A method for producing absorbent paper and absorbent paper produced by the method

Abstract

The present invention relates to the field of absorbent paper, and provides a method for producing absorbent paper and absorbent paper produced by the method. A polymer feeding device feeds polymer absorbent material onto semi-dry base paper, and the semi-dry base paper and fully dry base paper are moved to a compounding device for compounding to form absorbent paper. The absorbent paper is subjected to rotary drying by a rotating drying wheel, and the absorbent paper passes through a suspended hot air bed, and the suspended hot air bed blows hot air to the top and bottom of the absorbent paper for suspended drying. The absorbent paper is wound by a winding device. The present invention strongly blows hot air on the surface of the lower single-layer base paper in the composite absorbent paper, and the bulkiness, liquid absorption speed, and air permeability are significantly improved, and the quality of the product is greatly improved. The production process improves the production efficiency by 2.5 to 3 times or more without significantly increasing the length of the production line and the number of drying cylinders, and solves the technical problems that the drying efficiency of absorbent paper affects the production speed, and the drying and production efficiency are low.

Description

Technical Field

[0001] The invention relates to the field of absorbent paper, and in particular to a method for producing absorbent paper and the absorbent paper prepared by the method. Background Art

[0002] In the traditional wet papermaking production process, the moisture content of absorbent paper must be lower than 10%, which is stipulated by the national standard. As the square grammage of the paper increases, how to maintain the speed of the production line and ensure that the moisture content of the finished paper meets the standard is a technical problem that the industry has been seeking to break through. The lower the moisture content of the finished paper, the more difficult it is to dry. For example, to produce absorbent paper with a square grammage of less than 40 grams, when a 3.6m diameter drying cylinder is used, the usual line speed can only be controlled at 20m / min-40m / min. The drying cylinder is steam-heated. When the steam pressure is 0.3Mpa, the drying cylinder temperature is about 130 degrees. If you want to produce absorbent paper with a higher grammage, you need to increase the number of drying cylinders. Some high-grammage paper production lines have more than ten drying cylinders. Due to the large diameter of the drying cylinder, it occupies a large production space, consumes high energy, and is a high-pressure container, so the requirements for steam sealing and insulation are also high. In particular, high-weight paper production lines are not easy to be compatible with low-weight production lines. This is reflected in the fact that when a high-weight paper production line is used to produce a low-weight paper production line, its production process and energy consumption do not decrease in the same proportion. However, when a wet paper production line is used to produce composite absorbent paper, because the square gram weight of composite absorbent paper is generally 60g-200g, the contradiction between its production efficiency and the moisture content of absorbent paper is more prominent. When the upper layer of dry absorbent paper, polymer, and lower layer of wet absorbent paper are composited and dried, the upper layer of dry absorbent paper contacts the surface of the drying cylinder, while the lower layer of wet absorbent paper is located radially outside the drying cylinder. In this way, the drying cylinder is double-heat-blocked by the upper layer of dry absorbent paper and the middle polymer to the lower layer of wet absorbent paper. Compared with the situation where the integral paper web has moisture for heat transfer, the drying effect of the composite absorbent paper is further reduced.

[0003] Chinese Patent Publication No.: 210216014U, provides a production line for composite processing of absorbent paper, including a frame, a single-layer base paper unwinding machine, a polymer absorbent resin feeder, a pressure roller and a pressing roller, an upper felt carrying a single-layer semi-formed base paper is pressed in the pressing roller, the polymer absorbent resin feeder is filled with polymer absorbent resin particles, the single-layer base paper unwinding machine is rolled with a single-layer base paper, the upper felt and the single-layer semi-formed base paper are passed under the polymer absorbent resin feeder, the polymer absorbent resin particles are laid on the single-layer semi-formed base paper, the single-layer base paper is covered on the single-layer semi-formed base paper carrying the polymer absorbent resin particles, the single-layer base paper, the polymer absorbent resin particles, the single-layer semi-formed base paper and the upper felt extend into the pressure roller, so that the single-layer base paper and the single-layer semi-formed base paper carrying the polymer absorbent resin particles form an integrated multi-layer finished absorbent paper. The production speed of the production line is affected by the drying efficiency. If the production efficiency is accelerated, the moisture content of the product will increase, making it difficult to increase the production speed of absorbent paper, and the drying and production efficiency will be low. Summary of the invention

[0004] Therefore, in view of the above problems, the present invention provides a method for producing absorbent paper and absorbent paper produced by the method, which solves the technical problem that the drying efficiency of absorbent paper affects the production speed and the drying and production efficiency are low.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for producing absorbent paper comprises the following steps:

[0007] (1) Semi-dry base paper forming: Semi-dry base paper is formed on the semi-dry base paper production line;

[0008] (2) Fully dry base paper forming: Fully dry base paper is formed on the full dry base paper production line;

[0009] (3) Polymer material unloading: The polymer unloading device unloads the polymer water-absorbing material onto the semi-dry base paper;

[0010] (4) Compounding: The fully dry base paper bypasses the polymer unloading device and is pressed with the semi-dry base paper carrying the polymer absorbent material to the compounding device to form a polymer composite absorbent paper;

[0011] (5) Rotary drying: The absorbent paper is dried by a rotary drying wheel;

[0012] (6) Suspension drying: The absorbent paper passes through a suspension hot air bed, which blows hot air to one side of the semi-dry base paper, or to both sides of the semi-dry base paper and the fully dry base paper for suspension drying;

[0013] (7) Rewinding: The absorbent paper is rolled up through a rewinding device.

[0014] Further:

[0015] The semi-dry base paper forming in step (1) comprises: the semi-dry base paper is formed through pulp mixing, pulping, defibrating and pulping processes, wood pulp and fluff pulp are mixed to obtain a mixed slurry, the mixed slurry is pulped, and the fibers are defibrated to obtain a fiber defibrated slurry, and the fiber defibrated slurry is pulped in a pulping tank to obtain a pulping slurry; the first lower felt passes through a first mesh cylinder and contacts with the pulping slurry, the pulping slurry forms a first pulp on the first lower felt, the first lower felt conveys the first pulp from the first mesh cylinder, the first lower felt, the first pulp and the first upper felt pass through a pressing roller to form the first pulp into semi-dry base paper, and the semi-dry base paper is separated from the first lower felt and connected to the first upper felt at the same time.

[0016] The step (2) of forming the fully dry base paper comprises: forming the fully dry base paper through pulp mixing, pulping, defibrating, pulping and drying processes, mixing wood pulp and fluff pulp to obtain a mixed slurry, pulping the mixed slurry, and then defibrating the fibers to obtain a fiber defibrated slurry, and pulping the fiber defibrated slurry in a pulping tank to obtain a pulping slurry; the second felt passes through a second mesh cylinder to contact the pulping slurry, the pulping slurry forms a second pulp on the second felt, the second felt conveys the second pulp from the second mesh cylinder, the second pulp is then dried by a drying cylinder to form fully dry base paper, and the fully dry base paper leaves the second felt and moves to the composite device.

[0017] After the fully dry base paper passes through the drying cylinder, the fully dry base paper passes through the cooling roller for cooling and shaping.

[0018] In step (6), the burner burns to generate heat energy, heats the air to increase the temperature, and the fan generates hot air to blow toward the air nozzle, and the air nozzle blows the air toward one side of the semi-dry base paper to dry it. The air nozzle blows the hot air toward the semi-dry base paper, and the heat is transferred from the semi-dry base paper to the fully dry base paper. The temperature of the semi-dry base paper is higher than that of the fully dry base paper. The suspended hot air bed includes a box body arranged on a frame, at least one burner arranged in the box body, and at least one fan connected to the burner. A suspension channel is arranged in the middle of the box body, and a combustion channel is arranged on the box body on one side of the semi-dry base paper. Each of the combustion channels has at least one of the burner and the fan, and each of the combustion channels is connected to a plurality of air nozzles.

[0019] In step (6), the burner generates heat energy by combustion, and heats the air to increase the temperature. The fan generates hot air to blow toward the air nozzle, and the air nozzle blows the air toward both sides of the semi-dry base paper and the fully dry base paper to dry them. The hot air is blown from the air nozzle toward the surface of the absorbent paper to dry and heat the surface of the absorbent paper. The air nozzles of the two combustion channels are alternately arranged at the projection interval of the horizontal plane. When the air nozzle blows the hot air toward the semi-dry base paper, the heat is transferred from the semi-dry base paper to the fully dry base paper, and the temperature of the semi-dry base paper is higher than that of the fully dry base paper; when the air nozzle blows the hot air toward the fully dry base paper, the heat is transferred from the fully dry base paper to the semi-dry base paper, and the temperature of the fully dry base paper is higher than that of the semi-dry base paper. The semi-dry base paper and the fully dry base paper alternately receive the hot air and receive the heat transfer; when the hot air contacts the semi-dry base paper and the fully dry base paper, the semi-dry base paper and the fully dry base paper are heated. The dry base paper acts to move the semi-dry base paper and the fully dry base paper in opposite directions. The absorbent paper in the suspension channel forms a wavy structure that alternates up and down or forms a plurality of upper and lower protrusions, which not only increases the drying area of ​​the absorbent paper, but also changes the position of the absorbent paper in the vertical direction. The constantly changing movement direction can throw out part of the water, and the paper is constantly curled and deformed under alternating heating. The suspended hot air bed comprises a box body arranged on a frame, at least one burner arranged in the box body, and at least one fan connected to the burner. A suspension channel is arranged in the middle of the box body, and combustion channels are respectively arranged at the top and bottom of the box body. Each of the combustion channels has at least one burner and a fan, and each of the combustion channels is connected to a plurality of air nozzles.

[0020] The box body is provided with an upper bed body and a lower bed body, at least one adjusting cylinder is provided between the upper bed body and the lower bed body, the adjusting cylinder can adjust the distance between the upper bed body and the lower bed body, the suspension channel is formed between the upper bed body and the lower bed body, and the two combustion channels are respectively provided in the upper bed body and the lower bed body.

[0021] The absorbent paper is first preheated by passing through the first channel, the hot air speed and air volume of the air nozzle at the first channel are smaller than the hot air speed and air volume of the air nozzle at the second channel, and then the absorbent paper is fully heated by passing through the second channel, and the heat gradually heats the absorbent paper, and the combustion channel includes a first channel and a second channel sequentially arranged along the conveying direction, the cross-sectional areas of each position of the first channel are equal, and the cross-sectional area of ​​the second channel decreases along the conveying direction.

[0022] The hot air temperature of the suspended hot air bed is 130 to 200 degrees, and the production speed of the absorbent paper is 60m / min-100m / min.

[0023] Based on the same inventive concept, the present invention also proposes an absorbent paper, which is made based on the above absorbent paper production method. The absorbent paper includes a composite semi-dry base paper and a fully dry base paper, and a polymer absorbent material is provided between the semi-dry base paper and the fully dry base paper.

[0024] By adopting the above technical solution, the beneficial effects of the present invention are:

[0025] The drying method of the present invention adopts rotary drying and suspended drying. The rotary drying can dry absorbent paper in a curved state, and the suspended drying can dry absorbent paper in a nearly horizontal state. The temperature of the hot air after secondary combustion can reach 200 degrees. By blowing hot air strongly on the surface of the lower single-layer base paper in the composite absorbent paper, the wood pulp fibers in the paper web can be curled and deformed. Because the arrangement of the fibers is disordered, the curling of fibers with different orientations makes the entire paper web more fluffy. On the one hand, the fluffy paper web is more conducive to further drying of the moisture therein. More importantly, in the process of being applied to products in the later stage, the liquid absorption speed of the product can be more than 30% faster, and the product has better air permeability. A further improvement is to perform a second hot air blow on the upper and lower surfaces of the composite absorbent paper. The bulkiness, liquid absorption speed, and air permeability of the composite absorbent paper after the second heat treatment are significantly improved, greatly improving the quality of the product. On this basis, the contradiction between production efficiency and moisture content of the finished product is resolved. Therefore, when the composite absorbent paper is produced by this method, the production speed can reach 60m / min-100m / min for the same absorbent paper with a square weight of 60g-200g, and the moisture content of the finished paper can be controlled below 5%, which is far lower than the industry standard. That is, this production process can increase production efficiency by 2.5 to 3 times without significantly increasing the length of the production line or the number of drying cylinders. Furthermore, the two production lines simultaneously produce full-dry base paper and semi-dry base paper, and the full-dry base paper, semi-dry base paper and high-molecular absorbent material are compounded to form absorbent paper, realizing fully automated production and eliminating the step of workers putting the first produced single-layer base paper on the unwinding device, saving labor costs and improving production efficiency; further, the air nozzles are alternately arranged up and down to form a maze-like suspended channel, and the front and back sides of the fibers are constantly curled and deformed under alternating heating, making the composite material looser and more breathable, which not only improves the quality of the product, but also improves the drying efficiency and saves energy. Furthermore, the cross-section of the first channel is equal, and the absorbent paper is preheated. The cross-section area of ​​the second channel decreases along the conveying direction. The smaller the area, the greater the wind speed. The absorbent paper is dried step by step, and the absorbent paper will not be exposed to high temperature instantly, which prevents the absorbent paper from expanding instantly due to the large temperature difference between the absorbent paper and the surrounding temperature, and prevents the internal structure of the absorbent paper from being pulled and damaged, while also improving the drying efficiency; further, the upper bed and the lower bed can adjust their positions, thereby adjusting the width of the suspension channel, and adjusting according to the production of absorbent paper of different gram weights, improving the drying effect and production speed, and improving the quality of the product. Furthermore, the height of the suspension channel is 45cm, the hot air temperature of the suspended hot air bed is 150 degrees, and the air volume of the suspended hot air bed is 60,000 cubic meters per hour, which can maximize drying and improve the utilization rate of drying wind energy and heat energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a production process flow chart of absorbent paper.

[0027] Figure 2 It is a structural schematic diagram of a fully automatic absorbent paper production device.

[0028] Figure 3 It is a structural schematic diagram of a semi-dry base paper production line.

[0029] Figure 4 yes Figure 3 A schematic diagram of the structure.

[0030] Figure 5 It is a structural diagram of a fully dry base paper production line.

[0031] Figure 6 yes Figure 5 A schematic diagram of the structure.

[0032] Figure 7 It is a structural schematic diagram of a suspended hot air bed.

[0033] Figure 8 It is a partial cross-sectional view of absorbent paper.

[0034] Fig. 9 It is a structural schematic diagram of a winding device.

[0035] Fig.10 yes Fig. 9 A schematic diagram of the structure of another state.

[0036] Fig.11 It is a structural schematic diagram of a pressure detection device provided on a winding device.

[0037] Description of reference numerals:

[0038] 1. Frame; 2. Semi-dry base paper production line; 20. Polymer unloading device; 21. First mesh cage; 22. First guide roller; 23. First upper felt; 24. First lower felt; 25. Pressing roller; 3. Fully dry base paper production line; 31. Second mesh cage; 32. Second guide roller; 33. Drying cylinder; 34. Second felt; 35. Cooling roller; 4. Compounding device; 5. Rotating drying wheel; 6. Winding device; 61. Sliding seat; 62. Driving mechanism; 63. Winding roller; 64. Winding Roll motor; 65, radius detection device; 66, paper tube; 67, pressure sensor; 68, roller seat; 69, rotating roller; 7, absorbent paper; 71, semi-dry base paper; 72, fully dry base paper; 73, polymer absorbent material; 8, suspended hot air bed; 81, box body; 811, upper bed body; 812, lower bed body; 813, regulating cylinder; 82, suspension channel; 83, combustion channel; 831, first channel; 832, second channel; 84, fan; 85, air nozzle. DETAILED DESCRIPTION

[0039] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0040] refer to Figures 1 to 8 This embodiment provides a method for producing absorbent paper, comprising the following steps:

[0041] (1) Forming of semi-dry base paper 71: The semi-dry base paper 71 is formed through pulp mixing, pulping, defibering, and pulping processes. Wood pulp and fluff pulp are mixed to obtain a mixed pulp. The mixed pulp is pulped and then fiberized to obtain a fiber defibered pulp. The fiber defibered pulp is pulped in a pulping tank to obtain a pulping pulp. The first lower felt 24 passes through the first mesh cylinder 21 and contacts the pulping pulp. The pulping pulp forms the first paper pulp on the first lower felt 24. The first lower felt 24 The first pulp is conveyed from the first mesh cylinder 21, and the first lower felt 24, the first pulp, and the first upper felt 23 pass through the pressing roller 25 to form the first pulp into a semi-dry base paper 71. The semi-dry base paper 71 is separated from the first lower felt 24 and connected to the first upper felt 23 at the same time. The semi-dry base paper 71 is formed in the semi-dry base paper production line 2. The semi-dry base paper production line 2 includes a first mesh cylinder 21, multiple first guide rollers 22, a first upper felt 23, a first lower felt 24, and a pressing roller 25.

[0042] (2) Forming of the fully dry base paper 72: The fully dry base paper 72 is formed through the processes of pulp mixing, pulping, defibrating, pulping, drying, cooling and shaping. Wood pulp and fluff pulp are mixed to obtain a mixed slurry. The mixed slurry is pulped and then fiber defibrated to obtain a fiber defibrated slurry. The fiber defibrated slurry is mixed in a pulping tank to obtain a pulping slurry. The second felt 34 passes through the second mesh cylinder 31 and contacts the pulping slurry. The pulping slurry forms a second pulp on the second felt 34. The second felt 34 transports the second pulp from the second mesh cylinder 31. The second pulp is dried by the drying cylinder 33 to form the fully dry base paper 72. The fully dry base paper 72 then passes through the cooling roller 35 to be cooled and shaped. The fully dry base paper 72 is separated from the second felt 34 and moves to the compounding device 4.

[0043] The fully dry base paper 72 is formed in the fully dry base paper production line 3 , which includes a second mesh cylinder 31 , a plurality of second guide rollers 32 , a drying cylinder 33 , a second felt 34 , and a cooling roller 35 .

[0044] (3) Discharging polymer material: The first upper felt 23 drives the semi-dry base paper 71 to pass through the polymer discharging device 20 , and the polymer discharging device 20 discharges the polymer water-absorbing material 73 onto the semi-dry base paper 71 of the semi-dry base paper production line 2 .

[0045] (4) Compounding: The fully dry base paper 72 bypasses the polymer feeding device 20 and is pressed together with the semi-dry base paper 71 carrying the polymer absorbent material to the compounding device 4 to form a polymer composite absorbent paper 7.

[0046] (5) Rotary drying: The absorbent paper 7 is rotated and dried by the rotating drying wheel 5.

[0047] (6) Suspension drying: The absorbent paper 7 passes through the suspension channel 82, the burner of the suspension hot air bed 8 heats the gas, and the fan 84 blows the heated gas to the air nozzle 85. The air nozzle 85 blows the hot air to the top and bottom of the absorbent paper 7 to perform suspension drying. The air nozzles 85 are alternately arranged. When the air nozzles 85 blow the hot air to the semi-dry base paper 71, the heat is transferred from the semi-dry base paper 71 to the fully dry base paper 72. The temperature of the semi-dry base paper 71 is higher than that of the fully dry base paper 72. When the air nozzles 85 blow the hot air to the fully dry base paper 72, the heat is transferred from the semi-dry base paper 71 to the fully dry base paper 72. , heat is transferred from the fully dry base paper 72 to the semi-dry base paper 71, the temperature of the fully dry base paper 72 is higher than that of the semi-dry base paper 71, and the semi-dry base paper 71 and the fully dry base paper 72 receive hot air and heat transfer alternately; when the semi-dry base paper 71 and the fully dry base paper 72 are in contact, a force is exerted on the semi-dry base paper 71 and the fully dry base paper 72, so that the semi-dry base paper 71 and the fully dry base paper 72 move in opposite directions, and the absorbent paper 7 located in the suspension channel 82 forms a wavy structure that alternates up and down or forms a plurality of upper convex parts and The lower protrusion not only increases the drying area of ​​the absorbent paper 7, but also changes the position of the absorbent paper 7 in the vertical direction, constantly changes the direction of movement, can throw out part of the water, and the front and back sides of the fiber are constantly curled and deformed under alternating heating, making the composite material more loose and breathable. The bulkiness, liquid absorption speed and air permeability of the absorbent paper 7 are significantly improved. The absorbent paper 7 is first preheated through the first channel 831. The hot air speed and air volume of the air nozzle 85 at the first channel 831 are less than the hot air speed and air volume of the air nozzle 85 at the second channel 832. The absorbent paper 7 is then fully heated through the second channel 832. The heat gradually heats the absorbent paper 7, and the absorbent paper 7 will not be subjected to high temperature instantly, which prevents the absorbent paper 7 from expanding instantly due to the large temperature difference between the absorbent paper 7 and the ambient temperature, and prevents the internal structure of the absorbent paper 7 from being pulled and damaged. When the same flat surface weight of the absorbent paper 7 is 60g-200g, the production speed can reach 60m / min-100m / min.

[0048] The suspended hot air bed 8 includes a box body 81 arranged on the frame 1, a burner arranged in the box body 81, and a fan 84 connected to the burner. A suspension channel 82 is arranged in the middle of the box body 81, and combustion channels 83 are respectively arranged at the top and bottom of the box body 81. Each combustion channel 83 has a burner and a fan 84. Each combustion channel 83 is connected to multiple air nozzles 85, and the air nozzles 85 of the two combustion channels 83 are arranged alternately up and down. The combustion channel 83 includes a first channel 831 and a second channel 832 arranged in sequence along the conveying direction. The cross-sectional areas of each position of the first channel 831 are equal, and the cross-sectional area of ​​the second channel 832 decreases along the conveying direction. The cross-sectional area of ​​the first channel 831 is a rectangular structure, and the cross-sectional area of ​​the second channel 832 is a right-angled trapezoidal structure. The box 81 is provided with an upper bed 811 and a lower bed 812, and two adjusting cylinders 813 are provided between the upper bed 811 and the lower bed 812. The adjusting cylinders 813 can adjust the distance between the upper bed 811 and the lower bed 812. A suspension channel 82 is formed between the upper bed 811 and the lower bed 812, and two combustion channels 83 are respectively provided in the upper bed 811 and the lower bed 812. The hot air temperature of the suspended hot air bed 8 is 150 degrees, and the air volume of the suspended hot air bed 8 is 60,000 cubic meters per hour.

[0049] (7) Rewinding: The absorbent paper 7 is rewinded by the rewinding device 6.

[0050] The present invention also provides absorbent paper produced based on the above-mentioned fully automatic absorbent paper production method, comprising a composite semi-dry base paper 71 and a fully dry base paper 72, with a polymer absorbent material 73 arranged between the semi-dry base paper 71 and the fully dry base paper 72. The absorbent paper 7 produced by the above-mentioned method has significantly improved bulkiness, liquid absorption speed, and air permeability. The liquid absorption speed of the product can be more than 30% faster, the air permeability of the product is better, and the moisture content can be controlled below 5%, which is far lower than the industry standard.

[0051] The hot air temperature of the above-mentioned suspended hot air bed 8 is usually set to between 140 degrees and 160 degrees, and can also be other temperatures, which are set according to specific circumstances.

[0052] The air volume of the suspended hot air bed 8 is 60,000 cubic meters per hour, and can also be 55,000 cubic meters per hour, 65,000 cubic meters per hour or other air volumes, which can be set according to specific circumstances.

[0053] The composite device 4 can be a composite roller or other composite devices, which are well-known devices and will not be described in detail here.

[0054] The winding device 6 may be a winding roller or other winding devices, which are well-known devices and will not be described in detail here.

[0055] Thermal insulation rock wool may be arranged in the box body 81, depending on the specific situation.

[0056] The burner, fan 84 and polymer feeding device 20 are well-known devices and will not be described in detail here.

[0057] The above-mentioned air nozzles 85 may not be arranged to be arranged alternately up and down, and may be arranged according to specific circumstances.

[0058] The box body 81 may not be configured as an adjustable upper bed body 811 and a lower bed body 812, and may be configured according to specific circumstances.

[0059] The first mesh cylinder 21, the first guide roller 22, the first upper felt 23, the first lower felt 24, and the pressing roller 25 are well-known structures and will not be described in detail herein.

[0060] The second mesh cylinder 31, the plurality of second guide rollers 32, the rotary drying wheel 5, the drying cylinder 33, and the second felt 34 are well-known structures and will not be described in detail herein.

[0061] The hot air temperature of the above-mentioned suspended hot air bed 8 is usually set in the range of 130 degrees to 200 degrees, and can also be other temperatures, which are set according to specific circumstances.

[0062] The above-mentioned suspended hot air bed 8 can also be dried by using a hot air blower structure up and down, or by using other hot air devices, which can be set according to specific circumstances.

[0063] The present invention may also adopt the following method: after the above-mentioned fully dry base paper 72 is produced in the fully dry base paper production line 3, it is placed on a reel for unwinding; after the semi-dry base paper 71 is formed in the semi-dry base paper production line 2, it is compounded with the fully dry base paper 72, and then subjected to rotary drying, suspension drying and winding.

[0064] The present invention may also adopt the following method: after the semi-dry base paper 71 and the fully dry base paper 72 are produced, they are placed on two unwinding rollers, and then compounded, rotary dried, suspended dried and rolled.

[0065] The humidity of the semi-dry base paper 71 is usually greater than the humidity of the completely dry base paper 72 , and may also be less than or equal to the humidity of the completely dry base paper 72 , and is specifically set according to the situation.

[0066] The above-mentioned fully dry base paper production line 3 and semi-dry base paper production line 2 may also be the same device, and the fully dry base paper 72 and the semi-dry base paper 71 are both formed on the same device.

[0067] The present invention can adopt PLC system or other automatic control systems, which are well-known systems.

[0068] refer to Fig. 9 and Fig.10The winding device 6 of the present invention can adopt the following structure: the winding device 6 includes a slide 61 horizontally slidably arranged on the frame 1, a driving mechanism 62 for driving the slide 61 to slide, a winding roller 63 rotatably arranged on the slide 61, and a winding motor 64 for driving the winding roller 63 to rotate. The slide 61 is provided with a radius detection device 65 for detecting the real-time radius R of the absorbent paper 7, wherein the rotation speed of the winding motor 64 is n, the moving speed of the slide 61 is V1, and the radius of the paper tube 66 sleeved on the winding roller 63 is R0.

[0069] At radius R, the distance to be compensated is L=2π•(R-R0), and the speed V1 is adjusted every time the radius of the absorbent paper 7 increases by f.

[0070] When f≤0.5cm, V1=2π•(R-R0)•n.

[0071] When f>0.5cm, V1=2π•[R-R0+(f / 2)]•n.

[0072] During the winding process of the absorbent paper 7, the radius of the absorbent paper 7 becomes larger and larger, and the driving mechanism 62 drives the slide 61 to move along the direction of the suspended hot air bed 8. The moving speed V1 of the slide 61 gradually increases as the radius of the absorbent paper 7 increases to compensate for the error caused by the increase in the radius of the absorbent paper 7, thereby maintaining the rotation speed n of the winding motor 64. There is no need to change the rotation speed of the winding motor 64. Since the winding motor 64 runs at a high speed, it is difficult to accurately control the speed of the winding motor 64 by changing the speed of the winding motor 64 in real time. The speed of the winding motor 64 changes continuously, which will reduce the speed of the winding motor 64. Therefore, maintaining the rotation speed n of the winding motor 64 not only improves the winding stability of the absorbent paper 7, prevents the absorbent paper 7 from being difficult to control the tension force during the winding process, resulting in wrinkles, folding, and damage, thereby improving the winding efficiency, but also protects the winding motor 64 and increases the life of the winding motor 64.

[0073] The driving mechanism 62 may be a servo motor, a pneumatic cylinder, an oil cylinder or other motion mechanisms, which may be configured according to specific circumstances.

[0074] The radius detection device 65 may be a distance sensor, a position sensor or other devices for detecting the radius, which are well-known devices and will not be described in detail herein.

[0075] refer to Fig.11 The winding device 6 of the present invention may also be provided with a pressure detection device, which includes a pressure sensor 67 arranged on the frame 1, a roller seat 68 arranged on the pressure sensor 67, and a rotating roller 69 rotatably arranged on the roller seat 68.

[0076] The real-time value of the pressure sensor 67 is F, and F0 is the standard value of the pressure sensor 67 set by the system.

[0077] When F-F0>F0 / 5, increase the speed of V1:

[0078] V1=2π•(R-R0)•n•(6 / 5), or V1=2π•n•[R-R0+(f / 2)]•(6 / 5), until F=F0, the speed of V1 is restored.

[0079] When F0-F>F0 / 5, reduce the speed of V1:

[0080] V1=2π•(R-R0)•n•(4 / 5), or V1=2π•n•[R-R0+(f / 2)]•(4 / 5), until F=F0, the speed of V1 is restored.

[0081] This structure can adjust the tension of the absorbent paper 7 in real time, prevent the absorbent paper 7 from wrinkling, folding, and damage, improve the rolling effect of the absorbent paper 7, and improve the quality of the product.

[0082] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A method for producing absorbent paper, Features: The following steps are involved: (1) Semi-dry base paper forming: Semi-dry base paper is formed on the semi-dry base paper production line; (2) Fully dry base paper forming: Fully dry base paper is formed on the full dry base paper production line; (3) Polymer material unloading: The polymer unloading device unloads the polymer water-absorbing material onto the semi-dry base paper; (4) Compounding: The fully dry base paper bypasses the polymer unloading device and is pressed with the semi-dry base paper carrying the polymer absorbent material to the compounding device to form a polymer composite absorbent paper; (5) Rotary drying: The absorbent paper is dried by a rotary drying wheel; (6) Suspension drying: The absorbent paper passes through a suspension hot air bed, which blows hot air to one side of the semi-dry base paper, or to both sides of the semi-dry base paper and the fully dry base paper for suspension drying; (7) Rewinding: The absorbent paper is rewound by a rewinding device; the rewinding device comprises a slide seat horizontally slidably mounted on a frame, a driving mechanism driving the slide seat to slide, a rewinding roller rotatably mounted on the slide seat, and a rewinding motor driving the rewinding roller to rotate; the slide seat is provided with a radius detection device for detecting the real-time radius R of the absorbent paper; the speed of the rewinding motor is n, the moving speed of the slide seat is V1, and the radius of the paper tube sleeved on the rewinding roller is R0; the rewinding device comprises a pressure detection device, the pressure detection device comprises a pressure sensor mounted on the frame, a roller seat mounted on the pressure sensor, and a rotating roller rotatably mounted on the roller seat; the real-time value of the pressure sensor is F, and F0 is the standard value of the pressure sensor set by the system; At radius R, the distance to be compensated is L=2π•(R-R0), and the speed V1 is adjusted every time the radius of the absorbent paper 7 increases by f; (1) When f≤0.5cm, V1=2π•(R-R0)•n; Among them, when F-F0>F0 / 5, increase the speed of V1: V1=2π•(R-R0)•n•(6 / 5), until F=F0, restore the speed of V1; When F0-F>F0 / 5, reduce the speed of V1: V1=2π•(R-R0)•n•(4 / 5), until F=F0, restore the speed of V1; (2) When f>0.5cm, V1=2π•[R-R0+(f / 2)]•n; Among them, when F-F0>F0 / 5, increase the speed of V1: V1=2π•n•[R-R0+(f / 2)]•(6 / 5), until F=F0, restore the speed of V1; When F0-F>F0 / 5, reduce the speed of V1: V1=2π•n•[R-R0+(f / 2)]•(4 / 5), until F=F0, and then restore the speed of V1.

2. A method for producing absorbent paper according to claim 1, Features: The semi-dry base paper forming in step (1) comprises: the semi-dry base paper is formed through pulp mixing, pulping, defibrating and pulping processes, wood pulp and fluff pulp are mixed to obtain a mixed slurry, the mixed slurry is pulped, and the fibers are defibrated to obtain a fiber defibrated slurry, and the fiber defibrated slurry is pulped in a pulping tank to obtain a pulping slurry; the first lower felt passes through a first mesh cylinder and contacts with the pulping slurry, the pulping slurry forms a first pulp on the first lower felt, the first lower felt conveys the first pulp from the first mesh cylinder, the first lower felt, the first pulp and the first upper felt pass through a pressing roller to form the first pulp into semi-dry base paper, and the semi-dry base paper is separated from the first lower felt and connected to the first upper felt at the same time.

3. A method for producing absorbent paper according to claim 2, Features: The step (2) of forming the fully dry base paper comprises: forming the fully dry base paper through pulp mixing, pulping, defibrating, pulping and drying processes, mixing wood pulp and fluff pulp to obtain a mixed slurry, pulping the mixed slurry, and then defibrating the fibers to obtain a fiber defibrated slurry, and pulping the fiber defibrated slurry in a pulping tank to obtain a pulping slurry; the second felt passes through a second mesh cylinder to contact the pulping slurry, the pulping slurry forms a second pulp on the second felt, the second felt conveys the second pulp from the second mesh cylinder, the second pulp is then dried by a drying cylinder to form fully dry base paper, and the fully dry base paper leaves the second felt and moves to the composite device.

4. A method for producing absorbent paper according to claim 3, Features: After the fully dry base paper passes through the drying cylinder, the fully dry base paper passes through the cooling roller for cooling and shaping.

5. A method for producing absorbent paper according to claim 1, Features: In step (6), the suspended hot air bed includes a box body arranged on a frame, at least one burner arranged in the box body, and at least one fan connected to the burner. A suspension channel is provided in the middle of the box body. A combustion channel is provided on the box body on one side of the semi-dry base paper. Each of the combustion channels has at least one burner and the fan. Each of the combustion channels is connected to a plurality of air nozzles. The burner generates heat energy by combustion, which heats the air to increase the temperature. The fan generates hot air and blows it toward the air nozzle. The air nozzle blows the air toward one side of the semi-dry base paper for drying. The air nozzle blows the hot air toward the semi-dry base paper. Heat is transferred from the semi-dry base paper to the fully dry base paper. The temperature of the semi-dry base paper is higher than that of the fully dry base paper.

6. A method for producing absorbent paper according to claim 1, Features: In step (6), the suspended hot air bed comprises a box body arranged on a frame, at least one burner arranged in the box body, and at least one fan connected to the burner. A suspension channel is arranged in the middle of the box body, and combustion channels are arranged at the top and bottom of the box body respectively. Each of the combustion channels has at least one burner and the fan. Each of the combustion channels is connected to a plurality of air nozzles. The burner generates heat energy by combustion, which heats the air to increase the temperature. The fan generates hot air to blow toward the air nozzle. The air nozzle blows the air toward both sides of the semi-dry base paper and the fully dry base paper for drying. The hot air is blown from the air nozzle toward the surface of the absorbent paper to dry and heat the surface of the absorbent paper. The air nozzles of the two combustion channels are alternately arranged at a projection interval on the horizontal plane. When the air nozzle blows the hot air toward the semi-dry base paper, Heat is transferred from the semi-dry base paper to the fully dry base paper, and the temperature of the semi-dry base paper is higher than that of the fully dry base paper; when the air nozzle blows hot air to the fully dry base paper, heat is transferred from the fully dry base paper to the semi-dry base paper, and the temperature of the fully dry base paper is higher than that of the semi-dry base paper, and the semi-dry base paper and the fully dry base paper receive the hot air and heat transfer alternately; when the hot air contacts the semi-dry base paper and the fully dry base paper, a force is exerted on the semi-dry base paper and the fully dry base paper, so that the semi-dry base paper and the fully dry base paper move in opposite directions, and the absorbent paper located in the suspension channel forms an alternating wavy structure or multiple upper and lower convexities, which not only increases the drying area of ​​the absorbent paper, but also changes the position of the absorbent paper in the vertical direction. The constantly changing movement direction can throw out part of the water, and the absorbent paper continuously curls and deforms under the condition of alternating heating.

7. A method for producing absorbent paper according to claim 5 or 6, Features: The box body is provided with an upper bed body and a lower bed body, at least one adjusting cylinder is provided between the upper bed body and the lower bed body, the adjusting cylinder can adjust the distance between the upper bed body and the lower bed body, the suspension channel is formed between the upper bed body and the lower bed body, and the two combustion channels are respectively provided in the upper bed body and the lower bed body.

8. A method for producing absorbent paper according to claim 5 or 6, Features: The combustion channel includes a first channel and a second channel which are arranged in sequence along the conveying direction. The cross-sectional areas of the first channel at each position are equal, and the cross-sectional area of ​​the second channel decreases along the conveying direction. The absorbent paper first passes through the first channel for preheating. The hot air speed and air volume of the air nozzle at the first channel are smaller than the hot air speed and air volume of the air nozzle of the second channel. The absorbent paper then passes through the second channel for full heating, and the heat gradually heats the absorbent paper.

9. A method for producing absorbent paper according to claim 1, Features: The hot air temperature of the suspended hot air bed is 130 to 200 degrees, and the production speed of the absorbent paper is 60m / min-100m / min.

10. An absorbent paper produced by the absorbent paper production method according to claim 1, Features: The absorbent paper comprises a composite semi-dry base paper and a fully dry base paper, wherein a polymer absorbent material is arranged between the semi-dry base paper and the fully dry base paper.

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