A process for recycling waste paper into corrugated paper production using recycled pulp.

Abstract

This invention discloses a waste paper recycling process for corrugated paper production by recycling pulp. The process involves recovering pulp splashed out during the paper forming process and leakage from the paper forming equipment in a pulp recovery tank to obtain recycled pulp. After filtering the recycled pulp, a modifier is added and stirred evenly to obtain modified fine fiber pulp. The fine fiber pulp is sprayed through fine fiber pulp sprayers at the front and rear of the spray gun assembly, and the recycled pulp is directly used to assist in paper forming. This invention has a simple process, not only recycling the recycled pulp, but also improving the structural strength and toughness of the paper.

Description

Technical Field

[0001] This invention relates to the field of corrugated core paper and corrugated paper technology, and in particular to a waste paper recycling corrugated paper production process using recycled pulp. Background Technology

[0002] In the production process of reprocessing waste paper into corrugated paper, the waste paper is shredded by a pulping device, and the coarse pulp is discharged through the coarse pulp discharge port at the bottom. The coarse pulp is then pumped to a washing tank for washing treatment. After filtration, refining, and mixing, it is made into papermaking pulp for papermaking. Finally, in the forming workshop, the papermaking pulp is sprayed onto the surface of the forming wire using multiple sets of spray guns. The forming wire conveys the pulp forward, and finally, it is pressed and dewatered by the press rollers and dried by the drying rollers to obtain corrugated paper. During the papermaking process, a small amount of pulp splashes to the sides, and a small amount seeps downward through the fine pores of the forming wire. Current technology collects the splashed and seeped pulp. The recycled pulp is collected and pumped to a washing tank for washing treatment to achieve recycling. However, the fiber quality in the recycled pulp obtained during the papermaking process is extremely poor. More than 95% of the fibers in the recycled pulp are fine fibers with an average length of less than 0.5 mm by mass. These fine fibers reduce the structural strength and toughness of the paper and seriously affect the quality of the paper. Therefore, it is not very meaningful to mix the recycled pulp with the coarse pulp for reuse. Moreover, as the number of recycling cycles increases, the mass ratio of fine fibers in the paper pulp to water increases, which not only makes the pulp preparation process more complicated, but also affects the quality of the paper to varying degrees and is not conducive to controlling the stability of the paper quality. Therefore, it is necessary to improve this process. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a waste paper recycling corrugated paper production process that uses recycled pulp. This invention has a simple process, not only recycling the pulp, but also improving the structural strength and toughness of the paper.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a waste paper recycling and pulping process for corrugated paper production, comprising the following steps:

[0005] The papermaking pulp production process involves transporting waste paper to a pulping workshop for pulping to obtain coarse pulp. The coarse pulp then undergoes at least filtration, refining, and blending to obtain the papermaking pulp.

[0006] The slurry recycling step involves recovering the slurry that splashes out during the papermaking process and leaks from the papermaking equipment's screen to obtain recycled slurry.

[0007] The recycled slurry processing steps involve filtering and dewatering the recycled slurry to obtain finely crushed fiber slurry.

[0008] The pulp preparation process involves pumping the fine fiber pulp into a mixing tank, adding a modifier, and stirring until homogeneous to obtain modified fine fiber pulp.

[0009] The paper forming process involves a paper forming equipment consisting of a paper forming net and a spray gun assembly positioned above the net. The paper forming net is pulled into a ring shape and circulates via a power roller and multiple tension rollers. The paper forming net comprises an upper layer of forming mesh and a lower layer of forming mesh. A set of fine fiber slurry sprayers is positioned in front of and behind the spray gun assembly of the paper forming equipment.

[0010] Modified fine fiber pulp is sprayed onto the surface of the upper forming mesh by fine fiber pulp sprayers set in front of and behind the spray gun assembly. Papermaking pulp is sprayed onto the surface of the upper forming mesh by the spray gun assembly of the papermaking equipment. A pulp layer with a three-layer structure is obtained through papermaking.

[0011] In the papermaking process, the pulp layer undergoes at least pressing and dewatering treatment and drying treatment to obtain corrugated core paper.

[0012] The recycled slurry preparation step involves pumping the fine fiber slurry to a preparation tank, adding cationic surface-sizing starch and cellulose fiber used in the surface sizing process, with an addition ratio of 1-10 kg of cationic surface-sizing starch and 0.1-1 kg of cellulose fiber per ton of fine fiber slurry, and stirring evenly to obtain modified fine fiber slurry. The cationic surface-sizing starch dissolves in water to form cationic starch adhesive, and the modified fine fiber slurry contains a uniform mixture of fine fibers and cellulose fibers.

[0013] In the papermaking pulp preparation step, the fiber concentration of the papermaking pulp is controlled at 0.3-0.5%br through pulp preparation treatment; in the recycled pulp preparation step, water is added simultaneously during the stirring process of adding the modifying agent to control the fiber concentration of the modified fine fiber pulp at 5-10%br, and the modified fine fiber pulp is prepared into a high-concentration pulp, and the fiber concentration of the modified fine fiber pulp is controlled to be more than 10 times higher than the fiber concentration of the papermaking pulp.

[0014] A set of the fine fiber pulp sprayers includes multiple spray pipes spaced back and forth. Each spray pipe is horizontally fixed above the forming mesh by a bracket. Each spray pipe has multiple spray nozzles arranged horizontally at intervals, spraying towards the forming mesh. The bottom surface of each spray nozzle is provided with a "I"-shaped spray slit. When spraying modified fine fiber pulp, each spray nozzle forms a fan-shaped spray area between the spray nozzle and the forming mesh, which is smaller at the top and larger at the bottom. The slit length is set to 3-5mm and the slit width is set to 0.2-0.5mm, so that 10-20% of the water in the modified fine fiber pulp sprayed downward by the spray nozzle forms atomized particles after spraying out of the spray slit. The pushing force generated during atomization makes the fine fibers and cellulose fibers in the modified fine fiber pulp sprayed downward relatively evenly.

[0015] When two adjacent spray nozzles of the same spray pipe spray the modified fine fiber slurry, the lower parts of the adjacent sides of the two spray zones formed overlap the surface of the forming mesh, thereby forming a spray band with a longitudinal width of 3-5cm that covers the entire forming mesh horizontally on the surface of the forming mesh below each spray pipe. Each set of fine fiber slurry sprayers forms multiple spray bands on the surface of the forming mesh when spraying the modified fine fiber slurry.

[0016] In the copying process, the modified fine fiber slurry is pumped to two sets of fine fiber slurry sprayers, one before and one after.

[0017] Modified fine fiber slurry is sprayed onto the surface of the upper-layer formed mesh fabric by a set of fine fiber slurry sprayers located behind the spray gun assembly, forming a modified fine fiber slurry layer on the surface of the upper-layer formed mesh fabric. The thickness of the modified fine fiber slurry layer is controlled between 0.2-0.5 mm.

[0018] The papermaking pulp is pumped to the papermaking forming equipment, and the papermaking pulp is sprayed onto the surface of the upper forming mesh through the spray gun group of the papermaking forming equipment. The papermaking pulp is deposited on the upper surface of the lower modified fine fiber pulp layer, and the wet pulp layer is attached to the upper surface of the lower modified fine fiber pulp layer. The thickness of the wet pulp layer is controlled at 2-3mm.

[0019] Modified fine fiber pulp is sprayed onto the surface of the upper forming mesh by a set of fine fiber pulp sprayers set in front of the spray gun assembly. An upper modified fine fiber pulp layer is deposited on the upper surface of the wet pulp layer. The thickness of the upper modified fine fiber pulp layer is controlled at 0.2-0.5 mm. A pulp layer with a three-layer structure is obtained by paper forming.

[0020] The papermaking process includes a dewatering step and a drying step.

[0021] In the dewatering step, the pulp layer is adsorbed by the first vacuum suction roller and transferred to the blanket of the press equipment. The pulp layer is then transported through the blanket to the press equipment's various pressure roller groups for dewatering. After dewatering, the upper modified fine fiber pulp layer and the wet pulp layer are tightly bonded together, as are the wet pulp layer and the lower modified fine fiber pulp layer. During the pressing process, under the pressure of the pressure rollers, the fine fibers in the upper and lower modified fine fiber pulp layers are pressed into the upper and lower surfaces of the wet pulp layer, respectively. The strong affinity of cationic starch adhesive and cellulose fiber for water and fiber allows all the fine fibers in the upper and lower modified fine fiber pulp layers to be easily pressed into the upper and lower surfaces of the wet pulp layer, resulting in wet paper with a mixture of fine fibers, cationic starch adhesive, and cellulose fiber uniformly mixed in both the upper and lower surfaces.

[0022] In the drying step, the wet paper is adsorbed by the second vacuum suction roller and transferred to the drying equipment. The wet paper is then pulled forward by the drying rollers of the drying equipment and gradually dried into dry paper, resulting in corrugated core paper. The surface and interior of both the upper and lower surfaces of the corrugated core paper are uniformly mixed with fine fibers, cationic starch glue and cellulose fibers.

[0023] The papermaking process includes a surface sizing step.

[0024] In the surface sizing step, the corrugated core paper is pulled to the cationic surface sizing machine. The cationic surface sizing machine uses cationic starch adhesive, which is made from cationic surface sizing starch, to sizing the upper and lower surfaces of the corrugated core paper. A cationic starch adhesive layer is attached to the upper and lower surfaces of the corrugated core paper respectively. After drying, corrugated paper with a waterproof adhesive layer firmly attached to the surface is obtained.

[0025] A slurry recovery tank is set below the copy forming equipment. The copy forming net, which is circulating in the copy forming equipment, is lowered to the upper middle part of the slurry recovery tank. The slurry recovery tank is pre-filled with clean water, and the water level is lower than the upper layer of the forming net fabric of the copy forming equipment. The water in the slurry recovery tank is pumped to a high-pressure spray gun by a high-pressure circulation pump. The forming net fabric of the lower layer of the copy forming equipment is sprayed and washed by the high-pressure spray gun. The slurry that splashes, leaks out during the copy forming return process and drips downward during the spraying process is collected in the slurry recovery tank. The water level in the slurry recovery tank is controlled to never be higher than the lower layer of the forming net fabric.

[0026] The recycled pulp step involves first performing low-consistency filtration on the recycled pulp using a low-consistency filter press to remove impurities, followed by dewatering to increase the fiber concentration of the recycled pulp to 5-10%br. Then, the recycled pulp is subjected to high-consistency filtration using a high-consistency filter press to further remove impurities, followed by a second dewatering process to increase the fiber concentration of the recycled pulp to 15-20%br. Subsequently, during the stirring process of adding the modifying agent, clean water is simultaneously added to control the fiber concentration of the modified fine fiber pulp at 5-10%br, ensuring that the fiber concentration of the modified fine fiber pulp is more than 10 times higher than that of the paper pulp.

[0027] The advantages of this invention compared with the prior art are as follows: The process of this invention recovers the slurry splashed out during the papermaking process and the slurry leaking from the papermaking equipment through the slurry recovery tank. After the recovered slurry is filtered, a modifier is added and stirred evenly to obtain modified fine fiber slurry. The fine fiber slurry is directly used to assist in papermaking. This not only recycles the recovered slurry, but also improves the structural strength and toughness of the paper. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention for collecting and recycling slurry and using it in a screen.

[0029] Marked in the image:

[0030] 1-Formed mesh fabric

[0031] 2-Shotcrete gun assembly

[0032] 3-Fine Fiber Slurry Sprayer

[0033] 4-Spray pipe

[0034] 5-Spray nozzle

[0035] 6-First vacuum suction roller

[0036] 7-Slurry Recovery Tank

[0037] 8-High-pressure spray gun

[0038] 9-High-pressure circulating pump. Detailed Implementation

[0039] Comparative Example 1

[0040] The papermaking pulp, produced using the papermaking pulp preparation process, is pumped to the spray gun group 2 for spraying and forming by screen making. After pressing, dewatering, and drying, corrugated core paper is obtained. Finally, after surface sizing and secondary drying, corrugated paper with a firmly attached waterproof adhesive layer is obtained.

[0041] Example 1

[0042] A process for producing corrugated paper from recycled pulp includes the following steps:

[0043] The paper pulp production process involves transporting waste paper to a pulping workshop for pulping to obtain coarse pulp. The coarse pulp undergoes at least filtration, refining, and blending to obtain paper pulp. The fiber concentration of the paper pulp is controlled at 0.3-0.5%br, which means that every 100 grams of water contains 0.3-0.5 grams of dry fiber.

[0044] The slurry recycling step involves recovering the slurry that splashes out during the papermaking process and leaks from the papermaking equipment's screen to obtain recycled slurry.

[0045] The recycled slurry processing steps involve filtration and dewatering. First, the recycled slurry undergoes low-concentration filtration to remove impurities, followed by dewatering to increase the fiber concentration to 5-10%br. Then, it undergoes high-concentration filtration to further remove impurities, followed by a second dewatering process to increase the fiber concentration to 15-20%br. This yields finely crushed fiber slurry.

[0046] The pulp preparation process involves pumping the finely crushed fiber pulp into a mixing tank, adding a modifier, and stirring until homogeneous to obtain modified finely crushed fiber pulp.

[0047] The cationic surface-sizing starch and cellulose fiber used in the surface sizing process are added at a ratio of 1-10 kg of cationic surface-sizing starch and 0.1-1 kg of cellulose fiber per ton of finely shredded fiber pulp. After stirring evenly, a modified finely shredded fiber pulp is obtained. The cationic surface-sizing starch dissolves in water to form cationic starch adhesive. The modified finely shredded fiber pulp contains a uniform mixture of finely shredded fiber and cellulose fiber. During the stirring process of adding the modifying agent, water is simultaneously added to control the fiber concentration of the modified finely shredded fiber pulp at 5-10%br, thus preparing a high-concentration pulp, and ensuring that the fiber concentration of the modified finely shredded fiber pulp is more than 10 times higher than that of the paper pulp.

[0048] The paper forming process includes a paper forming equipment consisting of a paper forming net and a spray gun assembly 2 set above the paper forming net. The paper forming net is pulled into a ring shape and circulates by a power roller and multiple tension rollers. The paper forming net consists of an upper forming net 1 and a lower forming net 1. A set of fine fiber slurry sprayers 3 are respectively set in front of and behind the spray gun assembly 2 of the paper forming equipment.

[0049] A slurry recovery tank 7 is set below the paper forming equipment. The paper forming equipment's circulating screen is lowered to the upper middle part of the slurry recovery tank 7. The slurry recovery tank 7 is pre-filled with clean water, and the water level is lower than the upper forming mesh 1 of the paper forming equipment. The water in the slurry recovery tank 7 is pumped to the high-pressure spray gun 8 by the high-pressure spray gun 8. The forming mesh 1 of the lower layer of the paper forming equipment is sprayed and washed by the high-pressure spray gun 8. The slurry that splashes, leaks out during the return stroke of the paper forming equipment and drips downward during the spraying process is collected in the slurry recovery tank 7. The water level in the slurry recovery tank 7 is controlled to never be higher than the lower forming mesh 1.

[0050] A set of fine fiber pulp sprayers 3 includes multiple spray pipes 4 arranged at intervals. Each spray pipe 4 is horizontally fixed above the forming mesh 1 by a bracket. Each spray pipe 4 has multiple spray nozzles 5 arranged horizontally at intervals, spraying towards the forming mesh 1. Each spray nozzle 5 has an "I"-shaped spray gap on its bottom surface. When spraying modified fine fiber pulp, each spray nozzle 5 forms a fan-shaped spray area between itself and the forming mesh 1, which is smaller at the top and larger at the bottom. The gap length is set to 3-5mm and the gap width is set to 0.2-0.5mm, so that 10-20% of the water in the modified fine fiber pulp sprayed downward by the spray nozzle 5 forms atomized particles after spraying out of the spray gap. The pushing force generated during atomization makes the fine fibers and cellulose fibers in the modified fine fiber pulp sprayed downward relatively evenly.

[0051] Modified fine fiber slurry is sprayed onto the surface of the upper shaped mesh fabric 1 by a set of fine fiber slurry sprayers 3 located behind the spray gun assembly 2, forming a modified fine fiber slurry layer on the surface of the upper shaped mesh fabric 1. The thickness of the modified fine fiber slurry layer is controlled between 0.2-0.5 mm.

[0052] The papermaking pulp is pumped to the papermaking forming equipment. The papermaking pulp is sprayed onto the surface of the upper forming mesh 1 through the spray gun group 2 of the papermaking forming equipment. The papermaking pulp is deposited on the upper surface of the lower modified fine fiber pulp layer. The wet pulp layer is attached to the upper surface of the lower modified fine fiber pulp layer. The thickness of the wet pulp layer is controlled at 2-3mm.

[0053] Modified fine fiber pulp is sprayed onto the surface of the upper forming mesh 1 by a set of fine fiber pulp sprayers 3 set in front of the spray gun group 2. An upper modified fine fiber pulp layer is deposited on the upper surface of the wet pulp layer. The upper modified fine fiber pulp layer is attached to the upper surface of the wet pulp layer. The thickness of the upper modified fine fiber pulp layer is controlled at 0.2-0.5mm. A pulp layer with a three-layer structure is obtained by paper forming.

[0054] When spraying modified fine fiber slurry, the lower parts of the adjacent sides of the two spray zones formed by two adjacent spray nozzles 5 of the same spray pipe 4 overlap the surface of the forming mesh 1, thereby forming a spray band with a longitudinal width of 3-5cm that covers the entire forming mesh 1 laterally on the surface of the forming mesh 1 below each spray pipe 4. Each set of fine fiber slurry sprayers 3 forms multiple spray bands on the surface of the forming mesh 1 when spraying modified fine fiber slurry.

[0055] The modified fine fiber pulp is pumped to the front and rear sets of fine fiber pulp sprayers 3 respectively. The modified fine fiber pulp is sprayed onto the surface of the upper forming mesh 1 by the fine fiber pulp sprayers 3 set in front of and behind the spray gun group 2. The papermaking pulp is sprayed onto the surface of the upper forming mesh 1 by the spray gun group 2 of the papermaking equipment. A pulp layer with a three-layer structure is obtained by papermaking.

[0056] In the papermaking process, the pulp layer undergoes at least pressing and dewatering treatment and drying treatment to obtain corrugated core paper.

[0057] The papermaking process includes a dewatering step and a drying step.

[0058] In the dewatering step, the pulp layer is adsorbed by the first vacuum suction roller 6 and transferred to the blanket of the press equipment. The pulp layer is then transported through the blanket to the press rollers of the press equipment for dewatering. After dewatering, the upper modified fine fiber pulp layer and the wet pulp layer are tightly bonded, and the wet pulp layer and the lower modified fine fiber pulp layer are also tightly bonded. During the pressing process, under the pressure of the press rollers, the fine fibers in the upper and lower modified fine fiber pulp layers are pressed into the upper and lower surfaces of the wet pulp layer, respectively. The strong affinity of cationic starch adhesive and cellulose fiber for water and fiber makes it easy for all the fine fibers in the upper and lower modified fine fiber pulp layers to be pressed into the upper and lower surfaces of the wet pulp layer. This results in a wet paper with a mixture of fine fibers, cationic starch adhesive and cellulose fiber uniformly mixed in both the upper and lower surfaces, and the three-layer structure of the wet paper disappears.

[0059] In the drying step, the wet paper is adsorbed by the second vacuum suction roller and transferred to the drying equipment. The drying rollers of the drying equipment pull the wet paper forward and gradually dry it into dry paper, thus obtaining corrugated core paper. The surface layer of both the upper and lower surfaces of the corrugated core paper is uniformly doped with fine fibers, cationic starch glue, and cellulose fibers. The surface structure doped with fine fibers, cationic starch glue, and cellulose fibers can not only greatly improve the surface strength and structural strength of the corrugated core paper, but also greatly improve its toughness, and prevent delamination.

[0060] The papermaking process also includes a surface sizing step.

[0061] In the surface sizing step, the corrugated core paper is drawn to a cationic surface sizing machine. The cationic surface sizing machine uses cationic starch adhesive, which is made from cationic surface sizing starch, to sizing the upper and lower surfaces of the corrugated core paper. A cationic starch adhesive layer is attached to each of the upper and lower surfaces of the corrugated core paper. After drying, corrugated paper with a firmly attached waterproof adhesive layer is obtained. The cationic starch adhesive layer has a stronger adhesion to the surface structure mixed with fine fibers, cationic starch adhesive and cellulose fibers, resulting in a stronger bond.

[0062] Corrugated core paper with a thickness of 0.2 mm was produced according to Comparative Example 1 and Example 1 respectively. Samples were taken and various parameters were tested. The test results are shown in Table 1. The tensile strength of the corrugated core paper of Example 1 is more than 3 times that of the corrugated core paper of Comparative Example 1. The bursting strength and ring crush strength of the corrugated core paper of Example 1 are more than 2 times that of the corrugated core paper of Comparative Example 1. That is, the peel strength, tensile strength and bursting strength of the corrugated core paper of Example 1 according to the present invention are much higher than those of the corrugated core paper of Comparative Example 1.

[0063] Corrugated paper with a thickness of 0.2 mm and a firmly adhered waterproof adhesive layer was produced according to Comparative Example 1 and Example 1, respectively. The peel strength of the waterproof adhesive layer was tested. The peel strength of Comparative Example 1 was 25 N / mm, and the peel strength of Example 1 was 30 N / mm. The waterproof adhesive layer of the corrugated paper of Example 1 of this invention has a stronger bond with the corrugated core paper.

[0064] tensile strength Bursting strength Ring compression strength elongation Comparative Example 1 8Mpa 400kPa 320N 1％ Example 1 25Mpa 810 kPa 860N 0.8％

[0065] Table 1.

Claims

1. A process for producing corrugated paper from recycled pulp, characterized in that: Includes the following steps, The papermaking pulp production process involves transporting waste paper to a pulping workshop for pulping to obtain coarse pulp. The coarse pulp then undergoes at least filtration, refining, and blending to obtain the papermaking pulp. The slurry recycling step involves recovering the slurry that splashes out during the papermaking process and leaks from the papermaking equipment's screen to obtain recycled slurry. The recycled slurry processing steps involve filtering and dewatering the recycled slurry to obtain finely crushed fiber slurry. The pulp preparation process involves pumping the fine fiber pulp into a mixing tank, adding a modifier, and stirring until homogeneous to obtain modified fine fiber pulp. The fine fiber slurry is pumped to the mixing tank, and cationic surface-sizing starch and cellulose fiber used in the surface sizing process are added. The addition ratio is 1-10 kg of cationic surface-sizing starch and 0.1-1 kg of cellulose fiber per ton of fine fiber slurry. After stirring evenly, the modified fine fiber slurry is obtained. The cationic surface-sizing starch dissolves in water to form cationic starch glue. The modified fine fiber slurry contains fine fiber and cellulose fiber evenly mixed in. The paper forming process includes a paper forming net and a spray gun assembly (2) set above the paper forming net. The paper forming net is pulled in a ring shape and circulates by a power roller and multiple tension rollers. The paper forming net includes an upper forming net cloth (1) and a lower forming net cloth (1). A set of fine fiber slurry sprayers (3) are set in front of and behind the spray gun assembly (2) of the paper forming equipment. Modified fine fiber pulp is sprayed onto the surface of the upper forming mesh (1) by fine fiber pulp sprayers (3) set in front of and behind the spray gun group (2), and papermaking pulp is sprayed onto the surface of the upper forming mesh (1) by the spray gun group (2) of the papermaking equipment, and a pulp layer with a three-layer structure is obtained by papermaking. In the papermaking process, the pulp layer undergoes at least pressing and dewatering treatment and drying treatment to obtain corrugated core paper.

2. The waste paper recycling corrugated paper production process according to claim 1, characterized in that: The paper pulp preparation step involves controlling the fiber concentration of the paper pulp to 0.3-0.5%br through pulp preparation treatment; In the recycled pulp preparation step, while adding the modifying agent and stirring, water is added simultaneously to control the fiber concentration of the modified fine fiber pulp at 5-10%br, so that the modified fine fiber pulp is prepared into a high-concentration pulp, and the fiber concentration of the modified fine fiber pulp is controlled to be more than 10 times higher than that of the paper pulp.

3. The waste paper recycling corrugated paper production process according to claim 1, characterized in that: A set of fine fiber pulp sprayers (3) includes multiple spray pipes (4) arranged at intervals. Each spray pipe (4) is horizontally fixed above the forming mesh (1) by a bracket. Each spray pipe (4) has multiple spray nozzles (5) arranged horizontally at intervals, spraying towards the forming mesh (1). Each spray nozzle (5) has a "I"-shaped spray gap on its bottom surface. When spraying modified fine fiber pulp, each spray nozzle (5) forms a fan-shaped spray area between the spray nozzle (5) and the forming mesh (1), with the top smaller and the bottom larger. The gap length of the spray gap is set to 3-5mm and the gap width is set to 0.2-0.5mm, so that 10-20% of the water in the modified fine fiber pulp sprayed downward by the spray nozzle (5) forms atomized particles after spraying out of the spray gap. The pushing force generated during atomization makes the fine fibers and cellulose fibers in the modified fine fiber pulp sprayed downward relatively evenly. The lower parts of the adjacent sides of the two spray zones formed by the two adjacent spray nozzles (5) of the same spray pipe (4) when spraying modified fine fiber slurry overlap the surface of the forming mesh (1), thereby forming a spray band with a longitudinal width of 3-5cm that covers the entire forming mesh (1) laterally on the surface of the forming mesh (1) below each spray pipe (4). Each set of fine fiber slurry sprayers (3) forms multiple spray bands on the surface of the forming mesh (1) when spraying modified fine fiber slurry.

4. The waste paper recycling corrugated paper production process according to claim 1, characterized in that: In the copying process, the modified fine fiber slurry is pumped to the front and rear sets of fine fiber slurry sprayers (3). Modified fine fiber slurry is sprayed onto the surface of the upper shaped mesh fabric (1) by a set of fine fiber slurry sprayers (3) located behind the spray gun assembly (2), forming a modified fine fiber slurry layer on the surface of the upper shaped mesh fabric (1). The thickness of the modified fine fiber slurry layer is controlled at 0.2-0.5 mm. The papermaking pulp is pumped to the papermaking forming equipment. The papermaking pulp is sprayed onto the surface of the upper forming mesh (1) through the spray gun group (2) of the papermaking forming equipment. The papermaking pulp is deposited on the upper surface of the lower modified fine fiber pulp layer. The wet pulp layer is attached to the upper surface of the lower modified fine fiber pulp layer. The thickness of the wet pulp layer is controlled at 2-3 mm. Modified fine fiber pulp is sprayed onto the surface of the upper forming mesh (1) by a set of fine fiber pulp sprayers (3) set in front of the spray gun group (2). An upper modified fine fiber pulp layer is deposited on the upper surface of the wet pulp layer. The upper modified fine fiber pulp layer is attached to the upper surface of the wet pulp layer. The thickness of the upper modified fine fiber pulp layer is controlled at 0.2-0.5 mm. A pulp layer with a three-layer structure is obtained by paper forming.

5. The waste paper recycling corrugated paper production process according to claim 4, characterized in that: The papermaking process includes a dewatering step and a drying step. In the dewatering step, the pulp layer is adsorbed by the first vacuum suction roller (6) and transferred to the blanket of the pressing equipment. The pulp layer is transported by the blanket through each roller group of the pressing equipment for pressing and dewatering. The upper modified fine fiber pulp layer and the wet pulp layer are tightly bonded after dewatering, and the wet pulp layer and the lower modified fine fiber pulp layer are tightly bonded. Under the pressure of the rollers during the pressing process, the fine fibers in the upper modified fine fiber pulp layer and the lower modified fine fiber pulp layer are pressed into the upper and lower surfaces of the wet pulp layer respectively. The strong affinity of cationic starch glue to water and fiber, and the strong affinity of cellulose fiber to water and fiber make it easy for all the fine fibers in the upper modified fine fiber pulp layer and the lower modified fine fiber pulp layer to be pressed into the upper and lower surfaces of the wet pulp layer, resulting in a wet paper with a mixture of fine fibers, cationic starch glue and cellulose fiber uniformly mixed in the upper and lower surfaces. In the drying step, the wet paper is adsorbed by the second vacuum suction roller and transferred to the drying equipment. The wet paper is then pulled forward by the drying rollers of the drying equipment and gradually dried into dry paper, resulting in corrugated core paper. The surface and interior of both the upper and lower surfaces of the corrugated core paper are uniformly mixed with fine fibers, cationic starch glue and cellulose fibers.

6. The waste paper recycling corrugated paper production process according to claim 5, characterized in that: The papermaking process includes a surface sizing step. In the surface sizing step, the corrugated core paper is pulled to the cationic surface sizing machine. The cationic surface sizing machine uses cationic starch adhesive, which is made from cationic surface sizing starch, to sizing the upper and lower surfaces of the corrugated core paper. A cationic starch adhesive layer is attached to the upper and lower surfaces of the corrugated core paper respectively. After drying, corrugated paper with a waterproof adhesive layer firmly attached to the surface is obtained.

7. The waste paper recycling corrugated paper production process according to claim 1, characterized in that: A slurry recovery tank (7) is set below the paper forming equipment. The paper forming equipment is circulated and sinks to the middle and upper part of the slurry recovery tank (7). The slurry recovery tank (7) is pre-filled with clean water. The water level is lower than the forming mesh (1) of the upper layer of the paper forming equipment. The water in the slurry recovery tank (7) is circulated and pumped to the high-pressure spray gun (8) by the high-pressure spray gun (8). The forming mesh (1) of the lower layer of the paper forming equipment is sprayed and washed by the high-pressure spray gun (8). The slurry that splashes, leaks out and drips downward during the paper forming return process is collected by the slurry recovery tank (7). The water level in the slurry recovery tank (7) is controlled to never be higher than the lower forming mesh (1).

8. The waste paper recycling corrugated paper production process according to claim 1, characterized in that: The recycled pulp step involves first performing low-consistency filtration on the recycled pulp using a low-consistency filter press to remove impurities, followed by dewatering to increase the fiber concentration of the recycled pulp to 5-10%br. Then, the recycled pulp is subjected to high-consistency filtration using a high-consistency filter press to further remove impurities, followed by a second dewatering process to increase the fiber concentration of the recycled pulp to 15-20%br. Subsequently, during the stirring process of adding the modifying agent, clean water is simultaneously added to control the fiber concentration of the modified fine fiber pulp at 5-10%br, ensuring that the fiber concentration of the modified fine fiber pulp is more than 10 times higher than that of the paper pulp.

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