Skin-core structure super-absorbent non-woven fabric and preparation method thereof

Abstract

According to the skin-core structure super-absorbent non-woven fabric and the preparation method, a fiber skin layer of the skin-core structure super-absorbent non-woven fabric can absorb a part of water and form a gel state to achieve the water storage effect, on the other hand, gaps between fibers can also be used for water storage, the two parts form a synergistic effect, and therefore the skin-core structure super-absorbent non-woven fabric is formed. Good water absorption and retention functions are achieved. In addition, the fiber component structure of the skin-core structure super-absorbent non-woven fabric disclosed by the invention is as follows: the skin layer is modified acrylic acid grafted polylactic acid, so that good water absorption and retention characteristics are provided; and the core layer is a common spunbond polymer, so that the good strength of the spunbond fiber is ensured. The skin-core structure fiber is synthesized through a coaxial compound machine, and then the skin-core structure super-absorbent non-woven fabric is prepared through web curtain forming and hot rolling in sequence, so that the non-woven fabric is excellent in water absorption performance and good in mechanical property, and the whole preparation process is simple and low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of nonwoven fabrics, and in particular to a super absorbent nonwoven fabric with a skin-core structure and a preparation method thereof. Background Art

[0002] Super absorbent fiber (SAF) is a new type of material that has emerged since the mid-1980s. It has excellent water absorption capacity and can absorb water at a rate of dozens to hundreds of times, or even higher. Currently, super absorbent nonwoven fabrics are generally prepared by solution spinning or melt spinning. The super absorbent fibers are then blended with other fibers and air-opened and combed into a web. The super absorbent nonwoven fabrics are prepared by acupuncture, hot pressing and other reinforcement techniques. They can be widely used in medical and sanitary materials, packaging materials, filtration and drying materials, and other fields.

[0003] For example, the publication number CN116446103A discloses a highly absorbent polyvinyl alcohol fiber nonwoven fabric and its preparation method, the method adopted is to first prepare uncrosslinked polyvinyl alcohol fiber by wet spinning of polyvinyl alcohol solution, then freeze-thaw cyclically to obtain low crosslinked highly absorbent polyvinyl alcohol fiber, and finally cut the fiber into short pieces and mix them with hydrophobic fibers to form a net to prepare super absorbent nonwoven fabric. This method first prepares highly absorbent fiber, then mixes and combs the absorbent fiber with conventional fiber to prepare super absorbent nonwoven fabric, the process is relatively complicated, and the overall mechanical properties are average. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a super absorbent nonwoven fabric with a skin-core structure which is simple to prepare and low in cost and a preparation method thereof.

[0005] To achieve the above object, the present invention provides a solution: a water-absorbent nonwoven fabric with a skin-core structure, characterized in that: The water-absorbent nonwoven fabric with a sheath-core structure is composed of spunbonded filaments, wherein the spunbonded filaments include a sheath layer and a core layer arranged inside and outside, wherein the sheath layer is an acrylic acid grafted polylactic acid copolymer, and the core layer is a polymer suitable for spunbonding process, wherein the volume ratio of the sheath-core layer to the core layer is 1:9-5:5.

[0006] Furthermore, the volume ratio of the skin layer to the core layer is 2:8 to 4:6.

[0007] Furthermore, the grafting rate of the acrylic acid grafted polylactic acid copolymer in the skin layer is 5-15%, and the relative molecular mass is 5×10 4 -8×10 4 The water absorption rate is 300-1000%.

[0008] Furthermore, the grafting rate of the acrylic acid grafted polylactic acid copolymer in the skin layer is 10-15%.

[0009] Furthermore, the polymer suitable for the spunbond process is polypropylene or polyethylene or polylactic acid or polyethylene terephthalate or polyurethane or polyolefin elastomer.

[0010] The present invention also includes a method for preparing a super absorbent nonwoven fabric with a skin-core structure, comprising the following steps: S1. Weigh a set amount of PLA, then dissolve PLA in a dichloromethane solution and stir for 8-12h, then heat to 40-60°C and reflux, and add an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2-3min to obtain a grafting solution with a content of 7-15%; S2. The grafted solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried to obtain a crude graft copolymer; S3. The copolymer is placed in an extractor, and then a chloroform solution is added to the extractor and mixed, and extracted for 12-16 hours, refluxed 5 times per hour, and then the residue after extraction is placed in an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the oven temperature is 40-60 ° C; S4. The skin layer spunbond acrylic acid grafted polylactic acid copolymer and the core layer spunbond are dried; S5. The skin layer spunbond material and the core layer spunbond material are transported to the metering pump and the coaxial spinning box for extrusion to form a skin-core structure fiber, and then the skin-core structure fiber is laid onto the mesh curtain by cold wind traction; S6. After the core-skin structure fibers in step S5 are laid through a web curtain, they are hot-rolled and bonded to form a core-skin structure super absorbent non-woven fabric.

[0011] Furthermore, in step S1, the grafting solution contains 20%-60% of acrylic acid monomer and 6%-15% of benzoyl peroxide.

[0012] Furthermore, in the step S4, the skin layer spunbond material and the core layer spunbond material are dried in a dryer at 90-105° C. respectively until the water content is less than 800 pm.

[0013] Furthermore, in step S5, the skin layer spunbond material and the core layer spunbond material are transported to the coaxial spinning manifold for extrusion by two metering pumps, wherein the spinning temperature of the core layer spunbond material is 180-240°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 230-630Kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160-200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 10% to 50% of the core layer.

[0014] Furthermore, in step S6, the core-skin structure fibers are hot-rolled and bonded by hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 80-160°C.

[0015] The beneficial effects of the present invention are as follows: the fibers of conventional water-absorbent spunbond nonwoven fabrics are hydrophilic but do not absorb water, and only rely on the gaps between the fibers to store water. If squeezed hard, water will seep out, and the overall water absorption capacity is limited. Compared with the traditional absorbent spunbond nonwoven fabric, the super absorbent nonwoven fabric with a skin-core structure disclosed by the present invention can absorb a part of the water in the fiber skin layer to form a gel state to achieve the effect of water storage. On the other hand, the gaps between the fibers can also store water. The two parts form a synergistic effect to achieve good water absorption and water retention functions. In addition, the fiber component structure of the super absorbent nonwoven fabric with a skin-core structure disclosed by the present invention is that the skin layer is modified acrylic grafted polylactic acid, which provides good water absorption and water retention properties; The core layer is a common spunbond polymer to ensure the good strength of the spunbond fiber. The core-skin structure fiber is synthesized by a coaxial compounding machine, and then passed through a mesh curtain and hot rolling in sequence to obtain the core-skin structure super absorbent nonwoven fabric of the present invention, so that the nonwoven fabric has excellent water absorption performance and good mechanical properties, and the entire preparation process is simple and low in cost.

[0016] Furthermore, in step S1, the grafting solution contains 20%-60% of acrylic acid monomer and 6%-15% of benzoyl peroxide.

[0017] Furthermore, in step S4, the skin layer spunbond material and the core layer spunbond material are dried in a dryer at 90-105° C. respectively until the water content is less than 800 pm.

[0018] Further, in step S5, the skin layer spunbond material and the core layer spunbond material are transported to the coaxial spinning box by two metering pumps for extrusion, wherein the spinning temperature of the core layer spunbond material is 180-240°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 230-630Kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160-200°C, and the corresponding ratio of the melt extrusion amount per unit area of ​​the spinneret is 1:9 to 5:5.

[0019] Furthermore, in step S6, the core-skin structure fibers are hot-rolled and bonded by hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 80-160°C. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Embodiment 1

[0022] A water-absorbent nonwoven fabric with a sheath-core structure is composed of spunbonded filaments. The spunbonded filaments include a sheath layer and a core layer arranged inside and outside. The sheath layer is an acrylic acid grafted polylactic acid copolymer, and the core layer is polypropylene. The volume ratio of the sheath to the core layer is 3:7.

[0023] In this embodiment, the grafting rate of acrylic acid grafted polylactic acid copolymer in the skin layer is 10-15%, and the relative molecular mass is 5×10 4 -8×10 4 .

[0024] The present embodiment also includes a method for preparing a super absorbent non-woven fabric with a skin-core structure, comprising the following steps: S1. weighing a set amount of PLA, then dissolving the PLA in a dichloromethane solution and stirring it for 12 hours, then heating it to 60°C and refluxing it, and adding an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2 minutes to prepare a grafting solution with a content of 7%; wherein the grafting solution contains 20% acrylic acid monomer and 6% benzoyl peroxide.

[0025] S2. The graft solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried in sequence to obtain a crude graft copolymer.

[0026] S3. Place the copolymer in an extractor, then add chloroform solution into the extractor and mix, extract for 12 hours, reflux 5 times every hour, and then put the residue after extraction into an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the temperature of the oven is 40°C.

[0027] S4. Drying the skin layer spunbond material acrylic acid grafted polylactic acid copolymer and the core layer spunbond material.

[0028] S5. Put the skin layer spunbond material and the core layer spunbond material into a dryer, heat it to 90°C, and then dry it until the moisture content is less than 800pm. Then, convey the skin layer spunbond material and the core layer spunbond material to the coaxial spinning box through two metering pumps at a set volume ratio for extrusion to form skin-core structure fibers. Finally, the skin-core structure fibers are laid on the mesh curtain after cold wind pulling. Among them, the spinning temperature of the core layer spunbond material is 200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 210kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 90kg / (h*m 2 ).

[0029] S6. After the core-skin structure fibers in step S5 are laid through a web curtain, they are hot-rolled and bonded through hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 80°C. Embodiment 2

[0030] A water-absorbent nonwoven fabric with a skin-core structure, the water-absorbent nonwoven fabric with a skin-core structure is composed of spunbonded filaments, the spunbonded filaments include a skin layer and a core layer arranged inside and outside, the skin layer is an acrylic acid grafted polylactic acid copolymer, the core layer is polypropylene, wherein the skin core and the core layer The volume ratio is 1:9.

[0031] In this embodiment, the grafting rate of acrylic acid grafted polylactic acid copolymer in the skin layer is 10-15%, and the relative molecular mass is 5×10 4 -8×10 4 .

[0032] The present embodiment also includes a method for preparing a super absorbent non-woven fabric with a skin-core structure, comprising the following steps: S1. weighing a set amount of PLA, then dissolving the PLA in a dichloromethane solution and stirring it for 12 hours, then heating it to 60°C and refluxing it, and adding an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2 minutes to prepare a grafting solution with a content of 7%; wherein the grafting solution contains 20% acrylic acid monomer and 6% benzoyl peroxide.

[0033] S2. The graft solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried in sequence to obtain a crude graft copolymer.

[0034] S3. Place the copolymer in an extractor, then add chloroform solution into the extractor and mix, extract for 12 hours, reflux 5 times every hour, and then put the residue after extraction into an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the temperature of the oven is 40°C.

[0035] S4. Drying the skin layer spunbond material acrylic acid grafted polylactic acid copolymer and the core layer spunbond material.

[0036] S5. Put the skin layer spunbond material and the core layer spunbond material into a dryer, heat it to 90°C, and then dry it until the moisture content is less than 800pm. Then, convey the skin layer spunbond material and the core layer spunbond material to the coaxial spinning box through two metering pumps at a set volume ratio for extrusion to form skin-core structure fibers. Finally, the skin-core structure fibers are laid on the mesh curtain after cold wind pulling. Among them, the spinning temperature of the core layer spunbond material is 200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 270kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 30kg / (h*m 2 ).

[0037] S6. After the core-skin structure fibers in step S5 are laid through a web curtain, they are hot-rolled and bonded through hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 130°C. Embodiment 3

[0038] A water-absorbent nonwoven fabric with a sheath-core structure is composed of spunbonded filaments. The spunbonded filaments include a sheath layer and a core layer arranged inside and outside. The sheath layer is an acrylic acid grafted polylactic acid copolymer, and the core layer is polypropylene. The volume ratio of the sheath to the core layer is 5:5.

[0039] In this embodiment, the grafting rate of acrylic acid grafted polylactic acid copolymer in the skin layer is 10-15%, and the relative molecular mass is 5×10 4 -8×10 4 .

[0040] The present embodiment also includes a method for preparing a super absorbent non-woven fabric with a skin-core structure, comprising the following steps: S1. weighing a set amount of PLA, then dissolving the PLA in a dichloromethane solution and stirring it for 12 hours, then heating it to 60°C and refluxing it, and adding an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2 minutes to prepare a grafting solution with a content of 7%; wherein the grafting solution contains 20% acrylic acid monomer and 6% benzoyl peroxide.

[0041] S2. The graft solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried in sequence to obtain a crude graft copolymer.

[0042] S3. Place the copolymer in an extractor, then add chloroform solution into the extractor and mix, extract for 12 hours, reflux 5 times every hour, and then put the residue after extraction into an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the temperature of the oven is 40°C.

[0043] S4. Drying the skin layer spunbond material acrylic acid grafted polylactic acid copolymer and the core layer spunbond material.

[0044] S5. Put the skin layer spunbond material and the core layer spunbond material into a dryer, heat it to 90°C, and then dry it until the moisture content is less than 800pm. Then, convey the skin layer spunbond material and the core layer spunbond material to the coaxial spinning box through two metering pumps at a set volume ratio for extrusion to form skin-core structure fibers. Finally, the skin-core structure fibers are laid on the mesh curtain after cold wind pulling. Among them, the spinning temperature of the core layer spunbond material is 200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 150kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160℃, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 150kg / (h*m 2 ).

[0045] S6. After the core-skin structure fibers in step S5 are laid through a web curtain, they are hot-rolled and bonded through hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 130°C. Embodiment 4

[0046] A water-absorbent nonwoven fabric with a skin-core structure, the water-absorbent nonwoven fabric with a skin-core structure is composed of spunbonded filaments, the spunbonded filaments include a skin layer and a core layer arranged inside and outside, the skin layer is an acrylic acid grafted polylactic acid copolymer, the core layer is polylactic acid, wherein the skin core and the core layer The volume ratio is 3:7.

[0047] In this embodiment, the grafting rate of acrylic acid grafted polylactic acid copolymer in the skin layer is 10-15%, and the relative molecular mass is 5×10 4 -8×10 4 .

[0048] The present embodiment also includes a method for preparing a super absorbent non-woven fabric with a skin-core structure, comprising the following steps: S1. weighing a set amount of PLA, then dissolving the PLA in a dichloromethane solution and stirring it for 12 hours, then heating it to 60°C and refluxing it, and adding an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2 minutes to prepare a grafting solution with a content of 7%; wherein the grafting solution contains 20% acrylic acid monomer and 6% benzoyl peroxide.

[0049] S2. The graft solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried in sequence to obtain a crude graft copolymer.

[0050] S3. Place the copolymer in an extractor, then add chloroform solution into the extractor and mix, extract for 12 hours, reflux 5 times every hour, and then put the residue after extraction into an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the temperature of the oven is 40°C.

[0051] S4. Drying the skin layer spunbond material acrylic acid grafted polylactic acid copolymer and the core layer spunbond material.

[0052] S5. Put the skin layer spunbond material and the core layer spunbond material into a dryer, heat it to 90°C, and then dry it until the moisture content is less than 800pm. Then, convey the skin layer spunbond material and the core layer spunbond material to the coaxial spinning box through two metering pumps at a set volume ratio for extrusion to form skin-core structure fibers. Finally, the skin-core structure fibers are laid on the mesh curtain after cold wind pulling. Among them, the spinning temperature of the core layer spunbond material is 200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 210kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 90kg / (h*m 2 ).

[0053] S6. After the core-skin structure fibers in step S5 are laid on a web curtain, they are hot-rolled and bonded by hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 100°C.

[0054] Comparative Example 1: The difference between Comparative Example 1 and Example 1 lies in the composition of the non-woven fabric and steps S5 and S6 of the preparation method, specifically: a water-absorbent non-woven fabric with a sheath-core structure, the water-absorbent non-woven fabric with a sheath-core structure is composed of spunbond filaments, the spunbond filaments include a sheath layer and a core layer arranged inside and outside, the sheath layer is polylactic acid, and the core layer is polypropylene, wherein the volume ratio of the sheath-core layer to the core layer is 3:7.

[0055] S5. Put the skin layer spunbond material and the core layer spunbond material into a dryer, heat it to 90°C, and then dry it until the moisture content is less than 800pm. Then, convey the skin layer spunbond material and the core layer spunbond material to the coaxial spinning box through two metering pumps at a set volume ratio for extrusion to form skin-core structure fibers. Finally, the skin-core structure fibers are laid on the mesh curtain after cold wind pulling. The spinning temperature of the core layer spunbond material is 200°C, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 210kg / (h*m 2 ), the spinning temperature of the skin spunbond material is 160°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 90kg / (h*m 2 ).

[0056] S6. After the core-sheath structure fibers are laid through a mesh curtain, they are hot-rolled and bonded through a hot rolling roller to form a core-sheath structure water-absorbent non-woven fabric, wherein the temperature of the hot rolling roller is 130°C.

[0057] Comparative Example 2: A single-component water-absorbent spunbond nonwoven fabric is made of the same spinning equipment as in Example 4, wherein the skin layer and the core layer spunbond materials are both made of polypropylene, wherein the volume ratio of the skin layer to the core layer is 3:7.

[0058] Preparation method: melt into polypropylene melt at 200℃ and transport it to the spunbond spinning box for spinning, then after cold wind pulling, lay the fiber net on the net curtain, the melt extrusion rate per unit area of ​​the spinneret corresponding to the skin spinning box is 210kg / (h*m 2 ), the melt extrusion rate per unit area of ​​the spinneret corresponding to the core layer spinning box is 90kg / (h*m 2 ).

[0059] S6. After the polypropylene spunbond fibers are laid through a mesh curtain, the core-skin structure fibers are hot-rolled and bonded through a hot calendering roller to form a core-skin structure water-absorbent non-woven fabric, wherein the temperature of the hot calendering roller is 130°C.

[0060] Through the "kiss roll" online finishing liquid application method, an oil agent containing a surfactant is applied to the surface of the polypropylene spunbond nonwoven fabric to reduce the surface tension of the polypropylene spunbond nonwoven fabric and achieve a water-absorbent effect.

[0061] In Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 and Comparative Example 2, the raw material masterbatch of the core layer is melted by a screw, pressurized by a metering pump and enters a spinning die, extruded by the spinning die, cooled by side blowing, and then stretched into a web, and then hot-rolled, slit, and wound to prepare a water-absorbent non-woven fabric with a gram weight of about 20 gsm. The non-woven fabric samples of the above-mentioned examples and comparative examples are tested for performance, wherein the water absorption rate and water absorption time are tested according to ISO 9073-6, the reverse osmosis is tested according to ISO 9073-17, and the breaking strength is tested according to ASTM D5035. The test results are shown in Table 1.

[0062] Table 1 Test data of examples and comparative examples From the comparison of the above experimental test data, we can obtain various index data such as water absorption rate, water absorption time, reverse osmosis, and breaking strength.

[0063] Comparing samples a, b, and c, the water absorption ratio is sample c>sample a>sample b, the water absorption time is sample c<sample a<sample b, the reverse osmosis amount is sample c<sample a<sample b, and the breaking strength is sample b>sample a>sample c. It can be concluded that the skin-core structure super absorbent non-woven fabric disclosed in the present invention has good water absorption performance in the skin-core structure ratio of 1:9 to 5:5, wherein the skin layer is used as the water absorption layer, and the larger the proportion of this layer, the better the water absorption performance; and the core layer is used as the strong support layer, and the larger the proportion of this layer, the better the strength performance.

[0064] Comparing sample a with sample d, the water absorption rate, water absorption time, reverse osmosis amount, etc. of the two are similar, while the breaking strength is sample a>sample d. It can be concluded that the core layer of the skin-core structure super absorbent non-woven fabric disclosed by the present invention serves as a strong supporting layer, and the strength of the material determines the strength of the patented product. The strength of polypropylene is better than that of polylactic acid, so the breaking strength of sample a is better than that of sample d.

[0065] Comparing sample a with sample e and sample f, the skin layer of sample a is acrylic acid grafted polylactic acid copolymer, which has good water absorption and water retention effects. Therefore, the skin-core structure super absorbent non-woven fabric disclosed in the patent of the present invention has good water absorption performance (higher water absorption rate, shorter water absorption time) and good water retention performance (less reverse osmosis); and the skin layer of sample e is polylactic acid, because it has a certain hydrophilicity, so water droplets can enter the fiber gaps and achieve a certain water absorption performance, but will reverse osmosis if squeezed hard; sample f is a single-component polypropylene spunbond non-woven fabric, which itself exhibits hydrophobicity. After a layer of coating containing a surfactant is applied on its surface, it has hydrophilicity, and water droplets can enter the fiber gaps and achieve a certain It has a certain water absorption performance, but it will seep out if you squeeze it hard.

[0066] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any technician familiar with the art can use the above disclosed technical content to make more possible changes and modifications to the technical solution of the present invention without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent and equivalent changes made according to the ideas of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A water-absorbent nonwoven fabric with a skin-core structure, characterized in that: The water-absorbent nonwoven fabric with a sheath-core structure is composed of spunbonded filaments, wherein the spunbonded filaments include a sheath layer and a core layer arranged inside and outside, wherein the sheath layer is an acrylic acid grafted polylactic acid copolymer, and the core layer is a polymer suitable for spunbonding process, wherein the volume ratio of the sheath-core layer to the core layer is 1:9-5:

5.

2. The water-absorbent nonwoven fabric with a skin-core structure according to claim 1, characterized in that: The grafting rate of acrylic acid grafted polylactic acid copolymer in the skin layer is 5-15%, and the relative molecular mass is 5×10 4 -8×10 4 The water absorption rate is 300~1000%.

3. The water-absorbent nonwoven fabric with a skin-core structure according to claim 1, characterized in that: The polymer suitable for the spunbond process is polypropylene or polyethylene or polylactic acid or polyethylene terephthalate or polyurethane or polyolefin elastomer.

4. A method for preparing a super absorbent nonwoven fabric with a skin-core structure, characterized in that: The following steps are involved: S1. Weigh a set amount of PLA, then dissolve PLA in a dichloromethane solution and stir for 8-12h, then heat to 40-60°C and reflux, and add an acrylic acid solution and a benzoyl peroxide solution to the mixed solution in step S1 three times within 2-3min to obtain a grafting solution with a content of 7-15%; S2. The grafted solution obtained in step S1 is washed with an ethanol solution, and then filtered and dried to obtain a crude graft copolymer; S3. The copolymer is placed in an extractor, and then a chloroform solution is added to the extractor and mixed, and extracted for 12-16 hours, refluxed 5 times per hour, and then the residue after extraction is placed in an oven for drying to obtain an acrylic acid grafted polylactic acid copolymer, wherein the oven temperature is 40-60 ° C; S4. The skin layer spunbond acrylic acid grafted polylactic acid copolymer and the core layer spunbond are dried; S5. The skin layer spunbond material and the core layer spunbond material are transported to the metering pump and the coaxial spinning box for extrusion to form a skin-core structure fiber, and then the skin-core structure fiber is laid onto the mesh curtain by cold wind traction; S6. After the core-skin structure fibers in step S5 are laid through a web curtain, they are hot-rolled and bonded to form a core-skin structure super absorbent non-woven fabric.

5. The method for preparing a super absorbent nonwoven fabric with a skin-core structure according to claim 4, characterized in that: In step S1, the grafting solution contains 20%-60% of acrylic acid monomer and 6%-15% of benzoyl peroxide.

6. The method for preparing a super absorbent nonwoven fabric with a skin-core structure according to claim 4, characterized in that: In step S4, the skin layer spunbond material and the core layer spunbond material are dried in a dryer at 90-105° C. respectively until the water content is less than 800 pm.

7. The method for preparing a super absorbent nonwoven fabric with a skin-core structure according to claim 4, characterized in that: In step S5, the skin layer spunbond material and the core layer spunbond material are transported to the coaxial spinning box by two metering pumps for extrusion, wherein the spinning temperature of the core layer spunbond material is 180-240°C, and the corresponding melt extrusion rate per unit area of ​​the spinneret is 230-630 kg / (h*m 2 ); The spinning temperature of the skin spunbond material is 160-200℃, and the corresponding melt extrusion amount per unit area of ​​the spinneret is 10%~50% of the core layer.

8. The method for preparing a super absorbent nonwoven fabric with a skin-core structure according to claim 4, characterized in that: In the step S6, the core-skin structure fibers are hot-rolled and bonded by hot-rolling rollers to form a core-skin structure super absorbent non-woven fabric, wherein the temperature of the hot-rolling rollers is 80-160°C.

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