Carbon quantum dot spunlace and application thereof in sanitary napkin

Abstract

The invention belongs to the technical field of textile, and discloses a carbon quantum dot spunlaced fabric, application thereof in sanitary napkins and a preparation method of the carbon quantum dot spunlaced fabric. The core of the formula is as follows: a functional carbon quantum dot carbon source is medicinal and edible powder formed by mixing scutellaria baicalensis, isatis root and folium artemisiae argyi according to a ratio of 2: 1: 1, so that broad-spectrum antibacterial and anti-inflammatory effects are realized; the spunlace base material is composed of bamboo fibers, hollow polyester fibers, ES fibers, high-strength polyester staple fibers and chitin fibers according to the proportion of 5: 2: 5: 3: 4, and the fibers cooperate to guarantee breathability, elasticity, mechanical properties and permeability; auxiliary reagents are citric acid, PVP and deionized water, no toxic solvent is used in the whole process, and the sanitary towel is green and environmentally friendly and meets the requirements of sanitary towels.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, and mainly designs a method for preparing carbon quantum dot spunlace fabric, specifically involving carbon quantum dot spunlace fabric and its application in sanitary napkins. Background Technology

[0002] Carbon quantum dot spunlace fabric refers to a novel functional composite material formed by loading carbon quantum dots (CQDs) onto a spunlace fabric substrate through a specific process. It has broad application prospects in fields such as hygiene products. Although traditional spunlace fabric has basic advantages such as softness and breathability, it still faces the following core technical bottlenecks in meeting the increasingly high-end demands of hygiene products: First, inherent functional limitations. Its performance mainly relies on the physical properties of the fiber itself, generally lacking efficient and long-lasting active antibacterial and water-locking functions, making it difficult to meet key requirements such as antibacterial and infection prevention, dryness, and backflow prevention. Second, poor functional modification effects. Even if antibacterial components are added through finishing processes, traditional processes (such as simple impregnation) easily lead to weak bonding between the functional components and the substrate, resulting in easy loss and short-lived antibacterial function. Third, insufficient synergy between functional and matrix performance. In material design and processing, it is often difficult to balance multiple properties such as breathability, water absorption, and backflow resistance, easily resulting in the enhancement of one indicator at the expense of other properties. In addition, some chemically synthesized antibacterial agents introduced to impart functionality may have low biocompatibility or safety hazards with long-term use.

[0003] To address the aforementioned issues, this invention innovatively proposes a spunlace fabric and sanitary napkin preparation technology based on carbon quantum dots from traditional Chinese medicine compound: highly active carbon quantum dots are obtained through hydrothermal reaction using Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi as carbon sources. Uniform and firm loading is achieved through a hierarchical functionalization process. The five-fiber compound system is optimized and combined with gradient spunlace and precise thermal bonding processes. The final product has both high-efficiency broad-spectrum antibacterial properties, high breathability, high absorbency, and low rewetting characteristics, systematically solving the core technical bottlenecks of traditional spunlace fabric and its application in the sanitary napkin field. Summary of the Invention

[0004] In view of this, the present invention provides a method for preparing carbon quantum dot spunlace fabric suitable for use in sanitary napkins.

[0005] Firstly, this invention provides a carbon quantum dot spunlace fabric formulation, the specific composition of which is as follows: Functional carbon quantum dot carbon source: The dried powders of Scutellaria baicalensis, Isatis indigotica and Artemisia argyi are mixed in a mass ratio of 2:1:1. This compound not only has broad-spectrum antibacterial, anti-inflammatory and antipruritic effects, but also uses raw materials that are both food and medicine, making it safer. The spunlace fabric base fiber is composed of five types: bamboo fiber, hollow polyester fiber, ethylene-propylene copolymer fiber (ES fiber), high-strength polyester staple fiber, and chitosan fiber. The fiber ratio is bamboo fiber: hollow polyester fiber: ES fiber: high-strength polyester staple fiber: chitosan fiber = 5:2:5:3:4. Among them, bamboo fiber is naturally porous, which is the main breathable and highly efficient in water wicking; hollow polyester fiber uses its hollow structure to assist in breathability and ensure volumetric elasticity after water absorption; ethylene-propylene copolymer fiber (ES fiber) is the core bonding and reinforcing component, and its polyethylene skin melts to form strong weld points, which mainly improves the dry and wet tensile strength of the fabric; high-strength polyester staple fiber further enhances the mechanical toughness and structural stability of the fabric through tight fiber entanglement; chitosan fiber relies on hydrophilic groups and active sites to improve permeability and water retention capacity. Auxiliary reagents include citric acid (a green crosslinking agent), polyvinylpyrrolidone (PVP, a dispersant), and deionized water. No toxic solvents are used throughout the entire process, making it green and environmentally friendly.

[0006] Secondly, this invention provides a method for preparing carbon quantum dot spunlace fabric, the specific steps of which are as follows: S1. Preparation of carbon quantum dots from traditional Chinese medicine compound: The carbon source for functional carbon quantum dots is dried powder of Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi, weighed in a mass ratio of 2:1:1 (this ratio was determined by optimization through multiple pre-experiment systems). Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi are mixed according to the ratio in the formula. 5g of the mixed powder of traditional Chinese medicine is added to 100mL of deionized water and stirred at 80℃ for 3h to extract the active ingredients. The above extract is transferred to a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 160℃ for 8h to carbonize the active ingredients such as polysaccharides and flavonoids in the traditional Chinese medicine in situ to form carbon quantum dots. After the reaction is completed, the mixture is cooled to room temperature, centrifuged at 10000rpm for 20min, and the supernatant is filtered and diluted to 100mL to finally obtain a dispersion of carbon quantum dots of traditional Chinese medicine. S2. Molding of spunlace fabric substrate: (1) Fiber web formation: Weigh the bamboo fiber: hollow polyester fiber: ES fiber: high-strength polyester staple fiber: chitin fiber = 5:2:5:3:4 (this ratio has been screened and optimized through multiple pre-experiments to maximize the synergistic function of each fiber). After being processed by opening and mixing equipment, airflow web formation technology is used to form a fluffy and uniform three-dimensional fiber web. (2) Gradient hydroentanglement reinforcement: Pre-entanglement: Using a medium-pressure water jet of 80 bar, the fibers are initially entangled to form a stable framework; Main reinforcement: 150 bar high-pressure water jetting is used to perform multiple front-side hydroentanglement to deeply entangle the fibers and provide the main mechanical strength; Surface finishing: The reverse side is hydroentangled using a low-pressure water jet of 100 bar to reduce fabric fuzz and achieve a soft hand feel; (3) Precise thermal bonding: The hydroentangled fabric is immediately sent into a hot air dryer and dried at a precise temperature of 125℃ for 3-5 minutes; the melting temperature range of the polyethylene (PE) skin of ES fiber is 110-130℃, and 125℃ is in the middle of this range. This ensures that the PE skin is fully melted and forms a firm and uniform weld point at the fiber intersection, which significantly improves the dry and wet tensile strength and structural stability of the fabric; it also avoids excessive melting caused by the temperature exceeding 130℃, which prevents the fiber pores from being blocked. This temperature setting can completely preserve the original fluffy and porous structure of the fabric and ensure that the air permeability of the substrate is not affected. S3, functionalization of carbon quantum dots at the hierarchical level: (1) Substrate pretreatment: The spunlace fabric substrate was immersed in a 5% chitosan citric acid solution (w / v, solvent is 3% (v / v) citric acid solution) for 30 min, and dried at 40°C after immersion; this step introduces more amino active sites on the fiber surface and enhances the binding force with CQDs. (2) Hierarchical functionalization Surface spray enrichment: Take the Chinese medicine CQDs dispersion, add citric acid and PVP, and stir continuously at 500 rpm for 20 minutes to form a functional spray liquid; use a low flow air spraying device to evenly spray half the volume of the functional spray liquid onto the fabric surface, so that a large number of CQDs are preferentially enriched in the surface area where the liquid first contacts. Vacuum impregnation: The coated fabric is immersed in the remaining functional coating liquid and placed in a vacuum impregnation device (vacuum degree -0.09MPa) for 30 seconds. After that, the pressure is restored to normal. The instantaneous pressure difference is used to make the dispersion liquid penetrate evenly and slightly into the lower layer of the fiber network to achieve overall functionalization. (3) Crosslinking and curing: After impregnation, the fabric blank is rolled to remove excess liquid droplets and then sent to a hot air drying equipment to dry at a constant temperature of 105℃ for 60 minutes. During this process, the citric acid is fully esterified and crosslinked with the hydroxyl groups on the surface of the fiber and CQDs at a constant temperature of 105℃ to ensure that the CQDs are firmly fixed and to avoid damage to the fiber structure by high temperature. S4. After finishing, rinse with deionized water 2-3 times to remove unfixed substances, and vacuum dry at 60℃ to obtain carbon quantum dot spunlace fabric.

[0007] Thirdly: This invention provides a method for preparing a sanitary napkin containing the above-mentioned carbon quantum dot spunlace fabric, the specific steps of which are as follows: S5. Cutting process: The carbon quantum dot spunlace fabric prepared above is precisely cut according to the core size of the sanitary napkin and used as the core functional layer of the sanitary napkin for later use.

[0008] S6. Composite molding: The bottom leak-proof membrane, the flow guiding layer, the carbon quantum dot spunlace fabric functional layer, and the surface skin-friendly non-woven fabric are stacked in sequence. The layers are then bonded together using a hot-pressing composite equipment (temperature 110-120℃, pressure 0.3-0.5MPa) to ensure that each layer is firmly bonded and does not shift.

[0009] S7. Edge sealing: The edges of the composite sanitary napkin blank are sealed using an ultrasonic edge sealing machine, with the width controlled at 3-5mm, to prevent separation between layers or side leakage during use.

[0010] S8. Accessory Assembly: Attach the wing adhesive tape to both sides of the sanitary napkin, evenly attach the backing strip to the back, cover with release paper, and complete the structural assembly.

[0011] S9. Sterilization and Packaging: After the sanitary napkins are formed, they are placed in an ultraviolet sterilization chamber (wavelength 254nm, irradiation time 15-20min) for sterilization, and then individually sealed and packaged for bulk packaging.

[0012] Preferably, the filter membrane used for filtration in step S1 of the present invention is a 0.22μm microporous filter membrane.

[0013] Preferably, in step S3 (2) of the present invention, the amount of citric acid added is 1% (w / v) of the Chinese medicine CQDs dispersion, and it is used as a green crosslinking agent.

[0014] Preferably, in step S3 (2) of the present invention, the amount of PVP added is 0.8% (w / v) of the Chinese medicine CQDs dispersion, and it is used as a dispersant.

[0015] Preferably, in step S3 (2) of the present invention, the ratio of the total amount of functional spray liquid (including the total amount of functional spray liquid used for surface spray enrichment and vacuum impregnation) to the amount of spunlace fabric substrate (fabric surface) is 2:1 (v / w).

[0016] Preferably, in step S3 (2) of the present invention, the parameters of the low-flow air spraying equipment are set as follows: nozzle diameter 0.5mm, spraying pressure 0.2MPa, cloth walking speed 5m / min, and the uniformity of spraying is ensured by adjusting the distance between the nozzle and the cloth surface (controlled at 15-20cm).

[0017] Preferably, in step S3 (3) of the present invention, the rolling liquid ratio is controlled at 60%-65% during rolling.

[0018] Preferably, in step S4 of the present invention, the bath ratio is 1:20, the water temperature is 30-35℃, and the rinsing time is 5min / time.

[0019] Preferably, in step S6 of the present invention, the bottom leak-proof membrane is a PE breathable microporous leak-proof membrane.

[0020] Preferably, in step S6 of the present invention, the flow guiding layer is a hot air nonwoven fabric flow guiding layer.

[0021] Preferably, in step S6 of the present invention, the surface skin-friendly nonwoven fabric is selected as spunbond-hot air composite nonwoven fabric.

[0022] The present invention has the following beneficial effects: 1. The carbon quantum dot spunlace fabric prepared by this invention has antibacterial and breathable properties.

[0023] 2. The sanitary napkin made of carbon quantum dot spunlace fabric prepared by this invention has excellent absorbency and rewetting properties. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a carbon dot TEM image of the traditional Chinese medicine carbon quantum dot dispersion prepared in step S1 of Example 2.

[0026] Figure 2 This is a comparison chart of the air permeability of Example 2 and Comparative Examples 5-6.

[0027] Figure 3 This is a comparison chart of the air permeability of Example 2, Comparative Example 5, and Comparative Example 7.

[0028] Figure 4 This is a comparison chart of the re-infiltration volume between Example 2 and Comparative Examples 8-11.

[0029] Figure 5 This is a sample image of the carbon quantum dot spunlace fabric from Example 2. Detailed Implementation

[0030] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0031] Bamboo fiber was purchased from Fujian Bamboo Fiber Materials Technology Co., Ltd.; hollow polyester fiber was purchased from Dingxin Hongyuan Factory; ES fiber was purchased from Shanghai Jinbo Engineering Plastics Co., Ltd.; high-strength polyester staple fiber was purchased from Wanjia Ruiyuan Factory; and chitosan fiber was purchased from Qingdao Hailan Biological Products Co., Ltd.

[0032] Example 1

[0033] This embodiment provides a method for preparing carbon quantum dot spunlace fabric, the specific steps of which are as follows: S1. Preparation of carbon quantum dots in traditional Chinese medicine compound: Take dried powders of Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi, mix them evenly in a mass ratio of 2:1:1 to obtain a mixed powder of traditional Chinese medicine; take 5g of the mixed powder of traditional Chinese medicine, add 100mL of deionized water, and stir at 80℃ for 3h to extract the active ingredients; transfer the above extract into a hydrothermal reactor lined with polytetrafluoroethylene, and react at 160℃ for 8h to carbonize the active ingredients such as polysaccharides and flavonoids in the traditional Chinese medicine in situ to form carbon quantum dots; after the reaction is completed, cool to room temperature, centrifuge at 10000rpm for 20min, take the supernatant and filter it through a 0.22μm microporous membrane, and make up to 100mL to finally obtain a dispersion of carbon quantum dots of traditional Chinese medicine; S2. Molding of spunlace fabric substrate: (1) Fiber web formation: Take bamboo fiber, hollow polyester fiber, ES fiber, high-strength polyester staple fiber and chitin fiber and mix them evenly in a ratio of 5:2:5:3:4. After processing by opening and mixing equipment, airflow web formation technology is used to form a fluffy and uniform three-dimensional fiber web. (2) Gradient hydroentanglement reinforcement: Pre-entanglement: Using a medium-pressure water jet of 80 bar, the fibers are initially entangled to form a stable framework; Main reinforcement: 150 bar high-pressure water jetting is used to perform multiple front-side hydroentanglement to deeply entangle the fibers and provide the main mechanical strength; Surface finishing: The reverse side is hydroentangled using a low-pressure water jet of 100 bar to reduce fabric fuzz and achieve a soft hand feel; (3) Precise thermal bonding: The spunlace reinforced fabric is immediately sent into a hot air dryer and dried for 3 minutes at a precise temperature of 125°C. This temperature range can only melt the polyethylene (PE) skin of the ES fiber, forming a firm and uniform weld point at the fiber intersection. This can significantly improve the dry and wet tensile strength and structural stability of the fabric, while also preserving its original fluffy and porous structure, ensuring that the breathability of the substrate is not affected. S3, functionalization of carbon quantum dots at the hierarchical level: (1) Substrate pretreatment: The spunlace fabric substrate was immersed in a 5% chitosan-citric acid solution (w / v, solvent was 3% (v / v) citric acid solution) for 30 min, and then dried at 40°C after immersion. This process introduces more amino active sites on the fiber surface, enhancing the bonding force with CQDs; (2) Hierarchical functionalization Surface coating enrichment: Accurately weigh citric acid (used as a green crosslinking agent) at 1% (w / v) of the Chinese medicine CQDs dispersion, and accurately weigh PVP (used as a dispersant) at 0.8% (w / v); take the Chinese medicine CQDs dispersion, add the weighed citric acid and PVP, and stir continuously at 500 rpm for 20 min to form a functional coating liquid; evenly spray half the volume of the functional coating liquid onto the fabric surface using a low-flow air spraying device, so that a large number of CQDs are preferentially enriched in the surface area where the liquid first contacts; the parameters of the low-flow air spraying device are set as follows: nozzle diameter 0.5 mm, spraying pressure 0.2 MPa, fabric speed 5 m / min, and the distance between the nozzle and the fabric surface is controlled at 15 cm; the ratio of the total functional coating liquid to the spunlace fabric substrate (fabric surface) is 2:1 (v / w). Vacuum impregnation: The coated fabric is immersed in the remaining functional coating liquid and placed in a vacuum impregnation device (vacuum degree -0.09MPa) for 30 seconds. After that, the pressure is restored to normal. The instantaneous pressure difference is used to make the dispersion liquid penetrate evenly and slightly into the lower layer of the fiber network to achieve overall functionalization. (3) Crosslinking and curing: The impregnated fabric is rolled by a roller (with the liquid rate controlled at 60%) to remove excess liquid droplets, and then sent to a hot air drying device for drying at a constant temperature of 105℃ for 60 minutes. During this process, the citric acid is fully esterified and crosslinked with the hydroxyl groups on the surface of the fiber and CQDs at a constant temperature of 105℃ to ensure that the CQDs are firmly fixed, while avoiding damage to the fiber structure by high temperature; S4. After finishing, rinse twice with deionized water (each time with a bath ratio of 1:20, a water temperature of 30℃, and a rinsing time of 5 minutes) to remove unfixed substances. Then, vacuum dry at 60℃ to obtain carbon quantum dot spunlace fabric.

[0034] Example 2

[0035] This embodiment provides a method for preparing a sanitary napkin containing carbon quantum dot spunlace fabric, the specific steps of which are as follows: S1. Preparation of carbon quantum dots from traditional Chinese medicine compound: Dried powders of Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi were mixed evenly in a mass ratio of 2:1:1 to obtain a mixed powder of traditional Chinese medicine. 5g of the mixed powder was added to 100mL of deionized water and stirred at 80℃ for 3 hours to extract the active ingredients. The extract was transferred to a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 160℃ for 8 hours to allow the polysaccharides, flavonoids, and other active ingredients in the traditional Chinese medicine to carbonize in situ, forming carbon quantum dots. After the reaction, the mixture was cooled to room temperature and centrifuged at 10000rpm for 20 minutes. The supernatant was filtered through a 0.22μm microporous membrane and brought to a final volume of 100mL to obtain a dispersion of carbon quantum dots from the traditional Chinese medicine. The transmission electron microscope (TEM) image of the carbon quantum dots from this traditional Chinese medicine is shown below. Figure 1 .

[0036] S2. Molding of spunlace fabric substrate: (1) Fiber web formation: Take bamboo fiber, hollow polyester fiber, ES fiber, high-strength polyester staple fiber and chitin fiber and mix them evenly in a ratio of 5:2:5:3:4. After processing by opening and mixing equipment, airflow web formation technology is used to form a fluffy and uniform three-dimensional fiber web. (2) Gradient hydroentanglement reinforcement: Pre-entanglement: Using a medium-pressure water jet of 80 bar, the fibers are initially entangled to form a stable framework; Main reinforcement: 150 bar high-pressure water jetting is used to perform multiple front-side hydroentanglement to deeply entangle the fibers and provide the main mechanical strength; Surface finishing: The reverse side is hydroentangled using a low-pressure water jet of 100 bar to reduce fabric fuzz and achieve a soft hand feel; (3) Precise thermal bonding: The spunlace reinforced fabric is immediately sent into a hot air dryer and dried at a precise temperature of 127°C for 4 minutes. This temperature range can only melt the polyethylene (PE) skin of the ES fiber, forming a firm and uniform weld point at the fiber intersection. This can significantly improve the dry and wet tensile strength and structural stability of the fabric, while also preserving its original fluffy and porous structure, ensuring that the breathability of the substrate is not affected. S3, functionalization of carbon quantum dots at the hierarchical level: (1) Substrate pretreatment: The spunlace fabric substrate was immersed in a 5% chitosan-citric acid solution (w / v, solvent was 3% (v / v) citric acid solution) for 30 min, and then dried at 40°C after immersion. This process introduces more amino active sites on the fiber surface, enhancing the bonding force with CQDs; (2) Hierarchical functionalization Surface coating enrichment: Accurately weigh citric acid (used as a green crosslinking agent) at 1% (w / v) of the Chinese medicine CQDs dispersion, and accurately weigh PVP (used as a dispersant) at 0.8% (w / v); take the Chinese medicine CQDs dispersion, add the weighed citric acid and PVP, and stir continuously at 500 rpm for 20 min to form a functional coating liquid; evenly spray half the volume of the functional coating liquid onto the fabric surface using a low-flow air spraying device, so that a large number of CQDs are preferentially enriched in the surface area where the liquid first contacts; the parameters of the low-flow air spraying device are set as follows: nozzle diameter 0.5 mm, spraying pressure 0.2 MPa, fabric speed 5 m / min, and the distance between the nozzle and the fabric surface is controlled at 18 cm; the ratio of the total functional coating liquid to the spunlace fabric substrate (fabric surface) is 2:1 (v / w). Vacuum impregnation: The coated fabric is immersed in the remaining functional coating liquid and placed in a vacuum impregnation device (vacuum degree -0.09MPa) for 30 seconds. After that, the pressure is restored to normal. The instantaneous pressure difference is used to make the dispersion liquid penetrate evenly and slightly into the lower layer of the fiber network to achieve overall functionalization. (3) Crosslinking and curing: The impregnated fabric is rolled by a roller (with the liquid rate controlled at 62%) to remove excess liquid droplets, and then sent to a hot air drying device for drying at a constant temperature of 105℃ for 60 minutes. During this process, the citric acid is fully esterified and crosslinked with the hydroxyl groups on the surface of the fiber and CQDs at a constant temperature of 105℃ to ensure that the CQDs are firmly fixed, while avoiding damage to the fiber structure by high temperature; S4. After finishing, rinse three times with deionized water (each time bath ratio 1:20, water temperature 32℃, rinsing time 5min / time) to remove unfixed substances, and vacuum dry at 60℃ to obtain carbon quantum dot spunlace fabric; sample image of carbon quantum dot spunlace fabric is shown below. Figure 5 As shown.

[0037] S5. Cutting process: The carbon quantum dot spunlace fabric prepared above is precisely cut according to the core size of the sanitary napkin and used as the core functional layer of the sanitary napkin for later use.

[0038] S6. Composite Molding: PE breathable microporous leak-proof membrane is selected as the bottom leak-proof membrane, hot-air nonwoven fabric as the flow guiding layer, carbon quantum dot spunlace fabric as the functional layer, and spunbond-hot-air composite nonwoven fabric as the surface skin-friendly nonwoven fabric; the bottom leak-proof membrane, flow guiding layer, carbon quantum dot spunlace fabric functional layer and surface skin-friendly nonwoven fabric are stacked in sequence, and spot bonding is performed through hot-pressing composite equipment (temperature 110℃, pressure 0.3MPa) to ensure that each layer is firmly bonded and does not shift; S7. Edge sealing: The edges of the composite sanitary napkin blank are sealed using an ultrasonic edge sealing machine, with the width controlled at 3-5mm, to prevent separation between layers or side leakage during use. S8. Accessory Assembly: Attach the protective wings to both sides of the sanitary napkin, evenly attach the backing strip to the back, cover with release paper, and complete the structural assembly; S9. Sterilization and Packaging: After the sanitary napkins are formed, they are placed in an ultraviolet sterilization chamber (wavelength 254nm, irradiation time 15min) for sterilization, and then individually sealed and packaged for bulk packaging.

[0039] Example 3

[0040] This embodiment provides a method for preparing a sanitary napkin containing carbon quantum dot spunlace fabric, the specific steps of which are as follows: S1. Preparation of carbon quantum dots in traditional Chinese medicine compound: Take dried powders of Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi, mix them evenly in a mass ratio of 2:1:1 to obtain a mixed powder of traditional Chinese medicine; take 5g of the mixed powder of traditional Chinese medicine, add 100mL of deionized water, and stir at 80℃ for 3h to extract the active ingredients; transfer the above extract into a hydrothermal reactor lined with polytetrafluoroethylene, and react at 160℃ for 8h to carbonize the active ingredients such as polysaccharides and flavonoids in the traditional Chinese medicine in situ to form carbon quantum dots; after the reaction is completed, cool to room temperature, centrifuge at 10000rpm for 20min, take the supernatant and filter it through a 0.22μm microporous membrane, and make up to 100mL to finally obtain a dispersion of carbon quantum dots of traditional Chinese medicine; S2. Molding of spunlace fabric substrate: (1) Fiber web formation: Take bamboo fiber, hollow polyester fiber, ES fiber, high-strength polyester staple fiber and chitin fiber and mix them evenly in a ratio of 5:2:5:3:4. After processing by opening and mixing equipment, airflow web formation technology is used to form a fluffy and uniform three-dimensional fiber web. (2) Gradient hydroentanglement reinforcement: Pre-entanglement: Using a medium-pressure water jet of 80 bar, the fibers are initially entangled to form a stable framework; Main reinforcement: 150 bar high-pressure water jetting is used to perform multiple front-side hydroentanglement to deeply entangle the fibers and provide the main mechanical strength; Surface finishing: The reverse side is hydroentangled using a low-pressure water jet of 100 bar to reduce fabric fuzz and achieve a soft hand feel; (3) Precise thermal bonding: The spunlace reinforced fabric is immediately sent into a hot air dryer and dried for 5 minutes at a precise temperature of 130°C. This temperature range can only melt the polyethylene (PE) skin of the ES fiber, forming a firm and uniform weld point at the fiber intersection. This can significantly improve the dry and wet tensile strength and structural stability of the fabric, while also preserving its original fluffy and porous structure, ensuring that the breathability of the substrate is not affected. S3, functionalization of carbon quantum dots at the hierarchical level: (1) Substrate pretreatment: The spunlace fabric substrate was immersed in a 5% chitosan-citric acid solution (w / v, solvent was 3% (v / v) citric acid solution) for 30 min, and then dried at 40°C after immersion. This process introduces more amino active sites on the fiber surface, enhancing the bonding force with CQDs; (2) Hierarchical functionalization Surface coating enrichment: Accurately weigh citric acid (used as a green crosslinking agent) at 1% (w / v) of the Chinese medicine CQDs dispersion, and accurately weigh PVP (used as a dispersant) at 0.8% (w / v). Take the Chinese medicine CQDs dispersion, add the weighed citric acid and PVP, and stir continuously at 500 rpm for 20 minutes to form a functional coating liquid. Apply half the volume of the functional coating liquid evenly to the fabric surface using a low-flow air spraying device, so that a large number of CQDs are preferentially enriched in the surface area where the liquid first contacts. Use a low-flow air spraying device for fabric surface treatment, with the following equipment parameters set: nozzle diameter 0.5 mm, spraying pressure 0.2 MPa, and fabric speed 5 m / min. Ensure uniform spraying by adjusting the distance between the nozzle and the fabric surface to 20 cm. Vacuum impregnation: The coated fabric is immersed in the remaining functional coating liquid and placed in a vacuum impregnation device (vacuum degree -0.09MPa) for 30 seconds, then restored to normal pressure. The instantaneous pressure difference allows the dispersion liquid to penetrate evenly and slightly into the lower layers of the fiber network, achieving overall functionalization. The ratio of total functional coating liquid to spunlace fabric substrate (fabric surface) is 2:1 (v / w). (3) Crosslinking and curing: The impregnated fabric is rolled by a roller (with the liquid rate controlled at 65%) to remove excess liquid droplets, and then sent to a hot air drying device for drying at a constant temperature of 105℃ for 60 minutes. During this process, the citric acid is fully esterified and crosslinked with the hydroxyl groups on the surface of the fiber and CQDs at a constant temperature of 105℃ to ensure that the CQDs are firmly fixed, while avoiding damage to the fiber structure by high temperature; S4. After finishing, rinse three times with deionized water (each time with a bath ratio of 1:20, a water temperature of 35℃, and a rinsing time of 5 minutes each time) to remove unfixed substances, and then vacuum dry at 60℃ to obtain carbon quantum dot spunlace fabric. S5. Cutting process: The carbon quantum dot spunlace fabric prepared above is precisely cut according to the core size of the sanitary napkin and used as the core functional layer of the sanitary napkin for later use; S6. Composite Molding: PE breathable microporous leak-proof membrane is selected as the bottom leak-proof membrane, hot-air nonwoven fabric as the flow guiding layer, carbon quantum dot spunlace fabric as the functional layer, and spunbond-hot-air composite nonwoven fabric as the surface skin-friendly nonwoven fabric; the bottom leak-proof membrane, flow guiding layer, carbon quantum dot spunlace fabric functional layer and surface skin-friendly nonwoven fabric are stacked in sequence, and spot bonding is performed through hot-pressing composite equipment (temperature 110℃, pressure 0.3MPa) to ensure that each layer is firmly bonded and does not shift; S7. Edge sealing: The edges of the composite sanitary napkin blank are sealed using an ultrasonic edge sealing machine, with the width controlled at 3-5mm, to prevent separation between layers or side leakage during use. S8. Accessory Assembly: Attach the protective wings to both sides of the sanitary napkin, evenly attach the backing strip to the back, cover with release paper, and complete the structural assembly; S9. Sterilization and Packaging: After the sanitary napkins are formed, they are placed in an ultraviolet sterilization chamber (wavelength 254nm, irradiation time 20min) for sterilization, and then individually sealed and packaged for bulk packaging.

[0041] Comparative Example 1: Except for step S1, which does not involve a hydrothermal reaction, i.e., after stirring at 80°C for 3 hours, the supernatant is directly centrifuged and collected, all other steps are the same as in Example 2.

[0042] Comparative Example 2: Except for step S1, which does not include Scutellaria baicalensis, all other steps are the same as in Example 2.

[0043] Comparative Example 3: Except for step S1, which does not include Isatis root, all other steps are the same as in Example 2.

[0044] Comparative Example 4: Except for step S1, which does not include mugwort leaves, all other steps are the same as in Example 2.

[0045] Comparative Example 5: Except for step S2, in which bamboo fiber is not added, all other steps are the same as in Example 2.

[0046] Comparative Example 6: Except for step S2, in which hollow polyester fibers are not added, all other steps are the same as in Example 2.

[0047] Comparative Example 7: Except for step S2, in which chitin fibers are not added, all other steps are the same as in Example 2.

[0048] Comparative Example 8: The crosslinking curing temperature in step S3 was changed to 85°C, and all other steps were the same as in Example 2.

[0049] Comparative Example 9: The crosslinking curing temperature in step S3 was changed to 95°C, and all other steps were the same as in Example 2.

[0050] Comparative Example 10: The crosslinking curing temperature in step S3 was changed to 115°C, and all other steps were the same as in Example 2.

[0051] Comparative Example 11: The crosslinking curing temperature in step S3 was changed to 125°C, and all other steps were the same as in Example 2.

[0052] Performance testing of carbon quantum dot spunlace fabric and sanitary napkins

[0053] 1. Antibacterial activity test: The antibacterial activity of carbon quantum dot spunlace fabric was tested in accordance with GB15979-2002 "Requirements for Hygienic Standards of Disposable Sanitary Products". The test bacteria were Staphylococcus aureus B81854(A) (purchased from Ningbo Mingzhou Biotechnology Co., Ltd.), Escherichia coli B81038 (purchased from Ningbo Mingzhou Biotechnology Co., Ltd.), Candida albicans ATCC-10231 (purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd.), and Pseudomonas aeruginosa ATCC-9027 (purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd.). The experimental results are shown in Table 1.

[0054] Table 1

[0055] Table 1 compares the antibacterial rates of Examples 1-4 and Comparative Examples 1-4 against Staphylococcus aureus, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa. Examples 1-4, having fully preserved the preparation process of carbon quantum dots from traditional Chinese medicine compound (including hydrothermal carbonization reaction at 160℃), maintained high antibacterial rates against various bacterial species (Staphylococcus aureus ≥99.28%, Escherichia coli ≥99.16%, Candida albicans ≥97.69%, Pseudomonas aeruginosa ≥98.34%), demonstrating excellent antibacterial performance. In contrast, Comparative Example 1, having omitted the hydrothermal reaction step (only extracting the active ingredients of traditional Chinese medicine without generating carbon quantum dots), suffered from difficulty in firmly fixing the antibacterial components, resulting in a sharp drop in antibacterial rates against various bacterial species to 55.37%-62.42%, with significantly inferior antibacterial effects compared to the Example groups. This fully demonstrates that the carbon quantum dots generated by the hydrothermal reaction are the core carrier ensuring high antibacterial performance.

[0056] Comparative Examples 2-4, which lacked the single-herb components of Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi in their traditional Chinese medicine compound prescriptions, all showed significantly lower antibacterial rates compared to Example 2, with the rate of decrease exhibiting a clear gradient: Comparative Example 2 (without Scutellaria baicalensis) had the lowest antibacterial rate, with Staphylococcus aureus at 83.27%, Escherichia coli at 81.54%, Candida albicans at 75.36%, and Pseudomonas aeruginosa at 78.69%, representing decreases of 16.07%, 17.71%, 22.50%, and 19.92% respectively compared to Example 2; Comparative Example 3 (without Isatis indigotica) had a moderate antibacterial rate, with four types of bacteria... The antibacterial rates of the four strains were 85.64%, 84.19%, 77.82%, and 81.25%, respectively, representing decreases of 13.70%, 15.06%, 20.04%, and 17.36% compared to Example 2. Comparative Example 4 (without Artemisia argyi) had the highest antibacterial rate among the comparative examples, but it was still significantly lower than that of Example 2. The antibacterial rates of the four strains were 88.35%, 87.02%, 80.57%, and 84.43%, respectively, representing decreases of 10.99%, 12.23%, 17.29%, and 14.18% compared to Example 2.

[0057] The above results indicate that the three traditional Chinese medicines, Scutellaria baicalensis, Isatis indigotica, and Artemisia argyi, play an irreplaceable synergistic role in the formation of carbon quantum dots and the exertion of their antibacterial activity. Among them, Scutellaria baicalensis contributes the most to the antibacterial activity, followed by Isatis indigotica and Artemisia argyi. The synergistic effect of the three can significantly enhance the broad-spectrum antibacterial ability of carbon quantum dots. However, the absence of any one of the traditional Chinese medicines reduces the number of active sites and the loading of antibacterial components in the carbon quantum dots, resulting in a significant weakening of the antibacterial performance. This further confirms the scientific nature and necessity of the traditional Chinese medicine compound formula of this invention.

[0058] 2. Air permeability test: The air permeability of the carbon quantum dot spunlace fabric sample was tested using a YG461H fully automatic air permeability tester (purchased from Wenzhou Jigao Testing Instruments Co., Ltd.). The test area was set to 20 cm², the pressure drop was set to 100 Pa, and the test was repeated 10 times. The experimental results are as follows: Figure 2 As shown.

[0059] Figure 2 This is a comparison chart of the air permeability of Example 2 and Comparative Examples 5-6. Example 2 achieved an air permeability of 85.68 mm / s, while Comparative Example 5, due to the removal of bamboo fiber, saw its air permeability plummet to 35.12 mm / s, and Comparative Example 6, due to the removal of hollow polyester fiber, experienced a decrease in air permeability to 61.23 mm / s. Therefore, it can be seen that Example 2, thanks to the synergistic effect of bamboo fiber and hollow polyester fiber, significantly outperformed the comparative examples lacking only a single fiber in terms of air permeability, exhibiting the best air permeability performance.

[0060] 3. Absorbency Performance: Select a sanitary napkin sample, trim the left and right edges appropriately, and weigh the sample before absorption (recorded as m). Clamp one end of the sample with a clip, ensuring the clip opening is perpendicular to the sample's longitudinal direction and does not contact the internal absorbent core. Immerse the sample along with the clip in distilled water at a depth of approximately 10 cm and a temperature of (23±1)℃, with the sample's usable side facing upwards. Gently press the sample to completely submerge it for 60 seconds, then lift the clip to completely remove the sample from the water surface. After suspending it vertically for 90 seconds, weigh the sample after absorption (recorded as n) to calculate the absorbency ratio. Repeat the measurement 5 times. The experimental results are shown in Table 2 and... Figure 3 As shown.

[0061] Formula for calculating water absorption ratio:

[0062] Table 2

[0063] From Table 2 ( Figure 3As can be seen, compared with Comparative Examples 5 and 7, the water absorption ratio of Example 2 is significantly reduced, indicating that Example 2 achieves optimal water absorption performance through the synergistic effect of the high-speed water conduction of bamboo fiber and the deep water retention of chitosan fiber. Once the system is disrupted, the performance significantly decreases: the absence of bamboo fiber leads to insufficient water conduction and diffusion, resulting in a significant decrease in water absorption capacity; the absence of chitosan fiber limits the water retention capacity and weakens water holding capacity. The results show that the synergy of both is key to achieving a high water absorption ratio.

[0064] 4. Rewetting Test: Take the sanitary napkin sample to be tested and flatten it on the tester panel, aligning the center of the effective length and width of the sanitary napkin with the center of the bottom of the dispensing funnel. Adjust the height of the funnel so that the bottom of its opening is 10mm from the sample surface. Use a pipette to transfer 5mL of test solution into the funnel, and quickly open the funnel gate to its maximum to allow the solution to flow freely onto the sanitary napkin sample surface. After 4 minutes, place several layers of filter paper (125mm in diameter and of known mass, with the top layer of filter paper showing no absorption as the criterion) on the surface of the sanitary napkin, and place a standard pressure block (100mm in diameter, 1.2kg in weight). After 1 minute, remove the pressure block and weigh the filter paper using a balance to calculate the rewetting amount. Repeat the test 5 times. The experimental results are shown in Table 3 and... Figure 4 As shown.

[0065] Formula for calculating re-infiltration rate: m = m1 − m2 m1: Mass of the filter paper after absorption (g) m2: Mass of the filter paper before absorption (g)

[0066]

[0067] Table 3 ( Figure 4 The results show a comparison of the rewetting amount between Example 2 and Comparative Examples 8-11. The results indicate that the rewetting amount of Example 2 is significantly lower than that of Comparative Examples 8-11. Specifically, compared to the low-temperature group (Comparative Examples 8-9), its advantage lies in providing sufficient activation energy to drive the esterification reaction to completion, forming a complete and robust cross-linked network. This fundamentally solves the problems of poor water retention and easy loss of CQDs caused by a loose network. Compared to the high-temperature group (Comparative Examples 10-11), its advantage lies in avoiding the negative effects of ester bond hydrolysis, fiber thermal damage, and uneven cross-linking caused by high temperatures, protecting the integrity of the substrate, and thus obtaining the highest quality and most stable cross-linked structure. Therefore, 105℃ is the key temperature for achieving the optimal balance between efficient cross-linking and substrate protection in this system.

[0068] The above-described embodiments are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of protection of the present invention. It should be noted that for those skilled in the art, any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the scope of protection of the present invention.

Claims

1. A carbon quantum dot spunlace cloth, characterized by: The carbon quantum dot spunlace fabric formula, the specific composition is as follows: Functional carbon quantum dot carbon source: select the dry powder of scutellaria baicalensis, isatis root and artemisia leaf, mix the three according to the mass ratio of 2:1:1; Spunlace fabric substrate fiber: select 5 kinds of bamboo fiber, hollow polyester fiber, ES fiber, high-strength polyester staple fiber and chitin fiber, and the ratio of each fiber is bamboo fiber:hollow polyester fiber:ES fiber:high-strength polyester staple fiber:chitin fiber = 5:2:5:3:4; Auxiliary reagent: including citric acid, polyvinylpyrrolidone and deionized water. 2.The preparation method of the carbon quantum dot spunlace fabric according to claim 1, characterized in that: The specific preparation method of the carbon quantum dot spunlace fabric is as follows: S1, preparation of traditional Chinese medicine compound carbon quantum dots: mix scutellaria baicalensis, isatis root and artemisia leaf according to the ratio in the formula, take 5g of traditional Chinese medicine mixed powder, add 100ml of deionized water, stir at 80℃ constant temperature for 3h to extract active ingredients; the above extract is transferred into a polytetrafluoroethylene lined hydrothermal reactor, and the active ingredients in the traditional Chinese medicine are carbonized in situ at 160℃ for 8h to form carbon quantum dots. After the reaction, cool to room temperature, centrifuge at 10000rpm for 20min, take the supernatant, filter, and then constant volume to 100ml, finally get the traditional Chinese medicine carbon quantum dot dispersion liquid; S2, forming of spunlace fabric substrate: (1) fiber network: mix 5 kinds of fibers according to the formula, after treatment by opening and mixing equipment, form a fluffy and uniform three-dimensional fiber network by air laying technology; (2) gradient water jet reinforcement: Pre-interlacing: use 80bar medium pressure water needle to make the fiber preliminary interlaced and form a stable framework; Main reinforcement: use 150bar high pressure water needle to carry out multi-pass front water jet, make the fiber deeply interlaced and provide main mechanical strength; Surface finishing: use 100bar lower pressure water needle to carry out back water jet finishing, reduce the fabric hairiness and obtain soft hand feeling; (3) precise thermal bonding: the water jet reinforced fabric is immediately sent into hot air drying machine, and dried at 125℃ precise temperature for 3-5min; S3, hierarchical functional finishing of carbon quantum dots: (1) substrate pretreatment: immerse the spunlace fabric substrate in 5% chitin citric acid solution for 30min, and dry at 40℃ after immersion; (2) hierarchical functionalization Surface spraying enrichment: take traditional Chinese medicine CQDs dispersion liquid, add citric acid and PVP, continuously stir at 500rpm for 20min to form functional spraying liquid; spray the half volume of functional spraying liquid on the fabric surface uniformly by using low flow air spraying equipment, so that a large amount of CQDs is preferentially enriched in the surface layer area which is first contacted by liquid; Vacuum immersion penetration: immerse the sprayed fabric into the remaining functional spraying liquid, place it in vacuum immersion equipment for 30s, then restore normal pressure, use the instantaneous pressure difference to make the dispersion liquid uniformly and slightly penetrate into the lower layer of fiber network, realize the overall functionalization; (3) crosslinking and curing: remove the excess liquid drops from the immersed fabric by mangle, then immediately send it into hot air drying equipment, and dry at 105℃ constant temperature for 60min; S4, rinse 2-3 times with deionized water for post finishing, remove the unfixed substances, and vacuum dry at 60℃, then get the carbon quantum dot spunlace fabric.

3. The preparation method of the carbon quantum dot spunlace fabric according to claim 2, characterized in that: The amount of citric acid added in step S3 (2) is 1% of the traditional Chinese medicine CQDs dispersion liquid, which is used as a green crosslinking agent.

4. The preparation method of the carbon quantum dot spunlace fabric according to claim 2, characterized in that: The amount of PVP added in step S3 (2) is 0.8% of the traditional Chinese medicine CQDs dispersion liquid, which is used as a dispersing agent.

5. The preparation method of the carbon quantum dot spunlace fabric according to claim 2, characterized in that: The ratio of the total functional spraying liquid to the water-jet fabric substrate in step S3 (2) is 2:

1.

6. The preparation method of the carbon quantum dot spunlace fabric according to claim 2, characterized in that: In step S3 (2), the low-flow air spraying equipment parameters are set as follows: nozzle diameter 0.5 mm, spraying pressure 0.2 MPa, and cloth speed 5 m / min. The distance between the nozzle and the cloth is controlled at 15-20 cm to ensure uniform spraying.

7. The method for preparing a carbon quantum dot spunlace fabric according to claim 2, characterized in that: In step S3 (3), the pickling rate is controlled at 60%-65% during rolling.

8. The method for preparing a carbon quantum dot spunlace fabric according to claim 2, characterized in that: In step S4, the bath ratio is 1:20, the water temperature is 30-35℃, and the rinsing time is 5 min per time.

9. The use of the carbon quantum dots spunlace cloth according to any one of claims 2-8 in the preparation of sanitary napkins, characterized in that: The specific method for preparing sanitary napkins from carbon quantum dot water-jet fabric is as follows: S5, cutting piece processing: the carbon quantum dot water-jet fabric prepared above is accurately cut according to the size of the sanitary napkin core body, which is used as the core functional layer of the sanitary napkin and is ready for use; S6, composite molding: sequentially stack the bottom leakage-proof film, the flow guide layer, the carbon quantum dot water-jet fabric functional layer, and the surface skin-friendly non-woven fabric, and then perform point bonding under the conditions of temperature 110-120℃ and pressure 0.3-0.5 MPa through a hot-pressing composite equipment to ensure firm adhesion of each layer without displacement; S7, edge sealing: use an ultrasonic edge sealer to seal the edges of the composite sanitary napkin blank, with a width of 3-5 mm to prevent separation or side leakage between layers during use; S8, accessory assembly: paste the wing adhesive on both sides of the sanitary napkin, evenly paste the back adhesive tape on the back, cover the release paper, and complete the structure assembly; S9, sterilization and packaging: place the formed sanitary napkin into a ultraviolet sterilization box for sterilization treatment, and then individually seal and package, and batch pack.

10. Use according to claim 9, characterized in that: In step S6, the bottom leakage-proof film is selected as PE breathable microporous leakage-proof film, the flow layer is selected as hot air non-woven fabric flow guide layer, and the surface skin-friendly non-woven fabric is selected as spun-bonded-hot air composite non-woven fabric.

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