Kraft paper surface micro-texture pressing device and process

Abstract

The application discloses a kraft paper surface micro-line pressing treatment device and process and relates to the technical field of kraft paper processing. The device comprises a rack, a feeding device is installed at the starting end of the rack, a cleaning device, a pretreatment device, a rolling device and a shaping device are sequentially installed on the rack, the cleaning device is used for cleaning the surface of the kraft paper, the pretreatment device is used for heating the kraft paper and spraying water or solution on the kraft paper, the rolling device is used for pressing micro-lines on the surface of the kraft paper through a rolling die, and the shaping device is used for drying and hardening the kraft paper. The continuously conveyed kraft paper web is sequentially cleaned, heated, liquid-applied, pressed, dried, cooled and surface-detected, so that the micro-lines are formed on the surface of the kraft paper to be pressed in a clean and heated softening state, the paper fibers and the micro-lines are gradually stabilized through subsequent drying and cooling, the definition, integrity and uniformity of the micro-lines are improved, and paper surface damage, line rebound, web warping and interlayer adhesion are reduced.

Description

Technical Field

[0001] This invention relates to the technical field of kraft paper processing, and in particular to a device and process for pressing micro-textures on the surface of kraft paper. Background Technology

[0002] Kraft paper possesses high tensile strength, bursting strength, and stiffness, along with a natural and simple appearance. It is widely used in the production of disposable paper cups, bowls, plates, lunch boxes, and other paper tableware. Due to the food packaging industry's requirements for environmental protection, moisture resistance, oxygen barrier properties, and recyclability, using kraft paper as the base material and applying a moisture-proof and oxygen-barrier coating to its surface has become a common technical route in the production of paper tableware. The existing process for processing disposable paper cups and other paper tableware from kraft paper typically includes steps such as raw paper selection, surface treatment, printing, barrier layer coating or lamination, drying and curing, slitting, die-cutting, cup forming, bottom sealing, edge rolling, and finished product inspection. Among these steps, to prevent water, oil, beverages, or other components in food from penetrating into the paper, it is usually necessary to coat the kraft paper surface with water-based moisture-proof and oxygen-barrier coatings, biodegradable barrier materials, or other functional coatings for food contact. The strength of the bond between the coating and the kraft paper base material directly affects the leak-proof performance, structural stability, appearance quality, and service life of the paper cups and other tableware.

[0003] After some kraft paper is made, sized, calendered and processed, its surface is relatively flat and dense with small pores between fibers and insufficient surface roughness. When moisture-proof and oxygen-barrier materials are directly coated on the surface of the kraft paper, the coating material is difficult to fully wet and penetrate into the paper surface. The mechanical interlocking between the coating and the paper fibers is weak. The texture of traditional mechanical embossing process is usually coarse and is mainly used to form decorative patterns or improve the macroscopic three-dimensional effect of the paper. It is difficult to take into account the microscopic roughness of the paper surface, the uniformity of coating and the original strength of the paper.

[0004] Publication No. CN205970141U discloses a paper cup or bowl outer coating forming machine with a creasing function. It includes an outer coating sheet suction mechanism, a paper feeding mechanism, and an outer coating forming and bonding mechanism. An outer coating sheet creasing mechanism is provided between the suction mechanism and the bonding mechanism. This creasing mechanism includes an upper creasing roller and a lower creasing roller, both with mutually cooperating embossed patterns. The upper and lower creasing rollers are driven by a transmission device to rotate in coordination. The upper and lower creasing rollers can creasing the outer coating sheet, imprinting it with embossed shapes. These embossed shapes increase the geometric thickness of the paper sheet, creating point-like contact between the cup wall and the outer coating, forming a cavity and achieving a heat insulation effect. However, the embossed patterns in this technology are only for decorative and heat insulation purposes and are not micro-texture pressing; therefore, they do not effectively fix the coating layer. Summary of the Invention

[0005] To address the problem of weak adhesion of the moisture-proof and oxygen-barrier coating layer caused by insufficient wetting and mechanical bonding of the coating material on the relatively flat and dense surface of kraft paper, this invention provides a device and process for pressing micro-textures on the surface of kraft paper.

[0006] On the one hand, the kraft paper surface micro-texture pressing treatment device provided by the present invention adopts the following technical solution: A device and process for pressing micro-textures onto the surface of kraft paper includes a frame for mounting kraft paper processing equipment. A feeding device is installed at the beginning of the frame for mounting kraft paper rolls and releasing them onto the frame for processing via rolling. A cleaning device, a pretreatment device, a rolling device, and a shaping device are sequentially mounted on the frame. The cleaning device cleans the surface of the kraft paper. The pretreatment device heats the kraft paper and sprays water or a solution onto it. The rolling device uses a rolling die to press micro-textures onto the surface of the kraft paper. The shaping device dries and hardens the kraft paper.

[0007] The rolling die of the rolling device forms uniform and fine micro-textures on the surface of kraft paper, increasing the effective contact area and surface roughness of the kraft paper surface. This allows the subsequent moisture-proof and oxygen-barrier coating to penetrate the micro-textures and form a mechanical interlocking effect, thereby improving the bonding strength between the coating layer and the kraft paper substrate and reducing problems such as coating peeling, wrinkling, cracking, exposure of the substrate, and uneven distribution. Before the rolling process, the cleaning device removes paper scraps, dust, and other impurities from the surface of the kraft paper to prevent impurities from entering the rolling area and causing missing textures, uneven indentations, or contamination of the rolling die. This helps to improve the integrity of the micro-textures on the kraft paper surface. The pretreatment device heats the kraft paper and sprays water or a suitable treatment solution onto the surface of the kraft paper to moderately wet and soften the kraft paper fibers, reducing the possibility of fiber brittleness, breakage, or localized damage during the pressing process. The process allows for easier pressing and shaping of micro-textures, and helps to obtain clearer micro-textures while maintaining the basic strength and stiffness of kraft paper. After rolling, the setting device dries and hardens the kraft paper, which can promptly remove moisture or solvents introduced during the pretreatment process, making the compressed fiber structure more stable and reducing the rebound, fading, and deformation of micro-textures during conveying, winding, or subsequent processing. This improves the retention of micro-textures. Kraft paper treated with micro-textures has better coating wetting and load-bearing capacity, which can promote the uniform spreading of moisture-proof and oxygen-barrier coatings on the surface of the kraft paper, reduce pinholes, sagging, local accumulation, and missed coating during the coating process, and thus improve the consistency of coating thickness and barrier performance. This provides a more stable moisture-proof, oxygen-barrier, and leak-proof foundation for disposable paper cups, paper bowls, paper plates, and paper lunch boxes.

[0008] Furthermore, the feeding device includes a feeding frame, on which a positioning frame and a lifting frame are installed. The positioning frame is used to fix the position of the kraft paper roll and support the rotation of the kraft paper roll. The lifting frame is installed at the end of the feeding frame and is used to lift the kraft paper roll onto the feeding frame. The lifting frame is oscillating and a feeding cylinder is provided on the oscillating side.

[0009] By cooperating with the lifting frame, the feeding cylinder and the positioning frame, the receiving, lifting, transferring and positioning of kraft paper rolls can be completed in sequence, simplifying the loading and unloading operations of kraft paper rolls, shortening the time required for roll changing, reducing equipment downtime and waiting time, and improving the continuous processing efficiency of the device.

[0010] Furthermore, a feeding roller and a low-winding roller are installed on one side of the tail end of the feeding rack. After the kraft paper roll is drawn out from the feeding rack, it passes around the feeding roller and the low-winding roller in sequence. The feeding roller is connected to a power unit and is used to drag the kraft paper. A correction roller is installed at the bottom of the low-winding roller. The rolling shaft of the correction roller is perpendicular to the rolling shaft of the low-winding roller. The correction roller controls the lateral position of the kraft paper through rolling friction.

[0011] The feed roller is connected to the power unit and can actively drag the kraft paper drawn from the kraft paper roll by rotating, so that the kraft paper is conveyed to the subsequent process in a set direction and speed. This reduces the instability of feeding caused by relying solely on the traction of subsequent equipment and improves the continuity of kraft paper conveying. The feed roller and the low-winding roller work together to guide and support the kraft paper, reducing the occurrence of slack, drifting or partial folding of the kraft paper during conveying. The correction roller is set at the bottom of the low-winding roller, and the rolling axis of the correction roller is perpendicular to the rolling axis of the low-winding roller. When the kraft paper deviates laterally, the correction roller can apply a lateral adjustment action to it through the rolling friction between it and the kraft paper, so that the kraft paper gradually returns to the predetermined conveying position.

[0012] Furthermore, the cleaning device includes a cleaning brush, a negative pressure vacuum cleaner, and a dust-adhesive roller. The cleaning brush is roller-shaped and connected to an electrostatic discharger. The electrostatic discharger is used to remove static electricity from the cleaning brush and the kraft paper. The negative pressure vacuum cleaner is connected to a negative pressure suction hood through a pipe. The negative pressure suction hood is installed on the kraft paper conveying path and is positioned close to both sides of the kraft paper. The dust-adhesive rollers are arranged in pairs and clamped to both sides of the kraft paper.

[0013] By using a cleaning brush, a negative pressure vacuum cleaner, and a sticky roller in combination, paper scraps, dust, and other impurities on the surface of kraft paper can be removed through roller brush cleaning, negative pressure adsorption, and contact adhesion. This compensates for the blind spots in cleaning methods and improves the overall cleaning effect of the kraft paper surface. The cleaning brush is connected to an electrostatic discharger, which can release the static electricity accumulated on the cleaning brush and kraft paper, reducing the re-adsorption of dust and paper scraps on the surface of the kraft paper or cleaning brush due to static electricity. This facilitates the timely removal of impurities from the paper surface and improves the effectiveness of negative pressure vacuuming and sticky roller treatment. Through the synergistic effect of the cleaning brush, electrostatic discharger, negative pressure vacuum cleaner, and sticky roller, residual dust, paper scraps, and fiber impurities on the surface of kraft paper can be effectively reduced. This prevents impurities from entering the rolling area and causing problems such as interruption of the pressing pattern, uneven depth, local bumps, or roller contamination, which helps to improve the clarity, continuity, and uniformity of the micro-pattern.

[0014] Furthermore, the pretreatment device includes a heater and a water sprayer, the heater being used to heat the kraft paper and the water sprayer being used to spray water or solution onto the kraft paper.

[0015] By heating the kraft paper with a heater and spraying water or solution onto it with a water sprayer, the temperature, humidity, and surface condition of the kraft paper can be pre-adjusted before micro-textured rolling. This gives the kraft paper better physical properties for subsequent processing. Specifically, the water sprayed by the water sprayer moistens the kraft paper, allowing moisture to penetrate the paper fibers and reducing the paper's dryness and stiffness. The heater promotes the softening of the paper by heat, thereby improving the kraft paper's deformation ability during rolling and making it easier to form micro-textures. This reduces fiber breakage, surface cracking, edge damage, or localized tearing when the kraft paper is squeezed by the textured rollers, thus improving the stability of the processing.

[0016] Furthermore, the heater includes an insulation cover and an infrared lamp, the infrared lamp being installed inside the insulation cover and irradiating and heating both sides of the kraft paper.

[0017] Infrared lamps irradiate both sides of the kraft paper, simultaneously heating both surfaces and allowing heat to transfer from both sides inwards. This reduces uneven heating caused by heating from only one side. Infrared lamps feature fast response, easy start / stop, and adjustable output power. The heating intensity and time can be adjusted according to the kraft paper's thickness, conveying speed, and initial moisture content, maintaining the kraft paper within a suitable preheating temperature range. This prevents problems such as fiber embrittlement, paper discoloration, scorching, or decreased strength caused by excessively high temperatures, thus minimizing damage to the paper's properties during heating. The thermal effect of infrared irradiation promotes the escape of moisture, odor components, and volatile substances from the kraft paper's surface and interior. Under high irradiation intensity and high temperature conditions, it inhibits or reduces some microorganisms, thereby improving the cleanliness of the kraft paper and providing a cleaner and more stable paper material for subsequent micro-textured rolling processing.

[0018] Furthermore, the water sprayer is equipped with a spray head at its spray end, which sprays water toward the kraft paper. The water sprayer is connected to a water tank via a water heater, which is used to heat the water or solution in the water tank. The water tank is equipped with a dosing device and a stirrer. The dosing device is used to control the addition of chemical agents into the water tank, and the stirrer is used to stir the solution in the water tank. The water tank is connected to an external water supply via a pipe.

[0019] By spraying an appropriate amount of water or solution onto kraft paper, the paper fibers can absorb moisture and soften, improving the paper's flexibility and extensibility. This reduces the likelihood of cracking, breakage, or creases during subsequent rolling. The evenly moistened kraft paper adheres more easily to the textured rollers, facilitating the pressing and shaping of the texture, thereby improving the clarity, continuity, and consistency of the micro-textures and reducing texture rebound. The water heater heats the water or solution output from the tank, allowing the spray temperature to be adjusted according to the kraft paper's material, thickness, and processing speed. Warm water or solution softens the paper fibers and accelerates the diffusion and penetration of the solution within the kraft paper. A dosing device on the water tank allows for control of the amount of chemical agents added according to production process requirements, facilitating adjustments to solution concentration and ratio, improving solution preparation accuracy and process stability. By changing the type and proportion of chemical agents added to the water tank, the kraft paper can be softened, strengthened, treated with antibacterial agents, mold-resistant agents, or other functional treatments as needed, enhancing the device's adaptability to different kraft paper processing techniques.

[0020] Furthermore, the rolling device includes a horizontal embossing roller and a vertical embossing roller. The surfaces of the horizontal and vertical embossing rollers are provided with embossing patterns, and the embossing patterns are applied to the kraft paper by squeezing it. The horizontal and vertical embossing rollers are mounted on a pressure adjusting frame, and the squeezing pressure on the kraft paper is controlled by the pressure adjusting frame. A heat applicator is installed in the inner cavity of the horizontal and vertical embossing rollers to maintain the surface temperature of the horizontal and vertical embossing rollers.

[0021] By imprinting transverse and vertical lines onto kraft paper using horizontal and vertical imprinting rollers respectively, cross or composite micro-textures can be formed on the surface of the kraft paper. The horizontal and vertical imprinting rollers are mounted on a pressure adjustment frame, which can adjust the squeezing pressure of the imprinting rollers on the kraft paper according to the thickness, moisture content, material, and required texture depth of the kraft paper, thereby improving the adaptability of the device to different processing requirements. The heat exchanger can maintain a suitable surface temperature for the horizontal and vertical imprinting rollers, so that the kraft paper is heated while being pressed, which helps to soften the paper fibers and promote texture setting, thereby improving texture retention and reducing springback or fading after imprinting.

[0022] Furthermore, the shaping device includes a dryer for drying the moisture in the kraft paper. The dryer includes a hot air blower connected to a hot air hood via a pipe. The hot air hood is positioned towards the kraft paper and sprays hot air.

[0023] Hot air can heat and dry the kraft paper after printing, which gradually stabilizes the paper fibers after being deformed by pressure. This helps to maintain the shape of the horizontal and vertical grains and reduces the possibility of the grains becoming lighter or deformed due to the paper's rebound.

[0024] On the other hand, the micro-texture pressing process for kraft paper surface provided by the present invention adopts the following technical solution: A process for pressing micro-textures onto the surface of kraft paper includes the following steps: The continuously conveyed kraft paper web is cleaned to remove dust and adhering impurities from the surface of the kraft paper web to be pressed; The cleaned kraft paper web is heated so that the surface of the kraft paper web to be pressed reaches a temperature suitable for softening and printing. Apply water or a softener solution evenly to the heated surface to be pressed; When the surface of the kraft paper is in a softened state due to heat, the kraft paper web is embossed to form micro-textures. The kraft paper web with the micro-textures is dried to reduce the moisture in the surface layer or the solvent in the softener solution and to set the micro-textures. The dried kraft paper web is then cooled to reduce the temperature of the kraft paper web to the temperature required for winding or subsequent processing. The cooled kraft paper web is subjected to surface inspection to determine the integrity, uniformity, and surface defects of the formed microtextures. Based on the inspection results, qualified kraft paper webs are either wound up or conveyed to subsequent processes.

[0025] By sequentially cleaning, heating, applying liquid, pressing, drying, cooling, and surface inspection of continuously conveyed kraft paper webs, micro-textures are formed on the surface of the kraft paper to be pressed in a clean and softened state. Subsequent drying and cooling gradually stabilize the paper fibers and micro-textures, which helps improve the clarity, integrity, and uniformity of the micro-textures and reduces paper surface damage, texture rebound, paper web warping, and interlayer adhesion. At the same time, surface inspection and screening of qualified paper webs helps improve the consistency of finished product quality. Each step can be coordinated with the continuous paper web conveying process, thereby improving the continuity and production efficiency of kraft paper micro-texture pressing.

[0026] In summary, the present invention has the following beneficial technical effects: 1. The feeding device, cleaning device, pretreatment device, rolling device and shaping device are arranged in sequence along the kraft paper conveying direction, so that the kraft paper can continuously complete unwinding, cleaning, heating, wetting, rolling and drying shaping. The previous process provides a suitable paper surface state for the next process, reducing the pollution, deviation, wrinkles and state changes caused by repeated transfer of kraft paper between different equipment, which is conducive to improving the continuity, stability and production efficiency of the micro-texture pressing process.

[0027] 2. The cleaning brush first loosens the paper scraps, dust, and fibrous impurities attached to the surface of the kraft paper. The static discharge device simultaneously reduces the accumulation of static electricity on the cleaning brush and the surface of the kraft paper, making it difficult for the brushed impurities to be re-adsorbed. The negative pressure dust suction hood then sucks away the impurities that are suspended or detached from the paper surface. Paired adhesive rollers further remove residual fine particles. The above components complement each other through different cleaning methods, which can reduce the processing blind spots that exist in single roller brush, dust suction or adhesive cleaning, and provide a cleaner paper surface for subsequent uniform wetting and fine printing.

[0028] 3. Before rolling, the cleaning device reduces hard particles, paper scraps, and dust on the surface of the kraft paper, preventing impurities from being trapped between the kraft paper and the horizontal or vertical ribbed impression rollers. This reduces localized insufficient imprinting, abnormal bumps, and interruptions in the ribbed pattern caused by impurities raising or obscuring the ribbed pattern. At the same time, it reduces the possibility of impurities adhering to the surface of the impression rollers, causing pattern blockage or continuous contamination of the paper surface. Therefore, the composite cleaning not only improves the cleanliness of the paper surface, but also works with the rolling device to improve the clarity, continuity, and consistency of the micro-texture.

[0029] 4. The feed roller actively pulls the kraft paper, the low-winding roller guides and supports the kraft paper, and the correction roller uses its rolling direction perpendicular to the low-winding roller to apply a lateral adjustment to the kraft paper. The cooperation of the three can reduce paper web slack, drifting and lateral deviation, so that the kraft paper enters the cleaning device, pretreatment device and rolling device in a more stable tension and lateral position. This allows the lateral and vertical grains to be pressed in the predetermined position, reducing problems such as grain misalignment, edge under-pressing and uneven distribution of composite grains.

[0030] 5. Infrared lamps preheat the kraft paper from both sides, allowing heat to transfer from both sides of the paper web inwards. A water sprayer evenly sprays water or a softener solution onto the heated kraft paper. A water heater heats the spraying medium. Preheating the kraft paper facilitates the diffusion and penetration of the water or softener solution. The warm liquid also reduces the sudden drop in paper surface temperature caused by low-temperature spraying, keeping the temperature and moisture content of the kraft paper within a suitable range. Through the synergistic regulation of heat and moisture, the flexibility and deformability of the paper fibers can be improved, reducing the differences in texture depth caused by insufficient softening or uneven wetting.

[0031] 6. The dosing device can control the amount of chemical agents added, the stirrer can ensure that the agents are fully mixed with water, the water heater can regulate the solution temperature, and the spray head applies the prepared solution to the surface of the kraft paper. The above components work together to adjust the pretreatment conditions of the kraft paper in terms of solution concentration, uniformity, spraying temperature and application status, so as to adapt to kraft paper of different thicknesses, moisture contents, fiber composition and strength. It can also perform softening, strengthening, antibacterial or anti-mildew treatments as needed, improving the device's adaptability to different paper materials and subsequent uses.

[0032] 7. Kraft paper is first preheated with infrared lamps, then moistened with warm water or a softening agent solution, and then hot-rolled by horizontal and vertical rib impression rollers with internal heating devices. This forms a graded treatment process of preheating, moistening, and heat preservation imprinting. This process gradually softens the paper fibers before entering the high-pressure rolling area and maintains a suitable temperature during the pressing process. This reduces the need to excessively increase mechanical pressure to obtain the predetermined texture depth, and reduces fiber brittleness, paper surface cracking, local tearing, and strength reduction. At the same time, it helps to improve the indentation depth of micro-textures and the morphology reproduction effect.

[0033] 8. The horizontal and vertical ribbed impression rollers form micro-textures in different directions, giving the kraft paper surface a cross or composite texture structure. The pressure adjustment frame can adjust the impression force according to the paper thickness, moisture content, and target texture depth. The heat exchanger keeps the impression roller surface at a suitable temperature. The texture direction, impression pressure, and impression temperature work together to reduce excessive compaction or local damage to the paper, while improving the clarity, uniformity, and stability of the composite micro-textures and expanding the applicability of the device to different texture specifications and processing requirements.

[0034] 9. After being heated, moistened, and rolled, the fibers of kraft paper remain in a state of easy resilience and deformation. The hot air blower and hot air hood promptly dry the kraft paper after printing with hot air, which can reduce the moisture or solvent in the paper and gradually stabilize the structure of the compressed fibers. Subsequent cooling lowers the kraft paper to a temperature suitable for conveying, winding, or subsequent processing. The continuous connection between rolling, drying, and cooling can reduce the lightening, blurring, or deformation of micro-textures after leaving the impression roller due to fiber moisture absorption and rebound, and reduce the risk of adhesion, warping, and roll deformation caused by direct winding of high-temperature paper web.

[0035] 10. The composite microtexture formed by horizontal and vertical lines can increase the effective contact area and surface roughness of kraft paper, providing space for diffusion, wetting, and containment of moisture-proof, oxygen-barrier, or seepage-proof coatings. After the coating enters the microtexture, it can form a mechanical interlocking effect with the kraft paper, thereby improving the bonding stability between the coating and the paper substrate and reducing problems such as coating peeling, wrinkling, cracking, exposure of the substrate, pinholes, and local accumulation. At the same time, cleaning, uniform softening, stable rolling, and timely shaping together ensure the cleanliness and consistency of the microtexture, which is conducive to the uniform spread of the coating and improves the consistency of the coating thickness and moisture-proof, oxygen-barrier, and seepage-proof performance, providing a stable foundation for the subsequent processing of paper products such as paper cups, paper bowls, paper plates, and paper lunch boxes. Attached Figure Description

[0036] Figure 1 This is a three-dimensional structural diagram of the production line equipment for the present invention; Figure 2 for Figure 1 Another perspective structural diagram; Figure 3 for Figure 1 Schematic diagram of the full section structure at the central vertical plane.

[0037] Explanation of reference numerals in the attached figures: 10. Frame; 1. Feeding rack; 11. Positioning rack; 12. Lifting rack; 13. Feeding cylinder; 14. Feeding roller; 15. Low-level winding roller; 16. Correcting roller; 2. Cleaning brush; 21. Static discharge device; 22. Negative pressure dust collector; 23. Negative pressure dust collection hood; 24. Adhesive roller; 3. Heater; 31. Insulation cover; 32. Infrared lamp; 4. Water sprayer; 41. Water spray head; 42. Water heater; 43. Water tank; 44. Dosing device; 45. Agitator; 5. Horizontal embossing roller; 51. Vertical embossing roller; 52. Pressure regulating rack; 53. Heater; 6. Dryer; 61. Hot air blower; 62. Hot air hood. Detailed Implementation

[0038] The following will be combined with the appendix Figures 1-3The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0040] Example 1: This invention discloses a device for pressing micro-textures on the surface of kraft paper, referring to... Figure 1 and Figure 2 The system includes a frame 10 for mounting a kraft paper processing device. A feeding device is installed at the beginning of the frame 10. The feeding device is used to load kraft paper rolls and release them onto the frame 10 for processing by rolling. A cleaning device, a pretreatment device, a rolling device, and a shaping device are sequentially installed on the frame 10. The cleaning device is used to clean the surface of the kraft paper. The pretreatment device is used to heat the kraft paper and spray water or solution onto it. The rolling device uses a rolling die to imprint micro-textures on the surface of the kraft paper. The shaping device is used to dry and harden the kraft paper.

[0041] The feeding device is installed at the beginning of the frame 10 to carry the kraft paper roll and rotate it around its axis during unwinding to continuously release the kraft paper. As the kraft paper continuously passes through the cleaning area, it applies sweeping, adsorption, adhesion, blowing away, or other cleaning actions to the adhering substances on the surface of the kraft paper to be pressed, so that the impurities are separated from the kraft paper. The effective working width of the cleaning device is not less than the width of the kraft paper to be processed, so as to reduce the situation of insufficient cleaning in the edge area of ​​the kraft paper. For application scenarios that need to form micro-textures on both sides of the kraft paper or need to improve the overall cleanliness of the paper web, the two surfaces of the kraft paper are cleaned separately. The cleaning treatment can prevent paper scraps and dust from entering the pretreatment device with the kraft paper, reduce the adhesion of impurities to the paper surface after spraying water or solution to form local stains, and at the same time, reduce the possibility of impurities being trapped between the kraft paper and the rolling die after entering the rolling area, reducing the problems such as interruption of texture, local bumps, uneven depth of indentation, and contamination of the rolling die.

[0042] The pretreatment device can adjust the temperature, moisture content, and surface fiber softness of the kraft paper, ensuring it is in a suitable state for printing before entering the rolling device. First, heating is used to raise the temperature of the kraft paper, increasing the mobility of the surface fibers. Then, an appropriate amount of water or solution is applied to the surface of the kraft paper, allowing the liquid to diffuse and penetrate the surface under heating conditions, reducing the paper's stiffness and increasing its deformability. The combined effect of heating and liquid application makes it easier for the kraft paper to undergo plastic or quasi-plastic deformation according to the shape of the rolling die when squeezed. The sprayed liquid can be selected from clean water or a treatment solution compatible with the kraft paper and subsequent coating materials, depending on the processing requirements.

[0043] After the pre-treated kraft paper enters the rolling device, the rolling die applies pressure to the kraft paper, causing the surface fibers of the kraft paper to deform according to the concave and convex structure of the rolling die surface, thereby forming micro-textures on the surface of the kraft paper. Utilizing the continuous rolling contact between the rolling die and the kraft paper, the pressure concentrated in the rolling area is transmitted to the surface of the kraft paper. When the kraft paper passes through the rolling area in a heated, wetted, and softened state, its surface fibers are pressed into the gaps of the rolling die's texture or squeezed by the protruding structure of the die, thus forming micro-textures adapted to the rolling die. The setting device is set after the rolling device to dry and harden the kraft paper after the micro-texture imprinting is completed. The setting device gradually reduces the moisture or solvent in the kraft paper by providing drying conditions, and makes the fiber structure after pressure deformation tend to stabilize.

[0044] Through the above continuous synergistic treatment, the clarity, integrity and uniformity of micro-textures can be improved while reducing kraft paper fiber cracking, paper surface damage and texture loss. The formed micro-textures can increase the effective contact area and surface roughness of the kraft paper surface, which is conducive to the subsequent coating spreading on the paper surface and entering the interior of the texture, thereby improving the mechanical interlocking degree between the coating and the kraft paper, and providing a more stable paper surface foundation for the formation of subsequent moisture-proof, oxygen-barrier and seepage-proof coatings.

[0045] Reference Figures 1-3 The feeding device includes a feeding frame 1, on which a positioning frame 11 and a lifting frame 12 are installed. The positioning frame 11 is used to fix the position of the kraft paper roll and support the rotation of the kraft paper roll. The lifting frame 12 is installed at the end of the feeding frame 1 and is used to lift the kraft paper roll onto the feeding frame 1. The lifting frame 12 is oscillating and a feeding cylinder 13 is provided on the oscillating side.

[0046] Reference Figure 3The feeding rack 1 is equipped with a feeding roller 14 and a low-winding roller 15 on one side of its tail end. After the kraft paper roll is drawn out from the feeding rack 1, it passes around the feeding roller 14 and the low-winding roller 15 in sequence. The feeding roller 14 is connected to a power unit and is used to drag the kraft paper. The bottom of the low-winding roller 15 is equipped with a correction roller 16. The rolling shaft of the correction roller 16 is perpendicular to the rolling shaft of the low-winding roller 15. The correction roller 16 controls the lateral position of the kraft paper through rolling friction.

[0047] When installing the kraft paper roll, a spool can be threaded through the core of the kraft paper roll. Both ends of the spool are placed on the positioning frame 11, or the core ends of the kraft paper roll can be directly supported by suitable support components. Bearings, rollers, or low-friction support structures can be installed at the contact points between the positioning frame 11 and the spool to ensure smooth rotation of the kraft paper roll under the traction of the feed roller 14. The positioning frame 11 is equipped with an axial limiting part to restrict axial movement of the spool or the kraft paper roll, but the axial limiting does not impede the movement of the kraft paper roll. When the paper roll rotates normally and the lifting frame 12 is in a low position, its bearing end is close to the ground or the initial placement position of the kraft paper roll, which makes it easy to place the kraft paper roll or the two ends of the kraft paper roll's spool on the lifting frame 12. After the feeding cylinder 13 is activated, the lifting frame 12 swings upward, lifting the kraft paper roll to the height corresponding to the positioning frame 11. When the kraft paper roll's spool reaches the receiving position of the positioning frame 11, the spool enters the positioning frame 11, completing the transfer of the kraft paper roll to the feeding rack 1.

[0048] After being drawn from the kraft paper roll, the kraft paper passes between two sets of feed rollers 14. The two sets of feed rollers 14 clamp the kraft paper. When the feed rollers 14 rotate, friction is generated between their roller surfaces and the kraft paper. This friction exerts a traction force on the kraft paper along the conveying direction, causing the kraft paper roll to passively rotate and continuously unwind on the positioning frame 11. The low-winding roller 15 is mainly used to change the conveying direction of the kraft paper and, together with the feed rollers 14, increases the winding length and contact wrap angle of the kraft paper in the feeding area. After the kraft paper passes over the low-winding roller 15, the paper web is supported and guided at the low-winding roller 15. The rolling axis of the low-winding roller 15 is set along the width direction of the kraft paper, and it is mainly used for support and guidance during the longitudinal conveying of the kraft paper. The rolling axis of the straightening roller 16 is perpendicular to the rolling axis of the low-winding roller 15. Therefore, the rolling direction of the straightening roller 16 has a component along the width direction of the kraft paper. When the straightening roller 16 contacts the kraft paper and rotates, the rolling friction between the roller surface and the kraft paper can be used to move the paper web to one side in the width direction, thereby correcting the positional deviation of the paper web relative to the predetermined conveying center line.

[0049] The working steps of the above-mentioned components include: controlling the feeding cylinder 13 to swing the lifting frame 12 to the outside or below of the upward feeding frame 1 to a low feeding position to receive the kraft paper roll to be processed; inserting the roll into the core of the kraft paper roll, or supporting the kraft paper roll with a support member adapted to the core; placing both ends of the roll in the supporting position of the lifting frame 12; controlling the feeding cylinder 13 to slowly extend or retract, driving the lifting frame 12 to swing upward; and when the kraft paper roll is lifted to the corresponding height of the positioning frame 11, allowing both ends of the roll to smoothly enter the positioning frame 11. The positioning frame 11 supports the position of the kraft paper roll and limits the position of the kraft paper roll through the axial limiting part of the positioning frame 11. The starting end of the kraft paper is drawn out from the kraft paper roll and passes around the feed roller 14 and the low winding roller 15 in sequence according to the predetermined winding direction. The kraft paper forms an adjustable contact relationship with the correction roller 16 at the corresponding position of the low winding roller 15. The power device connected to the feed roller 14 is started, so that the feed roller 14 rotates at a low speed. The feed roller 14 uses friction to pull the kraft paper, and the kraft paper roll rotates on the positioning frame 11 and releases the kraft paper.

[0050] Reference Figure 1 and Figure 3 The cleaning device includes a cleaning brush 2, a negative pressure vacuum cleaner 22, and a dust-adhesive roller 24. The cleaning brush 2 is roller-shaped and is connected to an electrostatic discharger 21. The electrostatic discharger 21 is used to remove static electricity between the cleaning brush 2 and the kraft paper. The negative pressure vacuum cleaner 22 is connected to a negative pressure vacuum hood 23 through a pipe. The negative pressure vacuum hood 23 is installed on the kraft paper conveying path and is positioned close to both sides of the kraft paper. The dust-adhesive rollers 24 are arranged in pairs and clamped to both sides of the kraft paper.

[0051] Reference Figure 2 and Figure 3 The pretreatment device includes a heater 3 and a water sprayer 4. The heater 3 is used to heat the kraft paper, and the water sprayer 4 is used to spray water or solution onto the kraft paper.

[0052] Reference Figure 2 and Figure 3 The heater 3 includes a heat insulation cover 31 and an infrared lamp 32. The infrared lamp 32 is installed inside the heat insulation cover 31 and shines on both sides of the kraft paper to heat it.

[0053] Reference Figure 2 and Figure 3 The water sprayer 4 is equipped with a spray head 41 at its spray end, which sprays water toward the kraft paper. The water sprayer 4 is connected to a water tank 43 via a water heater 42, which heats the water or solution in the water tank 43. A dosing device 44 and a stirrer 45 are installed on the water tank 43. The dosing device 44 is used to control the addition of chemical agents into the water tank 43, and the stirrer 45 is used to stir the solution in the water tank 43. The water tank 43 is connected to an external water supply via a pipe.

[0054] When the kraft paper passes through the cleaning brush 2, the roller-shaped cleaning brush 2 rotates continuously. The bristles on the cleaning brush 2 sweep the surface of the kraft paper, causing paper scraps, dust, and loose particles attached to the gaps between the kraft paper fibers and the surface to be mechanically disturbed and detached from the paper surface. The cleaning brush 2 can pre-remove firmly attached particulate impurities from the surface of the kraft paper, reducing paper scraps and dust that are difficult to remove by negative pressure vacuuming alone. The static discharge device 21 can discharge static electricity from the cleaning brush 2 through a conductive connection structure, and can also use an ion release structure to neutralize static electricity on the cleaning brush 2 and the kraft paper in the adjacent area. After the negative pressure vacuum cleaner 22 is started, it draws air from inside the negative pressure vacuum hood 23 through the connecting pipe, creating an airflow near the suction port of the negative pressure vacuum hood 23 that flows towards the inside of the hood. When the kraft paper passes through the negative pressure dust collection hood 23, the dust, paper scraps, and suspended particles in the air separated from the paper surface by the cleaning brush 2 enter the negative pressure dust collection hood 23 under the action of negative pressure airflow, and are transported to the negative pressure vacuum cleaner 22 for collection through the pipe. After the negative pressure vacuum cleaner 22 is used in conjunction with the electrostatic release device 21, the negative pressure airflow can more easily absorb fine dust when the electrostatic adsorption effect is weakened, thereby improving cleaning efficiency and improving the working environment around the equipment. When the kraft paper passes between the two sticky rollers 24, the two sticky rollers 24 roll and contact the two sides of the kraft paper respectively. The roller surface of the sticky rollers 24 has appropriate adhesion ability and can stick the fine dust, short fibers and particulate impurities that are still left on the surface of the kraft paper after being treated by the cleaning brush 2 and the negative pressure dust collection hood 23.

[0055] When the kraft paper passes between the infrared lamps 32 arranged opposite each other, the infrared radiation generated by the infrared lamps 32 acts on both sides of the kraft paper. After absorbing the infrared radiation, the temperature of the kraft paper rises, causing changes in the state of the fibers and the moisture contained in the kraft paper, providing the temperature conditions for subsequent water spraying or solution treatment. The infrared lamps 32 convert the input electrical energy into infrared radiation energy. After the infrared radiation reaches the surface of the kraft paper, it is absorbed by the kraft paper and converted into heat. The water or solution in the water tank 43 enters the water sprayer 4 along the pipeline under the action of the conveying pressure, and then forms droplets, mist, or continuously distributed spray areas through the spray head 41. The spray head 41 sprays the water or solution onto the moving kraft paper, so that the water or solution adheres to the surface of the kraft paper and gradually penetrates into the interior of the kraft paper fibers.

[0056] The working steps of the above components include: starting the negative pressure vacuum cleaner 22 to create a stable suction airflow between the negative pressure suction hoods 23 on both sides of the kraft paper; adding a specified amount of water to the water tank 43; when a solution is needed, setting the addition amount of the dosing device 44 according to the processing requirements and adding the corresponding chemical agent to the water tank 43; starting the stirrer 45 to fully mix the water and chemical agent in the water tank 43; and heating and spraying the solution after the concentration is basically uniform. The kraft paper then passes through the cleaning brush 2, the negative pressure suction hood 23, and the paired sticky rollers 24 in sequence along a predetermined conveying path before entering the heater 3. In the pretreatment area corresponding to the water sprayer 4, the cleaning brush 2 rotates and maintains proper contact with the kraft paper surface. At the same time, the electrostatic release device 21 is activated to remove impurities from the paper surface and reduce the electrostatic adsorption effect in the cleaning area. When the kraft paper passes through the negative pressure dust suction hood 23, the negative pressure airflow sucks up the impurities on both sides of the paper. Then, the kraft paper passes between the two dust sticking rollers 24 to further remove residual fine particles. The cleaned kraft paper enters the heat preservation hood 31, where infrared lamps 32 irradiate and heat the kraft paper from both sides. The water sprayer 4 is turned on, and the heated water or solution is sprayed onto the kraft paper through the spray head 41.

[0057] Reference Figures 1-3 The rolling device includes a horizontal embossing roller 5 and a vertical embossing roller 51. The surfaces of the horizontal embossing roller 5 and the vertical embossing roller 51 are provided with embossing patterns, and the embossing patterns are formed on the kraft paper by squeezing the kraft paper. The horizontal embossing roller 5 and the vertical embossing roller 51 are mounted on a pressure adjusting frame 52, and the pressure on the kraft paper is controlled by the pressure adjusting frame 52. A heat applicator 53 is installed in the inner cavity of the horizontal embossing roller 5 and the vertical embossing roller 51. The heat applicator 53 is used to maintain the surface temperature of the horizontal embossing roller 5 and the vertical embossing roller 51.

[0058] Reference Figure 1 and Figure 3 The shaping device includes a dryer 6, which is used to dry the moisture in the kraft paper. The dryer 6 includes a hot air blower 61, which is connected to a hot air hood 62 through a pipe. The hot air hood 62 is positioned towards the kraft paper and sprays hot air.

[0059] The horizontal embossing roller 5 has horizontal embossing patterns on its roller surface. The horizontal embossing refers to the lines formed after embossing that generally extend along the width direction of the kraft paper, or intersect with the conveying direction of the kraft paper. The horizontal embossing patterns can be set as continuous patterns, intermittent patterns, straight lines, curved lines, or other regular patterns according to the required kraft paper surface structure. This embodiment does not limit the specific shape of the horizontal embossing patterns. The vertical embossing roller 51 has vertical embossing patterns on its roller surface. The vertical embossing refers to the lines formed after embossing that generally extend along the length direction or conveying direction of the kraft paper. The vertical embossing patterns can be set as continuously extending stripes, or as intermittent patterns arranged along the conveying direction of the kraft paper. The specific shape and spacing of the pattern can be determined according to the required kraft paper surface structure. The pressure adjustment frame 52 can adjust the squeezing pressure by changing the distance between the impression roller and the kraft paper, or by applying elastic pressure, pneumatic pressure, hydraulic pressure or mechanical pressure to the support position of the impression roller. The specific adjustment method can be selected according to the equipment structure and control requirements. The heat applicator 53 is installed in the inner cavity of the horizontal stripe impression roller 5 and the vertical stripe impression roller 51 respectively, and is used to heat the impression roller and keep the surface of the impression roller at a predetermined temperature. The heat applicator 53 can adopt an electric heating structure or a heat medium circulation structure, as long as it can transfer heat from the inner cavity of the impression roller to the roller surface and maintain the roller surface temperature.

[0060] The dryer 6 can reduce the moisture content of the kraft paper in time after the printing is completed, so that the paper fibers after being deformed by pressure can gradually stabilize under the printing pattern. This reduces the rebound of the pattern, surface wrinkling or local deformation caused by the redistribution of moisture in the kraft paper. The rolling device and the shaping device form a continuous process of heating printing and hot air drying. The horizontal and vertical printing rollers 51 use heat and pressure to form patterns on the kraft paper. The dryer 6 reduces the moisture of the kraft paper in time after the pattern is formed, thereby reducing the rebound of the printing pattern and improving the retention effect of the horizontal and vertical patterns.

[0061] Turn on the heat exchangers 53 inside the horizontal ribbed impression roller 5 and the vertical ribbed impression roller 51 to preheat the two impression rollers, so that the roller surfaces gradually reach the set impression temperature. After the horizontal ribbed impression roller 5 and the vertical ribbed impression roller 51 reach and basically stabilize at the set temperature, the formal impression is carried out. The kraft paper enters the rolling device along the predetermined conveying path and passes through the impression positions corresponding to the horizontal ribbed impression roller 5 and the vertical ribbed impression roller 51 in sequence. Then it enters the drying area corresponding to the hot air hood 62. Adjust the squeezing pressure of the horizontal ribbed impression roller 5 according to the depth and clarity of the horizontal ribbed lines. When the horizontal ribbed lines are too shallow, the pressure can be increased appropriately. When dents, cracks or obvious indentations occur, the pressure should be reduced.

[0062] The horizontal ribbed impression roller 5 and the vertical ribbed impression roller 51 are respectively equipped with driving structures so that the linear speed of the roller surface of the impression roller matches the speed of the kraft paper conveying, thereby reducing the sliding friction between the impression roller and the kraft paper.

[0063] Example 2: This invention discloses a process for pressing micro-textures onto the surface of kraft paper, using the kraft paper surface micro-texture pressing device as described in Example 1, and including the following process steps: The continuously conveyed kraft paper web is cleaned to remove dust and adhering impurities from the surface of the kraft paper web to be pressed; The cleaned kraft paper web is heated so that the surface of the kraft paper web to be pressed reaches a temperature suitable for softening and printing. Apply water or a softener solution evenly to the heated surface to be pressed; When the surface of the kraft paper is in a softened state due to heat, the kraft paper web is embossed to form micro-textures. The kraft paper web with the micro-textures is dried to reduce the moisture in the surface layer or the solvent in the softener solution and to set the micro-textures. The dried kraft paper web is then cooled to reduce the temperature of the kraft paper web to the temperature required for winding or subsequent processing. The cooled kraft paper web is subjected to surface inspection to determine the integrity, uniformity, and surface defects of the formed microtextures. Based on the inspection results, qualified kraft paper webs are either wound up or conveyed to subsequent processes.

[0064] In this embodiment, the surface to be pressed can be one side or both sides of the kraft paper web. The kraft paper web is continuously conveyed between each process, and the operating speed of each processing process is matched with the conveying speed of the kraft paper web to reduce paper web slack, stretching, wrinkling, shifting or breaking. The specific process parameters are adjusted according to the basis weight, thickness, fiber composition, initial moisture content, surface sizing state, required microtexture shape and microtexture depth of the kraft paper.

[0065] The continuously conveyed kraft paper web first enters the cleaning device, which removes dust, free fibers, paper scraps, and other attached impurities from the surface to be pressed. The cleaning process can employ one or more of the following methods: sweeping, electrostatic elimination, negative pressure dust collection, and adhesive dust removal. After cleaning, the kraft paper web enters the heating zone. The main purpose of the heating treatment is to improve the flexibility and deformability of the kraft paper surface fibers, making it easier for them to undergo local deformation according to the embossing pattern during subsequent liquid application and printing processes. After heating, the kraft paper web enters the liquid application zone, where water or a softening agent solution is evenly applied to the surface to be pressed by a water sprayer. The applied liquid is used to increase the wettability of the kraft paper surface and reduce the local bonding stiffness between the surface fibers, making it easier for the kraft paper to form micro-textures under subsequent hot pressing conditions.

[0066] The softener shall be compatible with the kraft paper material and its intended use, and shall not have an unacceptable impact on the strength, color, odor, adhesive properties, printability, or subsequent processing properties of the kraft paper. The type and amount of softener shall be determined by testing based on the kraft paper material and product requirements. For food contact, packaging, or other kraft paper with material compliance requirements, it shall also be confirmed that the softener used complies with the applicable requirements of the corresponding product.

[0067] After heating and liquid application, the kraft paper surface is in a heated, moistened, and softened state. The kraft paper web continues to enter the rolling device, where micro-textures are formed under the combined action of the roller pattern and extrusion pressure. After passing through two printing stations, the kraft paper web can form a surface structure in which transverse and vertical micro-textures intersect or combine. The kraft paper web with completed micro-texture printing enters the setting device, which reduces the moisture in the kraft paper surface or the solvent in the softener solution, and gradually sets the micro-textures. The drying process should be carried out promptly after the micro-textures are formed to reduce the recovery of the kraft paper surface fibers in the moist state, which would cause the texture to spring back. As the moisture or solvent content decreases, the kraft paper fibers gradually stabilize in the uneven state after printing, thereby improving the retention of the micro-textures.

[0068] The dried kraft paper web still has a certain temperature and should be cooled to a temperature suitable for winding or subsequent processing. Cooling can be achieved by one or more of the following methods: natural cooling, ambient air blowing cooling, and cooling roller contact cooling.

[0069] When using air cooling, the kraft paper web can pass through a cooling area with airflow, using the cooler air to remove heat from the paper web. The cooling air should be applied evenly along the width of the kraft paper, and the airflow should not be too large to prevent the kraft paper web from shaking, deviating, or curling. When using cooling rollers, the kraft paper web can contact the cooling rollers at an appropriate wrap angle, transferring heat from the kraft paper to the cooling rollers through heat conduction. The surface of the cooling rollers should be smooth and clean, and its temperature should not be too low to avoid condensation on the kraft paper surface due to rapid cooling or warping due to excessive temperature difference between the two sides.

[0070] The cooling process is not only used to lower the temperature of the kraft paper, but also to further stabilize the state of the dried paper web. If the kraft paper is directly wound at a high temperature, the heat inside the paper roll is not easily dissipated, which may cause uneven temperature and humidity inside the paper roll, interlayer adhesion, micro-texture deformation under pressure, or inconsistent tightness of the paper roll. The temperature of the kraft paper web after cooling is preferably close to the production environment temperature, or at least reduced to a range that will not adversely affect surface inspection, winding, and subsequent processing. Excessive rapid or unilateral cooling should be avoided to reduce warping and dimensional changes of the kraft paper caused by temperature gradients.

[0071] After cooling, the kraft paper web enters the surface inspection process to determine the integrity and uniformity of the formed micro-textures and the surface defects of the kraft paper. Surface inspection can be carried out by one or both of manual sampling and online inspection. During online inspection, an illumination structure and an image acquisition structure can be set on one or both sides of the kraft paper web. The illumination structure provides stable light to the surface of the kraft paper, and the image acquisition structure continuously acquires images of the paper web surface. Then, the continuous state, distribution state and local defects of the micro-textures are identified by image processing. To improve the recognizability of the micro-textures, it is preferable to use oblique illumination that can highlight the concave and convex structure of the paper surface. After the oblique light illuminates the micro-textures, different slopes form differences in brightness and darkness, so that the outline of the micro-textures can be reflected in the image. When inspecting double-sided micro-textures, corresponding illumination and image acquisition structures can be set on both sides of the kraft paper web respectively.

[0072] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the scope defined by the structure of the invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A kraft paper surface micro-texture pressing treatment device, comprising a frame (10) for mounting a kraft paper processing device, wherein a feeding device is mounted at the beginning of the frame (10), the feeding device being used to mount a kraft paper roll and release the kraft paper onto the frame (10) for processing by rolling, characterized in that: The frame (10) is sequentially equipped with a cleaning device, a pretreatment device, a rolling device and a shaping device. The cleaning device is used to clean the surface of the kraft paper. The pretreatment device is used to heat the kraft paper and spray water or solution onto it. The rolling device uses a rolling mold to imprint micro-textures onto the surface of the kraft paper. The shaping device is used to dry and harden the kraft paper.

2. The kraft paper surface micro-texture pressing treatment device according to claim 1, characterized in that: The feeding device includes a feeding frame (1), on which a positioning frame (11) and a lifting frame (12) are installed. The positioning frame (11) is used to fix the position of the kraft paper roll and support the rotation of the kraft paper roll. The lifting frame (12) is installed at the end of the feeding frame (1) and is used to lift the kraft paper roll onto the feeding frame (1). The lifting frame (12) is oscillating and a feeding cylinder (13) is provided on the oscillating side.

3. The kraft paper surface micro-texture pressing treatment device according to claim 2, characterized in that: The feeding rack (1) is equipped with a feeding roller (14) and a low-winding roller (15) on one side of its tail end. After the kraft paper roll is drawn out from the feeding rack (1), it passes around the feeding roller (14) and the low-winding roller (15) in sequence. The feeding roller (14) is connected to a power unit and is used to drag the kraft paper. The bottom of the low-winding roller (15) is equipped with a correction roller (16). The rolling shaft of the correction roller (16) is perpendicular to the rolling shaft of the low-winding roller (15). The correction roller (16) controls the transverse position of the kraft paper through rolling friction.

4. The kraft paper surface micro-texture pressing treatment device according to claim 1, characterized in that: The cleaning device includes a cleaning brush (2), a negative pressure vacuum cleaner (22), and a dust-sticking roller (24). The cleaning brush (2) is roller-shaped and is connected to an electrostatic discharger (21). The electrostatic discharger (21) is used to remove static electricity from the cleaning brush (2) and the kraft paper. The negative pressure vacuum cleaner (22) is connected to a negative pressure vacuum hood (23) through a pipe. The negative pressure vacuum hood (23) is installed on the kraft paper conveying path and is set close to both sides of the kraft paper. The dust-sticking rollers (24) are arranged in pairs and clamped on both sides of the kraft paper.

5. The kraft paper surface micro-texture pressing treatment device according to claim 1, characterized in that: The pretreatment device includes a heater (3) and a water sprayer (4), wherein the heater (3) is used to heat the kraft paper and the water sprayer (4) is used to spray water or solution onto the kraft paper.

6. The kraft paper surface micro-texture pressing treatment device according to claim 5, characterized in that: The heater (3) includes a heat insulation cover (31) and an infrared lamp (32). The infrared lamp (32) is installed inside the heat insulation cover (31) and irradiates and heats both sides of the kraft paper.

7. The kraft paper surface micro-texture pressing treatment device according to claim 5, characterized in that: The water sprayer (4) is equipped with a spray head (41) at the spray end. The spray head (41) is set to spray water towards the kraft paper. The water sprayer (4) is connected to the water tank (43) through the water heater (42). The water heater (42) is used to heat the water or solution in the water tank (43). The water tank (43) is equipped with a dosing device (44) and a stirrer (45). The dosing device (44) is used to control the addition of chemical agents into the water tank (43). The stirrer (45) is used to stir the solution in the water tank (43). The water tank (43) is connected to an external water supply through a pipe.

8. The kraft paper surface micro-texture pressing treatment device according to claim 1, characterized in that: The rolling device includes a horizontal embossing roller (5) and a vertical embossing roller (51). The horizontal embossing roller (5) and the vertical embossing roller (51) are provided with embossing patterns on their surfaces and embossing patterns on the kraft paper by squeezing the kraft paper. The horizontal embossing roller (5) and the vertical embossing roller (51) are mounted on a pressure adjusting frame (52) and the pressure adjusting frame (52) controls the squeezing force on the kraft paper. A heat applicator (53) is installed in the inner cavity of the horizontal embossing roller (5) and the vertical embossing roller (51). The heat applicator (53) is used to maintain the surface temperature of the horizontal embossing roller (5) and the vertical embossing roller (51).

9. The kraft paper surface micro-texture pressing treatment device according to claim 1, characterized in that: The shaping device includes a dryer (6) for drying the moisture in the kraft paper. The dryer (6) includes a hot air blower (61) connected to a hot air hood (62) via a pipe. The hot air hood (62) is positioned toward the kraft paper and sprays hot air.

10. A process for pressing micro-textures onto the surface of kraft paper, using the kraft paper surface micro-texture pressing device as described in any one of claims 1-9, characterized in that, The process includes the following steps: The continuously conveyed kraft paper web is cleaned to remove dust and adhering impurities from the surface of the kraft paper web to be pressed; The cleaned kraft paper web is heated so that the surface of the kraft paper web to be pressed reaches a temperature suitable for softening and printing. Apply water or a softener solution evenly to the heated surface to be pressed; When the surface of the kraft paper is in a softened state due to heat, the kraft paper web is embossed to form micro-textures. The kraft paper web with the micro-textures is dried to reduce the moisture in the surface layer or the solvent in the softener solution and to set the micro-textures. The dried kraft paper web is then cooled to reduce the temperature of the kraft paper web to the temperature required for winding or subsequent processing. The cooled kraft paper web is subjected to surface inspection to determine the integrity, uniformity, and surface defects of the formed microtextures. Based on the inspection results, qualified kraft paper webs are either wound up or conveyed to subsequent processes.

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