A glue-free reverse absorption water-absorbing core and its preparation process

Abstract

The present invention relates to a non-adhesive reverse-absorbing absorbent core and its preparation process. The core comprises an upper ES chemical fiber layer, an intermediate high-molecular-weight water-absorbing resin layer, and a lower wood pulp ES chemical fiber mixed layer. The upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer wrap the intermediate high-molecular-weight water-absorbing resin layer in between. The upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer are formed into an integrated structure through heat treatment. In the present invention, the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer are formed into a molded body without adhesive through heat treatment. Compared to bonding with adhesives, the liquid seeps down faster, thereby ensuring the dryness of the upper layer to the greatest extent possible, while also being more environmentally friendly and hygienic.

Description

Technical Field

[0001] The invention belongs to the technical field of sanitary products, and in particular relates to a glue-free reverse absorbing water-absorbing core and a preparation process thereof. Background Art

[0002] Absorbent cores have a wide range of uses. Currently, the absorbent cores of sanitary products sold on the market, such as sanitary napkins or diapers, are usually made of fluff pulp or non-woven fabrics. In order to improve the absorption performance of the absorbent core, people have developed a method of adding a polymer absorbent layer to the absorbent core. Since this absorbent core is very dense, the absorption and diffusion of liquid are very slow. If the liquid cannot be absorbed in a short time, it will cause discomfort and trouble to the user, and cannot meet the user's requirement for it to absorb a large amount of liquid in a short time.

[0003] Chinese patent CN209392255U discloses a water-absorbent core for sanitary products, which includes an upper layer of non-woven fabric, a middle layer of non-woven fabric and a lower layer of dust-free paper. The upper layer of non-woven fabric and the middle layer of non-woven fabric are bonded to each other by an adhesive, and the middle layer of non-woven fabric and the lower layer of dust-free paper are bonded to each other by an adhesive. The upper part of the middle layer of non-woven fabric is permeated with a first polymer water-absorbent resin, and the lower part is permeated with a second polymer water-absorbent resin. The particle size of the first polymer water-absorbent resin is larger than the particle size of the second polymer water-absorbent resin, and the water absorption performance of the first polymer water-absorbent resin is weaker than the water absorption performance of the second polymer water-absorbent resin.

[0004] In the absorbent core of the sanitary product disclosed above, the upper non-woven fabric, the middle non-woven fabric and the lower dust-free paper are all bonded by an adhesive. After the adhesive is dried, a film will be formed, thereby blocking the infiltration of water, resulting in a slow infiltration rate. The water remains on the surface of the upper non-woven fabric, affecting skin health. Summary of the Invention

[0005] In order to address the deficiencies of the prior art, the present invention provides a glue-free reverse absorption water-absorbing core and its preparation process, which has good penetration effect and high water absorption efficiency, keeps the skin surface dry, and significantly reduces problems such as diaper rash, allergies and microbial breeding.

[0006] In order to achieve the purpose, the technical solution provided by the present invention is:

[0007] The present invention relates to a glue-free reverse absorption water-absorbing core, which comprises an upper ES chemical fiber layer, a middle high-molecular water-absorbing resin layer and a lower wood pulp ES chemical fiber mixed layer. The upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer wrap the middle high-molecular water-absorbing resin layer in the middle, and the upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer are formed into an integrated structure through heat treatment.

[0008] Preferably, the particle size of the polymer water-absorbing resin in the intermediate polymer water-absorbing resin layer is 100 to 300 mesh.

[0009] Preferably, the weight of the upper ES chemical fiber layer is 20 to 60 g / m 2 The weight of the lower wood pulp ES chemical fiber mixed layer is 50-200g / m 2 The amount of polymer water-absorbing resin in the middle polymer water-absorbing resin layer is 100-400 g / m 2 .

[0010] Preferably, the thickness of the lower wood pulp ES chemical fiber mixed layer is greater than the thickness of the upper ES chemical fiber layer.

[0011] Preferably, the polymer water-absorbing resin layer includes a first polymer water-absorbing resin and a second polymer water-absorbing resin, the first polymer water-absorbing resin permeates the lower surface of the upper ES chemical fiber layer, and the second polymer water-absorbing resin permeates the upper surface of the lower wood pulp ES chemical fiber mixed layer.

[0012] Preferably, the particle size of the first polymer water-absorbing resin is 120-300 mesh, and the particle size of the second polymer water-absorbing resin is 100-120 mesh; the water absorption rate of the first polymer water-absorbing resin is 50-180 times, and the water absorption rate of the second polymer water-absorbing resin is 110-260 times; the dosage of the first polymer water-absorbing resin is 50-200 g / m 2 The amount of the second polymer water-absorbing resin is 50 to 200 g / m 2 .

[0013] A process for preparing a water-absorbing core body with no glue and reverse absorption, comprising the following steps:

[0014] Lay the wood pulp ES chemical fiber mixed layer on the workbench, and install an exhaust fan and a vibrator under the wood pulp ES chemical fiber mixed layer. Spray the high molecular water-absorbing resin evenly on the upper side of the wood pulp ES chemical fiber mixed layer.

[0015] Under the action of the exhaust fan and vibrator, the polymer water-absorbing resin penetrates into the wood pulp ES chemical fiber mixed layer;

[0016] Under the action of the exhaust fan, the ES chemical fiber layer is laid on top of the wood pulp ES chemical fiber mixed layer;

[0017] (4) Heat treatment is performed to make the ES fibers on the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer adhere to each other to form a molded body. After cooling, the ES fibers are rolled up and cut to obtain a water-absorbing core body with no glue and reverse absorption.

[0018] Preferably, in step (4), the temperature of the heating treatment is 100-150°C.

[0019] A process for preparing a water-absorbing core body with no glue and reverse absorption, comprising the following steps:

[0020] (1) Laying the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer on a workbench, with an exhaust fan and a vibrator provided below the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer, spraying the first polymer water-absorbing resin evenly on the upper side of the ES chemical fiber layer, and spraying the second polymer water-absorbing resin evenly on the upper side of the wood pulp ES chemical fiber mixed layer;

[0021] (2) Under the action of the exhaust fan and the vibrator, the first polymer water-absorbing resin penetrates into the ES chemical fiber layer, and the second polymer water-absorbing resin penetrates into the wood pulp ES chemical fiber mixed layer;

[0022] (3) Turn the upper side of the ES chemical fiber layer downward, and lay the ES chemical fiber layer on top of the wood pulp ES chemical fiber mixed layer under the action of the exhaust fan;

[0023] (4) Heat treatment is performed to make the ES fibers on the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer adhere to each other to form a molded body. After cooling, the ES fibers are rolled up and cut to obtain a water-absorbing core body with no glue and reverse absorption.

[0024] Preferably, in step (4), the temperature of the heating treatment is 100-150°C.

[0025] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0026] The ES chemical fiber layer and the pulp ES chemical fiber mixed layer in the present invention can be formed into a molded body without adhesive through heat treatment. Compared with the case of bonding with adhesives, the liquid seeps down quickly, thereby ensuring the dryness of the upper layer to the greatest extent, and the production is more environmentally friendly and hygienic.

[0027] Since the present invention does not use an adhesive in the middle, the liquid can quickly penetrate from the ES chemical fiber layer to the lower wood pulp ES chemical fiber mixed layer, and during the penetration process, it is absorbed in the middle polymer water-absorbing resin layer; there is always a diffusion effect during the liquid penetration process, and after reaching the lower wood pulp ES chemical fiber mixed layer, the liquid is completely diffused. The liquid that penetrates into the wood pulp ES chemical fiber mixed layer will also reversely penetrate from both ends of the water-absorbing core to the middle polymer water-absorbing resin layer, so that water can be absorbed quickly and the absorption efficiency of the water-absorbing core is improved.

[0028] The present invention uses polymer water-absorbing resins of different particle sizes. The polymer water-absorbing resin on the upper side has a larger particle size, while the polymer water-absorbing resin on the lower side has a smaller particle size. Therefore, the gaps between the polymer water-absorbing resins on the upper side are larger, allowing liquid to seep in quickly. Furthermore, because the polymer water-absorbing resin on the upper side is relatively weak, the polymer water-absorbing resin on the upper side does not rapidly expand and close the gaps between the particles when liquid seeps in. This also facilitates liquid seepage, keeping the upper ES chemical fiber layer dry and comfortable, making the wearer more comfortable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram in Example 2;

[0031] Figure 3 It is a schematic diagram of water osmosis and diffusion in the present invention;

[0032] Figure 4 Schematic diagram of the diffusion of the test solution on the surface of the water-absorbing core in the comparative example.

[0033] Notes on the diagram:

[0034] 1-ES chemical fiber layer; 2-polymer water-absorbing resin layer; 3-wood pulp ES chemical fiber mixed layer; 21-first polymer water-absorbing resin; 22-second polymer water-absorbing resin. DETAILED DESCRIPTION

[0035] In order to further understand the content of the present invention, the present invention is described in detail with reference to the examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention. Example

[0036] like Figure 1 As shown, this embodiment relates to a glue-free reverse-absorbing water-absorbing core, which includes an upper ES chemical fiber layer 1, a middle polymer water-absorbing resin layer 2 and a lower wood pulp ES chemical fiber mixed layer 3. The upper ES chemical fiber layer 1 and the lower wood pulp ES chemical fiber mixed layer 3 wrap the middle polymer water-absorbing resin layer 2 in the middle, and the upper ES chemical fiber layer 1 and the lower wood pulp ES chemical fiber mixed layer 3 are formed into an integrated structure through heat treatment.

[0037] The thickness of the lower wood pulp ES chemical fiber mixed layer 3 is greater than the thickness of the upper ES chemical fiber layer 1. The particle size of the polymer water-absorbing resin in the middle polymer water-absorbing resin layer 2 is 100 mesh. The gram weight of the upper ES chemical fiber layer 1 is 30g / m 2 The weight of the lower wood pulp ES chemical fiber mixed layer 3 is 90g / m 2The amount of the polymer water-absorbing resin in the middle polymer water-absorbing resin layer 2 is 250g / m 2 .

[0038] The preparation process of the above-mentioned adhesive-free reverse absorption water-absorbing core comprises the following steps:

[0039] (1) Lay the wood pulp ES chemical fiber mixed layer on the workbench, and set an exhaust fan and a vibrator under the wood pulp ES chemical fiber mixed layer, and evenly spray the polymer water-absorbing resin on the upper side of the wood pulp ES chemical fiber mixed layer;

[0040] (2) Under the action of the exhaust fan and vibrator, the polymer water-absorbing resin penetrates into the wood pulp ES chemical fiber mixed layer;

[0041] (3) Under the action of the exhaust fan, the ES chemical fiber layer is laid on top of the wood pulp ES chemical fiber mixed layer;

[0042] (4) Heat treatment is performed to make the ES fibers on the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer adhere to each other to form a molded body. After cooling, the ES fibers are rolled up and cut to obtain a water-absorbing core body with no glue and reverse absorption.

[0043] In step (4), the temperature of the heating treatment is 120°C.

[0044] like Figure 3 As shown, 80 ml of the test solution is poured above the middle of the upper ES chemical fiber layer 1 of the glue-free reverse absorbent core. The test solution will quickly penetrate downward and diffuse to the surroundings. Most of the upper ES chemical fiber layer 1 will remain dry. The test solution is absorbed in the middle polymer water-absorbent resin layer 2. The test solution that penetrates into the lower wood pulp ES chemical fiber mixed layer 3 begins to reversely penetrate into the middle polymer water-absorbent resin layer 2 and be absorbed.

[0045] According to the method for measuring the slippage amount in diapers (sheets, pads) as specified in the national standard of the People's Republic of China GB / T28004-2011, a baby diaper with the adhesive-free reverse-absorbing absorbent core was made into a sample. The sample was placed on an inclined board with an inclination of (30±2)°, with the surface facing upward. 100mm was taken from both ends of the center point of the adhesive-free reverse-absorbing absorbent core in the sample as the test area. 50ml of test solution was measured and allowed to flow freely on the surface of the sample and along the inclined surface. After multiple experiments, the final measured slippage amount was 11.6ml, which is lower than the national standard of 20ml.

[0046] According to the national standard of the People's Republic of China GB / T28004-2011, the method for measuring the rewet amount in diapers (sheets, pads) is used to make a medium-sized baby diaper with a water-absorbing core without adhesive reverse absorption as a test sample. 60 ml of the test solution is allowed to flow freely through a funnel to the surface of the center of the sample. After 5 minutes, the same amount of test solution is injected into the funnel again. After 10 minutes, several layers of filter paper with a diameter of 100 mm are placed on the surface of the sample. At the same time, a standard pressing block is pressed on the filter paper. After 1 minute of pressure, the standard pressing block is removed. Multiple tests using this measurement method are carried out, and the average rewet amount of the sample is finally measured to be 5.7 g, which is lower than the national standard of 10 g.

[0047] According to the national standard of the People's Republic of China GB / T28004-2011, the leakage measurement method of diapers (sheets and pads) is used to make adult diapers with this adhesive-free reverse absorption absorbent core as a test sample. The sample is laid flat on a horizontal surface. 80ml of the test solution is measured with a separatory funnel and poured uniformly into the center of the sample within 30 seconds. After 5 minutes, no liquid leakage is observed around the sample. Example

[0048] like Figure 2 As shown, this embodiment relates to a glue-free reverse-absorbing water-absorbing core, which includes an upper ES chemical fiber layer 1, a middle polymer water-absorbing resin layer 2 and a lower wood pulp ES chemical fiber mixed layer 3. The upper ES chemical fiber layer 1 and the lower wood pulp ES chemical fiber mixed layer 3 wrap the middle polymer water-absorbing resin layer 2 in the middle, and the upper ES chemical fiber layer 1 and the lower wood pulp ES chemical fiber mixed layer 3 are formed into an integrated structure through heat treatment.

[0049] The thickness of the lower wood pulp ES chemical fiber mixed layer 3 is greater than the thickness of the upper ES chemical fiber layer 1. The gram weight of the upper ES chemical fiber layer 1 is 30g / m 2 The weight of the lower wood pulp ES chemical fiber mixed layer 3 is 90g / m 2 .

[0050] The polymer water-absorbing resin layer 2 includes a first polymer water-absorbing resin 21 and a second polymer water-absorbing resin 22. The first polymer water-absorbing resin 21 permeates the lower surface of the upper ES chemical fiber layer 1, and the second polymer water-absorbing resin 22 permeates the upper surface of the lower wood pulp ES chemical fiber mixed layer 3.

[0051] The particle size of the first polymer water-absorbing resin 21 is 200 mesh, and the particle size of the second polymer water-absorbing resin is 100 mesh; the water absorption rate of the first polymer water-absorbing resin is 100 times, and the water absorption rate of the second polymer water-absorbing resin is 200 times; the dosage of the first polymer water-absorbing resin is 100 g / m 2 The dosage of the second polymer water-absorbing resin is 100g / m 2 .

[0052] The preparation process of the above-mentioned adhesive-free reverse absorption water-absorbing core comprises the following steps:

[0053] (1) Laying the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer on a workbench, with an exhaust fan and a vibrator provided below the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer, spraying the first polymer water-absorbing resin evenly on the upper side of the ES chemical fiber layer, and spraying the second polymer water-absorbing resin evenly on the upper side of the wood pulp ES chemical fiber mixed layer;

[0054] (2) Under the action of the exhaust fan and the vibrator, the first polymer water-absorbing resin penetrates into the ES chemical fiber layer, and the second polymer water-absorbing resin penetrates into the wood pulp ES chemical fiber mixed layer;

[0055] (3) Turn the upper side of the ES chemical fiber layer downward, and lay the ES chemical fiber layer on top of the wood pulp ES chemical fiber mixed layer under the action of the exhaust fan;

[0056] (4) Heat treatment is performed to make the ES fibers on the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer adhere to each other to form a molded body. After cooling, the ES fibers are rolled up and cut to obtain a water-absorbing core body with no glue and reverse absorption.

[0057] In step (4), the temperature of the heating treatment is 120°C.

[0058] like Figure 3 As shown, 80 ml of the test solution is poured above the middle of the upper ES chemical fiber layer 1 of the glue-free reverse absorbent core. The test solution will quickly penetrate downward and diffuse to the surroundings. Most of the upper ES chemical fiber layer 1 will remain dry. The test solution is absorbed in the middle polymer water-absorbent resin layer 2. The test solution that penetrates into the lower wood pulp ES chemical fiber mixed layer 3 begins to reversely penetrate into the middle polymer water-absorbent resin layer 2 and be absorbed.

[0059] According to the method for measuring the slippage amount in diapers (sheets, pads) as specified in the National Standard of the People's Republic of China GB / T28004-2011, a baby diaper with the adhesive-free reverse-absorbing absorbent core was made into a sample. The sample was placed on an inclined board with an inclination of (30±2)°, with the surface facing upward. 100mm from both ends of the center point of the adhesive-free reverse-absorbing absorbent core in the sample was used as the test area. 50ml of test solution was measured and allowed to flow freely on the surface of the sample and along the inclined surface. After multiple experiments, the final measured slippage amount was 9.7ml, which is lower than the national standard of 20ml.

[0060] According to the national standard of the People's Republic of China GB / T28004-2011, the method for measuring the rewet amount in diapers (sheets, pads), a medium-sized baby diaper with a non-glue reverse-absorbing absorbent core was made into a sample. 60 ml of the test solution was allowed to flow freely through a funnel to the surface of the center of the sample. After 5 minutes, the same amount of test solution was injected into the funnel again. After 10 minutes, several layers of filter paper with a diameter of 100 mm were placed on the surface of the sample, and a standard pressing block was pressed on the filter paper. The standard pressing block was removed after 1 minute of pressure. Multiple tests were conducted using this measurement method, and the average rewet amount of the sample was finally measured to be 4.9 g, which is lower than the national standard of 10 g.

[0061] According to the national standard of the People's Republic of China GB / T28004-2011, the leakage measurement method of diapers (sheets and pads) is used to make adult diapers with this adhesive-free reverse absorption absorbent core as a test sample. The sample is laid flat on a horizontal surface. 80ml of the test solution is measured with a separatory funnel and poured uniformly into the center of the sample within 30 seconds. After 5 minutes, no liquid leakage is observed around the sample.

[0062] Comparative Example 1

[0063] In this comparative example 1, the upper ES chemical fiber layer in Example 1 is replaced with a wood pulp fiber layer, and the wood pulp fiber layer, the middle polymer water-absorbing resin layer and the lower wood pulp ES chemical fiber mixed layer are bonded together by hot melt adhesive to form a comparative example 1 absorbent core with the same thickness as in Example 1.

[0064] The absorbent core of Comparative Example 1 and the absorbent core of Example 1 with no glue and reverse absorption, both with a size of 16*16 cm, were used as test objects. Figure 4 As shown, under identical conditions, 80 ml of test solution was poured onto the center of a horizontally placed absorbent core from Comparative Example 1 and a non-adhesive reverse-absorbing absorbent core over a period of 30 seconds. The diffusion of the test solution onto the upper surface (i.e., the upper layer) of the absorbent core from Comparative Example 1 and the non-adhesive reverse-absorbing absorbent core was observed. In the absorbent core from Comparative Example 1, after the test solution was poured, the liquid seeped down slowly, with most of it diffusing outward. By the 15th second, the test solution had already completely diffused to a position 8 cm from the center of the upper surface (i.e., the edge of the core), before it was completely poured. In contrast, in the non-adhesive reverse-absorbing absorbent core, after the test solution was poured, the liquid seeped down rapidly. By the 30th second, the upper layer of liquid had only diffused to a position 3.6 cm from the center of the upper surface and remained essentially at the upper surface, with no further outward diffusion. The rest of the core's upper surface remained dry, with the liquid largely absorbed by the middle and lower layers.

[0065] Comparative Example 2

[0066] In this comparative example 2, the absorbent core material of the same structure as in Example 1 is bonded by hot melt adhesive between the upper ES chemical fiber layer, the middle polymer water-absorbing resin layer and the lower wood pulp ES chemical fiber mixed layer to form an absorbent core with the same thickness as in Example 1.

[0067] Take the absorbent core of comparative example 2 and the absorbent core of embodiment 1 with no glue and reverse absorption, both with a size of 16*16 cm, as test objects. Figure 4 As shown, under identical conditions, 80 ml of test solution was poured onto the center points of a horizontally placed absorbent core from Example 2 and a non-adhesive reverse-absorbing absorbent core over a period of 30 seconds. The diffusion of the test solution onto the upper surface (i.e., the upper layer) of the absorbent core from Comparative Example 2 and the non-adhesive reverse-absorbing absorbent core was observed. In the absorbent core from Comparative Example 2, after the test solution was poured, the liquid seeped down slowly, with most of it diffusing outward. By the 15th second, the test solution had already completely diffused to a position 8 cm from the center point of the upper surface (i.e., the edge of the core), before it was completely poured. In contrast, in the non-adhesive reverse-absorbing absorbent core, after the test solution was poured, the liquid seeped down rapidly, diffusing only to a position 3.6 cm from the center point of the upper surface by the 30th second. It remained essentially at the upper surface, with no further outward diffusion. The rest of the core's upper surface remained dry, with the liquid essentially absorbed by the middle and lower layers.

[0068] Comparative Examples 1 and 2 demonstrate that the test solution in the adhesive-free reverse absorbent core of the present invention penetrates rapidly into the absorbent core and diffuses slowly on the surface. This indicates that the ES fiber layer penetrates more rapidly than the wood pulp fiber layer, and also demonstrates that the adhesive used for bonding significantly affects the penetration of the test solution.

[0069] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings are only embodiments of the present invention, and the actual structure is not limited thereto. Therefore, those skilled in the art can, inspired by the above, design structures and embodiments similar to the technical solution without creatively designing them without departing from the purpose of the present invention, and all of them should fall within the scope of protection of the present invention.

Claims

1. A glue-free reverse absorbing water-absorbing core, characterized in that: It includes an upper ES chemical fiber layer, a middle polymer water-absorbing resin layer and a lower wood pulp ES chemical fiber mixed layer. The upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer wrap the middle polymer water-absorbing resin layer in the middle. The upper ES chemical fiber layer and the lower wood pulp ES chemical fiber mixed layer are formed into an integrated structure through heat treatment. The polymer water-absorbing resin layer includes a first polymer water-absorbing resin and a second polymer water-absorbing resin, wherein the first polymer water-absorbing resin is infiltrated into the lower surface of the upper ES chemical fiber layer, and the second polymer water-absorbing resin is infiltrated into the upper surface of the lower wood pulp ES chemical fiber mixed layer; The particle size of the first polymer water-absorbing resin is 120-300 mesh, and the particle size of the second polymer water-absorbing resin is 100-120 mesh; the water absorption rate of the first polymer water-absorbing resin is 50-180 times, and the water absorption rate of the second polymer water-absorbing resin is 110-260 times; the dosage of the first polymer water-absorbing resin is 50-200 g / m 2 The amount of the second polymer water-absorbing resin is 50 to 200 g / m 2 .

2. The adhesive-free reverse absorbing water-absorbing core according to claim 1, characterized in that: The particle size of the polymer water-absorbing resin in the middle polymer water-absorbing resin layer is 100 to 300 meshes.

3. The adhesive-free reverse absorbing water-absorbing core according to claim 1, characterized in that: The weight of the upper ES chemical fiber layer is 20-60 g / m 2 The weight of the lower wood pulp ES chemical fiber mixed layer is 50-200g / m 2 The amount of polymer water-absorbing resin in the middle polymer water-absorbing resin layer is 100-400 g / m 2 .

4. The adhesive-free reverse absorbing water-absorbing core according to claim 1, characterized in that: The thickness of the lower wood pulp ES chemical fiber mixed layer is greater than the thickness of the upper ES chemical fiber layer.

5. A process for preparing the adhesive-free reverse absorbing water-absorbing core according to claim 1, characterized in that: It includes the following steps: (1) Laying the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer on a workbench, with an exhaust fan and a vibrator provided below the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer, spraying the first polymer water-absorbing resin evenly on the upper side of the ES chemical fiber layer, and spraying the second polymer water-absorbing resin evenly on the upper side of the wood pulp ES chemical fiber mixed layer; (2) Under the action of the exhaust fan and the vibrator, the first polymer water-absorbing resin penetrates into the ES chemical fiber layer, and the second polymer water-absorbing resin penetrates into the wood pulp ES chemical fiber mixed layer; (3) Turn the upper side of the ES chemical fiber layer downward, and lay the ES chemical fiber layer on top of the wood pulp ES chemical fiber mixed layer under the action of the exhaust fan; (4) performing a heating treatment to make the ES fibers on the ES chemical fiber layer and the wood pulp ES chemical fiber mixed layer adhere to each other to form a molded body, and then winding and slitting after cooling to obtain a water-absorbing core body with no glue and reverse absorption; The polymer water-absorbing resin layer includes a first polymer water-absorbing resin and a second polymer water-absorbing resin, wherein the first polymer water-absorbing resin is infiltrated into the lower surface of the upper ES chemical fiber layer, and the second polymer water-absorbing resin is infiltrated into the upper surface of the lower wood pulp ES chemical fiber mixed layer; The particle size of the first polymer water-absorbing resin is 120-300 mesh, and the particle size of the second polymer water-absorbing resin is 100-120 mesh; the water absorption rate of the first polymer water-absorbing resin is 50-180 times, and the water absorption rate of the second polymer water-absorbing resin is 110-260 times; the dosage of the first polymer water-absorbing resin is 50-200 g / m 2 The amount of the second polymer water-absorbing resin is 50 to 200 g / m 2 .

6. The process for preparing the adhesive-free reverse absorbing water-absorbing core according to claim 5, characterized in that: In step (4), the temperature of the heating treatment is 100 to 150°C.

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