A flow guide type spunlace material for sanitary facing and a preparation method thereof

Abstract

The application discloses a kind of sanitary facing layer water guide type spunlace material and preparation method thereof, comprising the following steps: step 1: (1) different molecular weight polyethylene glycol diacrylate is copolymerized with monomer, wet spinning is carried out, and zinc stearate aqueous dispersion is used to treat, to obtain superabsorbent fiber A, B;(2) polyethylene glycol diacrylate is copolymerized with monomer, modified cellulose fiber is added, wet spinning is carried out, and aluminum sulfate aqueous solution treatment, zinc stearate aqueous dispersion treatment are sequentially used, to obtain superabsorbent fiber C;Step 2: superabsorbent fiber A, superabsorbent fiber B, superabsorbent fiber C and fiber are respectively prepared into composite viscose fiber layer A, composite bamboo fiber layer B, composite bamboo fiber layer C;Hydrophilic PP fiber layer is laminated, spunlace treatment is carried out, dehydration is carried out, and drying treatment is carried out, to obtain water guide type spunlace material.The product of the application has higher moisture absorption capacity and anti-back seepage capacity.

Description

Technical Field

[0001] This invention relates to the field of textile manufacturing technology, specifically to a flow-guiding spunlace material for sanitary surface layers and its preparation method. Background Technology

[0002] With the development of the times, the requirements for women's hygiene products are becoming increasingly stringent; the sanitary surface layer is a key component that comes into direct contact with the skin, such as sanitary napkins; it plays a crucial role in the product's moisture absorption and backflow prevention capabilities. In existing technologies, most materials are single-layer or double-layered, which have limited moisture absorption and backflow prevention capabilities. To improve moisture absorption performance, most materials use polyacrylic acid superabsorbent fibers, but their salt resistance is generally poor, which affects their moisture absorption and backflow prevention capabilities.

[0003] In summary, addressing the aforementioned issues, developing a flow-guiding spunlace material for sanitary surfaces and its preparation method is of great significance. Summary of the Invention

[0004] In order to improve the hygroscopicity and backflow prevention of sanitary surface layers, the present invention provides a flow-guiding spunlace material for sanitary surface layers and its preparation method.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: A method for preparing a flow-guiding spunlace material for sanitary surfaces includes the following steps: Step 1: (1) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate, wet-spun, and treated with zinc stearate aqueous dispersion to obtain superabsorbent fiber A; (2) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid and potassium persulfate, wet-spun, and treated with zinc stearate aqueous dispersion to obtain superabsorbent fiber B; (3) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid and potassium persulfate, modified cellulose fiber is added, wet-spun, and treated with aluminum sulfate aqueous solution and zinc stearate aqueous dispersion in sequence to obtain superabsorbent fiber C; Step 2: (1) After opening the viscose fiber and superabsorbent fiber A, comb them into a web to obtain composite viscose fiber layer A; (2) After opening the bamboo fiber and superabsorbent fiber B, comb them into a web to obtain composite bamboo fiber layer B; (3) After opening the bamboo fiber and superabsorbent fiber C, comb them into a web to obtain composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydration, and drying to obtain the flow-guiding hydroentangling material.

[0006] In a further embodiment, the hydrophilic PP fiber layer is obtained by opening and carding hydrophilic PP fibers into a web; the specifications of the hydrophilic PP fibers are 1.67dt×38 / 51mm.

[0007] In a further embodiment, the average diameter of viscose fiber is 15.33 μm; the average diameter of bamboo fiber is 22.28 μm.

[0008] In a further embodiment, the process parameters for carding and web forming are as follows: feed roller speed is 0.55~0.60 m / min, cylinder speed is 500~600 m / min, randomizing roller speed is 5.1~5.2 m / min, doffer speed is 15~30 m / min, and coiling roller speed is 10.0~10.2 m / min.

[0009] In a more optimized manner, the molecular weight of polyethylene glycol diacrylate in the superabsorbent fiber A is 900-1100; In the superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700~900; In the superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400~600.

[0010] An optimized method for preparing the superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate, and potassium persulfate are added to deionized water at a mass ratio of 4:(8~10):(0.02~0.04):0.06, and polymerized at 60~70℃ for 5~7h to obtain a spinning solution A of 15~25wt%; the spinning solution A is filtered under pressure and coagulated in a coagulation bath of 10~15wt% calcium chloride aqueous solution at 40~50℃, and then heat-treated at 130~170℃ for 5~15min; subsequently, a 2~4wt% aqueous dispersion of zinc stearate is sprayed onto the surface and dried at 70~90℃ to obtain superabsorbent fiber A.

[0011] An optimized method for preparing the superabsorbent fiber B is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate are added to deionized water at a mass ratio of 4:(8~10):(0.01~0.02):(0.1~0.2):0.04, and polymerized at 60~70℃ for 4~6h to obtain a 15~25wt% spinning solution B; the 15~25wt% spinning solution B is pressure filtered and coagulated in a 10~15wt% calcium chloride aqueous solution coagulation bath at 40~50℃, and heat-treated at 130~170℃ for 5~15min; then, a 2~4wt% zinc stearate aqueous dispersion is sprayed onto the surface and dried at 70~90℃ to obtain the superabsorbent fiber B.

[0012] In a more optimized manner, the preparation method of the superabsorbent fiber C is as follows: Step 1: Cellulose fiber and γ-methacryloyloxypropyltrimethoxysilane are added to an ethanol aqueous solution at a mass ratio of 1:(0.03~0.05), reacted at 50~70℃ for 4~6h, washed and dried to obtain modified cellulose fiber; Step 2: Add acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate in a mass ratio of 4:(8~10):(0.01~0.02):(0.2~0.4):0.03 to deionized water. Add 0.005~0.03 wt% of modified cellulose fiber, which accounts for the total mass of the solute in spinning solution C. Polymerize at 60~70℃ for 4~6 hours to obtain 15~25 wt% spinning solution C. Filter the 15~25 wt% spinning solution C under pressure and coagulate it in a 10~15 wt% calcium chloride aqueous solution coagulation bath at 40~50℃. Heat treat at 130~170℃ for 5~15 minutes to obtain modified superabsorbent fiber. Step 3: Spray the surface of the modified superabsorbent fiber with 2-5 wt% aluminum sulfate aqueous solution and 2-4 wt% zinc stearate aqueous dispersion in sequence, and dry at 70-90℃ to obtain superabsorbent fiber C.

[0013] In a further embodiment, the 2-4 wt% zinc stearate aqueous dispersion is obtained by purchasing zinc stearate emulsion and diluting it to 2-4 wt% before use.

[0014] In a further proposed solution, polyacrylic superabsorbent fibers will absorb water and swell when exposed to water. However, the existing hydroentangling process uses high-pressure water jet impact. If untreated superabsorbent fibers are used directly in the traditional hydroentangling process, the polyacrylic superabsorbent fibers will undergo water absorption and gelation during the preparation process, affecting the interlayer bonding force and resulting in a significant reduction in moisture absorption and anti-backflow capabilities. To address the aforementioned issues, this application pre-hydrophobically treats superabsorbent fibers A, B, and C with a 2-4 wt% aqueous dispersion of zinc stearate, combined with a specific cold water stepped low-pressure hydroentangling process. This prevents the superabsorbent fibers A, B, and C from swelling upon contact with water during the hydroentangling process, which would affect the layer-to-layer bonding. Although the pre-hydrophobic treatment maintains interlayer stability, the water absorption capacity of superabsorbent fibers A, B, and C decreases. Therefore, this application utilizes drying at a specific temperature after hydroentangling to reduce the zinc stearate content and improve moisture absorption without affecting the inherent properties of the raw materials such as superabsorbent fiber A, superabsorbent fiber B, superabsorbent fiber C, and hydrophilic PP fiber.

[0015] In a more optimized manner, the mass ratio of viscose fiber to superabsorbent fiber A in the raw materials of the composite viscose fiber layer A is (8~9):(1~1.2); In the raw materials of the composite bamboo fiber layer B, the mass ratio of bamboo fiber to superabsorbent fiber B is (8~9):(1.3~1.6); In the raw materials of the composite bamboo fiber layer C, the mass ratio of bamboo fiber to superabsorbent fiber C is (8~9):(1.7~2.2).

[0016] In a more optimized manner, the process parameters for the hydroentangling treatment are as follows: hydroentangling is performed using cold water at 10~15℃; the pressure of the first hydroentangling stage is 8~10 bar; the pressure of the second hydroentangling stage is 15~18 bar; and the pressure of the third hydroentangling stage is 12~14 bar; the speed of the sizing screen is 4~5 m / min; the distance between the water needles is 16~20 mm; and the water spray diameter is 0.2~0.3 mm.

[0017] Ideally, the drying process is performed at a temperature of 190-200°C for 10-15 minutes.

[0018] Ideally, the thickness of the hydrophilic PP fiber layer is 10~15 g / m. 2 The thickness of the composite viscose fiber layer A is 10~15 g / m. 2 The thickness of the composite bamboo fiber layer B is 9~12 g / m. 2 The thickness of the composite bamboo fiber layer C is 7~12 g / m. 2 .

[0019] More preferably, the superabsorbent fiber A includes polyethylene glycol diacrylate (1000) with a molecular weight of 900-1100. The superabsorbent fiber B includes polyethylene glycol diacrylate (700) with a molecular weight of 700-900. The superabsorbent fiber C includes polyethylene glycol diacrylate (400) with a molecular weight of 400-600.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This application uses a specific hydrophilic PP fiber layer, a composite viscose fiber layer A, a composite bamboo fiber layer B, and a composite bamboo fiber layer C stacked together, combined with a specific hydroentangling treatment, to form a flow-guiding hydroentangling material with good moisture absorption properties and anti-backflow ability. Compared with single-layer and double-layer structures, the specific four-layer structure of this application is beneficial to forming a specific flow gradient.

[0021] 1. In the composite viscose fiber layer A, viscose fiber and superabsorbent fiber A are used as raw materials in a specific mass ratio to form the composite viscose fiber layer A; viscose fiber has good hydrophilic properties and can evenly disperse liquids that have seeped through the surface layer; superabsorbent fiber A uses polyethylene glycol diacrylate with a molecular weight of 900~1100 as a crosslinking agent, which has a low degree of crosslinking, which is conducive to liquid penetration and prevents liquids from seeping back to the hydrophilic PP surface layer, thereby improving the moisture absorption and anti-backflow capabilities.

[0022] 2. In the composite bamboo fiber layer B, bamboo fiber and superabsorbent fiber B are used as raw materials in a specific mass ratio to form the composite bamboo fiber layer B. Bamboo fiber has a certain antibacterial effect and its diameter is larger than that of viscose fiber, which is conducive to further moisture absorption of liquid. A small amount of 2-acrylamide-2-methylpropanesulfonic acid is introduced into the superabsorbent fiber B, and polyethylene glycol diacrylate with a molecular weight of 700~900 is used as a crosslinking agent. The crosslinking density is moderate, which can absorb the blood of the composite viscose fiber layer A and continue to penetrate downwards, preventing liquid from accumulating in the composite viscose fiber layer A.

[0023] 3. In the composite bamboo fiber layer C, bamboo fiber and superabsorbent fiber C are used as raw materials in a specific mass ratio to form the composite bamboo fiber layer C. Compared to superabsorbent fiber B, superabsorbent fiber C incorporates more 2-acrylamide-2-methylpropanesulfonic acid and uses low molecular weight polyethylene glycol diacrylate (400-600) as a crosslinking agent, resulting in the highest crosslinking density and stronger water retention capacity, which is beneficial for improving anti-backflow ability. Adding modified cellulose fiber to the preparation of superabsorbent fiber C can improve the fiber's mechanical properties and spinnability, enhance its resistance to external extrusion, and further... To improve backflow prevention, the process of first spraying an aqueous aluminum sulfate solution onto superabsorbent fiber C, followed by an aqueous zinc stearate dispersion, achieves the following specific effects: Aluminum ions form a coordination complex with the carboxylic acid on the fiber surface. On one hand, this complex synergizes with 2-acrylamido-2-methylpropanesulfonic acid to inhibit the influence of salt ions on water absorption, thereby further enhancing salt resistance, maintaining the hygroscopicity of superabsorbent fiber C, and reducing stickiness. On the other hand, the coordination complex possesses certain deformation resistance, improving resistance to external extrusion and further enhancing backflow prevention. After spraying with the aqueous aluminum sulfate solution, zinc ions further provide hydrophobic protection to prevent the superabsorbent fiber from swelling during hydroentangling.

[0024] 4. This application adjusts the proportion of each superabsorbent fiber in the composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C, as well as the molecular weight and type and proportion of each crosslinking agent in superabsorbent fibers A, B, and C; composite viscose fiber layer A plays a role in high water absorption, composite bamboo fiber layer B plays a role in medium water absorption and salt resistance, and composite bamboo fiber layer C plays a role in high salt resistance and water retention. The layers have a gradient transition, which synergistically improves the overall moisture absorption and anti-backflow ability of the product. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention are described in detail and completely below. It should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other equivalent embodiments obtained by those skilled in the art based on the embodiments disclosed in this invention without creative effort are within the protection scope of this invention.

[0026] Example 1: A method for preparing a flow-guiding spunlace material for sanitary surfaces, comprising the following steps: Step 1: (1) The preparation method of superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate are added to deionized water in a mass ratio of 4:9:0.02:0.06 and polymerized at 65°C for 6.5h to obtain 20wt% spinning solution A; 20wt% spinning solution A is filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C, and heat-treated at 150°C for 10min; then the surface is sprayed with 3wt% zinc stearate aqueous dispersion and dried at 80°C to obtain superabsorbent fiber A; (2) Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water in a mass ratio of 4:9:0.01:0.1:0.04 and polymerized at 65°C for 5 hours to obtain 20wt% spinning solution B. The 20wt% spinning solution B was filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C. It was then heat-treated at 150°C for 10 minutes. Subsequently, a 3wt% zinc stearate aqueous dispersion was sprayed onto the surface and dried at 80°C to obtain superabsorbent fiber B. (3) Cellulose fibers and γ-methacryloxypropyltrimethoxysilane were added to a 65wt% ethanol aqueous solution at a mass ratio of 1:0.04 and reacted at 60℃ for 5h. The mixture was then washed and dried to obtain modified cellulose fibers. Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water at a mass ratio of 4:9:0.01:0.2:0.03. The total mass of the solute in the spinning solution C was 0. 0.05 wt% modified cellulose fiber was polymerized at 65℃ for 5 h to obtain 20 wt% spinning solution C; the 20 wt% spinning solution C was filtered under pressure and coagulated in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45℃, and then heat-treated at 150℃ for 10 min to obtain modified superabsorbent fiber; the surface of the modified superabsorbent fiber was sequentially sprayed with 4 wt% aluminum sulfate aqueous solution and 3 wt% zinc stearate aqueous dispersion, and dried at 80℃ to obtain superabsorbent fiber C; Step 2: (1) Open and comb the hydrophilic PP fibers into a web to obtain a hydrophilic PP fiber layer; (2) Open and comb the viscose fiber and superabsorbent fiber A with a mass ratio of 8.5:1 to obtain a composite viscose fiber layer A; (3) Open and comb the bamboo fiber and superabsorbent fiber B with a mass ratio of 8.5:1.3 to obtain a composite bamboo fiber layer B; (4) Open and comb the bamboo fiber and superabsorbent fiber C with a mass ratio of 8.5:1.7 to obtain a composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydrate, and dry at 190℃ for 12 minutes to obtain the flow-guiding hydroentangling material. In Example 1 above, the thickness of the hydrophilic PP fiber layer is 12.5 g / m. 2 The thickness of composite viscose fiber layer A is 12.5 g / m. 2 The thickness of composite bamboo fiber layer B is 10.5 g / m². 2 The thickness of the composite bamboo fiber layer C is 9 g / m². 2 ; The hydrophilic PP fiber has a diameter of 1.67dt × 38 / 51mm; the viscose fiber has an average diameter of 15.33μm; and the bamboo fiber has an average diameter of 22.28μm. In superabsorbent fiber A, the molecular weight of polyethylene glycol diacrylate is 1000; in superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700; and in superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400. The process parameters for carding and web forming are: feed roller speed 0.58 m / min, cylinder speed 550 m / min, randomizing roller speed 5.15 m / min, doffer speed 22 m / min, and coiling roller speed 10.1 m / min; Process parameters for hydroentangling: use 12℃ cold water for hydroentangling, the pressure of the first hydroentangling is 9 bar, the pressure of the second hydroentangling is 16 bar, and the pressure of the third hydroentangling is 13 bar; the speed of the sizing screen is 4.5 m / min, the distance between water needles is 18 mm, and the diameter of the water spray is 0.25 mm.

[0027] Example 2: A method for preparing a flow-guiding spunlace material for sanitary surfaces, comprising the following steps: Step 1: (1) The preparation method of superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate are added to deionized water in a mass ratio of 4:9:0.03:0.06 and polymerized at 65°C for 6.5h to obtain 20wt% spinning solution A; 20wt% spinning solution A is filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C, and heat-treated at 150°C for 10min; then the surface is sprayed with 3wt% zinc stearate aqueous dispersion and dried at 80°C to obtain superabsorbent fiber A; (2) Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water in a mass ratio of 4:9:0.015:0.15:0.04 and polymerized at 65°C for 5 hours to obtain 20wt% spinning solution B. The 20wt% spinning solution B was filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C. It was then heat-treated at 150°C for 10 minutes. Subsequently, a 3wt% zinc stearate aqueous dispersion was sprayed onto the surface and dried at 80°C to obtain superabsorbent fiber B. (3) Cellulose fibers and γ-methacryloyloxypropyltrimethoxysilane were added to a 65wt% ethanol aqueous solution at a mass ratio of 1:0.04, reacted at 60℃ for 5h, washed and dried to obtain modified cellulose fibers; acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water at a mass ratio of 4:9:0.015:0.3:0.03, and the total mass of the solute in spinning solution C was 0. 0.018 wt% of modified cellulose fiber was polymerized at 65℃ for 5 h to obtain 20 wt% spinning solution C; 20 wt% spinning solution C was filtered under pressure and coagulated in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45℃, and then heat-treated at 150℃ for 10 min to obtain modified superabsorbent fiber; the surface of the modified superabsorbent fiber was sequentially sprayed with 4 wt% aluminum sulfate aqueous solution and 3 wt% zinc stearate aqueous dispersion, and dried at 80℃ to obtain superabsorbent fiber C; Step 2: (1) Open and comb the hydrophilic PP fibers into a web to obtain a hydrophilic PP fiber layer; (2) Open and comb the viscose fiber and superabsorbent fiber A with a mass ratio of 8.5:1.1 to obtain a composite viscose fiber layer A; (3) Open and comb the bamboo fiber and superabsorbent fiber B with a mass ratio of 8.5:1.45 to obtain a composite bamboo fiber layer B; (4) Open and comb the bamboo fiber and superabsorbent fiber C with a mass ratio of 8.5:2 to obtain a composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydrate, and dry at 190℃ for 12 minutes to obtain the flow-guiding hydroentangling material. In Example 2 above, the thickness of the hydrophilic PP fiber layer is 12.5 g / m. 2 The thickness of composite viscose fiber layer A is 12.5 g / m. 2 The thickness of composite bamboo fiber layer B is 10.5 g / m². 2 The thickness of the composite bamboo fiber layer C is 9 g / m². 2 ; The hydrophilic PP fiber has a diameter of 1.67dt × 38 / 51mm; the viscose fiber has an average diameter of 15.33μm; and the bamboo fiber has an average diameter of 22.28μm. In superabsorbent fiber A, the molecular weight of polyethylene glycol diacrylate is 1000; in superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700; and in superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400. The process parameters for carding and web forming are: feed roller speed 0.58 m / min, cylinder speed 550 m / min, randomizing roller speed 5.15 m / min, doffer speed 22 m / min, and coiling roller speed 10.1 m / min; Process parameters for hydroentangling: use 12℃ cold water for hydroentangling, the pressure of the first hydroentangling is 9 bar, the pressure of the second hydroentangling is 16 bar, and the pressure of the third hydroentangling is 13 bar; the speed of the sizing screen is 4.5 m / min, the distance between water needles is 18 mm, and the diameter of the water spray is 0.25 mm.

[0028] Example 3: A method for preparing a flow-guiding spunlace material for sanitary surfaces, comprising the following steps: Step 1: (1) The preparation method of superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate are added to deionized water in a mass ratio of 4:9:0.04:0.06 and polymerized at 65°C for 6.5h to obtain 20wt% spinning solution A; 20wt% spinning solution A is filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C, and heat-treated at 150°C for 10min; then the surface is sprayed with 3wt% zinc stearate aqueous dispersion and dried at 80°C to obtain superabsorbent fiber A; (2) Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water in a mass ratio of 4:9:0.02:0.2:0.04 and polymerized at 65°C for 5 hours to obtain 20wt% spinning solution B. The 20wt% spinning solution B was filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C. It was then heat-treated at 150°C for 10 minutes. Subsequently, a 3wt% zinc stearate aqueous dispersion was sprayed onto the surface and dried at 80°C to obtain superabsorbent fiber B. (3) Cellulose fibers and γ-methacryloyloxypropyltrimethoxysilane were added to a 65wt% ethanol aqueous solution at a mass ratio of 1:0.04, reacted at 60℃ for 5h, washed and dried to obtain modified cellulose fibers; acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water at a mass ratio of 4:9:0.02:0.4:0.03, and 0% of the total mass of the solute in spinning solution C was added. 0.03 wt% of modified cellulose fiber was polymerized at 65℃ for 5 h to obtain 20 wt% spinning solution C; 20 wt% spinning solution C was filtered under pressure and coagulated in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45℃, and then heat-treated at 150℃ for 10 min to obtain modified superabsorbent fiber; the surface of the modified superabsorbent fiber was sequentially sprayed with 4 wt% aluminum sulfate aqueous solution and 3 wt% zinc stearate aqueous dispersion, and dried at 80℃ to obtain superabsorbent fiber C; Step 2: (1) Open and comb the hydrophilic PP fibers into a web to obtain a hydrophilic PP fiber layer; (2) Open and comb the viscose fiber and superabsorbent fiber A with a mass ratio of 8.5:1.2 to obtain a composite viscose fiber layer A; (3) Open and comb the bamboo fiber and superabsorbent fiber B with a mass ratio of 8.5:1.6 to obtain a composite bamboo fiber layer B; (4) Open and comb the bamboo fiber and superabsorbent fiber C with a mass ratio of 8.5:2.2 to obtain a composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydrate, and dry at 190℃ for 12 minutes to obtain the flow-guiding hydroentangling material. In Example 3 above, the thickness of the hydrophilic PP fiber layer is 12.5 g / m. 2 The thickness of composite viscose fiber layer A is 12.5 g / m. 2 The thickness of composite bamboo fiber layer B is 10.5 g / m². 2 The thickness of the composite bamboo fiber layer C is 9 g / m². 2 ; The hydrophilic PP fiber has a diameter of 1.67dt × 38 / 51mm; the viscose fiber has an average diameter of 15.33μm; and the bamboo fiber has an average diameter of 22.28μm. In superabsorbent fiber A, the molecular weight of polyethylene glycol diacrylate is 1000; in superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700; and in superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400. The process parameters for carding and web forming are: feed roller speed 0.58 m / min, cylinder speed 550 m / min, randomizing roller speed 5.15 m / min, doffer speed 22 m / min, and coiling roller speed 10.1 m / min; The process parameters for hydroentangling are as follows: hydroentangling is performed using 12℃ cold water; the pressure of the first hydroentangling stage is 9 bar; the pressure of the second hydroentangling stage is 16 bar; and the pressure of the third hydroentangling stage is 13 bar; the speed of the sizing screen is 4.5 m / min; the distance between water needles is 18 mm; and the water spray diameter is 0.25 mm.

[0029] Comparative Example 1, based on Example 2, uses a conventional hydroentangling process, as follows: The process parameters for hydroentangling are as follows: room temperature deionized water is used; the pressure of the first hydroentangling stage is 25 bar; the pressure of the second hydroentangling stage is 35 bar; the pressure of the third hydroentangling stage is 45 bar; the speed of the sprue screen is 65 m / min; the distance between the water needles is 14 mm; and the spray diameter is 0.2 mm.

[0030] Comparative Example 2, based on Example 2, did not involve spraying the superabsorbent fibers in each layer with 3wt% zinc stearate aqueous dispersion for pre-hydrophobic treatment, as detailed below: (1) The preparation method of superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate are added to deionized water in a mass ratio of 4:9:0.03:0.06 and polymerized at 65°C for 6.5 h to obtain 20 wt% spinning solution A; 20 wt% spinning solution A is filtered under pressure and solidified in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45°C, and heat-treated at 150°C for 10 min; after cooling, superabsorbent fiber A is obtained; (2) Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water in a mass ratio of 4:9:0.015:0.15:0.04 and polymerized at 65°C for 5 hours to obtain a 20wt% spinning solution B. The 20wt% spinning solution B was filtered under pressure and solidified in a 12.5wt% calcium chloride aqueous solution coagulation bath at 45°C. The solidified solution was then heat-treated at 150°C for 10 minutes and cooled to obtain superabsorbent fiber B. (3) Cellulose fibers and γ-methacryloyloxypropyltrimethoxysilane were added to a 65wt% ethanol aqueous solution at a mass ratio of 1:0.04, reacted at 60℃ for 5h, washed and dried to obtain modified cellulose fibers; acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water at a mass ratio of 4:9:0.015:0.3:0.03, and a solvent accounting for C of the spinning solution was added. 0.018 wt% of modified cellulose fiber was polymerized at 65℃ for 5 h to obtain 20 wt% spinning solution C; 20 wt% spinning solution C was filtered under pressure and coagulated in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45℃, and then heat-treated at 150℃ for 10 min to obtain modified superabsorbent fiber; the surface of the modified superabsorbent fiber was sequentially sprayed with 4 wt% aluminum sulfate aqueous solution and dried at 80℃ to obtain superabsorbent fiber C; In Comparative Example 2 above, the untreated superabsorbent fibers A, B, and C could not form spunlace nonwoven materials.

[0031] Comparative Example 3, based on Example 2, adjusted the drying temperature after hydroentangling treatment to 140°C, as follows: Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydrate, and dry at 140℃ for 12 minutes to obtain the flow-guiding hydroentangling material.

[0032] Comparative Example 4, based on Example 2, uses a double-layer structure instead of a multi-layer structure, without adding composite viscose fiber layer A and composite bamboo fiber layer B, as follows: Step 1: Cellulose fibers and γ-methacryloyloxypropyltrimethoxysilane were added to a 65wt% ethanol aqueous solution at a mass ratio of 1:0.04, and reacted at 60℃ for 5 hours. After washing and drying, modified cellulose fibers were obtained. Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate were added to deionized water at a mass ratio of 4:9:0.015:0.3:0.03, accounting for 0.5% of the total mass of the solute in spinning solution C. 0.018 wt% of modified cellulose fiber was polymerized at 65℃ for 5 h to obtain 20 wt% spinning solution C; 20 wt% spinning solution C was filtered under pressure and coagulated in a 12.5 wt% calcium chloride aqueous solution coagulation bath at 45℃, and then heat-treated at 150℃ for 10 min to obtain modified superabsorbent fiber; the surface of the modified superabsorbent fiber was sequentially sprayed with 4 wt% aluminum sulfate aqueous solution and 3 wt% zinc stearate aqueous dispersion, and dried at 80℃ to obtain superabsorbent fiber C; Step 2: (1) Open and comb the hydrophilic PP fibers into a web to obtain a hydrophilic PP fiber layer; (2) Open and comb the bamboo fiber and superabsorbent fiber C with a mass ratio of 8.5:2 into a web to obtain a composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer and the composite bamboo fiber layer C in order from top to bottom, perform hydroentangling treatment, dehydrate, and dry at 190℃ for 12 minutes to obtain the flow-guiding hydroentangling material. In Example 2 above, the thickness of the hydrophilic PP fiber layer is 12.5 g / m. 2 The thickness of the composite bamboo fiber layer C is 9 g / m². 2 ; The hydrophilic PP fiber has a specification of 1.67dt×38 / 51mm; the bamboo fiber has an average diameter of 22.28μm. In superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400; The process parameters for carding and web forming are: feed roller speed 0.58 m / min, cylinder speed 550 m / min, randomizing roller speed 5.15 m / min, doffer speed 22 m / min, and coiling roller speed 10.1 m / min; Process parameters for hydroentangling: use 12℃ cold water for hydroentangling, the pressure of the first hydroentangling is 9 bar, the pressure of the second hydroentangling is 16 bar, and the pressure of the third hydroentangling is 13 bar; the speed of the sizing screen is 4.5 m / min, the distance between water needles is 18 mm, and the diameter of the water spray is 0.25 mm.

[0033] Comparative Example 5, based on Example 2, adjusted the molecular weight of polyethylene glycol diacrylate in each layer as follows: in superabsorbent fiber A, the molecular weight of polyethylene glycol diacrylate is 400; in superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700; in superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 1000.

[0034] Comparative Example 6, based on Example 2, shows an excess of superabsorbent fibers in each layer, as detailed below: Step 2: (1) Open and comb the hydrophilic PP fibers into a web in sequence to obtain a hydrophilic PP fiber layer; (2) Open and comb the viscose fiber and superabsorbent fiber A with a mass ratio of 8.5:2 to obtain a composite viscose fiber layer A; (3) Open and comb the bamboo fiber and superabsorbent fiber B with a mass ratio of 8.5:3 to obtain a composite bamboo fiber layer B; (4) Open and comb the bamboo fiber and superabsorbent fiber C with a mass ratio of 8.5:4 to obtain a composite bamboo fiber layer C.

[0035] Comparative Example 7, based on Example 2, except that superabsorbent fiber C is replaced with superabsorbent fiber B, and the rest remain the same.

[0036] Performance testing: The moisture absorption and anti-backflow properties of the flow-guiding spunlace materials prepared in Examples 1-3 and Comparative Examples 1 and 3-7 were tested. (1) Moisture absorption performance test: With the surface tension set at 68~72mN / m, a 9g / L sodium chloride aqueous solution was prepared at room temperature using a liquid penetration tester. The liquid penetration time of the sample was tested in GB / T24218.8-2010 to evaluate the moisture absorption performance of the sample. The test results are shown in Table 1. (2) Anti-backflow performance: Prepare a test solution as synthetic blood according to Appendix B of GB / T39391-2020; pour the test solution into the sample and test the liquid residue of the sample according to GB / T30133-2022; to evaluate the anti-backflow performance of the sample. The test results are shown in Table 1. Table 1

[0037] Conclusions: As shown in Table 1 above, the spunlace material prepared in this application has good moisture absorption and anti-backflow properties. Data from Comparative Example 1 shows that conventional spunlace technology affects the interlayer bonding strength of each layer and the performance of the superabsorbent fibers, resulting in a decrease in overall performance. Data from Comparative Example 3 shows that even with the drying temperature adjusted to 140℃ after spunlace treatment, the hydrophobic properties are still present, but the overall performance is significantly reduced. Data from Comparative Example 4 shows that replacing the multi-layer structure with a double-layer structure, without adding composite viscose fiber layer A and composite bamboo fiber layer B, results in a double-layer structure. While the liquid penetration time is shortened, it is not conducive to multi-gradient staged backflow prevention and salt resistance, resulting in a significant decrease in overall performance. According to the data from Comparative Example 5, adjusting the molecular weight of polyethylene glycol diacrylate in each layer results in slower water absorption in the upper layer and poorer salt resistance in the lower layer, leading to a decrease in overall performance. According to the data from Comparative Example 6, there is an excess of superabsorbent fibers in each layer, resulting in an overly dense network and decreased bonding strength between layers, thus reducing overall performance. According to the data from Comparative Example 7, replacing superabsorbent fiber C with superabsorbent fiber B, and lacking aluminum sulfate, modified cellulose fibers, etc., reduces salt resistance and overall performance.

[0038] Those skilled in the art should understand that the present invention is not limited to the details of the exemplary embodiments described above. Other specific embodiments may be adopted without departing from the spirit and essential characteristics of the invention. Therefore, the above embodiments should be considered exemplary only and not restrictive, and the scope of protection of the present invention is defined by the appended claims, not by the foregoing description. All changes within the meaning and scope of the claims and their equivalents should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a flow-guiding spunlace material for sanitary surface layers, characterized in that: Includes the following steps: Step 1: (1) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate and potassium persulfate, wet-spun, and treated with zinc stearate aqueous dispersion to obtain superabsorbent fiber A; (2) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid and potassium persulfate, wet-spun, and treated with zinc stearate aqueous dispersion to obtain superabsorbent fiber B; (3) Polyethylene glycol diacrylate is copolymerized with acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid and potassium persulfate, modified cellulose fiber is added, wet-spun, and treated with aluminum sulfate aqueous solution and zinc stearate aqueous dispersion in sequence to obtain superabsorbent fiber C; Step 2: (1) After opening the viscose fiber and superabsorbent fiber A, comb them into a web; (1) Obtain composite viscose fiber layer A; (2) After opening bamboo fiber and super absorbent fiber B, comb them into a web; obtain composite bamboo fiber layer B; (3) After opening bamboo fiber and super absorbent fiber C, comb them into a web; obtain composite bamboo fiber layer C; Step 3: Stack the hydrophilic PP fiber layer, composite viscose fiber layer A, composite bamboo fiber layer B, and composite bamboo fiber layer C in the order from top to bottom, perform hydroentangling treatment, dehydration, and drying to obtain the flow-guiding hydroentangling material.

2. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: In the superabsorbent fiber A, the molecular weight of polyethylene glycol diacrylate is 900~1100; In the superabsorbent fiber B, the molecular weight of polyethylene glycol diacrylate is 700~900; In the superabsorbent fiber C, the molecular weight of polyethylene glycol diacrylate is 400~600.

3. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: The preparation method of the superabsorbent fiber A is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate, and potassium persulfate are added to deionized water at a mass ratio of 4:(8~10):(0.02~0.04):0.06, and polymerized at 60~70℃ for 5~7h to obtain a spinning solution A of 15~25wt%; the spinning solution A of 15~25wt% is filtered under pressure and solidified in a coagulation bath of 10~15wt% calcium chloride aqueous solution at 40~50℃, and heat-treated at 130~170℃ for 5~15min; then the surface is sprayed with a 2~4wt% aqueous dispersion of zinc stearate and dried at 70~90℃ to obtain superabsorbent fiber A.

4. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: The preparation method of the superabsorbent fiber B is as follows: Acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate are added to deionized water at a mass ratio of 4:(8~10):(0.01~0.02):(0.1~0.2):0.04, and polymerized at 60~70℃ for 4~6h to obtain a spinning solution B of 15~25wt%; the spinning solution B of 15~25wt% is filtered under pressure and solidified in a coagulation bath of 10~15wt% calcium chloride aqueous solution at 40~50℃, and heat-treated at 130~170℃ for 5~15min; then the surface is sprayed with a 2~4wt% zinc stearate aqueous dispersion and dried at 70~90℃ to obtain superabsorbent fiber B.

5. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: Step 1: Add cellulose fibers and γ-methacryloyloxypropyltrimethoxysilane in a mass ratio of 1:(0.03~0.05) to an aqueous ethanol solution, react at 50~70℃ for 4~6h, wash and dry to obtain modified cellulose fibers; Step 2: Add acrylamide, acrylic acid, polyethylene glycol diacrylate, 2-acrylamide-2-methylpropanesulfonic acid, and potassium persulfate in a mass ratio of 4:(8~10):(0.01~0.02):(0.2~0.4):0.03 to deionized water. Add 0.005~0.03 wt% of modified cellulose fiber, which accounts for the total mass of the solute in spinning solution C. Polymerize at 60~70℃ for 4~6 hours to obtain 15~25 wt% spinning solution C. Filter the 15~25 wt% spinning solution C under pressure and coagulate it in a 10~15 wt% calcium chloride aqueous solution coagulation bath at 40~50℃. Heat treat at 130~170℃ for 5~15 minutes to obtain modified superabsorbent fiber. Step 3: Spray the surface of the modified superabsorbent fiber with 2-5 wt% aluminum sulfate aqueous solution and 2-4 wt% zinc stearate aqueous dispersion in sequence, and dry at 70-90℃ to obtain superabsorbent fiber C.

6. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: In the raw materials of the composite viscose fiber layer A, the mass ratio of viscose fiber to superabsorbent fiber A is (8~9):(1~1.2); In the raw materials of the composite bamboo fiber layer B, the mass ratio of bamboo fiber to superabsorbent fiber B is (8~9):(1.3~1.6); In the raw materials of the composite bamboo fiber layer C, the mass ratio of bamboo fiber to superabsorbent fiber C is (8~9):(1.7~2.2).

7. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: The process parameters for the hydroentangling treatment are as follows: hydroentangling is performed using cold water at 10~15℃; the pressure of the first hydroentangling stage is 8~10 bar; the pressure of the second hydroentangling stage is 15~18 bar; and the pressure of the third hydroentangling stage is 12~14 bar; the speed of the sizing screen is 4~5 m / min; the distance between the water needles is 16~20 mm; and the water spray diameter is 0.2~0.3 mm.

8. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: The drying process is carried out at a temperature of 190~200℃ for 10~15 minutes.

9. The method for preparing a flow-guiding spunlace material for sanitary surfaces according to claim 1, characterized in that: The thickness of the hydrophilic PP fiber layer is 10~15g / m. 2 The thickness of the composite viscose fiber layer A is 10~15 g / m. 2 The thickness of the composite bamboo fiber layer B is 9~12 g / m. 2 The thickness of the composite bamboo fiber layer C is 7~12 g / m. 2 .

10. The spunlace material prepared by the method for preparing a hygienic surface layer according to any one of claims 1 to 9.

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