Melt-blown cloth absorption core and preparation method thereof

Abstract

The invention discloses a melt-blown cloth absorption core and a preparation method thereof, and relates to the field of hygienic products. The melt-blown cloth absorption core comprises an upper coating layer, an SAPO / fluff pulp absorber and a lower coating layer which are sequentially arranged, the upper coating layer and the lower coating layer are both made of melt-blown non-woven cloth subjected to hydrophilic finishing, and the SAPO / fluff pulp absorber is obtained by evenly mixing modified wood pulp fibers and super absorbent resin according to the weight ratio of (10-30): (20-80). The melt-blown non-woven fabric is subjected to hydrophilic modification by grafting acrylamide and chitosan, and the modified wood pulp fibers are obtained by grafting wood pulp fibers and carboxymethyl cellulose. The absorption core body prepared by the invention keeps good liquid absorption speed and softness, does not lump, does not leak powder, and reduces back seepage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sanitary products, in particular to a melt-blown fabric absorbent core and a preparation method thereof. BACKGROUND

[0002] The absorbent core is commonly used in sanitary products such as paper diapers and sanitary napkins, and has the functions of absorbing and storing liquid, and is an indispensable component. The classification of the absorbent core includes two types of traditional fluff pulp core and new type of composite absorbent core.

[0003] The traditional fluff pulp absorbent core is mainly composed of a cover layer, SAP and fluff pulp, and the specific structure is an upper cover layer, an SAP / fluff pulp absorbent body and a lower cover layer, wherein the cover layer is usually made of non-woven fabric, dust-free paper and wet-strength sanitary paper. In use, the non-woven fabric has good softness, but has poor compatibility with the fluff pulp, which easily leads to delamination, and the problem of lumping and cotton breakage occurs during use. The air-through non-woven fabric has relatively large pores, and the SAP also leaks, i.e. the phenomenon of “powder leakage” occurs. The wet-strength sanitary paper has good compatibility with the absorbent body and strong adhesive interface, but the wet-strength sanitary paper has low tensile strength and is easily hardened after wetting. The dust-free paper has good softness and good compatibility with the absorbent body, but because the dust-free paper has good water retention, the water retained by the dust-free paper itself is difficult to be absorbed by the SAP, so the surface of the absorbent core is relatively wet during use.

[0004] Based on the deficiencies of the prior art, a new type of fluff pulp absorbent core is needed, which improves the cover layer of the absorbent core, maintains good liquid absorption speed and softness, has good compatibility with the fluff pulp, and keeps the surface dry without lumping. SUMMARY

[0005] In order to solve the above problems, the present application provides a melt-blown fabric absorbent core and a preparation method thereof.

[0006] The melt-blown fabric absorbent core and the preparation method thereof provided by the present application adopt the following technical scheme: In a first aspect, the present application discloses a melt-blown fabric absorbent core, which comprises an upper cover layer, an SAP / fluff pulp absorbent body and a lower cover layer arranged in sequence, wherein the upper cover layer and the lower cover layer are both made of melt-blown non-woven fabric subjected to hydrophilic finishing, and the SAP / fluff pulp absorbent body is obtained by uniformly mixing modified wood pulp fibers and superabsorbent resin at a weight ratio of (10-30):(20-80), wherein the melt-blown non-woven fabric is subjected to hydrophilic modification by grafting acrylamide and chitosan, and the modified wood pulp fibers are obtained by grafting wood pulp fibers and carboxymethyl cellulose.

[0007] By adopting the technical scheme, the covering layer of the absorbent core body is selected from hydrophilic finished melt-blown non-woven fabric, the melt-blown non-woven fabric has good softness, small fiber diameter and small pores, and the SAP leakage phenomenon does not occur, and the melt-blown non-woven fabric can provide good liquid filtration and flow guiding capacity, can guide the liquid to diffuse to the inside, and can reduce back seepage.

[0008] By grafting acrylamide and chitosan, the modification of acrylamide can introduce hydrophilic groups on the surface of the melt-blown non-woven fabric, reduce the water contact angle, and improve the hydrophilicity and liquid absorption speed; the grafting of chitosan can also improve the hydrophilicity of the melt-blown non-woven fabric and obtain certain antibacterial performance, and the grafting of chitosan makes the melt-blown non-woven fabric carry positive charges; and the wood pulp fiber can carry negative charges after being grafted with carboxymethyl cellulose, and the compatibility and interfacial adhesion of the covering layer and the SAP / wood pulp absorbent can be improved through the electrostatic adsorption of positive and negative charges, so that the integrity of the absorbent core body is good, and problems such as delamination and pilling do not occur.

[0009] Further, the specific steps of hydrophilic modification of the melt-blown non-woven fabric are as follows: The peroxide, Tween-80, toluene and deionized water are mixed to prepare an emulsion, the dried melt-blown non-woven fabric is soaked in the emulsion at a constant temperature of 40-45℃ for 30-40min, then is put into an acrylamide aqueous solution, heated to 80-90℃ for 2-3h, then the melt-blown non-woven fabric is taken out, boiled in water with a bath ratio of 1:1000 for 1-1.5h, and dried at 105-110℃ until the weight is constant to obtain a preliminary treated melt-blown fabric. The chitosan powder is dissolved in a 2% acetic acid solution to obtain a chitosan solution, the preliminary treated melt-blown fabric is soaked in the chitosan solution with positive charges for 20-30min, then is repeatedly washed with water to wash away the chitosan not combined with the preliminary treated melt-blown fabric, and is dried to obtain the hydrophilic modified melt-blown non-woven fabric.

[0010] By adopting the technical scheme, the grafting of acrylamide and chitosan on the melt-blown non-woven fabric is realized by sequential soaking, the hydrophilic performance of the melt-blown non-woven fabric is greatly improved, the antibacterial performance is improved, and positive charges are introduced.

[0011] Further, the weight ratio of the peroxide, Tween-80, toluene, deionized water, acrylamide and melt-blown non-woven fabric is (0.2-0.4):(0.3-0.5):(2-2.5):(1.5-2):(28-32):10, and the concentration of the chitosan solution is 3-4g / ml.

[0012] By adopting the technical scheme, the benzoyl peroxide is used as an initiator, the toluene and the Tween-80 are used as swelling agents, and the grafting rate is improved by controlling the proportion of the reactants, so that the grafting efficiency is optimal.

[0013] Further, the specific preparation steps of the modified wood pulp fiber are as follows: The carboxymethyl cellulose is dissolved in a sodium hydroxide solution to form a stock solution, the wood pulp fiber, water and the stock solution are mixed to form a mixed solution, HCl is added to adjust the pH to 10-11, the mixed solution is placed in a rotary pressure cooker, the temperature is raised to 60-65 DEG C within 10-15 min, and the modified wood pulp fiber is obtained after reaction for 1-2 h, cooling, filtering and washing with deionized water.

[0014] By grafting the carboxymethyl cellulose to the wood pulp fiber, negative charges can be introduced into the fluff pulp, the combination strength of the absorbent and the coating layer is improved, and the fluff pulp is more stable and less likely to shift or shrink.

[0015] Further, the mass concentration of the wood pulp fiber in the mixed solution is 50-70 g / L, the mass concentration of the carboxymethyl cellulose is 5-7 g / L, and the mass concentration of the sodium hydroxide is 60-80 g / L.

[0016] By adopting the technical scheme, the proportion of the reactants can be controlled to obtain a better grafting effect on the wood pulp fiber.

[0017] Further, the degree of substitution DS of the carboxymethyl cellulose is 0.2-0.35.

[0018] Further, a plurality of groove groups are formed on the upper coating layer, and the groove groups are arranged in parallel and inclined to the left and to the right.

[0019] By adopting the technical scheme, the groove groups are set to accelerate the penetration and drainage of the liquid into the absorbent core body, and the groove groups are formed by the deformation of each layer under pressure, and the whole of the absorbent core layer is formed by high-temperature compounding, so that the connection between the layers of the absorbent core body is more firm.

[0020] Further, each groove of the groove group is a circular groove with a diameter of 1-1.5 mm, and the distance between adjacent two grooves is 4-5 mm.

[0021] By adopting the technical scheme, the liquid is quickly and uniformly absorbed and diffused by uniformly setting each groove.

[0022] In a second aspect, the application discloses a preparation method of a melt-blown cloth absorbing core body, comprising the following steps: crushing and opening the modified wood pulp fibers, and then scattering and forming a floating state in a forming box, and then reaching a netting curtain under the action of airflow to obtain a coarse fiber net, and then scattering a high-molecular water-absorbing resin to the coarse fiber net to form a SAP / wood pulp absorbing body; The melt-blown non-woven fabric is subjected to hydrophilic finishing to obtain an upper cladding layer and a lower cladding layer, the upper cladding layer, the SAP / wood pulp absorbing body and the lower cladding layer are sequentially and neatly stacked on a workbench, and then a hot-pressing composite device is used to hot-press and composite the core body to obtain the melt-blown cloth absorbing core body. The upper cladding layer is extruded by using an extrusion head with a circular arc surface, so that a plurality of uniformly and regularly arranged rhombic patterns are formed on the upper cladding layer.

[0023] By using the above technical scheme, each layer is deformed under the action of a plurality of extrusion pieces with temperatures and is combined into a whole, and a groove group is formed at the same time, so that the connection of the absorbing core body is firm, the appearance is beautiful, and the body feeling is comfortable.

[0024] To sum up, the application has at least any one of the following beneficial effects: The cladding layer of the absorbing core body is selected from melt-blown non-woven fabric subjected to hydrophilic finishing, the melt-blown non-woven fabric has good softness, small fiber diameter and small pores, and does not have the leakage phenomenon of SAP, and the melt-blown non-woven fabric can provide good liquid filtering and flow guiding capacity, can guide the liquid to diffuse to the inside, and can reduce back seepage.

[0025] The grafting of acrylamide and chitosan can modify the melt-blown non-woven fabric, the modification of acrylamide can introduce hydrophilic groups on the surface of the melt-blown non-woven fabric to reduce the water contact angle, so that the hydrophilicity and liquid absorption speed are improved; the grafting of chitosan can also improve the hydrophilicity of the melt-blown non-woven fabric and obtain certain antibacterial performance, the grafting of chitosan makes the melt-blown non-woven fabric carry positive charges; and the wood pulp fibers can carry negative charges after the grafting of carboxymethyl cellulose, and the compatibility and interfacial adhesion of the cladding layer and the SAP / wood pulp absorbing body can be improved through the electrostatic adsorption of positive and negative charges, so that the integrity of the absorbing core body is good, and problems such as delamination and cotton breakage do not occur. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural schematic diagram of the absorbing core body of the application; Figure 2 is a structural schematic diagram of the upper cladding layer of the absorbing core body of the application; Mark explanation: 1, upper cladding layer; 2, SAP / wood pulp absorbing body; 3, lower cladding layer. DETAILED DESCRIPTION

[0027] The application will be further described in detail below in combination with Examples 1-3 and Comparative Examples 1-4. Examples

[0028] Example 1 The melt-blown fabric absorption core comprises an upper cladding layer, a SAP / wool pulp absorption body and a lower cladding layer arranged in sequence, the upper cladding layer and the lower cladding layer are both melt-blown non-woven fabrics subjected to hydrophilic finishing, and the SAP / wool pulp absorption body is obtained by uniformly mixing modified wood pulp fibers and super absorbent resin at a weight ratio of 10:20.

[0029] The melt-blown non-woven fabric is subjected to hydrophilic modification by grafting acrylamide and chitosan, and the specific steps are as follows: 0.2 parts of benzoyl peroxide, 0.3 parts of Tween-80, 2 parts of toluene and 1.5 parts of deionized water are mixed to prepare an emulsion, 10 parts of melt-blown polypropylene non-woven fabric is dried in an oven at 45℃ for 1h in advance, the dried melt-blown polypropylene non-woven fabric is soaked in the emulsion at 40℃ for 30min, then is placed in a solution of 28 parts of acrylamide and 20 parts of water, and is reacted at 80℃ for 3h, then is taken out, boiled in water at a bath ratio of 1:1000 for 1h, and dried at 105℃ until constant weight to obtain a preliminary treated melt-blown fabric. Chitosan powder is dissolved in a 2% acetic acid solution to obtain a chitosan solution, wherein the concentration of chitosan in the chitosan solution is 3g / ml, and the preliminary treated melt-blown fabric is soaked in the positively charged chitosan solution for 20min, then is repeatedly washed with water to wash away the chitosan that is not combined with the preliminary treated melt-blown fabric, and is dried to obtain a hydrophilic modified melt-blown non-woven fabric.

[0030] The modified wood pulp fibers are obtained by grafting wood pulp fibers and carboxymethyl cellulose, and the specific steps are as follows: Carboxymethyl cellulose with a degree of substitution DS of 0.2 is dissolved in a sodium hydroxide solution to prepare a stock solution, wood pulp fibers, water and the stock solution are mixed to form a mixed solution, the mass concentration of the wood pulp fibers in the mixed solution is 50g / L, the mass concentration of the carboxymethyl cellulose is 5g / L, and the mass concentration of the sodium hydroxide is 60g / L, then HCl is added to the mixed solution to adjust the pH to 10-11, the mixed solution is placed in a rotary pressure cooker, the temperature is raised to 60℃ within 10min, and the reaction is carried out for 1h, then the wood pulp fibers are cooled, filtered and washed with deionized water to obtain modified wood pulp fibers.

[0031] On the surface of the upper cladding layer of the melt-blown fabric absorption core, a plurality of groove groups arranged in parallel and inclined to the left and a plurality of groove groups arranged in parallel and inclined to the right are also formed, and a plurality of regularly distributed diamond patterns are formed by the groove groups, wherein each groove in the groove group is a circular groove with a diameter of 1mm, and the distance between two adjacent grooves is 4mm.

[0032] The preparation method of the melt-blown fabric absorption core comprises the following steps: The modified wood pulp fibers are crushed and opened, scattered in the forming box and in a floating state, and reach the netting curtain under the action of airflow to obtain a coarse fiber net. The high-molecular water-absorbing resin is scattered to the coarse fiber net to form a SAP / wood pulp absorption body. The melt-blown non-woven fabric is subjected to hydrophilic finishing to obtain an upper cladding layer and a lower cladding layer. The upper cladding layer, the SAP / wood pulp absorption body and the lower cladding layer are sequentially and neatly stacked on a workbench, and then a hot-pressing composite device is used to hot-press and composite the core body to obtain a melt-blown fabric absorption core. The upper cladding layer is extruded by using an extrusion head with a circular arc surface, and the extruded parts of the layers are deformed downward and connected together at a temperature of 150 DEG C, so that a plurality of uniformly and regularly arranged rhombic patterns are formed on the upper cladding layer.

[0033] Example 2 A melt-blown fabric absorption core comprises an upper cladding layer, a SAP / wood pulp absorption body and a lower cladding layer which are sequentially arranged. The upper cladding layer and the lower cladding layer are both melt-blown non-woven fabrics subjected to hydrophilic finishing. The SAP / wood pulp absorption body is obtained by uniformly mixing modified wood pulp fibers and super-absorbent resin at a weight ratio of 30:80.

[0034] The melt-blown non-woven fabric is subjected to hydrophilic modification by grafting acrylamide and chitosan. The specific steps are as follows: 0.4 parts of benzoyl peroxide, 0.5 parts of Tween-80, 2.5 parts of toluene and 2 parts of deionized water are mixed to prepare an emulsion. 10 parts of melt-blown polypropylene non-woven fabric is dried in a 45 DEG C oven for 1 h in advance. The dried melt-blown polypropylene non-woven fabric is soaked in the emulsion at 45 DEG C for 40 min, and then placed in a solution of 32 parts of acrylamide and 26 parts of water. The temperature is raised to 90 DEG C and reacted for 2 h. The melt-blown non-woven fabric is taken out, boiled in water with a bath ratio of 1:1000 for 1 h, and dried at 110 DEG C to constant weight to obtain a preliminary treated melt-blown fabric. Chitosan powder is dissolved in a 2% acetic acid solution to obtain a chitosan solution, wherein the concentration of chitosan in the chitosan solution is 4 g / ml. The preliminary treated melt-blown fabric is soaked in the positively charged chitosan solution for 30 min, and then washed repeatedly with water to wash away the chitosan that is not combined with the preliminary treated melt-blown fabric. After drying, a hydrophilically modified melt-blown non-woven fabric is obtained.

[0035] The modified wood pulp fibers are obtained by grafting wood pulp fibers and carboxymethyl cellulose. The specific steps are as follows: Carboxymethyl cellulose with a degree of substitution DS of 0.35 is dissolved in sodium hydroxide solution to form a stock solution, wood pulp fibers, water and the stock solution are mixed to form a mixed solution, the mass concentration of wood pulp fibers in the mixed solution is 70 g / L, the mass concentration of carboxymethyl cellulose is 7 g / L, and the mass concentration of sodium hydroxide is 80 g / L, then HCl is added to the mixed solution to adjust the pH to 10-11, the above mixed solution is placed in a rotary pressure cooker, the temperature is raised to 65℃ within 15 min, and after 2 h of reaction, it is cooled, filtered to take out the wood pulp fibers and washed with deionized water to obtain modified wood pulp fibers.

[0036] On the surface of the upper cover layer of the melt-blown cloth absorbent core, a plurality of groups of left parallel inclined grooves and a plurality of groups of right parallel inclined grooves are also formed, and a plurality of regularly distributed diamond patterns are formed by the groove groups, wherein each groove in the groove group is a circular groove with a diameter of 1.5 mm, and the distance between adjacent two grooves is 5 mm.

[0037] The preparation method of the melt-blown cloth absorbent core of the present application is the same as that of example 1.

[0038] Example 3 A melt-blown cloth absorbent core, comprising an upper cover layer, a SAP / wood pulp absorbent body and a lower cover layer arranged in sequence, the upper cover layer and the lower cover layer are both hydrophilic melt-blown non-woven fabrics, and the SAP / wood pulp absorbent body is obtained by uniformly mixing modified wood pulp fibers and super absorbent resin at a weight ratio of 20:50.

[0039] The melt-blown non-woven fabric is hydrophilically modified by grafting acrylamide and chitosan, and the specific steps are as follows: 0.3 parts of benzoyl peroxide, 0.4 parts of Tween-80, 2.2 parts of toluene and 1.8 parts of deionized water are mixed to prepare an emulsion, 10 parts of melt-blown polypropylene non-woven fabric is dried in an oven at 45℃ for 1 h in advance, the dried melt-blown polypropylene non-woven fabric is soaked in the emulsion at a constant temperature of 42℃ for 35 min, then it is placed in a solution of 30 parts of acrylamide and 23 parts of water, and the temperature is raised to 85℃ for 2.5 h, then the melt-blown non-woven fabric is taken out, boiled in water with a bath ratio of 1:1000 for 1 h, and dried at 105℃ to constant weight to obtain a preliminary treated melt-blown cloth. Chitosan powder is dissolved in a 2% acetic acid solution to obtain a chitosan solution, wherein the concentration of chitosan in the chitosan solution is 3.5 g / ml, and the preliminary treated melt-blown cloth is soaked in the positively charged chitosan solution for 25 min, then it is repeatedly washed with water to wash away the chitosan that is not combined with the preliminary treated melt-blown cloth, and then it is dried to obtain a hydrophilically modified melt-blown non-woven fabric.

[0040] The modified wood pulp fibers are obtained by grafting wood pulp fibers and carboxymethyl cellulose, and the specific steps are as follows: Carboxymethyl cellulose with a substitution degree DS of 0.2 is dissolved in a sodium hydroxide solution to form a stock solution, wood pulp fibers, water and the stock solution are mixed to form a mixed solution, the mass concentration of the wood pulp fibers in the mixed solution is 60 g / L, the mass concentration of the carboxymethyl cellulose is 6 g / L, and the mass concentration of the sodium hydroxide is 70 g / L, then HCl is added to the mixed solution to adjust the pH to 10-11, the mixed solution is placed in a rotary pressure cooker, the temperature is raised to 65 DEG C within 10 min, and after 1 h of reaction, the temperature is cooled, the wood pulp fibers are filtered out and washed with deionized water to obtain modified wood pulp fibers.

[0041] On the surface of the upper cover layer of the melt-blown fabric absorbent core, a plurality of groups of left parallel inclined grooves and a plurality of groups of right parallel inclined grooves are also formed, and the plurality of groups of grooves form a plurality of regularly distributed diamond patterns, wherein each groove in the group of grooves is a circular groove with a diameter of 1 mm, and the distance between adjacent two grooves is 5 mm.

[0042] The preparation method of the melt-blown fabric absorbent core of the present application is the same as that of example 1.

[0043] Comparative Example Comparative Example 1 The difference between the present comparative example and example 1 is that the upper cover layer and the lower cover layer of the absorbent core are both hot air non-woven fabrics subjected to hydrophilic finishing with an organic silicon polyether hydrophilic agent, and the SAP / wood pulp absorbent is obtained by uniformly mixing wood pulp fibers and super absorbent resin in a weight ratio of 10:20.

[0044] Comparative Example 2 The difference between the present comparative example and example 1 is that in the SAP / wood pulp absorbent of the absorbent core, wood pulp fibers are used instead of modified wood pulp fibers.

[0045] Comparative Example 3 The difference between the present comparative example and example 1 is that in the upper cover layer and the lower cover layer of the absorbent core, melt-blown non-woven fabrics subjected to hydrophilic finishing are used, and the melt-blown non-woven fabrics are only subjected to hydrophilic modification by grafting acrylamide, without grafting chitosan.

[0046] Comparative Example 4 The difference between the present comparative example and example 1 is that in the upper cover layer and the lower cover layer of the absorbent core, melt-blown non-woven fabrics subjected to hydrophilic finishing are used, and the melt-blown non-woven fabrics are only subjected to hydrophilic modification by grafting chitosan, without grafting acrylamide.

[0047] Performance Test 1. Take 100 mL of normal saline (mass concentration 0.9%) and heat to 40°C, then add the normal saline to the core body, and place the absorbent core sample in a 40±1°C, 65±1% RH test box for 10 min, then take out the absorbent core sample for testing; the tester holds the two ends of the absorbent core sample with both hands, first swings one end of the absorbent core sample with one hand, repeats 10 times, then reciprocally stretches the two ends of the absorbent core sample with both hands, repeats 10 times, then rubs the core body with both hands, repeats 10 times, finally observes whether the absorbent core appears the phenomenon of lumping, and records the phenomenon results in Table 1.

[0048] 2. According to QB / T 5650-2021 "Composite Absorbent Core for Disposable Paper Hygiene Products", test the absorption speed and backflow of the core, and the test liquid is normal saline.

[0049] Table 1 Test sample Pugging Absorption speed (s) Re-wet (g) Example 1 No pugging 13 2.5 Example 2 No pugging 12 2.8 Example 3 No pugging 12 2.3 Comparative Example 1 Pugging 13 4.6 Comparative Example 2 Pugging 16 3.1 Comparative Example 3 Pugging 27 3.7 Comparative Example 4 No pugging 23 3.4 According to the data in Table 1, the absorbent core of the present application is not easy to lump, and has a shorter absorption speed and a lower backflow, which proves that the absorbent core of the present application has excellent liquid absorption and storage performance, and the bonding strength between the material layers is high and the integrity is good.

[0050] This specific embodiment is only an explanation of the present application, and is not a limitation of the present application. Those skilled in the art can make modifications to the specific embodiment without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A meltblown fabric absorbent core, characterized in that: The device comprises an upper coating layer, a SAP / fluff pulp absorber, and a lower coating layer arranged sequentially. Both the upper and lower coating layers are made of meltblown nonwoven fabric that has undergone hydrophilic treatment. The SAP / fluff pulp absorber is obtained by uniformly mixing modified wood pulp fiber and superabsorbent resin in a weight ratio of (10-30):(20-80). The meltblown nonwoven fabric is hydrophilically modified by grafting acrylamide and chitosan. The modified wood pulp fiber is obtained by grafting wood pulp fiber with carboxymethyl cellulose.

2. The meltblown nonwoven absorbent core according to claim 1, characterized in that, The specific steps for hydrophilic modification of the meltblown nonwoven fabric are as follows: Benzoyl peroxide, Tween-80, toluene, and deionized water were mixed to prepare an emulsion. The dried meltblown nonwoven fabric was immersed in the emulsion at a constant temperature of 40-45℃ for 30-40 minutes, and then placed in an aqueous solution of acrylamide and heated to 80-90℃ for 2-3 hours. The meltblown nonwoven fabric was then removed and boiled in water at a bath ratio of 1:1000 for 1-1.5 hours. It was then dried at 105-110℃ to constant weight to obtain a pre-treated meltblown fabric. Chitosan powder was dissolved in a 2% (v / v) acetic acid solution and stirred until homogeneous to obtain a chitosan solution. The pre-treated meltblown fabric was then soaked in the positively charged chitosan solution for 20-30 minutes, and then repeatedly washed with water to remove the chitosan that was not bound to the pre-treated meltblown fabric. After drying, hydrophilic modified meltblown nonwoven fabric was obtained.

3. The meltblown nonwoven absorbent core according to claim 2, characterized in that: The weight ratio of benzoyl peroxide, Tween-80, toluene, deionized water, acrylamide and meltblown nonwoven fabric is (0.2-0.4):(0.3-0.5):(2-2.5):(1.5-2):(28-32):10, and the concentration of the chitosan solution is 3-4 g / ml.

4. The meltblown nonwoven absorbent core according to claim 1, characterized in that, The specific preparation steps for the modified wood pulp fiber are as follows: Carboxymethyl cellulose was dissolved in sodium hydroxide solution to prepare a stock solution. Wood pulp fiber, water and stock solution were mixed to form a mixture. HCl was added to adjust the pH to 10-11. The mixture was placed in a rotary pressure cooker and the temperature was raised to 60-65℃ within 10-15 minutes. After reacting for 1-2 hours, the mixture was cooled, filtered, and the wood pulp fiber was removed and washed with deionized water to obtain modified wood pulp fiber.

5. The meltblown nonwoven absorbent core according to claim 4, characterized in that: The mixture contains wood pulp fiber at a mass concentration of 50-70 g / L, carboxymethyl cellulose at a mass concentration of 5-7 g / L, and sodium hydroxide at a mass concentration of 60-80 g / L.

6. The meltblown nonwoven absorbent core according to claim 4, characterized in that: The degree of substitution (DS) of the carboxymethyl cellulose is 0.2-0.

35.

7. The meltblown nonwoven absorbent core according to claim 1, characterized in that: The upper covering layer has multiple sets of grooves arranged in parallel and inclined directions to the left and multiple sets arranged in parallel and inclined directions to the right, and the grooves form multiple regularly distributed rhomboid patterns.

8. The meltblown nonwoven absorbent core according to claim 7, characterized in that: Each groove in the groove group is a circular groove with a diameter of 1-1.5mm, and the distance between two adjacent grooves is 4-5mm.

9. A method for preparing a meltblown nonwoven absorbent core according to any one of claims 1-8, characterized in that, Includes the following steps: Modified wood pulp fibers are crushed and loosened, then dispersed and floated in a molding box. Under the action of airflow, they form a coarse fiber screen. Superabsorbent polymer (SAP) is then spread onto the coarse fiber screen to form a SAP / fluff pulp absorbent. The meltblown nonwoven fabric is hydrophilically treated to obtain an upper coating layer and a lower coating layer. The upper coating layer, SAP / fluff pulp absorber and lower coating layer are then neatly stacked on the workbench. The core is then hot-pressed and laminated using a hot-pressing composite device to obtain the meltblown fabric absorbent core. The upper coating layer is extruded using an extrusion head with a curved surface, thereby forming multiple uniformly and regularly arranged diamond patterns on the upper coating layer.

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