Preparation method of high wet strength and high water absorbency wet curtain paper

Abstract

The invention provides a preparation method of high wet strength and high water absorbency wet curtain paper. The wet papermaking process is adopted to uniformly disperse mixed fibers such as plant fibers, water-soluble synthetic PVA bonding fibers and two-component composite fibers in an oil-water medium, and the mixed fibers are piled into a fiber web in a certain proportion. Then, a thermal bonding process is combined to make the wet curtain paper have higher dry and wet strength and wet stiffness performance, and the wet curtain paper does not deform when immersed in water and has a long service life. A suitable antibacterial and mildew-proof agent is appropriately added to the fiber web to make the wet curtain paper have excellent antibacterial and mildew-proof functions.

Description

Technical Field

[0001] The invention belongs to the technical field of papermaking, and in particular relates to a method for preparing high-wet-strength and high-water-absorbent wet curtain paper. Background Art

[0002] The wet curtain cooling system consists of wet curtains, energy-saving fans, circulating water systems and control systems. Among them, wet curtain paper is an important air purification, humidification and filtration medium material, mainly used in special industries with high requirements for humidity and temperature, such as poultry and animal husbandry, greenhouse and horticulture, industrial cooling, etc. The performance requirements are strong water absorption, high dry and wet strength, fast diffusion speed, long-lasting efficiency, large evaporation specific surface area, good cooling efficiency, etc. At the same time, it also needs to have high air permeability and antibacterial and mildew-proof properties, and have a certain filtering and cleaning effect on the air. Summary of the invention

[0003] The present invention aims to solve the following technical problems: As an important air purification, humidification and filtration medium material, wet curtain paper has performance requirements such as strong water absorption, high dry and wet strength, fast diffusion speed, long-lasting efficiency, large evaporation specific surface area, good cooling efficiency, etc. At the same time, it also needs to have high air permeability and antibacterial and mildew-proof properties, and have a certain filtering and cleaning effect on the air.

[0004] The invention provides a method for preparing a wet curtain paper with high wet strength and high water absorption.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for preparing a high wet strength and high water absorbency wet curtain paper comprises the following steps:

[0007] S1. Using water as a medium, the plant fibers are evenly dispersed through a pulping process, and in an oil-water dispersant medium, the water-soluble synthetic PVA bonding fibers and the two-component composite fibers are evenly dispersed into single fibers;

[0008] S2. In a mixer, the water-soluble synthetic PVA binder fiber and plant fiber are diluted with water and evenly mixed, and in a mixer, the water-soluble synthetic PVA binder fiber, plant fiber and two-component composite fiber are diluted with water and evenly mixed;

[0009] S3 controls the sizing flow rate ratio of the mixer and the mixer two, the dispersed and diluted mixed fibers are formed by the paper machine mesh section and most of the water is removed to form a fiber web;

[0010] S4. The fiber web is dehydrated by mechanical pressing and then led to a dryer for drying.

[0011] As a preferred technical solution, the method for preparing the high wet strength and high water absorbency wet curtain paper further comprises the following steps:

[0012] S5. The fiber web after the first drying is passed through an impregnation tank, and the chemical additive liquid is added to the fiber web after the impregnation process, and part of the impregnation mixture is removed by a squeeze roller;

[0013] S6. Lead the fiber web to dryer 2 for secondary drying.

[0014] As a preferred technical solution, the method for preparing the high wet strength and high water absorbency wet curtain paper further comprises the following steps:

[0015] S7. The fiber web after the second drying is subjected to a heat bonding and shaping process by an infrared heater.

[0016] As a preferred technical solution, the pulping concentration of the pulping process in step 1 is 3.0-6.0%, and the pulping stirring time is 30.0-60.0 min.

[0017] As a preferred technical solution, the plant fiber includes one or more of broadleaf pulp, coniferous pulp, cotton pulp, hemp pulp, and fluff pulp, with a beating degree of 10-15 °SR and a length of 0.2-5.0 mm, and the ratio of plant fiber to mixed fiber is 40.0%-75.0%; the average length of the water-soluble synthetic PVA bonding fiber is 2.0-10.0 mm, the fineness is 1.0-3.0D, and the ratio of PVA bonding fiber to mixed fiber is 5.0-30.0%; the two-component composite fiber is selected from one or more of PE / PP, PE / PET, CO-PET / PET, with an average length of 2.0-10.0 mm, the fineness is 2.0-5.0D, and the ratio of two-component fiber to mixed fiber is 20.0-50.0%.

[0018] As a preferred technical solution, in step 2, the stirring time of mixer 1 is 10-40 min, and the fiber dilution concentration is 0.2-1.0%; the stirring time of mixer 2 is 10-60 min, and the fiber dilution concentration is 0.2-1.0%; in step 3, the sizing flow ratio of mixer 1 and mixer 2 is 1:3-1:6.

[0019] As a preferred technical solution, the oil-water dispersant in step 1 is one of polyphosphates, polyacrylamide, anionic organic dispersants, cationic organic dispersants and non-ionic organic dispersants.

[0020] As a preferred technical solution, in step 4, the pressure of mechanical pressing is 0.1-0.4MPa, the drying temperature of dryer 1 is 80-150°C, and the moisture content of the fiber web after the first drying is 2.0%-10.0%; in step 5, the pressure of the liquid squeezing roller is 0.1-0.4MPa; in step 6, the drying temperature of dryer 2 is 100-180°C, and the moisture content of the fiber web after the second drying is 2.0%-10.0%.

[0021] As a preferred technical solution, the chemical additive liquid in step 5 includes 30.0-70.0% of an adhesive and 2.0-8.0% of an antibacterial and mildew-proof agent. The concentration of the chemical additive liquid is 1.0-5.0%. The adhesive is one or more of an acrylic adhesive, a pure acrylic adhesive, and a styrene-butadiene adhesive. The antibacterial and mildew-proof agent is one or more of nanosilver, zinc oxide, and copper ions.

[0022] As a preferred technical solution, the heating temperature of the infrared heater in step 7 is 200-300°C, the heating time is 5-15S, and the moisture content of the fiber web after drying is 0.1-2.0%.

[0023] After adopting the above technical solution, the present invention has the following advantages:

[0024] (1) The high-wet strength and high-absorbency wet curtain paper of the present invention has high water absorption. The international industry standard for natural water absorption is 60-70 mm / 5 min. The wet curtain paper produced by this method can naturally absorb 90-100 mm / 5 min, and the total amount of water absorbed can reach 2.8-3.3 times that of ordinary wet curtain paper. It has the characteristics of high water absorption, fast diffusion speed, large evaporation specific surface area, and good cooling efficiency.

[0025] (2) The high wet strength and high water absorbency wet curtain paper of the present invention has high wet strength. Compared with ordinary all-wood pulp absorbent paper, the wet curtain paper of the present invention has higher wet strength and wet stiffness performance, and is characterized by not deforming when immersed in water, and has a long service life. When the plant fibers are piled into a fiber web with uniform pore size, the water-soluble synthetic PVA bonding fiber and the two-component composite fiber are uniformly adhered to the surface of the plant fibers. When dehydrated at high temperature in a dryer, the water-soluble synthetic PVA bonding fiber and the two-component composite fiber produce hot melt bonding, so that the dried fiber web has higher dry and wet strength performance. After the mixed fiber is evenly dispersed into single fibers, because there are many hydrogen bonds on its surface, when the free water between the fibers is gradually removed (water content 35.0-40.0%) to form a wet fiber web, the hydrogen bonds between the plant fibers are gradually tightly combined, so that the wet fiber web has certain wet strength performance. The high wet strength and high water absorbency wet curtain paper adopts a thermal bonding process. Compared with absorbent paper, the wet curtain paper of the present invention has higher dry and wet strength and wet stiffness performance, and has the characteristics of not deforming when immersed in water, and has a long service life.

[0026] (3) The high wet strength and high water absorption wet curtain paper of the present invention adopts a two-component composite fiber, the fiber surface is smooth, there is no bonding force between the fibers, and it does not disperse in the water medium. With an oil-water dispersant as the medium and a wet process for papermaking, the two-component composite fiber can be evenly dispersed into single fibers, and stacked with plant fibers and water-soluble synthetic PVA bonding fibers into a fiber net with uniform pore size, and the fibers are evenly distributed, which cannot be achieved by dry process papermaking.

[0027] (3) The present invention adds a suitable amount of antibacterial and mildew-proof agent to the fiber web, so that the wet curtain paper has excellent antibacterial and mildew-proof functions, the antibacterial efficiency reaches 99.9%, and the mildew-proof grade reaches level 0.

[0028] (4) The high humidity strength and high water absorption wet curtain of the present invention has good economic benefits. As an important air purification, humidification and filtration medium material, the high humidity strength and high water absorption wet curtain paper has a cost of less than 15,000.0 yuan / T and a service life of up to 3-5 years. It is a non-toxic, harmless, green, safe, energy-saving and environmentally friendly material. It is mainly used in special industries with high temperature and humidity requirements such as poultry and animal husbandry, greenhouse and horticulture, and industrial cooling. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments.

[0030] Comparative Example

[0031] A method for preparing a high wet strength and high water absorbency wet curtain paper comprises the following steps:

[0032] (1) Raw materials preparation:

[0033] a. Using water as the medium, the plant fibers are evenly dispersed through a pulping process with a pulping concentration of 5.0% and a stirring time of 30.0 min.

[0034] The plant fiber is selected from one or more of hardwood pulp, conifer pulp, cotton pulp, hemp pulp, and fluff pulp, wherein the hardwood pulp accounts for 65.0% of the mixed fiber, the beating degree is 12°SR, and the average length is 4.0 mm;

[0035] b. In order to realize wet papermaking, a water-soluble synthetic PVA (polyvinyl alcohol) bonding fiber and PET (polyethylene terephthalate) fiber are added in the pulping process. When the plant fibers are piled into a fiber web with uniform pore size, the water-soluble synthetic PVA bonding fiber and PET fiber are uniformly adhered to the surface of the plant fibers. When dehydrated at high temperature in a dryer, the water-soluble synthetic PVA bonding fiber and PET fiber produce hot-melt bonding, so that the dried fiber web has higher dry and wet strength properties.

[0036] The average length of the water-soluble synthetic PVA bonding fiber is 4.0 mm, the fineness is 1.5D, and the proportion of the PVA bonding fiber to the mixed fiber is 5.0%.

[0037] The average length of the PET fibers is 12.0 mm, the fineness is 3.0D, and the proportion of the PET fibers in the mixed fibers is 30.0%.

[0038] (2) Preparation of fiber web:

[0039] a. In an aqueous medium, water-soluble synthetic PVA bonding fibers and PET fibers are uniformly dispersed into single fibers.

[0040] b. Dilute the synthetic PVA bonding fiber, PET fiber and plant fiber with water in a certain proportion in mixer 1 and mixer 2 respectively and mix them evenly;

[0041] In the two mixers, the plant fiber, PET fiber and synthetic PVA bonding fiber account for 65%, 30% and 5% of the mixed fiber respectively, the fiber stirring time is 30.0 min, and the dilution concentration is 0.5%.

[0042] The mass ratio of the mixed fibers in the mixer 1 and the mixer 2 is 1:1;

[0043] c. Control the sizing flow rate ratio of mixer 1 and mixer 2, form the dispersed and diluted mixed fibers through the paper machine net part, remove most of the water, and evenly stack them into a fiber net;

[0044] The sizing flow ratio of the mixer 1 and the mixer 2 is 1:1;

[0045] (3) In the water medium, after the mixed fiber is evenly dispersed into single fibers, there are many hydrogen bonds on its surface. When the free water between the fibers is gradually removed to form a wet fiber web, the hydrogen bonds between the plant fibers are gradually tightly combined, so that the wet fiber web has certain strength properties. After mechanical dehydration in the pressing section, the pressing pressure is 0.3MPa and the moisture content is 40.0%. The wet fiber web is then led to the 1# dryer for the first drying at a drying temperature of 140°C. After heating to evaporate the water, a dry fiber web with a moisture content of 8% is obtained;

[0046] (4) Fiber web impregnation treatment

[0047] a. According to the functional requirements of the multifunctional material, add the chemical additive mixture with corresponding functions into the dipping tank, stir at room temperature for 40 minutes, and dilute to a concentration of 3.0%;

[0048] The adhesive is one or more of acrylic adhesive, pure acrylic adhesive, styrene-butadiene adhesive, etc., and the amount of the adhesive is 40.0%.

[0049] The antibacterial and mildew-proof agent is one or more of nano silver, zinc oxide, copper ions, etc., and the dosage of the antibacterial and mildew-proof agent is 6.0%.

[0050] b. Pass the fiber web after the first drying through the impregnation tank, and add the chemical additive liquid to the fiber web through the impregnation process, with a speed of 35m / min; remove part of the mixed liquid through the squeezing roller, and the pressure of the squeezing roller is 0.3MPa;

[0051] c. Then the wet fiber web is led to the 2# dryer for high temperature heating and dehydration. The drying temperature is 160°C and the moisture content of the dried fiber web is 6%. The second dryer can also be equipped with an air flotation circulation fan with a power of 35Hz, so that the fiber web has antibacterial and anti-mildew functions.

[0052] (5) In order to improve the strength performance of the fiber web, the fiber web dried for the second time in the 2# dryer is subjected to a thermal bonding and shaping process using an infrared heater, so that the fiber web has higher dry and wet strength and wet stiffness performance, and does not deform when immersed in water.

[0053] The temperature of the infrared heater is 250°C, the heating time is 10S, and the moisture content of the fiber web after drying is 0.5%. Example 1

[0054] (1) Raw materials preparation:

[0055] a. Using water as the medium, the plant fibers are evenly dispersed through a pulping process with a pulping concentration of 5.0% and a stirring time of 30.0 min.

[0056] The plant fiber is selected from one or more of hardwood pulp, conifer pulp, cotton pulp, hemp pulp, and fluff pulp, wherein the hardwood pulp accounts for 65.0% of the mixed fiber, the beating degree is 12°SR, and the average length is 4.0 mm;

[0057] b. In order to realize wet papermaking, a water-soluble synthetic PVA bonding fiber and a two-component composite fiber are added during the pulping process. When the plant fibers are piled up into a fiber web with uniform pore size, the PVA bonding fiber and the two-component composite fiber are evenly adhered to the surface of the plant fibers. When dehydrated at high temperature in a dryer, the PVA bonding fiber and the two-component composite fiber produce hot-melt bonding, so that the dried fiber web has higher dry and wet strength properties.

[0058] The average length of the water-soluble synthetic PVA bonding fiber is 4.0 mm, the fineness is 1.5D, and the proportion of the PVA bonding fiber to the mixed fiber is 5.0%.

[0059] The two-component composite fiber is one or more of PE / PP, PE / PET, CO-PET / PET, with an average length of 5.0 mm and a fineness of 3.0D. The proportion of the two-component composite fiber to the mixed fiber is 30.0%.

[0060] (2) Preparation of fiber web:

[0061] a. In an oil-water dispersant medium, commercial synthetic PVA fibers and two-component composite fibers are uniformly dispersed into single fibers.

[0062] The oil-water dispersant is one of polyphosphate, polyacrylamide (PAM), anionic, cationic and nonionic;

[0063] b. In a mixer 1, the synthetic PVA bonding fiber and the plant fiber are diluted with water in a certain proportion and uniformly mixed; in a mixer 2, the synthetic PVA bonding fiber, the plant fiber and the two-component composite fiber are uniformly mixed in a certain proportion;

[0064] In the mixer, the plant fiber and the synthetic PVA bonding fiber account for 93% and 7% of the mixed fiber in the mixer, respectively, the fiber stirring time is 30.0 minutes, and the dilution concentration is 0.5%.

[0065] In the mixer 2, the proportions of plant fiber, two-component composite fiber and synthetic PVA bonding fiber to the mixed fiber in the mixer 2 are 65%, 30% and 5% respectively, the fiber stirring time is 60.0 minutes, and the dilution concentration is 0.5%.

[0066] The mass ratio of the mixed fibers in the mixer 1 to the mixed fibers in the mixer 2 is 1:4;

[0067] c. Controlling the sizing flow rate ratio of the mixer 1 and the mixer 2, forming the dispersed and diluted mixed fibers through the paper machine mesh part and removing most of the water, and respectively stacking them into fiber webs 1 and fiber webs 2 of different weights;

[0068] The sizing flow rate ratio of the mixer 1 to the mixer 2 is 1:6, and the quantitative ratio of the fiber web 1 to the fiber web 2 is 1:6;

[0069] (3) After the mixed fiber is evenly dispersed into single fibers in the oil-water dispersant medium, there are many hydrogen bonds on its surface. When the free water between the fibers is gradually removed to form a wet fiber web, the hydrogen bonds between the plant fibers are gradually tightly combined, so that the wet fiber web has certain strength properties. After mechanical dehydration in the pressing section, the pressing pressure is 0.3MPa and the moisture content is 40.0%. The wet fiber web is then led to the 1# dryer for the first drying at a drying temperature of 140°C. After heating to evaporate the water, a dry fiber web with a moisture content of 8% is obtained;

[0070] (4) Fiber web impregnation treatment

[0071] a. According to the functional requirements of the multifunctional material, add the chemical additive mixture with corresponding functions into the dipping tank, stir at room temperature for 40 minutes, and dilute to a concentration of 3.0%;

[0072] The adhesive is one or more of acrylic adhesive, pure acrylic adhesive, styrene-butadiene adhesive, etc., and the amount of the adhesive is 40.0%.

[0073] The antibacterial and mildew-proof agent is one or more of nano silver, zinc oxide, copper ions, etc., and the dosage of the antibacterial and mildew-proof agent is 6.0%.

[0074] b. Pass the fiber web after the first drying through the impregnation tank, and add the chemical additive liquid to the fiber web through the impregnation process, with a speed of 35m / min; remove part of the mixed liquid through the squeezing roller, and the pressure of the squeezing roller is 0.3MPa;

[0075] c. Then the wet fiber web is led to the 2# dryer for high temperature heating and dehydration. The drying temperature is 160°C and the moisture content of the dried fiber web is 6%. The second dryer can also be equipped with an air flotation circulation fan with a power of 35Hz, so that the fiber web has antibacterial and anti-mildew functions.

[0076] (5) In order to improve the strength performance of the fiber web, the fiber web dried for the second time in the 2# dryer is subjected to a thermal bonding and shaping process using an infrared heater, so that the fiber web has higher dry and wet strength and wet stiffness performance, and does not deform when immersed in water.

[0077] The temperature of the infrared heater is 250°C, the heating time is 10S, and the moisture content of the fiber web after drying is 0.5%. Example 2

[0078] (1) Raw materials preparation:

[0079] a. Using water as the medium, the plant fibers are evenly dispersed through a pulping process with a pulping concentration of 5.0% and a stirring time of 30.0 min.

[0080] The plant fiber is selected from one or more of hardwood pulp, conifer pulp, cotton pulp, hemp pulp, and fluff pulp, wherein the hardwood pulp accounts for 65.0% of the mixed fiber, the beating degree is 12°SR, and the average length is 4.0 mm;

[0081] b. In order to realize wet papermaking, a water-soluble synthetic PVA bonding fiber and a two-component composite fiber are added during the pulping process. When the plant fibers are piled up into a fiber web with uniform pore size, the PVA bonding fiber and the two-component composite fiber are evenly adhered to the surface of the plant fibers. When dehydrated at high temperature in a dryer, the PVA bonding fiber and the two-component composite fiber produce hot-melt bonding, so that the dried fiber web has higher dry and wet strength properties.

[0082] The average length of the water-soluble synthetic PVA bonding fiber is 4.0 mm, the fineness is 1.5D, and the proportion of the PVA bonding fiber to the mixed fiber is 5.0%.

[0083] The two-component composite fiber is one or more of PE / PP, PE / PET, CO-PET / PET, with an average length of 8.0 mm and a fineness of 5.0D. The proportion of the two-component composite fiber to the mixed fiber is 30.0%.

[0084] (2) Preparation of fiber web:

[0085] a. In an oil-water dispersant medium, commercial synthetic PVA fibers and two-component composite fibers are uniformly dispersed into single fibers.

[0086] The oil-water dispersant is one of polyphosphate, polyacrylamide (PAM), anionic, cationic and nonionic;

[0087] b. In a mixer 1, the synthetic PVA bonding fiber and the plant fiber are diluted with water in a certain proportion and uniformly mixed; in a mixer 2, the synthetic PVA bonding fiber, the plant fiber and the two-component composite fiber are uniformly mixed in a certain proportion;

[0088] In the mixer, the plant fiber and the synthetic PVA bonding fiber account for 93% and 7% of the mixed fiber in the mixer, respectively, the fiber stirring time is 30.0 minutes, and the dilution concentration is 0.5%.

[0089] In the mixer 2, the proportions of plant fiber, two-component composite fiber and synthetic PVA bonding fiber to the mixed fiber in the mixer 2 are 65%, 30% and 5% respectively, the fiber stirring time is 60.0 minutes, and the dilution concentration is 0.5%.

[0090] The mass ratio of the mixed fibers in the mixer 1 to the mixed fibers in the mixer 2 is 1:4;

[0091] c. Controlling the sizing flow rate ratio of the mixer 1 and the mixer 2, forming the dispersed and diluted mixed fibers through the paper machine mesh part and removing most of the water, and respectively stacking them into fiber webs 1 and fiber webs 2 of different weights;

[0092] The sizing flow rate ratio of the mixer 1 to the mixer 2 is 1:6, and the quantitative ratio of the fiber web 1 to the fiber web 2 is 1:6;

[0093] (3) After the mixed fiber is evenly dispersed into single fibers in the oil-water dispersant medium, there are many hydrogen bonds on its surface. When the free water between the fibers is gradually removed to form a wet fiber web, the hydrogen bonds between the plant fibers are gradually tightly combined, so that the wet fiber web has certain strength properties. After mechanical dehydration in the pressing section, the pressing pressure is 0.3MPa and the moisture content is 40.0%. The wet fiber web is then led to the 1# dryer for the first drying at a drying temperature of 140°C. After heating to evaporate the water, a dry fiber web with a moisture content of 8% is obtained;

[0094] (4) Fiber web impregnation treatment

[0095] a. According to the functional requirements of the multifunctional material, add the chemical additive mixture with corresponding functions into the dipping tank, stir at room temperature for 40 minutes, and dilute to a concentration of 3.0%;

[0096] The adhesive is one or more of acrylic adhesive, pure acrylic adhesive, styrene-butadiene adhesive, etc., and the amount of the adhesive is 40.0%.

[0097] The antibacterial and mildew-proof agent is one or more of nano silver, zinc oxide, copper ions, etc., and the dosage of the antibacterial and mildew-proof agent is 6.0%.

[0098] b. Pass the fiber web after the first drying through the impregnation tank, and add the chemical additive liquid to the fiber web through the impregnation process, with a speed of 35m / min; remove part of the mixed liquid through the squeezing roller, and the pressure of the squeezing roller is 0.3MPa;

[0099] c. Then the wet fiber web is led to the 2# dryer for high temperature heating and dehydration. The drying temperature is 160°C and the moisture content of the dried fiber web is 6%. The second dryer can also be equipped with an air flotation circulation fan with a power of 35Hz, so that the fiber web has antibacterial and anti-mildew functions.

[0100] (5) In order to improve the strength performance of the fiber web, the fiber web dried for the second time in the 2# dryer is subjected to a thermal bonding and shaping process using an infrared heater, so that the fiber web has higher dry and wet strength and wet stiffness performance, and does not deform when immersed in water.

[0101] The temperature of the infrared heater is 250°C, the heating time is 10S, and the moisture content of the fiber web after drying is 0.5%.

[0102] The effects of different contents and specifications of the two-component composite fibers on the performance of the wet curtain paper are listed in the examples, and the specific data are shown in Table 1.

[0103] Table 1 Effect of two-component composite fiber on the performance of wet curtain paper

[0104]

[0105] Compared with Example 1 and Example 2, the wet curtain paper in the comparative example uses PET fiber. The data show that when the content of the two-component composite fiber in the comparative example is 0%, the longitudinal and transverse wet tensile strengths of the wet curtain paper are only 0.60kN / m and 0.37kN / m; and when the content of the two-component composite fiber increases to 30%, the longitudinal and transverse wet tensile strengths of the wet curtain paper are significantly improved. Compared with the wet curtain paper obtained in the comparative example, the wet curtain paper with the two-component composite fiber added does not deform when immersed in water.

[0106] The performance data in Example 1 and Example 2 show the influence of different specifications of bicomponent composite fibers on the performance of wet curtain paper. Under the condition that other parameters remain unchanged, when the specifications of the bicomponent composite fiber are increased from 3.0D*5mm to 5.0D*8mm, the dry and wet transverse tensile strengths of the wet curtain paper are increased to 2.01kN / m and 0.8kN / m, respectively.

[0107] The international industry standard for natural water absorption is 60-70mm / 5min. The wet curtain paper made in this way can absorb 90-100mm / 5min of water naturally, and the total water absorption can reach 2.8-3.3 times / 5min. It is a wet curtain paper material with high wet strength, high water absorption, fast diffusion speed, and large evaporation specific surface area. It is non-toxic, harmless, green and safe, energy-saving and environmentally friendly.

[0108] In addition to the above preferred embodiments, the present invention has other implementation modes. Those skilled in the art may make various changes and modifications based on the present invention. As long as they do not depart from the spirit of the present invention, they should all fall within the scope defined by the claims attached to the present invention.

Claims

1. A method for preparing a high wet strength and high water absorbency wet curtain paper, characterized in that: The following steps are involved: S1. Using water as a medium, the plant fibers are uniformly dispersed through a pulping process, and in an oil-water dispersant medium, water-soluble synthetic PVA bonding fibers and bicomponent composite fibers are uniformly dispersed into single fibers; the oil-water dispersant is one of a polyphosphate, an anionic organic dispersant, a cationic organic dispersant and a non-ionic organic dispersant; S2. The water-soluble synthetic PVA binder fiber and the plant fiber are diluted with water and evenly mixed in a mixer, and the water-soluble synthetic PVA binder fiber, the plant fiber and the two-component composite fiber are diluted with water and evenly mixed in a mixer; S3 controls the sizing flow rate ratio of the mixer and the mixer two, the dispersed and diluted mixed fibers are formed by the paper machine mesh section and most of the water is removed to form a fiber web; S4. The fiber web is mechanically squeezed and dehydrated, and then introduced into a dryer for drying; the plant fiber comprises one or more of hardwood pulp, conifer pulp, cotton pulp, hemp pulp, and fluff pulp, the beating degree is 10-15 °SR, the length is 0.2-5.0 mm, and the ratio of plant fiber to mixed fiber is 40.0%-75.0%; the average length of the water-soluble synthetic PVA bonding fiber is 2.0-10.0 mm, the fineness is 1.0-3.0D, and the ratio of PVA bonding fiber to mixed fiber is 5.0-30.0%; the two-component composite fiber is selected from one or more of PE / PP, PE / PET, and CO-PET / PET, the average length is 2.0-10.0 mm, the fineness is 2.0-5.0D, and the ratio of the two-component composite fiber to mixed fiber is 20.0-50.0%; S5. The fiber web after the first drying is passed through an impregnation tank, and a chemical additive liquid is added to the fiber web through an impregnation process, and a portion of the impregnation mixture is removed by a squeeze roller; the chemical additive liquid includes 30.0-70.0% of an adhesive, 2.0-8.0% of an antibacterial and mildew-proof agent, and the concentration of the chemical additive liquid is 1.0-5.0%, the adhesive is one or more of an acrylic adhesive, a pure acrylic adhesive, and a styrene-butadiene adhesive, and the antibacterial and mildew-proof agent is one or more of nano-silver, zinc oxide, and copper ions; S6. The fiber web is directed to the second dryer for secondary drying; S7. The fiber web after the second drying is subjected to a heat bonding and shaping process by an infrared heater.

2. The method for preparing the high wet strength and high water absorbency wet curtain paper according to claim 1, characterized in that: The pulping concentration of the pulping process in step S1 is 3.0-6.0%, and the pulping stirring time is 30.0-60.0 min.

3. The method for preparing the high wet strength and high water absorbency wet curtain paper according to claim 1, characterized in that: The oil-water dispersant in step S1 is polyacrylamide.

4. The method for preparing the high wet strength and high water absorbency wet curtain paper according to claim 1, characterized in that: In step S2, the stirring time of mixer 1 is 10-40min, and the fiber dilution concentration is 0.2-1.0%; the stirring time of mixer 2 is 10-60min, and the fiber dilution concentration is 0.2-1.0%. In step S3, the sizing flow ratio of mixer 1 to mixer 2 is 1:3-1:

6.

5. The method for preparing the high wet strength and high water absorbency wet curtain paper according to claim 1, characterized in that: In step S4, the pressure of mechanical pressing is 0.1-0.4 MPa, the drying temperature of dryer 1 is 80-150 °C, and the moisture content of the fiber web after the first drying is 2.0%-10.0%; in step S5, the pressure of the liquid squeezing roller is 0.1-0.4 MPa; in step S6, the drying temperature of dryer 2 is 100-180 °C, and the moisture content of the fiber web after the second drying is 2.0%-10.0%.

6. The method for preparing the high wet strength and high water absorbency wet curtain paper according to claim 4, characterized in that: In step S7, the heating temperature of the infrared heater is 200-300° C., the heating time is 5-15 seconds, and the moisture content of the fiber web after drying is 0.1-2.0%.

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