A production method of environment-friendly handbag paper

Abstract

The present application belongs to the field of new papermaking materials, and particularly relates to a production method of an environment-friendly handbag paper, which mainly comprises coniferous wood pulp, broadleaf wood pulp, regenerated cellulose fiber and carboxyl styrene butadiene latex, wherein the coating amount of the carboxyl styrene butadiene latex on the paper surface is 1.5-2.5 g / m 2 The environment-friendly handbag paper uses cellulose as the main raw material, belongs to the category of biomass products, can be completely degraded, and has the characteristics of high toughness in dry or wet state due to the use of regenerated cellulose fiber. The environment-friendly handbag paper is helpful to improve the elasticity of paper, is an especially important performance for producing handbag paper, and finally obtains paper with the characteristics of high strength, degradability, high softness, comfortable hand feeling and the like, and has a broad development prospect in the packaging field.

Description

Technical Field

[0001] The invention belongs to the field of new papermaking materials, and specifically provides an environmentally friendly handbag paper and a production method thereof. Background Art

[0002] As environmental awareness grows, many countries have introduced plastic restrictions or bans. These policies are gradually limiting the use of plastic products in daily life. Green and environmentally friendly packaging will become a key development trend in the packaging industry, accelerating the implementation of policies related to carbon reduction, environmental protection, and plastic pollution control. Specifically, market demand is increasing for food-grade cardboard and environmentally friendly paper-plastic lunch boxes. Environmentally friendly cloth and paper bags are also being promoted and used more frequently in shopping malls and supermarkets.

[0003] Currently, paper bags are available in a variety of forms and materials on the market. Their primary raw material is wood fiber, also known as virgin fiber. These fibers are relatively short, and the resulting mesh structure lacks sufficient strength. To address this, pulping and fibrillation are commonly used to increase hydrogen bonding points. However, this also reduces the paper's flexibility, making it stiff, brittle, and prone to breakage. This poor hand feel and limited reusability make it unsuitable for packaging. Furthermore, laminating ordinary packaging paper to improve its moisture resistance is detrimental to environmental protection.

[0004] The problem that the applicant needs to solve is whether it is possible to provide a special paper that can meet the use scenarios of handbags, provide a biodegradable material that complies with environmental protection policies, has a soft feel similar to plastic bags and cloth bags, and is shape-plastic; has the bursting strength to withstand the sharp corners of the goods; will not be easily torn like ordinary paper when slightly damaged; and has sufficient strength under normal conditions and under moisture. Summary of the Invention

[0005] The present invention aims to solve the problems existing in the above-mentioned technologies and provides an environmentally friendly handbag paper and a production method thereof. The main raw materials of the handbag paper are softwood pulp, hardwood pulp, regenerated cellulose fiber and carboxylated styrene butadiene latex, wherein the coating amount of the carboxylated styrene butadiene latex on the paper surface is 1.5-2.5g / m 2 This eco-friendly paper for handbags is made primarily from cellulose, a biomass product that is fully biodegradable. The regenerated cellulose fiber, known for its exceptional toughness both wet and dry, contributes to its increased elasticity. Combined with its excellent breathability, this property is crucial for producing paper for handbags. The resulting paper boasts high strength, biodegradability, exceptional softness, and a comfortable feel, demonstrating broad development prospects in the packaging industry.

[0006] The specific technical solutions of the present invention are as follows:

[0007] An environmentally friendly handbag paper, the main raw materials of which are softwood pulp, hardwood pulp, regenerated cellulose fiber and carboxylated styrene butadiene latex, wherein the coating amount of carboxylated styrene butadiene latex on the paper surface is 1.5-2.5g / m 2 .

[0008] Furthermore, the softwood pulp is bleached chemical softwood pulp or unbleached chemical softwood pulp; the hardwood pulp is bleached chemical hardwood pulp or unbleached chemical hardwood pulp.

[0009] The regenerated cellulose fiber can be one or more of viscose fiber, Tencel fiber (also known as "Tencel" or "Lyocell"), Modal fiber (also known as "Modal" or "Modal"), and bamboo fiber.

[0010] Carboxylated styrene butadiene latex is a copolymer produced by emulsion polymerization of butadiene, styrene, a small amount of carboxylic acid and other additives.

[0011] The above four raw materials are directly purchased from the market, and the reason why this application uses the above four main raw materials is as follows:

[0012] Coniferous wood pulp is one of the main raw materials for paper. There is hydrogen bonding between the fibers, which can provide bonding strength. Broadleaf wood pulp is also one of the main raw materials for paper. The fiber length is relatively short and it is more evenly dispersed in the water system, which can improve the uniformity of the paper during the papermaking process.

[0013] Regenerated cellulose fiber is made from natural cellulose (cotton, linen, bamboo, trees, and shrubs). By modifying the physical structure of natural cellulose without altering its chemical structure, we create a regenerated cellulose fiber with improved performance. Its structural composition is similar to cotton, but its moisture absorption and breathability are superior, making it arguably the best of all chemical fibers in terms of moisture absorption and breathability. Regenerated cellulose fiber products are made from natural plant fibers, are 100% pure, biodegradable, additive-free, heavy metal-free, and chemical-free, and are gentle and non-irritating to the skin. They are an excellent, environmentally friendly, "green" fiber. Regenerated cellulose is similar to virgin fiber, with active hydroxyl groups on its molecules and a smoother surface. The exposed hydroxyl groups form a low hydrogen bond density, and its long length ensures sufficient binding force, allowing various steps in the production of regenerated cellulose fiber to be grafted and copolymerized with many other molecules for combined modification. Therefore, the regenerated cellulose fiber used in this application overcomes the shortcomings of virgin fiber and can be arbitrarily increased in length while ensuring normal use. By utilizing its hydrogen bonding and the advantages of its long length, its flexibility, tensile strength, and tear resistance can be significantly improved while ensuring strength, thereby meeting the excellent properties required for packaging paper. At the same time, regenerated cellulose fiber is extremely tough, whether dry or wet, and has better dry elongation at break and wet elongation at break than virgin plant fibers, thus helping to improve the elasticity of paper. Coupled with its excellent air permeability, it is a particularly important property in the production of paper bags.

[0014] The inventors selected coniferous wood pulp, hardwood pulp, and regenerated cellulose fiber as the main raw materials for papermaking. The synergistic effects between them are as follows: coniferous wood pulp and hardwood pulp fibers are relatively short, which ensures the uniformity of the paper. Moreover, after slight beating, these two types of fibers have relatively dense hydroxyl groups on the fiber surface, which will form a certain number of hydrogen bonding points between the fibers, providing a certain strength and stiffness to the paper sheet. Regenerated cellulose fiber has a smooth and uniform surface, but is longer in length, forming more interweaving, making greater contributions in terms of flexibility, tear resistance, and bursting strength. In order to ensure flexibility, the loss of bonding strength of the above-mentioned various types of fibers is compensated by ultra-low glass transition temperature carboxyl styrene butadiene latex, thus ensuring that the paper has excellent performance in terms of flexibility, tear resistance, and bursting resistance. At the same time, a water-resistant sizing agent is added to the paper, and the styrene butadiene latex used on the surface also has very good water resistance, which ensures the water resistance of the product, and the strength is not lost in a humid environment.

[0015] This application uses carboxylated styrene-butadiene latex with an extremely low glass transition temperature (Tg). One of the purposes is that the latex is relatively soft at room temperature, which can ensure the softness of the paper sheet; the second is that the latex has a relatively strong adhesive force, which can increase the bonding force between fibers; and the third is that after coating the surface of the paper sheet, a water-resistant layer can be formed to improve the water resistance of the paper.

[0016] Among the above raw materials, coniferous wood pulp, broadleaf wood pulp and regenerated cellulose fiber constitute the fiber raw materials for paper, among which, by weight percentage, coniferous wood pulp is 30%-40%, broadleaf wood pulp is 15%-30%, and regenerated cellulose pulp is 30%-50%, and the total of the three is 100%.

[0017] Furthermore, the softwood pulp has the following characteristics: beating degree 20-22°SR, wet weight 8-10g, beating concentration 2.5-3.0%;

[0018] Hardwood pulp: beating degree 20-22°SR, wet weight 1.8-2.5g, beating concentration 2.5-3.0%;

[0019] Regenerated cellulose fiber: 0.6-1.5mm in length, dispersed and loosened at a concentration of 1.5-2.0%; specifically, it can be loosened using a hydraulic pulper and clean water or papermaking white water.

[0020] The carboxylated styrene-butadiene latex product has a solid content of ≥40%, a pH value of ≥6.5, a viscosity of ≤100 mPa.s (25° C.), and a Tg of ≤-10° C.

[0021] When using, add water online to dilute 4-5 times and adjust the coating amount on the paper surface to 1.5-2.5g / m 2 .

[0022] In addition, AKD sizing agents and cationic polyacrylamide can be added during the production of the environmentally friendly handbag paper. The in-pulp AKD sizing agent is 5-15 kg / ton of paper, and the cationic polyacrylamide is 0.3-0.7 kg / ton of paper. The AKD's main function is to provide sizing within the pulp, improving the paper's water resistance; the cationic polyacrylamide's main function is to aid retention, improving the AKD's retention rate.

[0023] The production method of the environmentally friendly paper bag comprises the following steps:

[0024] Bleached chemical coniferous pulp, bleached chemical hardwood pulp and regenerated cellulose fiber are mixed evenly in a mixed pulp pool, purified by a pressure screen, and then AKD sizing agent and cationic polyacrylamide are added online through a pipeline. The pulp is pumped to the pre-papermaking pool and enters the papermaking machine for papermaking and forming.

[0025] The water content is dried to ≤5% in the front drying area of ​​the papermaking machine, and the diluted carboxylated styrene butadiene latex mixture is coated on the paper surface with 1.5-2.5g / m 2 The latex is then dried in the post-drying area to a moisture content of 4-6%, and then formed into paper rolls in the reel section of the paper machine. Finally, it is cut into different sizes according to customer requirements and packaged for storage.

[0026] Apart from this, the other specific steps of this application are the same as those in the prior art and the inventor will not elaborate on them.

[0027] Compared with the prior art, the main features of this application are:

[0028] First, the regenerated cellulose fiber staple used in this application. The filaments of this type of fiber are mainly used in the textile industry. Compared with wood pulp used in papermaking, the fiber length is relatively long, which has the advantage of increased strength and is relatively soft;

[0029] Secondly, the carboxylated styrene-butadiene latex emulsion used in this application has a low glass transition temperature. This type of emulsion is widely used in industrial and medical gloves. It is relatively soft at room temperature and has strong adhesive strength after drying. It also has excellent water resistance. Therefore, it helps to maintain the softness of paper and improves its strength and water resistance, thereby increasing the wet strength of the paper sheet.

[0030] Third, the softwood pulp and hardwood pulp in this application are lighter and have a lower beating degree than ordinary paper. The reason for this is that the hydroxyl groups on the wood pulp fibers are used to form hydrogen bonds, but the paper sheet becomes stiff due to excessive hydrogen bonding. The reduced hydrogen bonding strength is compensated by the adhesive force of the carboxylated styrene butadiene latex.

[0031] Fourth, the handbag paper finally obtained by this application can replace non-woven fabrics, etc., but compared with non-woven fabrics, this patent uses 100% biodegradable fiber raw materials, which is a new product that complies with environmental protection policies. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure is a schematic diagram of the production process of the handbag paper of the present invention. Implementation Method

[0033] The following examples further illustrate the above content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention. Unless otherwise specified, the following examples are all implemented using conventional existing technologies. Unless otherwise specified, the percentages below are all weight percentages. Example 1

[0034] An environmentally friendly handbag paper and its production method:

[0035] Raw material selection:

[0036] The coniferous pulp is bleached chemical coniferous pulp, which is added at 30% of the total fiber raw materials, with a pulping concentration of 3.0%, a beating degree of 20-22°SR after beating, and a wet weight of 8-10g.

[0037] Bleached chemical hardwood pulp is used as the hardwood pulp, which is added at 30% of the total fiber raw materials, with a pulping concentration of 2.0%, a beating degree of 20-22°SR after beating, and a wet weight of 2-2.5g.

[0038] The regenerated cellulose fiber is viscose fiber with a length of 1.5 mm, which is added at 40% of the total fiber raw materials and evenly dispersed at a concentration of 1.5%.

[0039] The carboxylated styrene butadiene latex is HGL1001 produced by Huatai Qinghe Paper Co., Ltd., with a solid content of 45%, a pH value of 7.0, a viscosity of ≤89mPa.s (25°C), and a glass transition temperature (Tg) of -15°C. When used, it is diluted 4 times with water online, and the coating amount on the paper surface is 2.0g / m 2 .

[0040] AKD sizing agent and cationic polyacrylamide are common papermaking chemical raw materials in the market. The dosage of AKD sizing agent is 10kg / ton of paper; the dosage of cationic polyacrylamide is 0.5kg / ton of paper.

[0041] The specific steps of the production method are:

[0042] The treated bleached chemical softwood pulp, bleached chemical hardwood pulp and viscose fiber are mixed evenly in a mixed pulp pool, purified by a pressure screen, and then AKD sizing agent and cationic polyacrylamide are added online through a pipeline, pumped to the pre-papermaking pool, and enter the papermaking machine for papermaking and forming.

[0043] The water content is dried to ≤5% in the front drying area of ​​the papermaking machine, and the diluted carboxylated styrene butadiene latex mixture is coated on the paper surface with 2.0g / m 2 (absolute dry weight) latex. Then it is dried in the post-drying area to a moisture content of 4-6%, and forms a paper roll in the paper machine reel. Finally, it is cut into different specifications and sizes according to customer needs, and finally obtains 150g / m 2 White tote bag paper, packed and put into storage.

[0044] Comparative Example 1: 150g / m 2 The main production process of white kraft paper used to make handbags:

[0045] The coniferous pulp is bleached chemical coniferous pulp, which is added at 50% of the total fiber raw materials, with a beating concentration of 4.0%, a beating degree of 38-40°SR after beating, and a wet weight of 6-7g.

[0046] Bleached chemical hardwood pulp is used as the hardwood pulp, which is added at 50% of the total fiber raw materials, with a pulping concentration of 4.0%, a beating degree of 42-45°SR after beating, and a wet weight of 1.5-2.0g.

[0047] In addition, AKD sizing agent and cationic polyacrylamide are used in the pulp, and starch sizing agent is used on the paper surface.

[0048] The specific steps of the production method are:

[0049] The treated bleached chemical coniferous pulp and bleached chemical hardwood pulp are mixed evenly in the mixed pulp pool, purified by the pressure screen, and then added with AKD sizing agent and cationic polyacrylamide online through the pipeline, pumped to the pre-papermaking pool, and enter the papermaking machine for papermaking and forming.

[0050] The paper is dried in the front drying area of ​​the paper machine to a moisture content of ≤5%. The surface is sizing as per normal packaging paper production, with starch as the main sizing agent. The paper is then dried in the back drying area to a moisture content of 4-6%, and formed into paper rolls in the reeling section of the paper machine. Finally, it is cut into different sizes according to customer needs, and the final product is 150g / m 2 White kraft paper is used to make handbags and is packaged and stored. Example 2

[0051] An environmentally friendly handbag paper and its production method:

[0052] Raw material selection:

[0053] The coniferous pulp is made of unbleached chemical coniferous pulp, which is added at 50% of the total fiber raw materials, with a pulping concentration of 2.5%, a beating degree of 20-22°SR after beating, and a wet weight of 8-10g.

[0054] The broadleaf pulp is unbleached chemical broadleaf pulp, which is added at 15% of the total fiber raw materials, with a beating concentration of 3.0%, a beating degree of 20-22°SR after beating, and a wet weight of 2-2.5g.

[0055] The regenerated cellulose fiber is Modal fiber with a length of 1.0 mm, which is added at 35% of the total fiber raw material and evenly dispersed at a concentration of 2.0%.

[0056] The carboxylated styrene butadiene latex is HGL1001 produced by Qinghe Huatai Paper Co., Ltd., with a solid content of 45%, a pH value of 7.0, a viscosity of ≤89mPa.s (25°C), and a glass transition temperature (Tg) of -15°C. When used, it is diluted 4 times with water online, and the coating amount on the paper surface is 2.5g / m2 .

[0057] AKD sizing agent and cationic polyacrylamide are common papermaking chemical raw materials in the market. The dosage of AKD sizing agent is 5kg / ton of paper; the dosage of cationic polyacrylamide is 0.3kg / ton of paper.

[0058] The specific steps of the production method are:

[0059] The treated bleached chemical softwood pulp, bleached chemical hardwood pulp and viscose fiber are mixed evenly in a mixed pulp pool, purified by a pressure screen, and then AKD sizing agent and cationic polyacrylamide are added online through a pipeline, pumped to the pre-papermaking pool, and enter the papermaking machine for papermaking and forming.

[0060] The water content is dried to ≤5% in the front drying area of ​​the papermaking machine, and the diluted carboxylated styrene butadiene latex mixture is coated on the paper surface with 2.5g / m 2 (absolute dry weight) latex. Then it is dried in the post-drying area to a moisture content of 4-6%, and forms a paper roll in the paper machine reeling section. Finally, it is cut into different specifications and sizes according to customer needs, and finally obtains 50g / m 2 Natural color handbag paper, packed and put into storage.

[0061] Comparative Example 2: 50g / m 2 The main production process of natural kraft paper used to make handbags:

[0062] The coniferous pulp is made of unbleached chemical coniferous pulp, which is added at 70% of the total fiber raw materials, with a beating concentration of 4.0%, a beating degree of 38-40°SR after beating, and a wet weight of 6-7g.

[0063] The broadleaf pulp is unbleached chemical broadleaf pulp, which is added at 30% of the total fiber raw materials, with a beating concentration of 4.0%, a beating degree of 42-45°SR after beating, and a wet weight of 1.5-2.0g.

[0064] In addition, AKD sizing agent and cationic polyacrylamide are used in the pulp, and starch sizing agent is used on the paper surface.

[0065] The specific steps of the production method are:

[0066] The treated bleached chemical coniferous pulp and bleached chemical hardwood pulp are mixed evenly in the mixed pulp pool, purified by the pressure screen, and then added with AKD sizing agent and cationic polyacrylamide online through the pipeline, pumped to the pre-papermaking pool, and enter the papermaking machine for papermaking and forming.

[0067] The paper is dried in the front drying area of ​​the paper machine to a moisture content of ≤5%, and the surface is sizing as per normal packaging paper production. The sizing agent is mainly starch. It is then dried in the back drying area to a moisture content of 4-6%, and formed into paper rolls in the reeling section of the paper machine. Finally, it is cut into different sizes according to customer needs, and the final product is 50g / m 2 The natural color is used for making kraft paper for handbags, packaging and storage.

[0068] Experimental example

[0069] The papers obtained in the examples and comparative examples were subjected to performance tests, and the results are shown below:

[0070] Product Name Dry tensile index (transverse direction) Nm / g Wet tensile index (transverse) (immersion for 10 minutes) Nm / g <![CDATA[Burst index Kpa.m 2 / g]]> Stiffness (longitudinal / transverse) mN / Nmm <![CDATA[Tear Index (Longitudinal) mN.m 2 / g]]> Example 1 <![CDATA[150g / m 2 White tote bag paper]]> 50.4 12.3 9.3 184 / 83 16.4 Comparative Example 1 <![CDATA[150g / m 2 White kraft paper for making handbags]]> 45.1 5.1 6.7 528 / 341 8.1 Example 2 <![CDATA[50g / m 2 Natural color handbag paper]]> 55.6 14.6 11.2 28 / 11 19.3 Comparative Example 2 <![CDATA[50g / m 2 Natural kraft paper for making handbags]]> 53.2 4.9 7.9 110 / 75 7.4

[0071] Among them, the dry tensile index (transverse): the examples are all higher than the comparative examples, because after the softwood pulp and hardwood pulp are lightly beaten, there are relatively dense hydroxyl groups on the fiber surface, which will form a certain number of hydrogen bonding points between the fibers, providing a certain strength and stiffness to the paper. However, the regenerated cellulose fibers used in the examples have a smooth and uniform surface, but are longer in length, forming more interweaving, and also making more contributions to the strength index. Although the beating degree of various fiber raw materials is low, some hydrogen bonding is lost, but it is compensated by the longer length of the regenerated cellulose fibers and the higher bonding strength of the carboxy styrene butadiene latex. Wet tensile index (transverse): The carboxy styrene butadiene latex used in this technology replaces the starch glue of the comparative example. The latex has stronger moisture resistance. It is coated on the fiber surface to ensure that the hydrogen bonds of various fibers will not be opened and the strength will not decrease under humid factors. The bonding property of the latex itself also maintains a high wet strength.

[0072] Burst index and tear index: The examples are significantly higher than the comparative examples because these two indicators are greatly affected by fiber length. The regenerated cellulose fiber used in this patent is much longer than that of coniferous wood pulp and hardwood pulp. In addition, the carboxylated styrene butadiene latex has a greater bonding force and a lower glass transition temperature (i.e., it can maintain its flexibility at room temperature), which ensures the elasticity of the paper and also improves the burst and tear resistance.

[0073] Stiffness: From the data, it can be seen that the stiffness of the embodiment is lower, which means that it is softer. In the embodiment of this patent, the beating strength of coniferous wood pulp and hardwood wood pulp is particularly reduced to reduce the hydrogen bonding points between fibers; the regenerated cellulose fiber has fewer exposed hydroxyl groups and a smooth and uniform surface, but is longer and forms more interweaving. Therefore, there are fewer fixed hydrogen bonding points between fibers, and the fibers can move relatively freely. In order to ensure flexibility, this patent uses carboxylated styrene butadiene latex with an ultra-low glass transition temperature. This latex can have strong adhesion at room temperature and is particularly flexible. Under the above synergistic effect, the softness of the paper sheet is guaranteed under high strength.

[0074] According to the above content, the handbag paper obtained in this application has obvious advantages in dry strength and wet strength indicators. The paper sheet is very soft (low stiffness) and feels comfortable. Moreover, since it uses 100% degradable fiber raw materials, it can meet the requirements of environmental degradation.

[0075] Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection set forth in the claims.

Claims

1. An environmentally friendly paper bag, characterized by: The main raw materials are softwood pulp, hardwood pulp, regenerated cellulose fiber and carboxylated styrene butadiene latex, of which the coating amount of carboxylated styrene butadiene latex on the paper surface is 1.5-2.5g / m 2 ; Coniferous wood pulp, hardwood pulp, and regenerated cellulose fiber constitute the fiber raw materials for paper. The total weight percentage of the three is 100%, of which coniferous wood pulp is 30%-40%, hardwood pulp is 15%-30%, and regenerated cellulose pulp is 30%-50%; The regenerated cellulose fiber is selected from one or more of Tencel fiber, Modal fiber, and bamboo fiber, and the regenerated cellulose fiber has a length of 0.6-1.5 mm and is dispersed at a concentration of 1.5-2.0%. The carboxylated styrene-butadiene latex product has a solid content of ≥40%, a pH value of ≥6.5, a viscosity of ≤100 mPa·s at 25°C, and a Tg of ≤-10°C. The coniferous pulp is bleached chemical coniferous pulp or unbleached chemical coniferous pulp; the broadleaf pulp is bleached chemical broadleaf pulp or unbleached chemical broadleaf pulp, wherein the coniferous pulp has a beating degree of 20-22° SR, a wet weight of 8-10g, and a beating concentration of 2.5-3.0%; the broadleaf pulp has a beating degree of 20-22° SR, a wet weight of 1.8-2.5g, and a beating concentration of 2.5-3.0%.

2. The environmentally friendly paper bag according to claim 1, characterized in that: The raw materials also include AKD sizing agent and cationic polyacrylamide; the dosage of AKD sizing agent in the pulp is 5-15kg / ton of paper; the dosage of cationic polyacrylamide is 0.3-0.7kg / ton of paper.

3. The method for producing the environmentally friendly handbag paper according to claim 1, characterized in that: The specific steps are as follows: Bleached chemical softwood pulp, bleached chemical hardwood pulp and regenerated cellulose fiber are mixed evenly in a mixing pulp tank, purified by a pressure screen, and then AKD sizing agent and cationic polyacrylamide are added online through a pipeline, pumped to the pre-papermaking tank, and then enter the papermaking machine for papermaking and forming; The water content is dried to ≤5% in the front drying area of ​​the papermaking machine, and the diluted carboxylated styrene butadiene latex mixture is coated on the paper surface with 1.5-2.5g / m 2 The latex is then dried in the post-drying area to a moisture content of 4-6%, and formed into a paper roll in the reeling section of the paper machine; finally, it is cut into different specifications and sizes according to demand, and packaged for storage.

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