Preparation process of an ultra-thin absorbent paper

Abstract

The present invention belongs to the technical field of hygiene product materials, and particularly relates to a preparation process of an ultra-thin absorbent paper. Among them, the ultra-thin absorbent paper comprises the following raw materials in parts by weight: 15-35 parts of base paper pulp, 3-5.5 parts of SAP, 0.2-0.4 part of wet strength agent, 0.8-1.2 parts of passivating agent, and 20 parts of wet pulp. The wet pulp prepared by defibrating fluff pulp and softwood pulp can form an oily physical barrier by relying on the abundant hydrophobic groups in the molecular chain after being compounded with the passivating agent, reducing the direct contact ability between SAP and water molecules, improving the "water robbing" phenomenon of SAP. At the same time, the process flow is improved, the feeding uniformity of SAP and the production efficiency are improved, providing a safer, more efficient and more stable technical solution for the industrial production of absorbent paper.

Description

Technical Field

[0001] The present invention belongs to the technical field of hygiene product materials, and particularly relates to a preparation process for ultra-thin absorbent paper. Background Art

[0002] As a special kind of household paper, absorbent paper is widely used in the field of hygiene materials, especially playing a key role in absorbing and storing water molecules in the absorbent core. Its main absorption component is superabsorbent polymer (SAP), which realizes the functions of water absorption, water diversion and distribution by being compounded with fiber materials. However, there are still significant defects in the preparation process of absorbent paper on the market at present. In the traditional dry compounding process, SAP and fluff pulp are mainly combined mechanically, and they are dispersed in a physical state. This combination method not only causes SAP to easily detach from the fiber material, affecting the overall performance of the absorbent paper, but also may cause allergic reactions to some sensitive people due to the direct contact of SAP particles with the skin. Although the wet compounding process can improve the combination of SAP and fibers to a certain extent, there is a phenomenon of "water robbing" of the absorbent resin during the production process, resulting in a significant attenuation of its water absorption performance. In addition, production instability problems are also prone to occur in the wet process, such as uneven distribution of SAP polymers, particle dispersion and blockage of equipment, etc., thus affecting product quality and production efficiency.

[0003] Therefore, it is particularly important to solve the problems of unstable material combination, attenuation of water absorption performance and potential skin safety during the production and use of absorbent paper by improving the existing technologies and processes. Summary of the Invention

[0004] In view of the above situation, the present invention provides a preparation process for ultra-thin absorbent paper. By introducing an oily hydrophobic group onto the SAP material using a passivating agent, combining the passivation technology and optimizing the composite papermaking process, a new type of absorbent paper is developed, which greatly improves the "water robbing" phenomenon of SAP by relying on strong chemical bonding, enhances the comprehensive performance of the absorbent paper, overcomes the defects of traditional processes, and improves the continuity and stability of production.

[0005] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0006] The present invention provides a preparation process for ultra-thin absorbent paper for preparing ultra-thin absorbent paper. The ultra-thin absorbent paper comprises the following raw materials in parts by weight: 15 - 35 parts of base paper stock, 3 - 5.5 parts of SAP, 0.2 - 0.4 part of wet strength agent, 0.8 - 1.2 parts of passivating agent and 20 parts of wet pulp.

[0007] Further, the passivating agent is composed of the following raw materials in weight percentages: 50% SDBS (sodium dodecylbenzenesulfonate), 25% TX-10 (alkylphenol polyoxyethylene ether) and 25% OP-10 (octylphenol polyoxyethylene ether).

[0008] Further, the wet strength agent is selected from any one of PEI (polyethyleneimine resin), UF (urea-formaldehyde resin), and PAE (polyamide polyamine epichlorohydrin resin).

[0009] Further, the base paper pulp comprises the following raw materials in weight percentages: 40% fluff pulp and 60% softwood pulp, and the base paper pulp is prepared by pulping 40% fluff pulp and 60% softwood pulp.

[0010] Further, the wet pulp comprises the following raw materials in weight percentages: 40% fluff pulp and 60% softwood pulp, and the preparation process of the wet pulp comprises the following steps:

[0011] S1: Weigh fluff pulp and softwood pulp in a mass ratio of 2:3, place them in a pulper and pulp for 10 min to obtain wet base pulp;

[0012] S2: Transfer the wet base pulp obtained in step S1 to a refiner, and refine it at a power of 30 kWh / t to obtain wet pulp, controlling the beating degree to be 13 - 15°SR and the wet weight to be 23 - 24 g.

[0013] The preparation process of the ultra-thin absorbent paper specifically comprises the following steps:

[0014] Step 1: Weigh 15 - 35 parts of base paper pulp and beat it in a refiner at a power of 40 kWh / t to obtain base paper for papermaking, controlling the beating degree to be 15 - 18°SR and the wet weight to be 19 - 21 g;

[0015] Step 2: Weigh 0.2 - 0.4 parts of wet strength agent, and use a paper machine to make paper from the base paper for papermaking obtained in step 1, continuously adding the weighed wet strength agent during the papermaking process to obtain base paper, controlling the weight of the base paper to be 15 - 35 g / m 2 、longitudinal dry strength to be 5 - 7 N / m, longitudinal wet tensile strength to be 0.3 - 0.5 N / m, and the density of the base paper to be 175 - 177 kg / m 3 ;

[0016] Step 3: After unrolling the base paper obtained in step 2 through an unrolling frame, obtain the unrolled base paper. Weigh 20 parts of wet pulp and 0.8 - 1.2 parts of passivator, mix them and then make paper in a vacuum cylinder rewinder. The vacuum cylinder rewinder includes a blanking machine, guide roller 1, guide roller 2, guide roller 3, traction roller, upper pressure roller, lower pressure roller, support roller, felt, and drying cylinder;

[0017] Step 4: Weigh 3 - 5.5 parts of SAP and place it in the blanking machine, controlling the SAP blanking speed to be 10 - 60 g / m 2, after starting the feeding, SAP will be dispersed on the surface of the wet paper. Meanwhile, the unwinding base paper is introduced to the upper and lower pressing rollers by the traction rollers, and is compounded and extruded with the wet paper with SAP dispersed on its surface, and then is pressed, dried, wrinkled and wound by the supporting rollers and the drying cylinder to obtain the ultra-thin absorbent paper.

[0018] Furthermore, the feeder is located above the felt.

[0019] Furthermore, the angle between the unwinding base paper between the traction rollers and the upper pressing roller and the felt is 45°.

[0020] Furthermore, the feeder is heated and insulated by an oil pipe.

[0021] The beneficial effects obtained by the present invention are as follows:

[0022] For the ultra-thin absorbent paper prepared by the present invention, using fluff pulp and softwood pulp as the main pulp base paper, by adding a passivator during the wet paper making process, it can effectively solve the defect of the attenuation of the absorption performance of the absorbent paper caused by the "water grabbing" of SAP. The rich hydrophobic alkyl chains, aryl structures, sulfonic acid groups and other surface active groups and polyoxyethylene chains and other weakly polar groups in the passivator can have a physical shielding effect with the hydrophilic groups such as carboxyl and hydroxyl groups of SAP, reducing the direct contact ability between SAP and water molecules, and at the same time forming a molecular-level oily barrier on the surface of SAP; in addition, the present invention optimizes the preparation process of the absorbent paper, combines the vacuum cylinder rewinder, the polymer passivation technology and the unwinding rack, provides an improved preparation method, greatly improves the production efficiency, and at the same time increases the traction rollers, so that the angle between the base paper and the felt is adjusted to 45°, avoiding the fine powder particles of SAP from flying outside the wet paper, swelling and adsorbing with water and blocking the felt, ensuring the continuous and stable production. The oil pipe heating and insulation design adopted by the feeder effectively prevents SAP from gelling in the water vapor environment and causing uneven feeding.

[0023] The present invention improves the performance of the absorbent paper and the reliability of the production process by improving the passivation technology and optimizing the composite process, reduces the dosage of SAP, and provides a safer, more efficient and more stable technical solution for the industrial production of absorbent paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the process flow chart of the preparation of the ultra-thin absorbent paper of the present invention;

[0025] Figure 2 is the schematic diagram of the production line of Examples 1-4 and Comparative Example 1 in the vacuum cylinder rewinder;

[0026] Figure 3 is the detection result of the rewet amount of Examples 1-4 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are only for illustration purposes and do not limit the content of this application.

[0029] In the following embodiments, the preparation process of the ultra-thin absorbent paper is as Figure 1 shown, and the working process of the vacuum cylinder multi-cylinder former is as Figure 2 shown. Unless otherwise specified, they are all conventional methods; the materials used in the following embodiments, unless otherwise specified, the raw materials are all new materials purchased from the market.

[0030] Embodiment 1: This embodiment provides a preparation process for an ultra-thin absorbent paper for preparing an ultra-thin absorbent paper. The ultra-thin absorbent paper comprises the following raw materials in parts by weight: 25 parts of base paper pulp, 4.5 parts of SAP, 0.3 part of PEI, 1 part of passivator, and 20 parts of wet pulp.

[0031] The wet pulp comprises the following raw materials in parts by weight: 12 parts of fluff pulp and 18 parts of softwood pulp. The specific preparation process comprises the following steps:

[0032] S1: Weigh 12 parts of fluff pulp and 18 parts of softwood pulp and place them in a pulper for pulping for 10 min to obtain wet base pulp.

[0033] S2: Transfer the wet base pulp obtained in step S1 to a refiner and carry out refining under the condition of 30 kWh / t to obtain wet pulp. Use a freeness meter and a wet weight meter of pulp fibers to monitor and control the freeness and wet weight of the wet pulp in real time, and control the freeness to be 13°SR and the wet weight to be 24 g.

[0034] The preparation process of the ultra-thin absorbent paper specifically comprises the following steps:

[0035] Step 1: Weigh 25 parts of base paper pulp and beat it in a beater with a power of 40 kWh / t to obtain base paper for copying, and control the freeness to be 16°SR and the wet weight to be 20 g.

[0036] Step 2: Weigh 0.3 parts of PEI. Use a paper-making machine to make the base paper obtained in Step 1. Continuously add the weighed wet strength agent during the papermaking process to obtain the base paper. Control the basis weight of the base paper to be 20 g / m 2 , the longitudinal dry strength is 6 N / m, the longitudinal wet tensile strength is 0.4 N / m, and the density of the base paper is 177 kg / m 3 ;

[0037] Step 3: After unwinding the base paper obtained in Step 2 through an unwinding rack, obtain the unwound base paper. Weigh 20 parts of wet pulp and 1 part of passivator, mix them, and then make paper on a vacuum cylinder rewinder to obtain wet paper. The vacuum cylinder rewinder includes a feeding machine, guide roller 1, guide roller 2, guide roller 3, traction roller, upper pressure roller, lower pressure roller, support roller, felt, and drying cylinder;

[0038] Step 4: Weigh 4.5 parts of SAP and place it in the feeding machine. Control the feeding speed of SAP to be 30 g / m 2 . After starting the feeding, SAP will be dispersed on the surface of the wet paper. At the same time, use the traction roller to introduce the unwound base paper to the upper pressure roller and the lower pressure roller, and compound and extrude it with the wet paper with SAP dispersed on the surface. Then, through the support roller and the drying cylinder, it is pressed, dried, wrinkled, and wound to obtain the ultra-thin absorbent paper.

[0039] Example 2: This example provides a preparation process for ultra-thin absorbent paper for preparing ultra-thin absorbent paper. The ultra-thin absorbent paper includes the following raw materials in parts by weight: 15 parts of base paper stock, 9 parts of softwood pulp, 3 parts of SAP, 0.2 parts of UF, 0.8 parts of passivator, and 20 parts of wet pulp.

[0040] The wet pulp includes the following raw materials in parts by weight: 12 parts of fluff pulp and 18 parts of softwood pulp. The specific preparation process includes the following steps:

[0041] S1: Weigh 12 parts of fluff pulp and 18 parts of softwood pulp and place them in a pulper for pulping for 10 min to obtain wet paper stock;

[0042] S2: Transfer the wet paper stock obtained in Step S1 to a refiner and refine it under the condition of 30 kWh / t to obtain wet pulp. Use a beating degree meter and a wet weight meter of pulp fibers to monitor and control the beating degree and wet weight of the wet pulp in real time. Control the beating degree to be 15°SR and the wet weight to be 23 g.

[0043] The preparation process of the ultra-thin absorbent paper specifically includes the following steps:

[0044] Step 1: Weigh 15 parts of base paper stock and beat it in a beater at a power of 40 kWh / t to obtain the base paper for papermaking. Control the beating degree to be 18°SR and the wet weight to be 19 g;

[0045] Step 2: Weigh 0.2 parts of UF. Use a paper-making machine to form the base paper obtained in Step 1. Continuously add the weighed wet strength agent during the papermaking process to obtain the base paper. Control the basis weight of the base paper to be 25 g / m 2 , the longitudinal dry strength to be 7 N / m, the longitudinal wet tensile strength to be 0.3 N / m, and the density of the base paper to be 175 kg / m 3 ;

[0046] Step 3: After unwinding the base paper obtained in Step 2 through an unwinding rack, obtain the unwound base paper. Weigh 20 parts of wet pulp and 0.8 parts of passivator, mix them, and then form them in a vacuum cylinder rewinder to obtain wet paper. The vacuum cylinder rewinder includes a feeding machine, guide roller 1, guide roller 2, guide roller 3, traction roller, upper pressing roller, lower pressing roller, supporting roller, felt, and drying cylinder;

[0047] Step 4: Weigh 3 parts of SAP and place it in the feeding machine. Control the feeding speed of SAP to be 10 g / m 2 . After starting the feeding, SAP will disperse on the surface of the wet paper. At the same time, use the traction roller to introduce the unwound base paper to the upper pressing roller and the lower pressing roller, and compound and extrude it with the wet paper with SAP dispersed on the surface. Then, through the supporting roller and the drying cylinder, it is pressed, dried, wrinkled, and wound to obtain the ultra-thin absorbent paper.

[0048] Example 3: This example provides a preparation process for ultra-thin absorbent paper for preparing ultra-thin absorbent paper. The ultra-thin absorbent paper includes the following raw materials in parts by weight: 35 parts of base paper stock, 5.5 parts of SAP, 0.4 parts of PAE, 1.2 parts of passivator, and 20 parts of wet pulp.

[0049] The wet pulp includes the following raw materials in parts by weight: 12 parts of fluff pulp and 18 parts of softwood pulp. The specific preparation process includes the following steps:

[0050] S1: Weigh 12 parts of fluff pulp and 18 parts of softwood pulp, place them in a pulper, and disintegrate for 10 min to obtain wet paper stock;

[0051] S2: Transfer the wet paper stock obtained in Step S1 to a refiner, and refine it under the condition of 30 kWh / t to obtain wet pulp. Use a beating degree meter and a wet weight meter of pulp fibers to monitor and control the beating degree and wet weight of the wet pulp in real time, and control the beating degree to be 14°SR and the wet weight to be 23 g.

[0052] The preparation process of the ultra-thin absorbent paper specifically includes the following steps:

[0053] Step 1: Weigh 35 parts of base paper stock and beat it in a beater at a power of 40 kWh / t to obtain the base paper for forming. Control the beating degree to be 17°SR and the wet weight to be 21 g;

[0054] Step 2: Weigh 0.2 parts of PAE, and use a paper-making machine to make the base paper obtained in Step 1. Continuously add the weighed wet strength agent during the papermaking process to obtain the base paper. Control the basis weight of the base paper to be 35 g / m 2 , the longitudinal dry strength is 5 N / m, the longitudinal wet tensile strength is 0.5 N / m, and the density of the base paper is 176 kg / m 3 ;

[0055] Step 3: After unwinding the base paper obtained in Step 2 through an unwinding rack, the unwound base paper is obtained. Weigh 20 parts of wet pulp and 1.2 parts of passivator, mix them and then carry out papermaking in a vacuum cylinder rewinder to obtain wet paper. The vacuum cylinder rewinder includes a feeding machine, guide roller 1, guide roller 2, guide roller 3, traction roller, upper pressing roller, lower pressing roller, supporting roller, felt and drying cylinder;

[0056] Step 4: Weigh 5.5 parts of SAP and place it in the feeding machine, control the feeding speed of SAP to be 60 g / m 2 , after starting the feeding, SAP will be dispersed on the surface of the wet paper. At the same time, use the traction roller to introduce the unwound base paper to the upper pressing roller and the lower pressing roller, and compound and extrude it with the wet paper with SAP dispersed on the surface, and then carry out calendering, drying, wrinkling and winding through the supporting roller and the drying cylinder to obtain the ultra-thin absorbent paper.

[0057] Example 4: This example provides a preparation process for ultra-thin absorbent paper for preparing ultra-thin absorbent paper. The ultra-thin absorbent paper includes the following raw materials in parts by weight: 20 parts of base paper stock, 12 parts of softwood pulp, 3 parts of SAP, 0.4 parts of PAE, 1 part of passivator and 20 parts of wet pulp.

[0058] The wet pulp includes the following raw materials in parts by weight: 12 parts of fluff pulp and 18 parts of softwood pulp. The specific preparation process includes the following steps:

[0059] S1: Weigh 12 parts of fluff pulp and 18 parts of softwood pulp and place them in a pulper for pulping for 10 min to obtain wet paper stock;

[0060] S2: Transfer the wet paper stock obtained in Step S1 to a refiner and carry out refining under the condition of 30 kWh / t to obtain wet pulp. Use a beating degree meter and a wet weight measuring instrument for pulp fibers to monitor and control the beating degree and wet weight of the wet pulp in real time, and control the beating degree to be 13°SR and the wet weight to be 23 g.

[0061] The preparation process of the ultra-thin absorbent paper specifically includes the following steps:

[0062] Step 1: Weigh 20 parts of base paper stock and beat it in a beater at a power of 40 kWh / t to obtain the base paper for papermaking. Control the beating degree to be 15°SR and the wet weight to be 20 g;

[0063] Step 2: Weigh 0.4 parts of PAE. Use a paper making machine to make the base paper obtained in Step 1. Continuously add the weighed wet strength agent during the papermaking process to obtain the base paper. Control the basis weight of the base paper to be 15 g / m 2 , the longitudinal dry strength to be 6 N / m, the longitudinal wet tensile strength to be 0.5 N / m, and the density of the base paper to be 175 kg / m 3 ;

[0064] Step 3: After unwinding the base paper obtained in Step 2 through an unwinding rack, obtain the unwound base paper. Weigh 20 parts of wet pulp and 1 part of passivator, mix them, and then make paper on a vacuum cylinder rewinder to obtain wet paper. The vacuum cylinder rewinder includes a feeding machine, guide roller 1, guide roller 2, guide roller 3, traction roller, upper pressing roller, lower pressing roller, supporting roller, felt, and drying cylinder;

[0065] Step 4: Weigh 3 parts of SAP and place them in the feeding machine. Control the feeding speed of SAP to be 20 g / m 2 . After starting the feeding, the SAP will be dispersed on the surface of the wet paper. At the same time, use the traction roller to introduce the unwound base paper to the upper pressing roller and the lower pressing roller, and compound and extrude it with the wet paper with SAP dispersed on the surface. Then, perform calendering and drying, wrinkling, and winding through the supporting roller and the drying cylinder to obtain the ultra-thin absorbent paper.

[0066] The difference between Comparative Example 1 and Example 4 is that the passivator is not added, and the rest is the same as Example 4.

[0067] Investigation of water absorption performance

[0068] Respectively weigh 10.0 g (W 0 ) of the ultra-thin absorbent paper prepared in Examples 1-4 and Comparative Example 1. After measuring the thickness of the ultra-thin absorbent paper with a vernier caliper, lay it flat at the bottom of a 200-mesh sieve, and then completely immerse it in 0.9% physiological saline at 37°C. Take it out after 5 minutes and hang it for 2 minutes, and weigh the weight of the ultra-thin absorbent paper (W). According to the formula: water absorption ratio = (W - W 0 ) / W 0 , calculate the water absorption ratio of the ultra-thin absorbent paper prepared in Examples 1-4 and Comparative Example 1. The results are shown in Table 1.

[0069] Investigation of rewetting amount

[0070] Respectively weigh 10.0 g of the ultra-thin absorbent paper prepared in Examples 1-4 and Comparative Example 1, place it on a liquid penetration comprehensive tester, measure 40 mL of 0.9% physiological saline and quickly pour it into the funnel. After discharging the liquid for 5 minutes, place a sufficient amount of filter paper on the surface of the ultra-thin absorbent paper, press a standard pressing block with a diameter of 100 mm and a mass of (1.2 ± 0.002) kg, and start timing. After 1 minute, read the result, accurate to 0.01 g. Repeat the above operation 5 times, and take the average value of the results, as shown in Figure 3 .

[0071] Table 1 Water Absorption Performance of Ultra-Thin Water Absorbent Paper

[0072]

[0073] The results in Table 1 show that when the thickness of the ultra-thin water absorbent paper prepared in Examples 1-4 is less than 1 mm, the water absorption ratio is as high as about 40 times. Compared with the water absorption ratio of Comparative Example 1, it has a significant water absorption advantage, indicating that the addition of the passivator can greatly improve the "water robbing" phenomenon of SAP.

[0074] Figure 2 Figure 1 is a schematic diagram of the production line based on a vacuum cylinder rewinder for Examples 1-4 and Comparative Example 1. The unwound base paper reaches the upper and lower pressing rollers through guide roller 1, guide roller 2 and the traction roller. The wet paper is on the felt, and after being compounded with SAP through guide roller 3, it is then compounded with the unwound base paper at the upper and lower pressing rollers, extruded, and then pressed again and dried, wrinkled and wound at the drying cylinder and the supporting roller to obtain the ultra-thin water absorbent paper in one step.

[0075] Figure 3 The results of the rewetting amount show that when the liquid addition amount is below 80 mL, the rewetting amounts of Examples 1-4 are all less. As the liquid addition amount increases, the rewetting amount increases. This is because when the physiological saline enters the ultra-thin water absorbent paper, the good fiber state and a large number of hydrophilic groups of the fluff pulp and the softwood pulp are prone to capillary action, enabling the physiological saline to better diffuse in the water absorbent paper and be quickly absorbed by SAP. At the same time, the passivator reduces the "water robbing" ability of SAP and is more likely to lock in the moisture.

[0076] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0077] The above describes the present invention and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar ways and embodiments without creative efforts without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A process for preparing ultra-thin absorbent paper, for preparing ultra-thin absorbent paper, characterized in that: The ultra-thin absorbent paper comprises the following raw materials in parts by weight: 15-35 parts of base paper pulp, 3-5.5 parts of SAP, 0.2-0.4 parts of wet strength agent, 0.8-1.2 parts of passivating agent and 20 parts of wet paper pulp; The passivator is composed of the following raw materials in weight percentage: 50% SDBS, 25% TX-10 and 25% OP-10; The preparation process of the ultra-thin absorbent paper specifically comprises the following steps: Step 1: weighing the base paper pulp and beating it to obtain the base paper for copying; Step 2: papermaking the base paper obtained in step 1, and adding a wet strength agent thereto to obtain base paper; Step 3: After the base paper obtained in step 2 is unwound, the unwound base paper is obtained, and wet pulp and a passivating agent are weighed, mixed, and paper-made to obtain wet paper; Step 4: Weigh the SAP blank, compound the unrolled base paper, SAP and wet paper, dry and roll them up to obtain ultra-thin absorbent paper.

2. The process for preparing ultrathin absorbent paper according to claim 1, characterized in that: In step 1, the base paper for copying has a beating degree of 15-18°SR and a wet weight of 19-21 g; In step 2, the papermaking process is carried out in a papermaking machine, and the base paper parameters are 15-35 g / m 2 , longitudinal dry strength 5-7 N / m, longitudinal wet tensile strength 0.3-0.5 N / m, density 175-177 kg / m 3 .

3. The process for preparing ultra-thin absorbent paper according to claim 1, characterized in that: The wet strength agent is selected from any one of PEI, UF ​​and PAE.

4. The process for preparing ultra-thin absorbent paper according to claim 1, characterized in that: The base paper pulp comprises the following raw materials in weight percentage: 40% fluff pulp and 60% coniferous wood pulp. The base paper pulp is prepared by crushing 40% fluff pulp and 60% coniferous wood pulp.

5. The process for preparing ultra-thin absorbent paper according to claim 1, characterized in that: The wet pulp comprises the following raw materials in weight percentage: 40% fluff pulp and 60% coniferous wood pulp. The preparation process of the wet pulp comprises the following steps: S1: Weigh fluff pulp and coniferous wood pulp and crush them to obtain wet paper pulp; S2: The wet paper stock obtained in step S1 is deflocculent to obtain wet paper pulp.

6. The process for preparing ultra-thin absorbent paper according to claim 5, characterized in that: In step S2, the wet pulp has a beating degree of 13-15°SR and a wet weight of 23-24 g.

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