ±100 W. First, hot-press the composite surface layer and the absorbent core, and then ultrasonically weld the odor-removing layer. Online inspection is carried out after each process, and the inspection items include appearance quality, dimensional deviation, performance indicators, etc., to ensure the stable quality of the product. Before each shift of production, debug and calibrate the parameters such as temperature, pressure, and power of the hot-pressing and ultrasonic welding composite device, and calibrate the online inspection device.

[0052] Table 1: Comparison of materials and process parameters

[0053]

[0054]

[0055] Furthermore, in Example 1, Xinjiang long-staple cotton is selected. Its fibers are slender and soft, and the average fiber diameter is 2 - 5 μm smaller than that of ordinary cotton, which reduces the friction coefficient by about 0.3 when in contact with the skin and significantly improves the skin-friendly property. The photocatalyst loading is 0.2 g / m 2 , the particle size of nano-TiO2 is 8 nm. This small-particle-size photocatalyst has higher photocatalytic activity and can decompose odor molecules more efficiently under light conditions. The decomposition efficiency is 30% - 40% higher than that of the ordinary-particle-size photocatalyst.

[0056] Furthermore, in Example 2, the ordinary pure cotton non-woven fabric is treated by plasma. Under the conditions of a power of 100 W, a treatment time of 5 minutes, and the internal gas flow rate of the device controlled at 5 L / min, a large number of micro-nano pores are formed on the fiber surface, and the specific surface area increases by 2.5 times. This enables the bio-enzyme loading to be accurately controlled at 0.15 g / m 2, and the enzyme binds more tightly to the fiber, with the catalytic efficiency increased by about 40%, and it can more effectively inhibit the generation of odors from the source.

[0057] Furthermore, in Comparative Examples 1-2, ordinary cotton fibers were used. The fiber diameter is relatively large and the surface is rough, with an average roughness Ra reaching 3.2 μm - 6.3 μm, and the friction coefficient is as high as 0.6. When used, it is easy to cause greater friction to the skin and trigger discomfort. At the same time, they do not have a functional layer design and cannot achieve functions such as decomposing odors and inhibiting the growth of bacteria, and are far inferior to the products of the examples in terms of the functionality and comfort of the products.

[0058] Even further, the selected fluff pulp used in Examples 1-4 has a fiber length between 1 - 2 mm. After special treatment, the fluffiness of the fiber is good, providing a favorable channel for the rapid diffusion of liquids. The high water-absorbing SAP paired with it has a water absorption ratio of up to 45 times, can absorb 30 times its own weight of liquid within 1 minute, and the water retention rate is as high as over 90%. The two are mixed in a precise ratio of 7:3. Through an optimized preparation process, the structure of the absorption core is more reasonable, and the absorption speed is 30% - 40% faster than that of ordinary mixing ratios, and it can quickly absorb and firmly lock the menstrual blood, greatly reducing the possibility of back leakage.

[0059] Even further, the ordinary fluff pulp used in Comparative Examples 1-2 has short fibers and contains more impurities, with the impurity content exceeding 1%. This not only affects the fluffiness and uniformity of the fibers but also reduces the absorption efficiency. The SAP paired with it has a water absorption ratio of only 30 - 35 times, and the water retention rate is between 60% - 70%. The mixing ratio is also not reasonable enough, resulting in a slow absorption speed. It takes more than 4 - 5 minutes to absorb 50 mL of liquid, and the back leakage amount is relatively large, exceeding 5 mL, and it cannot provide a good user experience.

[0060] Even further, the nano-TiO₂ (8 nm) photocatalyst in Example 1 has an anatase crystal structure, and this structure makes its photocatalytic activity 40% - 50% higher than that of ordinary TiO₂. Under light illumination, it can generate a large number of free radicals with strong oxidizing properties, quickly decompose odor molecules, and at the same time, the antibacterial rate against common bacteria reaches 99%, effectively reducing the generation of odors.

[0061] Even further, the bioenzymes in Example 2 (lipase enzyme activity 50000 U / g + protease enzyme activity 30000 U / g) have the best catalytic activity in an environment with a pH value of 6 - 8 and a temperature of 30 - 40 °C. They can specifically catalyze and decompose the organic components in menstrual blood, inhibit the generation of odors from the source, and the odor inhibition rate reaches over 90%.

[0062] Even further, the mesoporous SiO₂ in Example 3 is prepared by the sol-gel method, with a specific surface area as high as 1500 m 2 / g, with a pore size of 2.5nm and a narrow pore size distribution, which makes it have a strong adsorption capacity, and the adsorption capacity for odor molecules is 2-3 times higher than that of ordinary adsorption materials. When used with a quaternary ammonium salt ion exchange resin with an ion exchange capacity of 2.0mmol / g, it can convert the adsorbed odor molecules into harmless substances, and the total deodorization efficiency reaches 92%.

[0063] Furthermore, Example 4 combines photocatalyst, bio-enzyme and nano-adsorption technology to achieve triple deodorization of "decomposition + inhibition + adsorption". The three technologies work together to keep the odor intensity <1 level throughout the use process, and the antibacterial rate is as high as 99.9%, with the most significant deodorization and antibacterial effects.

[0064] Furthermore, in Comparative Example 2, only quaternary ammonium salt antibacterial agent is used to inhibit bacteria, and the antibacterial rate is only 60%. Moreover, the antibacterial agent can only inhibit bacterial growth, but cannot decompose the odor molecules that have been produced. As the use time increases, the antibacterial effect gradually weakens, and the odor intensity still reaches level 3 after 2 hours, which cannot meet the user's demand for product deodorization and antibacterial.

[0065] Furthermore, in the preparation process of Example 1, the metering pump accuracy can reach ±0.01mL, which enables the coating amount of the photocatalyst dispersion to be accurately controlled at 0.2±0.01g / m 2 , ensuring the uniform distribution of photocatalyst on non-woven fabrics. Five temperature sensors in the oven ensure that the temperature uniformity error is within ±1°C. Drying at 60°C for 30 minutes can make the photocatalyst firmly adhere to the fiber surface with an adhesion of more than 5N / cm, effectively improving the stability and reliability of the product.

[0066] Furthermore, in Example 2, during the surface bio-enzyme loading process, a high-precision electronic balance (with an accuracy of ±0.001g) and a high-precision peristaltic pump (with an accuracy of ±0.01mL / min) are used to accurately control the preparation and coating of the bio-enzyme solution. After coating, it is placed in a vacuum freeze dryer, first pre-frozen at -40°C for 2 hours, the pre-freezing rate is controlled at 1°C / min, and then dried at 20°C and a vacuum degree of 10Pa, and monitored in real time by a high-precision humidity sensor, with a humidity measurement accuracy of ±2%RH. This process can maintain the activity of the bio-enzyme to the greatest extent, and the enzyme activity is still >95% after 6 months, ensuring the long-term performance of the product.

[0067] Furthermore, in Example 3, a twin-planet mixer was used to mix mesoporous silica and ion exchange resin at 200 revolutions per minute for 1 hour. The mixing uniformity was monitored by an on-line particle size analyzer to ensure the full mixing of the two materials. The hot pressing equipment was kept under pressure at 150 °C and 5 MPa for 10 minutes, with the temperature uniformity error controlled within ±3 °C and the pressure uniformity error controlled within ±0.1 MPa, to produce a composite film with a thickness of 0.2 mm ± 0.02 mm, ensuring the stable quality and performance of the composite film.

[0068] Furthermore, Example 4 was produced in a Class 1000 clean workshop, with the number of particles ≥ 0.5 μm in the air ≤ 3520 particles / m 3 , effectively avoiding impurity contamination during the production process. During the surface layer treatment process, first, a dip-coating equipment was used to load nano-titanium dioxide photocatalyst on pure cotton non-woven fabric, with a loading amount of 0.18 g / m 2 , a dip-coating time of 5 minutes, the speed of the dip-coating equipment controlled at 0.2 m / min, and the loading amount deviation controlled within ±0.01 g / m 2 ; after drying, a spray coating equipment was used to evenly spray and coat the bio-enzyme solution at a pressure of 0.2 MPa, with a loading amount of 0.12 g / m 2 , the flow rate of the spray equipment controlled at 5 - 8 mL / min, and the loading amount deviation controlled within ±0.01 g / m 2 . Online inspection was carried out after each process, and the inspection items included appearance quality, dimensional deviation, performance indicators, etc., to ensure the stable quality of the product.

[0069] Furthermore, in Comparative Examples 1 - 2, there was a lack of precise process control during the production process, and the key parameters of the equipment were not strictly calibrated and monitored. For example, during the preparation of the absorbent core body, the stirring was uneven, resulting in inconsistent material distribution; the mold accuracy was low, and the core body thickness deviation was ±2 mm, which made the product quality unstable and the performance differences between different batches were large, unable to ensure the consistency and reliability of the product.

[0070] Table 2: Comparison of Performance Indicators and Stability

[0071]

[0072]

[0073] Further, in Examples 1 - 4, through their respective odor removal technologies, the odor intensity was always < 1 level throughout the whole usage process, and almost no odor could be felt. In Example 1, the photocatalytic effect of the photocatalyst was used to decompose odor molecules; in Example 2, bio-enzyme was relied on to inhibit odor from the source; in Example 3, odor was removed through adsorption and conversion technologies; and in Example 4, a variety of technologies were integrated to achieve a more efficient odor removal effect.

[0074] Furthermore, Comparative Example 1 does not have any odor removal technology. After 1 hour of use, the odor intensity reaches level 4, and the odor is obvious, bringing a very poor user experience. Although quaternary ammonium salt antibacterial agent is added in Comparative Example 2, it can only inhibit bacteria from producing odor and cannot decompose the already generated odor molecules. After 2 hours, the odor intensity is still level 3, and the odor problem remains serious.

[0075] Furthermore, the absorption speed of Examples 1-4 is extremely fast. It only takes 0.8-1.2 minutes to absorb 50 mL of liquid. Among them, due to the use of optimized materials and preparation processes in Example 4, the absorption speed is the fastest, only taking 0.8 minutes. This is because the selected fluff pulp and SAP with a high water absorption rate are mixed in the best proportion to form an efficient absorption structure, which can quickly absorb menstrual blood.

[0076] Furthermore, the absorption speed of Comparative Example 1 is greater than 5 minutes, and that of Comparative Example 2 is 4 minutes. The ordinary fluff pulp and SAP with a low water absorption rate they use, as well as the unreasonable mixing ratio, result in an absorption speed far lower than that of the Example products, and they cannot absorb menstrual blood in time, easily causing problems such as side leakage.

[0077] Furthermore, the rewet amount of Examples 1-4 is all <1 mL, and that of Example 4 is even as low as <0.5 mL. This benefits from its optimized absorption core structure and high-performance water-absorbing materials, which can firmly lock the liquid, effectively keep the surface dry, prevent side leakage, and provide reliable protection for users.

[0078] Furthermore, the rewet amount of Comparative Example 1 is >5 mL, and that of Comparative Example 2 is 4 mL. A higher rewet amount will make the product surface wet, which not only affects the use comfort but also increases the risk of side leakage, bringing inconvenience and trouble to users.

[0079] Furthermore, the friction coefficients of Examples 1-4 are between 0.2 and 0.35, with relatively low values. For example, in Example 2, the micro-nano scale pores on the fiber surface are increased through plasma treatment, making the fiber softer, and the friction coefficient is reduced to 0.25; in Example 4, through the selection of high-quality raw materials and special treatment processes, the friction coefficient is as low as 0.2. A lower friction coefficient means that the product is more comfortable when contacting the skin, can reduce the friction with the skin, and lower the risk of skin discomfort and allergy.

[0080] Furthermore, the friction coefficient of Comparative Example 1 is 0.6, and that of Comparative Example 2 is 0.55. A higher friction coefficient makes the product prone to cause greater friction to the skin during use, which may lead to discomfort symptoms such as skin flushing and itching, affecting the user experience.

[0081] Furthermore, the antibacterial rate of Example 1 reaches 99%, that of Example 2 is 98%, that of Example 3 is 95%, and that of Example 4 is as high as 99.9%. Through technologies such as photocatalyst, bioenzyme, and ion exchange resin, these examples can effectively inhibit the growth and reproduction of bacteria, providing a more hygienic use environment for users.

[0082] Furthermore, the antibacterial rate of Comparative Example 2 is only 60%, and the antibacterial effect is prone to failure. The low antibacterial rate cannot effectively inhibit the growth of bacteria, increasing the risk of user infection and failing to meet the requirements of users for the hygienic performance of the product.

[0083] Specifically, in Example 1, by precisely controlling the photocatalyst loading amount with a deviation controlled within ±0.01 g / m 2 , the consistency of product functions is ensured. In Example 2, the bioenzyme activity is maintained through the vacuum freeze-drying process, and the enzyme activity is still >95% after 6 months, ensuring the long-term performance of the product. In Example 3, by strictly controlling the hot-pressing forming process parameters, the deviation of the composite film thickness is ±0.02 mm, ensuring the stability of product quality. In Example 4, through on-line full inspection of appearance, dimensions, and performance, problems in the production process are promptly discovered and corrected, further guaranteeing product quality and ensuring that the performance differences between different batches of products are extremely small.

[0084] Specifically, the core thickness deviation of Comparative Example 1 is ±2 mm, which will lead to unstable absorption performance of the product; the antibacterial rate of Comparative Example 2 fluctuates by ±15%, and the antibacterial effect of the product cannot be effectively guaranteed. Their deficiencies in stability result in uneven product quality and cannot provide users with a stable and reliable use experience.

[0085] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A pure cotton deodorizing sanitary napkin, comprising a surface layer, an absorbent core, and a deodorizing layer, characterized in that: The surface layer is made of pure cotton and is loaded with nano-scale photocatalyst materials or bio-enzyme preparations. The absorbent core is made of a mixture of fluff pulp and highly absorbent resin, and its surface is loaded with nano-scale photocatalyst materials. The deodorizing layer contains active ingredients such as nanoporous adsorbents, ion exchange functional particles or plant extracts.

2. A pure cotton deodorizing sanitary napkin according to claim 1, characterized in that: The nano-scale photocatalyst material is nano-scale titanium dioxide, with a particle size of 6-8nm, a purity of not less than 99.9%, and an anatase crystal structure.

3. A pure cotton deodorizing sanitary napkin according to claim 1, characterized in that: The biological enzyme preparation comprises lipase and protease, wherein the lipase has an enzymatic activity of 50,000-60,000 U / g, and the protease has an enzymatic activity of 30,000-40,000 U / g.

4. A pure cotton deodorizing sanitary napkin according to claim 1, characterized in that: The mass ratio of fluff pulp to super absorbent resin in the absorbent core is 7:

3. The super absorbent resin is sodium polyacrylate and has a water absorption rate of 45 times.

5. A pure cotton deodorizing sanitary napkin according to claim 1, characterized in that: The nanoporous adsorbent in the deodorizing layer is mesoporous silica with a specific surface area of ​​1500 m2 / g and a mesopore diameter of 2.5 nm; the ion exchange functional particles are quaternary ammonium salt ion exchange resins with an ion exchange capacity of 2.0 mmol / g.

6. A pure cotton deodorizing sanitary napkin according to claim 1, characterized in that: The surface layer is a long-staple cotton non-woven fabric with a gram weight of 35g / m²; or the surface layer is an ordinary pure cotton non-woven fabric, and the specific surface area is increased by 2.5 times after plasma treatment.

7. A method for preparing a pure cotton deodorizing sanitary napkin according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, surface treatment step: prepare a nano-scale photocatalyst material and a dispersant into a dispersion, load it on a pure cotton non-woven fabric, and dry it; if a biological enzyme preparation is loaded, prepare a solution with a buffer solution, spray-coat it on the non-woven fabric loaded with the photocatalyst material, or directly spray-coat it on the pure cotton non-woven fabric that has not been treated with the photocatalyst, and then dry it; S2. Preparation of absorbent core: Evenly mix the fluff pulp and the super absorbent resin to form a core prototype, and then spray the dispersion containing the photocatalyst on the surface of the core; if microcapsules containing biological enzymes are used, mix the microcapsules into the core material; S3, preparation of deodorizing layer: mixing nanoporous adsorbent and ion exchange functional particles, hot pressing to form a composite membrane, and then compounding with a non-woven fabric containing active ingredients; or preparing a non-woven fabric containing active ingredients such as plant extracts for subsequent assembly; S4. Assembly: Assemble the treated surface layer, absorbent core and deodorizing layer by hot pressing or ultrasonic welding.

8. The method for preparing the pure cotton deodorizing sanitary napkin according to claim 7, characterized in that: In the surface layer treatment step, when loading the photocatalyst material, the dispersion concentration is 0.5%, and the loading amount is 0.2g / m²; when loading the biological enzyme preparation, the solution concentration is 1%, and the loading amount is 0.12-0.15g / m². In the preparation of the absorption core, the concentration of the dispersion containing the photocatalyst is 0.3-0.25%, and the coating thickness is about 0.05mm. In the preparation of the deodorizing layer, the mixing time of the nanoporous adsorbent and the ion exchange functional particles is 1 hour, the hot pressing temperature is 150°C, the pressure is 5MPa, the holding time is 10 minutes, and the adhesive coating amount is 0.05g / m². In the assembly, the hot pressing temperature is 120-130°C, and the pressure is 0.3-0.4MPa; the ultrasonic welding power is 1000-1500W, and the welding speed is 0.3-0.5m / min.

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