A high-dryness, odor-resistant, antibacterial and water-absorbing core material with a flow guide groove and a preparation method thereof

Abstract

The present application relates to sanitary product water-absorbing material field, disclose a kind of high dry and fresh odor-resistant antibacterial water-absorbing core material with flow guide groove and preparation method thereof.Water-absorbing core layer body is made of bamboo pulp fiber 30-60 parts, polyacrylic acid sodium water-absorbing resin 20-45 parts, thioctic acid modified chitosan 0.2-0.5 parts, antibacterial odor-resistant composite component 5-6 parts and polyvinyl alcohol binder 5-8 parts, the upper surface is provided with continuous flow guide groove and is compounded with liquid-permeable coated non-woven fabric layer, the lower surface is compounded with air-permeable flow guide non-woven fabric layer.Thioctic acid modified chitosan is dispersed and fixed in the core layer as solid component, does not form exposed coating of skin contact surface.Raw material mixing, airflow laying, adhesive liquid spraying, pre-drying pre-setting, flow guide groove hot pressing and final drying compound setting are carried out to obtain finished product.The present application can promote liquid diffusion and infiltration, reduce functional particle migration, so that the core has dry, antibacterial odor-resistant, low irritation and structural stability.

Description

Technical Field

[0001] This invention relates to the field of absorbent materials for hygiene products, specifically to a highly dry, odor-suppressing, antibacterial absorbent core material with a drainage channel and its preparation method. Background Technology

[0002] Absorbent core material is a key material in disposable hygiene products such as diapers, sanitary napkins, and incontinence pads, responsible for liquid absorption, diffusion, and storage. Existing absorbent cores typically use a composite of fluff pulp, absorbent fibers, and superabsorbent polymers to form the absorbent layer. When liquid is applied in concentrated amounts, it tends to accumulate rapidly in the receiving area, causing the localized superabsorbent polymer to swell and form a gel, blocking subsequent liquid diffusion into the core both longitudinally and laterally. This leads to surface residue, localized saturation, and backflow, thus affecting dryness during use.

[0003] To improve absorption rate, existing technologies typically improve liquid conduction by reducing core density, increasing hydrophilic fiber content, or incorporating embossed structures. However, simply reducing density weakens the wet integrity of the core, and ordinary embossing is prone to springback or closure after liquid absorption and expansion, making it difficult to continuously form a stable liquid transport channel. Therefore, how to construct a continuous, stable, and clearly directional flow-guiding structure while maintaining the strength of the core structure is a problem that needs to be solved to improve absorption uniformity and reduce reverse osmosis.

[0004] Furthermore, after absorbing urine, menstrual blood, or other bodily fluids, the warm and humid environment of hygiene products easily generates odors and provides conditions for microbial attachment and reproduction. Relying solely on a single inorganic antibacterial agent is usually insufficient to simultaneously achieve antibacterial activity, odor absorption, and core material processing stability; if functional particles migrate during airflow networking and liquid absorption, it may also cause uneven localized function. Therefore, it is necessary to develop an absorbent core material that synergistically integrates a flow-guiding structure, an absorbent network, antibacterial components, and odor-suppressing components, along with a stable molding process, to achieve rapid absorption, a dry surface, antibacterial and odor suppression, and structural stability. Summary of the Invention

[0005] To overcome the problems of insufficient liquid diffusion, local saturation and backflow in existing absorbent cores when concentrated liquid is absorbed, as well as the generation of odors and insufficient stability of functional component distribution after liquid absorption, this invention provides a high-dryness, odor-suppressing, and antibacterial absorbent core material with a flow channel and its preparation method. By combining continuous flow channels, a composite absorbent network, and antibacterial and odor-suppressing composite components, the efficiency of liquid diffusion and infiltration is improved, while taking into account both antibacterial and odor-suppressing performance and wet structural stability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a guide channel, characterized in that it includes a water-absorbing core layer body, the upper surface of which is provided with a plurality of continuously extending guide channels, and the water-absorbing core layer body is composed of the following components by weight: 30-60 parts bamboo pulp fiber, 20-45 parts sodium polyacrylate water-absorbing resin, 0.2-0.5 parts thioctic acid modified chitosan, 5-6 parts antibacterial and odor-suppressing composite component, and 5-8 parts polyvinyl alcohol binder; The guide channels are continuously arranged along the liquid conduction direction, so that after the liquid comes into contact with the absorbent core layer body, it will spread rapidly along the direction of the guide channels and penetrate into the interior of the absorbent core layer body from the bottom and wall of the guide channels. This will increase the effective contact area between the liquid and the absorbent core layer body, reduce the degree of local polyacrylate sodium water-absorbing resin rapid liquid absorption and swelling to form gel blockage, and improve the longitudinal diffusion speed and infiltration efficiency of the liquid.

[0007] Further, the preparation method of the lipoic acid modified chitosan is as follows: 50-60 mL of morpholine ethanesulfonic acid buffer with a concentration of 0.1 mol / L and a pH of 5.5, 50-60 mL of anhydrous ethanol, and lipoic acid are added to a reactor and stirred at room temperature until completely dissolved. Then, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added and stirred until dissolved. Then, N-hydroxysuccinimide is added and stirred for 3-4 h. Finally, chitosan is added and stirred at room temperature for 22-25 h. After the reaction is completed, the crude product is dialyzed in pure water for 4-5 days, and the dialysate is freeze-dried to obtain lipoic acid modified chitosan. The thioctic acid-modified chitosan is dispersed between bamboo pulp fiber and sodium polyacrylate superabsorbent resin to improve the antibacterial properties inside the absorbent core layer. It also improves the dispersion stability of the antibacterial and odor-suppressing composite components in the absorbent core layer by forming an interface between the amino and hydroxyl groups on the chitosan molecular chain and the grafted thioctic acid structure.

[0008] Furthermore, the amount of thioctic acid modified chitosan added is 0.2 to 0.5 parts by weight. It is uniformly dispersed in a low amount inside the water-absorbing network composed of bamboo pulp fiber and sodium polyacrylate water-absorbing resin, and is not used as an independent coating layer on the surface of the water-absorbing core layer, so as to take into account the antibacterial synergistic effect, absorption and conduction performance and skin contact safety.

[0009] Furthermore, the thioctic acid-modified chitosan of this invention is not used as an exposed coating on the skin contact surface of the diaper, but rather as a solid functional component uniformly dispersed within the absorbent core layer and fixed by a polyvinyl alcohol binder and a bamboo pulp fiber network. A liquid-permeable nonwoven fabric layer is provided on the skin contact side of the absorbent core layer to reduce the migration of functional component particles during absorption and use, and to reduce the possibility of direct contact between the thioctic acid-modified chitosan and the user's skin.

[0010] Furthermore, the liquid-permeable nonwoven fabric layer is a hydrophilic hot-air nonwoven fabric or a hydrophilic spunbond nonwoven fabric with a basis weight of 10-30 g / m². It covers the flow channel and is composite and fixed along the periphery of the absorbent core layer body, so that the liquid can pass through the coating layer into the flow channel, while forming a physical isolation between the functional particles inside the absorbent core layer.

[0011] Further, the mass ratio of lipoic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, and chitosan is 1–1.3: 2.7–2.82: 1.57–1.65: 0.73–0.81.

[0012] Furthermore, the antibacterial and odor-suppressing composite component is composed of an inorganic antibacterial agent and an odor-suppressing adsorbent in a mass ratio of 1:(1-3); the inorganic antibacterial agent is nano-zinc oxide; and the odor-suppressing adsorbent is powdered activated carbon. By combining nano-zinc oxide with powdered activated carbon, the nano-zinc oxide inhibits bacteria that grow during the use of the absorbent core, while the porous structure of the powdered activated carbon adsorbs ammonia, amines, and other odor substances, thus forming a composite functional system that combines antibacterial and odor-suppressing properties.

[0013] Furthermore, the basis weight of the absorbent core layer is 80-250 g / m², and the lower surface of the absorbent core layer is laminated with a breathable and flow-guiding nonwoven fabric layer.

[0014] Furthermore, it includes the following steps: S1. Raw material pretreatment and mixing: Bamboo pulp fiber is dried at 60-80℃ for 1-2 hours, and then opened for 5-10 minutes. Bamboo pulp fiber, sodium polyacrylate superabsorbent resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components are weighed according to the weight parts, and stirred and mixed for 5-10 minutes to obtain a uniformly dispersed solid mixture. S2, Airflow web forming: The solid mixture is conveyed to the airflow web laying equipment for web laying and forming. The negative pressure of web laying is controlled at 2-3 kPa and the running speed of the forming mesh belt is 8-12 m / min, so that bamboo pulp fiber, sodium polyacrylate water-absorbing resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components are uniformly deposited to obtain a continuous fiber web blank. S3. Preparation and spraying of adhesive solution: Weigh out the polyvinyl alcohol binder according to the specified weight proportions, add the polyvinyl alcohol binder to deionized water, and stir for 30 to 60 minutes at 85 to 95°C and 300 to 600 r / min to completely dissolve the polyvinyl alcohol and obtain a polyvinyl alcohol binder solution. After cooling the polyvinyl alcohol binder solution to 40 to 50°C, spray it evenly onto the surface and interior of the continuous fiber web blank. S4. Pre-drying and pre-setting: After spraying polyvinyl alcohol binder in step S3, the continuous fiber web blank is pre-dried with hot air at 70-90℃ for 3-8 minutes to reduce the moisture content of the web blank to 10%-18%. Then, it is pre-pressed and shaped using a pre-pressing roller with a pre-pressing pressure of 0.05-0.20MPa and a pre-pressing roller linear speed of 5-15m / min to obtain a structurally stable water-absorbing core blank. S5, hot pressing molding of the guide groove: The absorbent core blank obtained in step S4 is roll-formed using a hot press roller with a raised ridge structure on its surface, so that the raised ridge structure is pressed into the upper surface of the absorbent core blank to form a number of continuously extending guide grooves; the depth of the guide groove is 0.5-3mm, the groove opening width is 1-5mm, and the distance between two adjacent guide grooves is 5-20mm. S6. Final drying and composite setting: The absorbent core blank with the flow channel obtained in step S5 is hot-air dried at 100-120℃ for 3-6 minutes to reduce its moisture content to 6%-10%. After cooling to room temperature, a breathable and flow-guiding nonwoven fabric layer is laminated onto the lower surface of the absorbent core blank, and a liquid-permeable nonwoven fabric layer is covered on its upper surface and laminated and fixed along the periphery. The lamination pressure is controlled at 0.1-0.3MPa and the lamination linear speed is 5-15m / min. Finally, it is cut and shaped to obtain the high dryness, odor-suppressing, antibacterial absorbent core material with the flow channel.

[0015] Further, in step S3, the mass concentration of the polyvinyl alcohol adhesive is 10% to 12%, the spraying pressure is 0.20 to 0.30 MPa, and the spraying amount of the polyvinyl alcohol adhesive is 50 to 100 g / m².

[0016] Furthermore, in step S5, the temperature of the hot press roller is 90-100℃, the roller pressure is 0.3-0.8MPa, and the roller linear speed is 5-12m / min.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: (1) The present invention provides a continuous extension of the guide groove on the upper surface of the absorbent core body, and controls the depth, groove width and groove spacing of the guide groove by hot pressing, so that the liquid diffuses preferentially along the direction of the guide groove after entering the core, and at the same time seeps into the internal absorbent network composed of bamboo pulp fiber and sodium polyacrylate absorbent resin, reducing the accumulation of liquid at a single liquid receiving point, which is beneficial to increase the effective absorption area of ​​the core and reduce surface residual liquid and back osmosis.

[0018] (2) In this invention, lipoic acid modified chitosan is introduced into the water-absorbing core layer at a low dosage of 0.2 to 0.5 parts by weight, and together with nano zinc oxide and powdered activated carbon, it forms a functional system. Lipoic acid modified chitosan and nano zinc oxide synergistically improve the antibacterial effect, and powdered activated carbon adsorbs odor molecules. While maintaining the antibacterial and odor-suppressing properties, it reduces the occupation of the absorption network by the functional components and reduces the risk of skin irritation that may be caused by excessive addition.

[0019] (3) The present invention uses airflow to lay the web so that each solid phase component is deposited evenly, and then sprays polyvinyl alcohol adhesive and performs pre-drying, pre-pressing and shaping, hot pressing in the guide groove and final drying treatment, so that the functional particles and superabsorbent polymer are kept relatively stably in the fiber network; the lower surface of the core is further composited with a breathable and flow-guiding nonwoven fabric layer, which can improve the integrity of the finished product in the processing, cutting and liquid absorption process.

[0020] (4) In this invention, thioctic acid modified chitosan is dispersed as a solid functional component inside the absorbent core layer and fixed with polyvinyl alcohol binder and bamboo pulp fiber network. This prevents the formation of an exposed thioctic acid modified chitosan coating on the skin contact surface of the diaper, which reduces the possibility of functional particles migrating to the core surface during liquid absorption, pressure and repeated deformation, and structurally reduces the chance of direct contact between the functional particles and the user's skin.

[0021] (5) The present invention provides a liquid-permeable nonwoven fabric layer on the skin contact side of the absorbent core layer body. The liquid can enter the continuous flow channel through the coating layer and further diffuse into the core layer. The coating layer also forms a physical isolation for the internal functional particles and together with the breathable flow-guiding nonwoven fabric layer on the lower surface, it forms an upper and lower coating structure, which is beneficial to take into account liquid conduction, particle retention, skin contact safety and overall stability of the finished product. Attached Figure Description

[0022] Figure 1 The process flow diagram is for a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow channel. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The bamboo pulp fiber is bleached bamboo pulp fiber supplied by Luzhou Yongfeng Pulp & Paper Co., Ltd.; sodium polyacrylate superabsorbent polymer (SABIP) is brand name AQUAKEEPSA60S; polyvinyl alcohol (PVA1788) is brand name PVA1788; nano zinc oxide particles are ≤50nm; and powdered activated carbon is 100-mesh powder. The liquid-permeable nonwoven fabric layer is made of hydrophilic hot-air nonwoven fabric or hydrophilic spunbond nonwoven fabric, with a basis weight of 10-30g / m².

[0025] Example 1 This embodiment provides a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a drainage channel. By weight, it includes 30 parts bamboo pulp fiber, 20 parts sodium polyacrylate water-absorbing resin, 0.20 parts thioctic acid-modified chitosan, 5 parts antibacterial and odor-suppressing composite component, and 5 parts polyvinyl alcohol binder. The antibacterial and odor-suppressing composite component is a compound of nano zinc oxide and powdered activated carbon in a mass ratio of 1:1. The target basis weight of the water-absorbing core layer is 80 g / m².

[0026] Preparation of lipoic acid modified chitosan: 50 mL of morpholine ethanesulfonic acid buffer (0.1 mol / L, pH 5.5) and 50 mL of anhydrous ethanol were added to a reactor, followed by 1.00 g of lipoic acid. The mixture was stirred at room temperature until dissolved. 2.70 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added and stirred until dissolved. Then, 1.57 g of N-hydroxysuccinimide was added and the mixture was stirred at room temperature for 3 h. Subsequently, 0.73 g of chitosan was added and the mixture was stirred at room temperature for 22 h. After the reaction was completed, the crude product was dialyzed in pure water for 4 days. The dialysate was freeze-dried to obtain lipoic acid modified chitosan.

[0027] S1. Dry the bamboo pulp fiber at 60℃ for 1 hour, then loosen it for 5 minutes; weigh the bamboo pulp fiber, sodium polyacrylate water-absorbing resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components according to the above weight parts, stir and mix for 5 minutes to obtain a solid mixture.

[0028] S2. The solid mixture is fed into the air-flow web-laying equipment, and the negative pressure of web-laying is controlled at 2.0 kPa and the running speed of the forming mesh belt is 8 m / min, so that the components are deposited uniformly to obtain a continuous fiber web blank.

[0029] S3. Add polyvinyl alcohol to deionized water to prepare a polyvinyl alcohol binder solution with a mass concentration of 10%. Stir at 85℃ and 300r / min for 30min until completely dissolved. After cooling to 40℃, spray evenly onto the surface and interior of the continuous fiber web blank at a spraying pressure of 0.20MPa and a spraying amount of 50g / m².

[0030] S4. The sprayed continuous fiber web blank is pre-dried with hot air at 70℃ for 3 minutes to reduce the moisture content of the web blank to 18%. Then, it is pre-pressed and shaped with a pre-pressing pressure of 0.05MPa and a pre-pressing roller speed of 5m / min to obtain the water-absorbing core blank.

[0031] S5. A hot press roller with a raised ridge structure is used to roll the water-absorbing core blank at 90℃, 0.30MPa and 5m / min to form a continuous guide groove on the upper surface; the guide groove depth is 0.5mm, the groove opening width is 1mm and the distance between adjacent guide grooves is 5mm.

[0032] S6. The absorbent core blank with the flow channel is dried with hot air at 100°C for 3 minutes to reduce the moisture content to 10%. After cooling to room temperature, a breathable and flow-guiding nonwoven fabric layer is laminated on its lower surface, and a hydrophilic hot air nonwoven fabric with a basis weight of 10 g / m² is covered on the upper surface and heat-sealed along the periphery. The lamination pressure is 0.10 MPa and the lamination linear speed is 5 m / min. After cutting and shaping, the absorbent core material of Example 1 is obtained.

[0033] Example 2 This embodiment provides a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a drainage channel. By weight, it includes 45 parts bamboo pulp fiber, 32 parts sodium polyacrylate water-absorbing resin, 0.35 parts thioctic acid-modified chitosan, 5.5 parts antibacterial and odor-suppressing composite component, and 6.5 parts polyvinyl alcohol binder. The antibacterial and odor-suppressing composite component is a compound of nano zinc oxide and powdered activated carbon in a mass ratio of 1:2. The target basis weight of the water-absorbing core layer is 165 g / m².

[0034] Preparation of lipoic acid modified chitosan: 55 mL of morpholine ethanesulfonic acid buffer (0.1 mol / L, pH 5.5) and 55 mL of anhydrous ethanol were added to a reactor, followed by 1.15 g of lipoic acid. The mixture was stirred at room temperature until dissolved. 2.76 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added and stirred until dissolved. Then, 1.61 g of N-hydroxysuccinimide was added and the mixture was stirred at room temperature for 3.5 h. Subsequently, 0.77 g of chitosan was added and the mixture was stirred at room temperature for 24 h. After the reaction was completed, the crude product was dialyzed in pure water for 4.5 days. The dialysate was then freeze-dried to obtain lipoic acid modified chitosan.

[0035] S1. Dry the bamboo pulp fiber at 70℃ for 1.5h, then loosen it for 8min; weigh the bamboo pulp fiber, sodium polyacrylate water-absorbing resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components according to the above weight parts, stir and mix for 8min to obtain a solid mixture.

[0036] S2. The solid mixture is fed into the air-flow web-laying equipment, and the negative pressure of web-laying is controlled at 2.5 kPa and the running speed of the forming mesh belt is 10 m / min, so that each component is deposited uniformly to obtain a continuous fiber web blank.

[0037] S3. Add polyvinyl alcohol to deionized water to prepare a polyvinyl alcohol binder solution with a mass concentration of 11%. Stir at 90℃ and 450r / min for 45min until completely dissolved. After cooling to 45℃, spray evenly onto the surface and interior of the continuous fiber web blank at a spraying pressure of 0.25MPa and a spraying amount of 75g / m².

[0038] S4. The sprayed continuous fiber web blank is pre-dried with hot air at 80℃ for 5 minutes to reduce the moisture content of the web blank to 14%. Then, it is pre-pressed and shaped with a pre-pressing pressure of 0.12MPa and a pre-pressing roller speed of 10m / min to obtain the water-absorbing core blank.

[0039] S5. A hot press roller with a raised ridge structure is used to roll the water-absorbing core blank at 95℃, 0.55MPa and 8m / min to form a continuous guide groove on the upper surface; the guide groove depth is 1.75mm, the groove opening width is 3mm and the distance between adjacent guide grooves is 12mm.

[0040] S6. The absorbent core blank with the flow channel is dried with hot air at 110°C for 4.5 min to reduce the moisture content to 8%. After cooling to room temperature, a breathable and flow-guiding nonwoven fabric layer is laminated on its lower surface, and a hydrophilic hot air nonwoven fabric with a basis weight of 20 g / m² is covered on the upper surface and heat-sealed along the periphery. The lamination pressure is 0.20 MPa and the lamination linear speed is 10 m / min. After cutting and shaping, the absorbent core material of Example 2 is obtained.

[0041] Example 3 This embodiment provides a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a drainage channel. By weight, it includes 60 parts bamboo pulp fiber, 45 parts sodium polyacrylate water-absorbing resin, 0.50 parts thioctic acid-modified chitosan, 6 parts antibacterial and odor-suppressing composite component, and 8 parts polyvinyl alcohol binder. The antibacterial and odor-suppressing composite component is a compound of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3. The target basis weight of the water-absorbing core layer is 250 g / m².

[0042] Preparation of lipoic acid modified chitosan: 60 mL of morpholine ethanesulfonic acid buffer (0.1 mol / L, pH 5.5) and 60 mL of anhydrous ethanol were added to a reactor, followed by 1.30 g of lipoic acid. The mixture was stirred at room temperature until dissolved. 2.82 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added and stirred until dissolved. Then, 1.65 g of N-hydroxysuccinimide was added and the mixture was stirred at room temperature for 4 h. Subsequently, 0.81 g of chitosan was added and the mixture was stirred at room temperature for 25 h. After the reaction was completed, the crude product was dialyzed in pure water for 5 days. The dialysate was freeze-dried to obtain lipoic acid modified chitosan.

[0043] S1. Dry the bamboo pulp fiber at 80℃ for 2 hours, then loosen it for 10 minutes; weigh the bamboo pulp fiber, sodium polyacrylate water-absorbing resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components according to the above weight parts, stir and mix for 10 minutes to obtain a solid mixture.

[0044] S2. The solid mixture is fed into the air-flow web-laying equipment, and the negative pressure of web-laying is controlled at 3.0 kPa and the running speed of the forming mesh belt is 12 m / min, so that each component is deposited uniformly to obtain a continuous fiber web blank.

[0045] S3. Add polyvinyl alcohol to deionized water to prepare a polyvinyl alcohol binder solution with a mass concentration of 12%. Stir at 95℃ and 600r / min for 60min until completely dissolved. After cooling to 50℃, spray evenly onto the surface and interior of the continuous fiber web blank at a spraying pressure of 0.30MPa and a spraying amount of 100g / m².

[0046] S4. The sprayed continuous fiber web blank is pre-dried with hot air at 90℃ for 8 minutes to reduce the moisture content of the web blank to 10%. Then, it is pre-pressed and shaped with a pre-pressing pressure of 0.20MPa and a pre-pressing roller speed of 15m / min to obtain the water-absorbing core blank.

[0047] S5. A hot press roller with a raised ridge structure is used to roll the water-absorbing core blank at 100℃, 0.80MPa and 12m / min to form a continuous guide groove on the upper surface; the guide groove depth is 3mm, the groove opening width is 5mm and the spacing between adjacent guide grooves is 20mm.

[0048] S6. The absorbent core blank with the flow channel is dried with hot air at 120°C for 6 minutes to reduce the moisture content to 6%. After cooling to room temperature, a breathable and flow-guiding nonwoven fabric layer is laminated on its lower surface, and a hydrophilic spunbond nonwoven fabric with a basis weight of 30 g / m² is covered on the upper surface and heat-sealed along the periphery. The lamination pressure is 0.30 MPa and the lamination linear speed is 15 m / min. After cutting and shaping, the absorbent core material of Example 3 is obtained.

[0049] Comparative Example 1 The difference between this comparative example and Example 3 is that 0.50 parts of lipoic acid modified chitosan were replaced with 0.50 parts of ordinary chitosan without lipoic acid modification, while the antibacterial and flavor-inhibiting compound component remained at 6 parts.

[0050] The antibacterial and flavor-suppressing compound is still composed of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3. Except for the differences mentioned above, the composition, dosage, and preparation process of all other raw materials are the same as in Example 3. Comparative Example 2 The difference between this comparative example and Example 3 is that the amount of lipoic acid modified chitosan added is reduced from 0.50 parts to 0.05 parts, which is lower than the 0.2 to 0.5 parts specified in this invention; the antibacterial and flavor-inhibiting compound component is still 6 parts.

[0051] The antibacterial and flavor-suppressing compound is still composed of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3. Apart from the differences mentioned above, the composition, dosage, and preparation process of the other raw materials are the same as in Example 3.

[0052] Comparative Example 3 The difference between this comparative example and Example 3 is that the amount of antibacterial and flavor-inhibiting compound component added is reduced from 6 parts to 2 parts, which is lower than the 5-6 parts specified in this invention; the amount of thioctic acid modified chitosan is still 0.50 parts.

[0053] The antibacterial and flavor-suppressing compound is still composed of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3. Apart from the differences mentioned above, the composition, dosage, and preparation process of the other raw materials are the same as in Example 3. Comparative Example 4 The difference between this comparative example and Example 3 is that the amount of lipoic acid modified chitosan added is increased from 0.50 parts to 1.00 parts, which is higher than the 0.2 to 0.5 parts specified in this invention; the amount of antibacterial and flavor-inhibiting compound component added is still 6 parts.

[0054] The antibacterial and flavor-suppressing composite component is still composed of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3.

[0055] Apart from the differences mentioned above, the composition, dosage, and preparation process of the other raw materials are the same as in Example 3.

[0056] Comparative Example 5 The difference between this comparative example and Example 3 is that the amount of antibacterial and flavor-inhibiting compound added is increased from 6 parts to 8 parts, which is higher than the 5-6 parts limited by this invention; the amount of thioctic acid modified chitosan added is still 0.50 parts.

[0057] The antibacterial and flavor-suppressing composite component is still composed of nano zinc oxide and powdered activated carbon in a mass ratio of 1:3. Apart from the differences mentioned above, the composition, dosage, and preparation process of the other raw materials are the same as in Example 3.

[0058] Comparative Example 6 The difference between this comparative example and Example 3 is that the hot pressing of the guide groove is not performed in step S5. Instead, a smooth hot pressing roller is used to roll the water-absorbing core blank in a plane, so that the upper surface of the resulting water-absorbing core material does not form a guide groove. Apart from the differences mentioned above, the composition, dosage, and preparation process of the other raw materials are the same as in Example 3.

[0059] Performance testing To verify the absorption and conduction performance, surface dryness, antibacterial properties, odor suppression properties, and skin irritation of the absorbent core material of the present invention, performance tests were conducted on the absorbent core materials obtained in Examples 1-3 and Comparative Examples 1-6. Before the tests, each sample was placed in an environment with a temperature of (23±2)℃ and a relative humidity of (50±5)% for 24 hours to equilibrate. The absorption and conduction, dryness, and odor suppression tests were all performed in parallel for 5 times and the average value was taken. The antibacterial test was performed in parallel for 3 times and the average value was taken. The skin irritation test was conducted according to the method specified in GB15979-2024.

[0060] 1. Liquid penetration time Test standard: Refer to the liquid penetration test principle of GB / T24218.8-2010 "Textiles - Nonwovens - Test methods - Part 8: Determination of liquid penetration time (simulated urine)" and adapt it according to the structure of the absorbent core sample.

[0061] Test Method: Cut a 100mm × 150mm sample and place it horizontally with the liquid-permeable nonwoven fabric layer facing upwards, so that the guide groove is located below the liquid-permeable nonwoven fabric layer. Place a liquid-adding ring with an inner diameter of 30mm at the center of the sample. Use a sodium chloride solution with a temperature of (23±2)℃ and a mass fraction of 0.9% as the simulated liquid. Add the solution in increments of (10.0±0.1)mL over 2 seconds. The timing starts when the simulated liquid first contacts the sample surface and ends when the visible continuous liquid film inside the liquid-adding ring completely disappears and all liquid enters the core. Record the liquid penetration time in seconds; the smaller the value, the faster the liquid penetration rate.

[0062] 2. Longitudinal flow diffusion length Testing standard: Evaluation is conducted using a quantitative comparative testing method for the core material of the flow channel.

[0063] Test Method: Cut an 80mm × 200mm sample, with the liquid-permeable nonwoven fabric layer facing upwards, and arrange the guide channel along the 200mm direction while keeping the sample horizontal. Add 10.0mL of 0.9% sodium chloride solution containing 0.01% water-soluble blue tracer to the geometric center of the sample in one go; start timing 30s from the end of the liquid addition, and measure the maximum continuous wetting length formed by the liquid along the direction of the guide channel. Five parallel samples are selected for testing for each sample, and the average value is taken as the longitudinal guide diffusion length, in mm; the larger the value, the stronger the longitudinal spreading ability of the guide channel for the liquid.

[0064] 3. Reverse osmosis volume Test standard: Refer to the evaluation principle of absorbency in GB / T28004.1-2021 "Diapers Part 1: Baby Diapers", and compare samples of equal mass for the core material.

[0065] Test method: Weigh (2.00±0.05) g of dry sample, lay the liquid-permeable nonwoven fabric layer facing upwards on a horizontal test platform, with the guide channel positioned below it; uniformly add 20.0 mL of 0.9% sodium chloride solution at (23±2) ℃ to the center of the sample, and let it stand for 5 min. Cover the receiving area with 5 layers of quantitative filter paper with a pre-weighed mass of m0, apply a uniform pressure of 4.0 kPa to the filter paper and maintain it for 2 min, and immediately weigh the mass m1 after removing the filter paper. Calculate the reverse osmosis amount as m1-m0, in g; the smaller the value, the better the surface dryness.

[0066] 4. Absorption rate Test standard: Refer to GB / T24218.6-2010 "Textiles - Nonwovens - Test methods - Part 6: Determination of absorbency".

[0067] Test method: Weigh the dry sample (m2) to an accuracy of 0.001 g; immerse the sample completely in a 0.9% sodium chloride solution at (23±2)℃ for 60 s to allow it to fully absorb the liquid; remove the sample and hang it vertically to drain the liquid for 120 s; then weigh the sample after liquid absorption (m3). Calculate the absorption ratio Q = (m3-m2) / m2, in g / g; the larger the value, the stronger the liquid retention capacity of the core per unit mass.

[0068] 5. Antibacterial rate Test standard: Refer to GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method".

[0069] Test method: *Escherichia coli* (ATCC 25922) and *Staphylococcus aureus* (ATCC 6538) were selected as test bacteria. 0.75 g of aseptically treated sample was placed in a sterile Erlenmeyer flask, and 70 mL of phosphate buffer and bacterial suspension were added to bring the initial bacterial concentration to 1 × 10⁻⁶. 5 ~5×10 5 CFU / mL; a blank control without sample was also set up. The samples were cultured at (37±1)℃ and 150 r / min for 18 h with shaking. The viable bacterial count (B) in the blank control and the viable bacterial count (A) in the sample group were determined using the plate count method. The antibacterial rate R was calculated as (BA) / B × 100%. The antibacterial rates against Escherichia coli and Staphylococcus aureus were reported separately.

[0070] 6. Ammonia deodorization rate Test standard: Refer to GB / T33610.2-2017 "Determination of deodorizing properties of textiles - Part 2: Detection tube method".

[0071] Test method: Place a 2.00g sample in a 5L gas sampling bag, and set up a blank bag without the sample. Fill both sampling bags with the same volume of dry air and inject ammonia gas to make the initial ammonia concentration approximately 100ppm. After sealing, let them stand at (23±2)℃ for 2h. Use an ammonia detection tube to measure the ammonia concentration Cb in the blank bag and the ammonia concentration Cs in the sample bag, respectively. Calculate the deodorization rate D according to the formula: D=(Cb-Cs) / Cb×100%; the larger the value, the stronger the ability to remove ammonia odors.

[0072] 7. Skin irritation test Testing standards: Samples were processed according to Appendix F of GB15979—2024 "Hygienic Requirements for Disposable Sanitary Products", and multiple complete skin irritation tests were conducted and results were determined in accordance with GB / T38496—2020 "Procedures and Methods for Toxicological Evaluation of Disinfectant Safety" and WS / T10009—2023 "Test Methods for Disinfectant Products".

[0073] Test Method: Four healthy adult New Zealand rabbits with intact skin were selected. 24 hours prior to the test, the hair on both sides of the spine on the back was removed, creating a complete skin test area of ​​approximately 3cm × 3cm on each side. Each finished sample with a liquid-permeable nonwoven fabric layer was cut into 2.5cm × 2.5cm pieces. After moistening with 0.5mL of sterile physiological saline, the liquid-permeable nonwoven fabric layer side was applied to the test area and secured. The other side was treated with sterile physiological saline without the sample as a control. Application was performed for 4 hours daily for 14 consecutive days. Erythema and edema reactions were observed and recorded after each sample removal. After the last application, observation continued for 24 hours and 48 hours. The degree of erythema and edema was evaluated on a scale of 0 to 4. The average irritation index was calculated for each animal and at each observation time point. An average irritation index less than 0.5 was considered non-irritating, and 0.5 to less than 2.0 was considered mildly irritating.

[0074] Table 1: Absorption, diversion, and dryness performance tests of each embodiment and comparative example

[0075] Table 2: Antibacterial and Flavor-Inhibiting Performance Tests of Each Example and Comparative Example

[0076] Table 3: Skin Irritation Test

[0077] Table 1 shows that the liquid penetration time of Examples 1-3 was 2.5-2.7 s, the longitudinal diffusion length was 116-119 mm, and the reverse osmosis amount was 0.17-0.19 g. This indicates that even after reducing the amount of lipoic acid-modified chitosan to 0.2-0.5 parts, the composition ratio and the channel structure still exhibit good absorption and flow stability. Comparative Examples 1-3, using ordinary chitosan, reducing the amount of lipoic acid-modified chitosan to 0.05 parts, and reducing the amount of antibacterial and flavor-suppressing composite component to 2 parts, respectively, showed varying degrees of decrease in overall performance. In Comparative Examples 4 and 5, after increasing the amount of lipoic acid-modified chitosan or the antibacterial and flavor-suppressing composite component to above the specified range, the liquid penetration time increased to 3.0-3.5 s, the longitudinal diffusion length decreased to 105-111 mm, and the reverse osmosis amount increased to 0.23-0.29 g, while the absorption rate decreased to 23.7-24.8 g / g. This indicates that higher amounts of functional components are not necessarily better. In particular, after the diversion channel was removed in Comparative Example 6, the liquid penetration time increased to 5.6s, the longitudinal diversion diffusion length was only 76mm, and the reverse osmosis amount increased to 0.44g, indicating that the continuous diversion channel has a significant effect on promoting the rapid spread and infiltration of liquid and reducing surface reverse osmosis.

[0078] Table 2 further shows that the antibacterial rates against Escherichia coli and Staphylococcus aureus in Examples 1-3 still reached 98.5%-99.1% and 98.0%-98.7%, respectively, and the ammonia deodorization rate reached 91.6%-92.8%, indicating that a low amount of lipoic acid-modified chitosan can still form an effective synergy with nano-zinc oxide and powdered activated carbon. In Comparative Example 1, the antibacterial rate decreased significantly after using ordinary chitosan; in Comparative Example 2, after reducing the lipoic acid-modified chitosan to 0.05 parts, the antibacterial rates of the two bacteria decreased to 95.0% and 94.1%, respectively, proving that the antibacterial effect is maintained while controlling it at 0.2-0.5 parts. In Comparative Example 3, the antibacterial and deodorizing composite components decreased significantly after reducing the antibacterial and deodorizing rates; in Comparative Examples 4 and 5, although the corresponding functional components were increased, the antibacterial and deodorizing rates did not further improve, indicating that it is difficult to produce additional benefits beyond the specified range. Comparative Example 6 showed that the antibacterial and odor-suppressing properties remained at a high level even after the diversion channel was removed, indicating that the diversion channel mainly improves absorption, diffusion and drying performance, while the low-dosage lipoic acid modified chitosan and antibacterial and odor-suppressing composite components mainly undertake the antibacterial and deodorizing functions.

[0079] Table 3 shows that Examples 1-3 were all determined to be non-irritating, indicating that controlling the amount of lipoic acid-modified chitosan to 0.2-0.5 parts maintains good skin contact safety while preserving antibacterial and deodorizing effects. In Comparative Example 4, increasing the amount of lipoic acid-modified chitosan to 1.00 parts increased the average irritation index to 0.58; in Comparative Example 5, increasing the amount of the antibacterial and deodorizing composite component to 8 parts resulted in an average irritation index of 0.50, both showing mild irritation. This indicates that controlling the amount of the two functional components helps reduce the risk of skin irritation that may be caused by excessive functional materials. The above irritation tests used the side of the finished product's liquid-permeable nonwoven fabric layer as the contact surface, which more closely resembles the skin contact state during actual use of the diaper.

[0080] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0082] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A highly absorbent, dry, odor-suppressing, antibacterial, and moisture-absorbing core material with a flow channel, characterized in that, The product includes a water-absorbing core layer body, the upper surface of which is provided with several continuously extending guide grooves. The water-absorbing core layer body is composed of the following components by weight: 30-60 parts bamboo pulp fiber, 20-45 parts sodium polyacrylate water-absorbing resin, 0.2-0.5 parts thioctic acid modified chitosan, 5-6 parts antibacterial and odor-inhibiting composite components, and 5-8 parts polyvinyl alcohol binder. The flow channel is arranged along the direction of liquid conduction to guide the liquid to spread rapidly along the flow channel and seep into the interior of the water-absorbing core layer.

2. The high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove according to claim 1, characterized in that, The preparation method of the lipoic acid modified chitosan is as follows: 50-60 mL of morpholine ethanesulfonic acid buffer solution with a concentration of 0.1 mol / L and a pH of 5.5, anhydrous ethanol, and lipoic acid are added to a reactor and stirred at room temperature until completely dissolved. Then, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added and stirred until dissolved. After that, N-hydroxysuccinimide is added and stirred for 3-4 h. Finally, chitosan is added and stirred at room temperature for 22-25 h. After the reaction is completed, the crude product is dialyzed in pure water for 4-5 days, and the dialysate is freeze-dried to obtain lipoic acid modified chitosan.

3. The high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove according to claim 2, characterized in that, The mass ratio of lipoic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, and chitosan is 1-1.3:2.7-2.82:1.57-1.65:0.73-0.

81.

4. The high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove according to claim 1, characterized in that, The antibacterial and flavor-suppressing composite component is composed of an inorganic antibacterial agent and a flavor-suppressing adsorbent in a mass ratio of 1:(1-3); the inorganic antibacterial agent is nano zinc oxide; and the flavor-suppressing adsorbent is powdered activated carbon.

5. The high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove according to claim 1, characterized in that, The basis weight of the absorbent core layer is 80-250 g / m², and the lower surface of the absorbent core layer is laminated with a breathable and flow-guiding nonwoven fabric layer.

6. A method for preparing a high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Raw material pretreatment and mixing: Bamboo pulp fiber is dried at 60-80℃ for 1-2 hours, and then opened for 5-10 minutes. Bamboo pulp fiber, sodium polyacrylate superabsorbent resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components are weighed according to the weight parts, and stirred and mixed for 5-10 minutes to obtain a uniformly dispersed solid mixture. S2, Airflow web forming: The solid mixture is conveyed to the airflow web laying equipment for web laying and forming. The negative pressure of web laying is controlled at 2-3 kPa and the running speed of the forming mesh belt is 8-12 m / min, so that bamboo pulp fiber, sodium polyacrylate water-absorbing resin, thioctic acid modified chitosan and antibacterial and deodorizing composite components are uniformly deposited to obtain a continuous fiber web blank. S3. Preparation and spraying of adhesive solution: Weigh out the polyvinyl alcohol binder according to the weight proportions, add the polyvinyl alcohol binder to deionized water, and stir for 30 to 60 minutes at 85 to 95°C and 300 to 600 r / min to completely dissolve the polyvinyl alcohol and obtain the polyvinyl alcohol binder solution. After cooling the polyvinyl alcohol binder to 40-50°C, it is sprayed evenly onto the surface and interior of the continuous fiber web blank. S4. Pre-drying and pre-setting: After spraying polyvinyl alcohol binder in step S3, the continuous fiber web blank is pre-dried with hot air at 70-90℃ for 3-8 minutes to reduce the moisture content of the web blank to 10%-18%. Then, it is pre-pressed and shaped using a pre-pressing roller with a pre-pressing pressure of 0.05-0.20MPa and a pre-pressing roller linear speed of 5-15m / min to obtain a structurally stable water-absorbing core blank. S5, hot pressing molding of the guide groove: The absorbent core blank obtained in step S4 is roll-formed using a hot press roller with a raised ridge structure on its surface, so that the raised ridge structure is pressed into the upper surface of the absorbent core blank to form a number of continuously extending guide grooves; the depth of the guide groove is 0.5-3mm, the groove opening width is 1-5mm, and the distance between two adjacent guide grooves is 5-20mm. S6. Final drying and composite setting: The absorbent core blank with the flow channel obtained in step S5 is hot-air dried at 100-120℃ for 3-6 minutes to reduce its moisture content to 6%-10%. After cooling to room temperature, a breathable and flow-guiding nonwoven fabric layer is laminated onto the lower surface of the absorbent core blank, and a liquid-permeable nonwoven fabric layer is covered on its upper surface and laminated and fixed along the periphery. The lamination pressure is controlled at 0.1-0.3MPa and the lamination linear speed is 5-15m / min. Finally, it is cut and shaped to obtain the high dryness, odor-suppressing, antibacterial absorbent core material with the flow channel.

7. The preparation method of the high dryness, odor suppression, antibacterial, and water-absorbing core material with a flow guide groove according to claim 6, characterized in that, In step S3, the mass concentration of the polyvinyl alcohol adhesive is 10% to 12%, the spraying pressure is 0.20 to 0.30 MPa, and the spraying amount of the polyvinyl alcohol adhesive is 50 to 100 g / m².

8. The method for preparing the high-dryness, odor-suppressing, antibacterial, and water-absorbing core material with a flow-guiding groove according to claim 6, characterized in that, In step S5, the temperature of the hot press roller is 90-100℃, the roller pressure is 0.3-0.8MPa, and the roller linear speed is 5-12m / min.

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