Anti-fatigue composite paper tube raw paper for high-speed spinning tube and preparation process of anti-fatigue composite paper tube raw paper

Abstract

The invention belongs to the technical field of papermaking, and particularly relates to anti-fatigue composite paper tube base paper for a high-speed spinning bobbin and a preparation process of the anti-fatigue composite paper tube base paper. According to the scheme, in the key dehydration stage (waterline position) of wet paper web forming, a high-polymerization-degree and high-alcoholysis-degree polyvinyl alcohol (PVA) fiber solution is quantitatively sprayed to a surface layer and a bottom layer, and the anti-fatigue composite paper tube base paper is obtained; the PVA fibers are dissolved and re-crosslinked in the subsequent drying process, a uniform and compact microfiber network is formed in a fiber skeleton of the paper, and the'reinforcing mesh 'structure formed in situ and spreading all over the interior of the paper can effectively disperse and absorb repeated shear stress and centrifugal force generated during high-speed rotation of bobbins, so that the high-speed rotation of the bobbins is realized. The toughness and the dynamic fatigue resistance of the paper sheet are greatly enhanced, so that the service life of the spinning tube is remarkably prolonged.

Description

Technical Field

[0001] This invention belongs to the field of papermaking technology, specifically relating to fatigue-resistant composite paper tube base paper for high-speed spinning tubes and its preparation process. Background Technology

[0002] Currently, the market demand for fatigue-resistant composite paper tubes used in high-speed spinning continues to rise, showing a steady growth trend. Driven by the ongoing "dual carbon" goals and environmental policies, paper-based materials, with their advantages of recyclability and biodegradability, are accelerating their replacement of traditional plastic and metal cores, becoming an important choice for the textile industry's green transformation. The downstream textile industry's upgrade towards high-speed and intelligent processes places higher demands on the performance of supporting paper tubes, further fueling the demand for high-strength, fatigue-resistant, and other high-end functional paper tubes.

[0003] High-speed spinning processes, characterized by repeated stress impacts during high-speed rotation and long storage times after winding, impose stringent performance standards on paper tubes. These standards include excellent fatigue resistance and high strength, as well as high-precision dimensional stability, roundness, and concentricity. The core reason for these requirements is to ensure the continuity and stability of the high-speed spinning process. As a key supporting component for yarn winding, the performance of the paper tube directly affects production efficiency, yarn forming quality, and the service life of textile machinery, making it an indispensable and crucial component in the upgrading of the textile industry.

[0004] However, traditional paper tubes have insufficient fatigue resistance under repeated stress during high-speed spinning, and low smoothness. They are prone to fatigue cracks and deformation under high-speed rotation conditions above 2500 rpm, resulting in short service life and frequent replacement. This increases downtime and production costs, and fails to meet the requirements of high-end spinning processes for the reliability and consistency of consumables, thus hindering the improvement of textile production efficiency and product quality. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing an anti-fatigue composite paper tube base paper for high-speed spinning tubes and its preparation process, effectively solving the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The preparation process of fatigue-resistant composite paper tube base paper for high-speed spinning tubes includes the sequential processes of pulping, conveying and auxiliary material addition, papermaking, pressing, drying and packaging. In the papermaking process, when water lines appear on the wet paper sheets, polyvinyl alcohol fiber solution is added to the wet paper sheets and the bottom pulp sheets in the form of spraying when the wet paper sheets are formed by dewatering the mixed pulp through the three-layer wire forming machine. After the three layers of wet paper sheets are compounded, they enter the pressing process. In the pulping process, long-fiber pulp and short-fiber pulp obtained from waste paper pulp, as well as good sulfate softwood pulp obtained from sulfate softwood pulp, are mixed according to a preset ratio to obtain a mixed pulp. In the flow and auxiliary material addition process, cationic starch, polyaluminum chloride, solid additives and flocculants, and bentonite are added in stages according to the preset segmented addition strategy to construct the optimal wet-end chemical environment.

[0007] Furthermore, the polyvinyl alcohol fiber solution is sprayed after the water line.

[0008] Furthermore, before laminating the three layers of wet paper, a starch solution is added by spraying and then laminating is performed. The laminated wet paper web is then preliminarily dehydrated before entering the pressing process.

[0009] Furthermore, the pre-defined segmented addition strategy specifically involves the following steps: In the conveying and auxiliary material addition process, the mixed slurry sequentially passes through a white water tower, a slurry pump, a pressure screen, and a pulse attenuator before entering the headbox; cationic starch and polyaluminum chloride are added at the inlet of the slurry pump; and after the mixed slurry is fully mixed and diluted with white water by the slurry pump, solid additives and flocculants are added, and bentonite is added directionally at the outlet of the pressure screen.

[0010] Furthermore, the long-fiber pulp, short-fiber pulp, and sulfate softwood pulp are mixed according to a preset ratio, wherein the ratio of long-fiber pulp, short-fiber pulp, and sulfate softwood pulp is set to 3:2:5, and the pulp concentration needs to be prepared to be 3.0. 4.0%.

[0011] Furthermore, the mixed slurry obtained from the pulping process needs to be mixed with a wet strength agent that meets the preset requirements, and then pumped into the high-level tank after being fully stirred and diluted in the pre-pulping tank.

[0012] Furthermore, the mixed slurry in the headbox is coated onto the surface slurry forming mesh, the lining slurry forming mesh, and the bottom slurry forming mesh according to a preset coating ratio, wherein the preset coating ratio is a:b:c, where a is the coating ratio of the surface slurry forming mesh, with a value range of [29, 31], b is the coating ratio of the lining slurry forming mesh, with a value range of [37, 39], and c is the coating ratio of the bottom slurry forming mesh, with a value range of [31, 33].

[0013] Furthermore, in the papermaking process, the composite wet paper web is sequentially dewatered through a vacuum box, a vacuum roll, and a roll press before entering the pressing process.

[0014] The anti-fatigue composite paper tube base paper for high-speed spinning tubes is prepared by the above-mentioned preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows: (1) The present invention provides a fatigue-resistant composite paper tube base paper for high-speed spinning tube and its preparation process. The present invention introduces a polyvinyl alcohol fiber solution (i.e. PVA fiber solution) to implant a high-strength fiber network in the wet end forming stage, thereby realizing in-situ reinforcement of the paper in the wet end and significantly improving the toughness, folding endurance and fatigue resistance of the paper. (2) In the key dehydration stage of wet paper web forming ("water line" position), the solution described in this invention sprays a quantitative solution of polyvinyl alcohol (PVA) fiber with high degree of polymerization and high degree of alcoholysis on the surface and bottom layers. Based on the dissolution and re-crosslinking of PVA fibers during the subsequent drying process, a uniform and dense microfiber network is formed inside the fiber skeleton of the paper. This in-situ formed "steel mesh" structure that is distributed throughout the paper can effectively disperse and absorb the repeated shear stress and centrifugal force generated when the yarn tube rotates at high speed, which greatly enhances the toughness and resistance to dynamic fatigue of the paper, thereby significantly extending the service life of the spinning tube. (3) The solution described in this invention precisely constructs the optimal wet charge balance and flocculation environment by using a pre-set segmented addition strategy (precisely adding cationic starch and polyaluminum chloride, solid additives and flocculants and bentonite in sequence). This not only improves the retention rate of fine fibers and fillers, but more importantly, enhances the internal strength and homogeneity of the multilayer wet paper web before lamination. At the same time, in conjunction with the measure of spraying starch solution before interlayer lamination, the chemical bonding and mechanical interlocking between the surface layer, liner layer and bottom layer are actively strengthened, effectively preventing delamination and peeling problems caused by poor interlayer bonding during subsequent high-speed use of the paper tube, and ensuring the structural integrity of the product. (4) The present invention creatively designs an optimized fiber ratio scheme in the pulping process (i.e., the ratio of long fiber pulp, short fiber pulp and sulfate softwood pulp is set to 3:2:5). Through careful selection and compounding, about 50% of high-strength virgin wood pulp lays the foundation for the product's performance. At the same time, a large-scale (about 50%) of graded waste paper pulp (long fiber and short fiber) is introduced, and the ratio of long and short fibers is functionally adjusted. Long fibers provide auxiliary reinforcement, and short fibers improve uniformity and filling properties. This refined and functional fiber engineering design significantly reduces raw material costs while ensuring that the core mechanical properties (stiffness, ring crush) are close to or reach the level of whole wood pulp products, thus achieving an effective unity of high performance and low cost. (5) The anti-fatigue composite paper tube prepared by the above scheme has a high surface smoothness, no burrs, no peeling, and a stable coefficient of friction. It will not snag or damage the yarn during the winding process, avoid yarn breakage or surface defects, and ensure the quality of the finished yarn tube. At the same time, the surface has strong wear resistance and can withstand the friction loss during high-speed winding of the yarn. It can still maintain the surface integrity after long-term use. (6) The anti-fatigue composite paper tube base paper prepared by the present invention greatly improves the paper tube's resistance to repeated stress impacts, effectively delays the initiation and propagation of fatigue cracks, and can withstand cyclic tensile and compressive stresses for a long time under high-speed rotation conditions above 2500 rpm without easily deforming or cracking. Its service life is significantly extended compared to traditional paper tubes, reducing the frequency of paper tube replacement and production costs, and reducing downtime losses. (7) The anti-fatigue composite paper tube base paper prepared by the scheme described in this invention has significantly better ring crush strength, compressive strength and interlayer bonding strength than traditional products by adding polyvinyl alcohol fiber (i.e. PVA fiber). The paper tubes rolled up can withstand high winding pressure without being crushed, collapsed or delaminated. At the same time, it has good rigidity, avoids radial runout caused by insufficient rigidity during high-speed rotation, and ensures the regularity of the yarn winding. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below: Figure 1 This is a basic flow chart of the preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes described in this embodiment; Figure 2 This is a schematic diagram of the preparation process framework for the anti-fatigue composite paper tube base paper used in high-speed spinning tubes as described in this embodiment. Figure 3 This is a schematic diagram of the pulping process framework described in this embodiment; Figure 4 This is a schematic diagram of the flow and auxiliary material addition process framework described in this embodiment; Figure 5 This is a schematic diagram of the papermaking and subsequent process framework described in this embodiment. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0019] Definitions: Pre-beating pool: A storage pool for pulp before beating (i.e., beating). Post-beating pool: A storage pool for pulp after beating.

[0020] Example 1 The preparation process of an anti-fatigue composite paper tube base paper for high-speed spinning tubes in Example 1 will be described in detail below with reference to the accompanying drawings.

[0021] like Figure 1 and Figure 2 As shown, a process for preparing fatigue-resistant composite paper tube base paper for high-speed spinning tubes includes the sequential execution of pulping, conveying and auxiliary material addition, papermaking, pressing, drying and packaging processes; In the papermaking process, when water lines appear on the wet paper sheets, polyvinyl alcohol fiber solution is added to the wet paper sheets and the bottom pulp sheets in the form of spraying when the wet paper sheets are formed by dewatering the mixed pulp through the three-layer wire forming machine. After the three layers of wet paper sheets are compounded, they enter the pressing process. In the pulping process, long-fiber pulp and short-fiber pulp obtained from waste paper pulp, as well as good sulfate softwood pulp obtained from sulfate softwood pulp, are mixed according to a preset ratio to obtain a mixed pulp. In the flow and auxiliary material addition process: cationic starch, polyaluminum chloride, solid additives and flocculants, and bentonite are added in stages according to the preset segmented addition strategy to construct the optimal wet-end chemical environment.

[0022] In a specific implementation, the polyvinyl alcohol fiber solution is sprayed after the water line.

[0023] In specific implementation, the degree of alcoholysis of the polyvinyl alcohol fiber solution is 95%, the water solubility temperature is not less than 75℃, and the addition amount is 10kg / ton of paper.

[0024] It should be noted that 10kg / ton of paper refers to the amount of paper that needs to be added to produce one ton of finished paper (not oven-dried finished paper, the moisture content of the finished paper here is about 6.5%). The "kg / ton of paper" mentioned below will have the same meaning, and will not be repeated here.

[0025] In practice, starch solution is added by spraying before the three-layer wet paper web is laminated, and the laminated wet paper web is then preliminarily dehydrated before entering the pressing process.

[0026] In one or more embodiments, the preset segmented addition strategy specifically involves: in the conveying and auxiliary material addition process, the mixed slurry sequentially passes through a white water tower, a slurry pump, a pressure screen, and a pulse attenuator before entering the headbox; wherein, cationic starch and polyaluminum chloride are added at the inlet of the slurry pump; and, after the mixed slurry is fully mixed and diluted with white water by the slurry pump, solid additives and flocculants are added, and bentonite is added directionally at the outlet of the pressure screen.

[0027] In specific implementation, the pulping process uses sulfate softwood pulp and waste paper pulp as raw materials, which are sequentially processed through crushing and multi-stage screening and purification to obtain good sulfate softwood pulp and good waste paper pulp; the good waste paper pulp is graded to obtain long fiber components and short fiber components; the long fiber components and short fiber components are sequentially concentrated and beaten to obtain beaten long fiber pulp and short fiber pulp; the long fiber pulp, short fiber pulp and sulfate softwood pulp are mixed according to a preset ratio to obtain a mixed pulp; The process of using sulfate softwood pulp and waste paper pulp as raw materials, and subjecting them to sequential pulping and multi-stage screening and purification treatment, specifically includes: pulping the sulfate softwood pulp and waste paper pulp separately in a hydraulic pulper, and then sequentially passing them through a high-consistency desander, a coarse screen, a medium-consistency desander, and a fine screen for multi-stage screening and purification to remove metal impurities, fiber bundles, and dust from the pulp, thereby obtaining high-quality sulfate softwood pulp and high-quality waste paper pulp with purity meeting preset requirements; and adding a wet strength agent meeting preset requirements to the mixed pulp obtained from the pulping process, thoroughly stirring and diluting it in the pre-paper tank before pumping it into the high-level tank, wherein the amount of wet strength agent added is set at 5 kg / ton of paper, and after thorough stirring and dilution in the pre-paper tank to a concentration of 3.0%, it is pumped into the high-level tank.

[0028] Specifically, such as Figure 3 As shown, the pulping process includes: First, sulfate softwood pulp and waste paper pulp are crushed separately by a hydraulic pulper. Then, they are sequentially screened and purified through a high-consistency desander, a coarse screen, a medium-consistency desander, and a fine screen to efficiently remove metal impurities, fiber bundles, dust and other pollutants from the pulp, thus producing high-quality sulfate softwood pulp and waste paper pulp with the required purity.

[0029] The waste paper pulp is transported to a fiber grading screen for grading and separation of long and short fiber components. The separated long and short fibers are then introduced into dedicated thickeners for concentration. Once the pulp concentration reaches the set range of the process, they are pumped to the corresponding disc mills for pulping.

[0030] After pulping, long fibers and short fibers are temporarily stored in separate tapping tanks. The three fibers are then pumped to the pulping tank in a ratio of long fibers: short fibers: sulfate softwood pulp = 3:2:5 for mixing, and the concentration of the mixed pulp is adjusted to 3.0%. 4.0%, add a small amount of wet strength agent to the mixed slurry, stir and dilute it thoroughly in the pre-stirring tank, and then pump the mixed slurry into the high-level tank.

[0031] In one or more embodiments, sulfate softwood pulp and waste paper pulp are separately fed into a hydrauler for pulping, with a pulp concentration of 4.0. 4.4%, after pulping, they enter different pre-beating tanks; softwood pulp is pulped in series using a dual-disc mill and a conical refiner, employing a semi-free to semi-viscous pulping method, with a pulp concentration of 4.5±0.2% and a freeness controlled at 36±1°SR; waste paper pulp is pulped using a dual-disc mill, employing viscous pulping and long / short fiber graded pulping, with the long fiber pulp concentration controlled within the range of 5.2±0.2% and the freeness controlled at 45±1°SR; the short fiber pulp concentration is controlled within the range of 4.8±0.2% and the freeness controlled at 40±1°SR. After pulping, softwood pulp and waste paper pulp enter their respective post-beating tanks.

[0032] In one or more embodiments, the long-fiber pulp, short-fiber pulp, and sulfate softwood pulp are mixed according to a preset ratio to obtain a mixed pulp, wherein the ratio of long-fiber pulp, short-fiber pulp, and sulfate softwood pulp is set to 3:2:5, and the pulp concentration needs to be prepared to be 3.0. 4.0%; and, add wet strength agent to the mixed pulp at a rate of 5 kg / ton of paper, disperse it evenly, then pump the mixed pulp into the pre-papering tank, dilute it to a concentration of 3.0%, and then pump it to the high-level tank.

[0033] In specific implementation, during the conveying and auxiliary material addition process, the mixed slurry is sequentially processed by a white water tower, a slurry pump, a pressure screen, and a pulse attenuator before entering the headbox; cationic starch and polyaluminum chloride are added at the inlet of the slurry pump; and after the mixed slurry is fully mixed and diluted with white water by the slurry pump, solid additives and flocculants are added, and bentonite is added directionally at the outlet of the pressure screen. It is important to note that dry strength agents (such as polyacrylamide and cationic starch) preemptively bind to the fibers after addition, forming a reinforcing network that hinders the penetration of PVA solution and also occupies effective binding sites. Specifically, cationic starch, being positively charged, can quickly and firmly adsorb onto the negatively charged fiber surface. Its numerous hydroxyl groups can become perfect binding sites for PVA molecules, promoting the binding of PVA fibers. Polyaluminum chloride can effectively neutralize the negative charge of fibers and dissolved colloidal substances, reducing anionic interference in the system. By neutralizing the charge, it causes fine substances to flocculate, thereby significantly improving the filtration speed of the formed mesh. However, excessive addition will make the entire slurry system highly positively charged, preventing PVA fibers from effectively adsorbing the solution.

[0034] Secondly, although solid additives and filtration aids (such as flocculants) also improve water filtration, they compete for binding sites, so it is necessary to control their addition amount.

[0035] In specific implementation, the mixed slurry in the headbox is coated onto the surface slurry forming mesh, the lining slurry forming mesh, and the bottom slurry forming mesh according to a preset coating ratio. The preset coating ratio is a:b:c, where a is the coating ratio of the surface slurry forming mesh, with a value range of [29, 31], b is the coating ratio of the lining slurry forming mesh, with a value range of [37, 39], and c is the coating ratio of the bottom slurry forming mesh, with a value range of [31, 33].

[0036] Specifically, such as Figure 4 As shown, the conveying and auxiliary material addition process is as follows: The pretreated mixed pulp in the high-level tank flows sequentially through the white water tower, the pulp pump, the pressure screen, and the pulse attenuator, finally being stably delivered to the headbox to provide a homogeneous pulp base for paper forming. Cationic starch is added at the inlet of the pulp pump to achieve in-sizing, along with polyaluminum chloride as a synergistic agent. After the pulp is thoroughly mixed and diluted with white water by the pulp pump, solid additives and flocculants are further added. Finally, bentonite is directionally added at the outlet of the pressure screen, utilizing its high specific surface area and adsorption properties to adsorb residual fine particles and improve pulp uniformity.

[0037] In one or more embodiments, at the inlet of the slurry pump, the concentration of the cationic starch liquid added is 10.8%, and the amount added is 70g. 80 kg / ton of paper, the concentration of polyaluminum chloride liquid is 9.6%, and the addition amount is 3. 5 kg / ton of paper; and, the concentration of solid additives is 0.2%, and the amount added is 0.15g. 0.25 kg / ton of paper, flocculant concentration of 0.25%, dosage of 0.15 g / ton. 0.25 kg / ton of paper, bentonite concentration of 2.5%, addition amount of 1 1.5 kg / ton of paper.

[0038] In specific implementation, the papermaking process adopts a three-layer wire form including a face pulp forming wire, a liner pulp forming wire, and a bottom pulp forming wire. The mixed pulp in the headbox is coated on the face pulp forming wire, the liner pulp forming wire, and the bottom pulp forming wire according to a preset coating ratio, and then dewatered to form three layers of wet paper sheets. When water lines appear on the wet paper sheets, polyvinyl alcohol (PVA) fiber solution is added to the face pulp wet paper sheets and the bottom pulp wet paper sheets in the form of a spray. Before the three layers of wet paper sheets are laminated, a starch solution is added in the form of a spray and then a lamination process is performed. The laminated wet paper sheets are then preliminarily dewatered before entering the pressing process.

[0039] It is important to note that when adding polyvinyl alcohol (PVA) fiber solution or starch solution by spraying, the spraying temperature must be carefully controlled. Due to the heat solubility of PVA fiber, high spraying temperatures can cause the PVA fiber to dissolve or soften, resulting in loss of fiber shape and skeletal reinforcement. At the same time, it is necessary to ensure that the PVA fiber is easily and evenly sprayed on the forming mesh and that the temperature is slowly increased and shaped during the drying process.

[0040] Specifically, such as Figure 5 As shown, the papermaking process is as follows: A three-layer mesh system (surface slurry forming mesh, lining slurry forming mesh, and bottom slurry forming mesh) is used. The slurry in the headbox is coated onto the forming meshes separately, with a coating ratio of 29:1. 31:37 39:31 33. Then, the paper is dehydrated in a vacuum box to form three independent wet paper sheets. After water lines appear on the wet paper sheets, PVA fiber solution is added to the top pulp wet paper sheets and the bottom pulp wet paper sheets in the form of spraying. Before the top, backing and bottom pulps are laminated, starch solution is added again in the form of spraying. The laminated wet paper web then passes through a vacuum box, a vacuum roll, and a roll press for dehydration. After the dryness reaches 22±1%, it enters the press section. In one or more embodiments, in the papermaking process, the composite wet paper web sequentially passes through a vacuum box, a vacuum couch roll, and a couch roll press for preliminary dewatering before entering the pressing process. The preliminary dewatering requires the wet paper web to achieve a dryness of 22±1%. The vacuum degree of the face pulp wet paper sheet and the liner pulp wet paper sheet is set to 0. The vacuum degree of the wet paper sheet is set to 0.03 MPa and 0. The vacuum level at the lamination points of the face pulp wet paper sheet, the liner pulp wet paper sheet, and the liner pulp wet paper sheet and the base pulp wet paper sheet is set to 0.025 MPa, and the vacuum level of the laminated wet paper web is set to 0.03 MPa. 0.06 MPa; the vacuum degree of the vacuum roll is set to 0.065 MPa, the pressure of the roll press line is 20 kN / m, and the dryness of the wet paper web entering the press process is set to 22 ± 1%.

[0041] In one or more embodiments, the degree of alcoholysis of the polyvinyl alcohol fiber solution (i.e., PVA fiber solution) is 95%, the water solubility temperature is not less than 75°C, and the addition amount is 10 kg / ton of paper; and the concentration of the sprayed starch solution is set to 10.8%, and the addition amount is 30 kg / ton of paper. 35 kg / ton of paper; and the polyvinyl alcohol fiber solution is sprayed after the water line, at which point the paper dryness is 13%. At 15%, the zate potential is approximately -5mV.

[0042] In the preparation of the polyvinyl alcohol fiber solution (i.e., PVA fiber solution), purified water is used for dissolving. Before adding the materials, the stirring device is started, and then the PVA powder is slowly and uniformly added through the feeding device, controlling the stirrer speed to 150 rpm. After the addition is complete, the mixture is first stirred continuously at room temperature for 30 minutes, then heated to 90°C at a gentle rate, and kept at this temperature while stirring for 30 minutes to ensure that the powder is fully dissolved; subsequently, the temperature is lowered to 40°C using cooling water. At 50℃, a 200-mesh filter canister is installed at the front end of the spray pipe, and the dosing pipe is wrapped with thermal insulation cotton. In specific implementation, during the pressing process, the initially dehydrated wet paper web undergoes secondary dewatering through two vacuum pre-presses and three positive presses; and the pressing process employs progressive linear pressing, with the vacuum level of the pressing process vacuum chamber set to 0.04 MPa. 0.05 MPa, the dryness of the wet paper web after the pressing process is 50%. 55%.

[0043] Specifically, the pressing, drying, and packaging process is as follows: The pressing process employs two vacuum pre-presses and three positive presses to further dewater the wet paper web. The press rolls are polyurethane-coated with a Shore D8 hardness. The first vacuum pre-press has a pressure of 10. 15 kN / m, vacuum degree 0.04 MPa, the second vacuum pre-compression pressure is 56 kN / m. 69 kN / m, vacuum degree 0.05 MPa, third positive pressure is 128 156 kN / m, the fourth positive pressure is 189 229 kN / m, the fifth positive pressure is 239. 280 kN / m, the vacuum level of the vacuum chamber in the pressing process is 0.04 MPa. 0.05 MPa, the dryness after the pressing process is 50. 55%.

[0044] In one or more embodiments, the third positive pressure pressing adopts a boot press form to reduce the pressing peak, increase the pressing time, and spray a felt cleaning agent at a concentration of 0.1% onto the pressing section, with a spraying amount of [missing information]. That is, 8 ml per meter of length per minute, spraying an anti-sticking agent at a concentration of 0.1% onto the smooth rollers of the pressing section, with a spraying volume of [missing information]. .

[0045] After the wet paper web exits the pressing process, it undergoes a drying process. This drying process comprises 96 drying cylinders divided into four sections: one low-temperature section, two medium-temperature sections, two mid-temperature sections, and five high-temperature sections. The low-temperature section has a temperature of 55°C. 75℃, the medium temperature range is 80℃. 95℃. The temperature of the second highest temperature range is 95℃. 105℃, the high-temperature range temperature is 105℃. At 120℃, drying cylinders No. 75 and No. 76 in the 8th group of drying cylinders used condensate water to control the temperature at 30℃. At 40℃, the temperature of drying cylinders No. 95 and No. 96 in the 10th group of drying cylinders was controlled at 100℃. 105℃.

[0046] After drying, the paper sheets enter a calender for calendering. After winding, rewinding, and packaging, the paper tube base paper is obtained. The calender uses two pressing zones, with the first pressing zone having a linear pressure of 1. 1.5 kN / m, the linear pressure of the second pressure zone is 4. The upper roller is made of polyurethane soft roller with a Shore D75 hardness, and the lower roller is made of steel roller. The surface of the lower roller is treated with a micro-roughening process of 1.5μm.

[0047] Example 2 Based on the design in Example 1, the following is a specific implementation method for the preparation process of fatigue-resistant composite paper tube base paper for high-speed spinning tubes, including: A. Pulping: First, sulfate softwood pulp and waste paper pulp are separately pulped using a hydrapulper to a pulp concentration of 4.0. The pulp was initially 4.4% pure, and then passed through a high-consistency sand remover, a coarse screen, a medium-consistency sand remover, and a fine screen for four-stage purification. This process effectively removed metal impurities, fiber bundles, dust, and other contaminants from the pulp, resulting in high-purity sulfate softwood pulp and waste paper pulp.

[0048] The waste paper pulp is transported to a fiber grading screen for grading at a ratio of 64.2:35.8. The separated long and short fibers are then introduced into a thickener for concentration, increasing the concentration of long fibers to 5.2% and short fibers to 4.7%. The thickeners are then pumped to their respective disc mills for pulping, and the softwood pulp is concentrated to 4.6%. A double disc mill and a conical refiner are then used for pulping in series.

[0049] Sulfate softwood pulp is beaten using a semi-free to semi-viscous method, with a freeness controlled at 36°SR. Waste paper pulp is beaten using a double-disc mill with a viscous beating method, with the long fiber beating controlled at 45°SR and the short fiber beating controlled at 39°SR. After beating, the softwood pulp and waste paper pulp are respectively sent to their respective beating tanks.

[0050] After pulping, long fibers and short fibers are temporarily stored in separate post-beating tanks. The three fibers are then pumped to the pulping tank in a ratio of long fiber: short fiber: sulfate softwood pulp = 3:2:5 for mixing. The concentration of the mixed pulp is adjusted to 3.5%. Wet strength agent is added to the mixed pulp at a rate of 5 kg / ton of paper. After thorough mixing and dilution in the pre-papering tank to a concentration of 3.1%, the mixed pulp is pumped into the high-level tank.

[0051] B. Flowing and Adding of Auxiliary Materials: The pretreated mixed pulp in the high-level tank flows sequentially through the white water tower, the pulp pump, the pressure screen, and the pulse attenuator, and is finally stably delivered to the headbox. At the inlet of the pulp pump, cationic starch is added to achieve in-sizing of the pulp, and aluminum chloride is added at the same time. The cationic starch used is cassava starch with a concentration of 10.8% and an addition amount of 73 kg / ton of paper. The polyaluminum chloride has a concentration of 9.6% and an addition amount of 3.2 kg / ton of paper.

[0052] After the pulp is thoroughly mixed and diluted with white water by the pulp pump, solid additives and flocculants are added at the outlet of the pulp pump. The concentration of solid additives is 0.2%, and the amount added is 0.17 kg / ton of paper. The concentration of flocculants is 0.25%, and the amount added is 0.16 kg / ton of paper. Finally, bentonite is added to the good pulp outlet pipe of the pressure screen. The concentration of bentonite is 2.5%, and the amount added is 1.0 kg / ton of paper.

[0053] C. Papermaking: A three-layer mesh is used, where the slurry in the headbox is coated onto the forming mesh at a coating ratio of 29%. 31:37 39:31 33. Then, the paper is dehydrated in a vacuum chamber to form a wet paper web. The vacuum degree of the surface layer is set to 0.017MPa / 0.020MPa / 0.022MPa / 0.025MPa, the vacuum degree of the liner layer is set to 0.014MPa / 0.016MPa / 0.022MPa / 0.025MPa / 0.028MPa, the vacuum degree of the bottom layer is set to 0.012MPa / 0.018MPa / 0.020MPa / 0.024MPa, the vacuum degree of the lamination is set to 0.03MPa, and the vacuum degree after lamination is set to 0.038MPa / 0.042MPa / 0.048MPa / 0.052MPa / 0.055MPa / 0.058MPa. The PVA fiber solution was prepared using purified water. Before adding the powder, the stirring device was started, and then the PVA powder was slowly and uniformly added through the feeding device, with the stirrer speed controlled at 150 rpm. After addition, the solution was stirred continuously at room temperature for 30 minutes, then heated to 90°C at a rate of 2°C / min, and held at this temperature with stirring for 30 minutes. Finally, the solution was cooled to 40°C using cooling water. At 50℃, after being filtered through a 200-mesh filter tank, it is sprayed after the surface and bottom water lines; After spraying the PVA solution, a starch solution is sprayed again before the three layers of pulp (face, backing, and base) are laminated. The starch solution used is edible corn starch with a concentration of 10.8% and an addition amount of 32 kg / ton of paper. The PVA solution has a concentration of 10% and an addition amount of 10 kg / ton of paper. At this position, the paper dryness is 14.72% and the Zate potential is -5 mV. The laminated wet paper web then passes through a vacuum box, a vacuum couch roll, and a couch roll press for dewatering. After the dryness reaches 22.85%, it enters the press section. The vacuum degree of the vacuum couch roll is set to 0.065 MPa, and the couch roll press line pressure is 20 kN / m. D. Pressing, drying, and packaging: The pressing section employs two stages of vacuum pre-pressing and three stages of positive pressure. The press rollers are polyurethane-coated with a Shore D8 hardness. The third pressing stage uses a shoe-type pressing method. A 0.1% cloth cleaning agent is sprayed onto the pressing section at a specific concentration. An anti-sticking agent with a concentration of 0.1% is sprayed onto the smooth rollers of the pressing section, and the spraying amount is... ; The first vacuum pre-compression pressure is 12 kN / m, with a vacuum degree of 0.04 MPa; the second vacuum pre-compression pressure is 56 kN / m, with a vacuum degree of 0.05 MPa; the third pressure is 138 kN / m; the fourth pressure is 202 kN / m; and the fifth pressure is 250 kN / m. The vacuum degree in the pressing section vacuum chamber is 0.04 MPa-0.05 MPa, and the dryness of the product exiting the pressing section is 52.47%. After the wet paper exits the press section, it passes through the drying section for drying, with the low-temperature section at a temperature of 55°C. 75℃, the medium temperature range is 80℃. 95℃. The temperature of the second highest temperature range is 95℃. 105℃, the high-temperature range temperature is 105℃. 120℃; the temperatures of drying cylinders No. 75 and No. 76 are 35℃ and 37℃ respectively; the temperatures of drying cylinders No. 95 and No. 96 are 102℃ and 106℃ respectively. After drying, the paper sheet enters the calender for calendering. The linear pressure of the first calendering zone is 1.2 kN / m, and the linear pressure of the second calendering zone is 4.3 kN / m. The upper roll is a polyurethane soft roll with a Shore D75 hardness, and the lower roll is a steel roll. The surface of the lower roll is treated with a micro-textured finish of 1.5 μm. After winding, rewinding, and packaging, the paper tube base paper is obtained.

[0054] The main indicators of the fatigue-resistant composite paper tube base paper prepared by the above preparation method for high-speed spinning tube were tested, and the results are shown in Table 1: Table 1. Indicator Detection Results In Table 1, the "Standard Value" column represents the quality inspection standard for the anti-fatigue composite paper tube base paper used in high-speed spinning tubes; the "Detection Value" column represents the average detection value of the anti-fatigue composite paper tube base paper after multiple tests.

[0055] As shown in Table 1, the cross-sectional and longitudinal basis weight of the base paper of the high-speed spinning tube anti-fatigue composite paper tube are well controlled, and the paper uniformity, ring crush strength, interlayer bonding strength and other key paper indicators are all higher than the standard values.

[0056] Example 3 In one or more embodiments, this embodiment provides a fatigue-resistant composite paper tube base paper for high-speed spinning tubes, which is prepared by the above-described preparation process of the fatigue-resistant composite paper tube base paper for high-speed spinning tubes.

[0057] Specifically, the fatigue-resistant composite paper tube base paper prepared based on the above preparation process has the following characteristics: the basis weight of the fatigue-resistant composite paper tube base paper is 360 g / m³. 2 Tightness ≥ 0.75 g / cm³, Moisture 6.0±1.0%, Transverse basis weight difference ≤ 1.1%, Longitudinal basis weight difference ≤ 1.1%, Longitudinal tensile energy absorption ≥ 150 J / m², Flexural endurance ≥ 3000 cycles, Smoothness 70-90 S on the front and 10-30 S on the back, Longitudinal ring crush strength ≥ 32.5 kN / m, Short-distance compressive strength ≥ 10.0 kN / m, Interlaminar bond strength ≥ 1000 J / m², Bursting strength ≥ 3.0 kPa·m² / g, Tear index ≥ 18.0 mN·m² / g.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A process for preparing fatigue-resistant composite paper tube base paper for high-speed spinning tubes, comprising sequentially executed processes of pulping, conveying and additive addition, papermaking, pressing, drying, and packaging; characterized in that: In the papermaking process, when water lines appear on the wet paper sheets, polyvinyl alcohol fiber solution is added to the wet paper sheets and the bottom pulp sheets in the form of spraying when the wet paper sheets are formed by dewatering the mixed pulp through the three-layer wire forming machine. After the three layers of wet paper sheets are compounded, they enter the pressing process. In the pulping process, long-fiber pulp and short-fiber pulp obtained from waste paper pulp, as well as good sulfate softwood pulp obtained from sulfate softwood pulp, are mixed according to a preset ratio to obtain a mixed pulp. In the flow and auxiliary material addition process, cationic starch, polyaluminum chloride, solid additives and flocculants, and bentonite are added in stages according to the preset segmented addition strategy to construct the optimal wet-end chemical environment.

2. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, The polyvinyl alcohol fiber solution is sprayed after the water line.

3. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, Before laminating the three-layer wet paper sheets, a starch solution is added by spraying and then laminating is performed. After the laminated wet paper sheets are initially dehydrated, they are then put into the pressing process.

4. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, The pre-defined segmented addition strategy is as follows: In the conveying and auxiliary material addition process, the mixed slurry is sequentially processed by the white water tower, the slurry pump, the pressure screen and the pulse attenuator before entering the headbox; cationic starch and polyaluminum chloride are added at the inlet of the slurry pump; and after the mixed slurry is fully mixed and diluted with white water by the slurry pump, solid additives and flocculants are added, and bentonite is added directionally at the outlet of the pressure screen.

5. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, The process involves mixing long-fiber pulp, short-fiber pulp, and sulfate softwood pulp according to a preset ratio, wherein the ratio of long-fiber pulp, short-fiber pulp, and sulfate softwood pulp is set to 3:2:5, and the pulp concentration needs to be prepared to be 3.

0. 4.0%.

6. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, The mixed slurry obtained from the pulping process needs to be mixed with a wet strength agent that meets the preset requirements. After being fully stirred and diluted in the pre-stirring tank, it is pumped into the high-level tank.

7. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, The mixed slurry in the headbox is coated onto the surface slurry forming mesh, the lining slurry forming mesh, and the bottom slurry forming mesh according to a preset coating ratio, which is a:b:c, where a is the coating ratio of the surface slurry forming mesh, with a value range of [29, 31], b is the coating ratio of the lining slurry forming mesh, with a value range of [37, 39], and c is the coating ratio of the bottom slurry forming mesh, with a value range of [31, 33].

8. The preparation process of the anti-fatigue composite paper tube base paper for high-speed spinning tubes as described in claim 1, characterized in that, In the papermaking process, the composite wet paper web passes through a vacuum box, a vacuum roll, and a roll press for preliminary dewatering before entering the pressing process.

9. A fatigue-resistant composite paper tube base paper for high-speed spinning tubes, characterized in that, It is prepared by the preparation process of anti-fatigue composite paper tube base paper for high-speed spinning tube as described in any one of claims 1-8.

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