A control method for controlling the quality of paperboard

Abstract

The present application relates to the technical field of carton production, and discloses a control method for controlling paperboard quality, comprising the following steps: step one, collecting the temperature and humidity of the environment to control the paperboard wrap angle of each level of corrugated heating roller, and adjusting the baking angle of the corrugated heating roller and the paperboard surface in real time according to the paperboard wrap angle, the paperboard surface thickness and the water content of the paperboard surface; step two, folding the respective corresponding paperboard surface into corrugated core boards through a multi-stage corrugator, collecting the water content in the corrugated core board on the same day, adjusting the spraying amount of the adhesive glue associated with the environment, continuously applying different stages of temperature to the multi-layer corrugated paperboard through the air pressure of the heating press plate, so that the corrugated core board gradually forms at the top of the corrugated core board in the corrugated paperboard, and the corrugated core board is dried by being pressed with the paperboard surface to form a multi-layer corrugated paperboard. Thus, the present application avoids the phenomenon that the middle layer of the multi-layer corrugated core board is prone to segment-shaped delamination and the edge of the multi-layer corrugated core board is prone to delamination during the bonding process of the multi-layer corrugated core board.

Description

Technical Field

[0001] This invention relates to the technical field of cardboard box production, and specifically to a method for controlling the quality of cardboard. Background Technology

[0002] Corrugated cardboard is made by corrugating base paper to form a wavy corrugated core, and then gluing linerboard to the top and bottom of the core with adhesive to form a thick sheet of paper. Generally, corrugated cardboard is thicker than 0.1mm and has a basis weight of 250g / m³. 2 The above describes how corrugated cardboard boxes are formed by folding corrugated cardboard to create a box structure. Corrugated cardboard boxes, with their superior performance and good processing properties, have gradually replaced wooden boxes and other transport packaging containers, becoming the mainstay of transport packaging.

[0003] However, currently, most adhesives used in the processing of corrugated cardboard are single-component, with limited bonding strength, which easily leads to seam cracking during the transportation of corrugated boxes, resulting in poor durability. To address this, our company has researched a new multi-component adhesive, a novel adhesive composed of corn starch, primary alkali solution, secondary alkali solution, a stabilizer, and borax. However, in actual use, our company has found that, due to our location in Chongqing, which has a subtropical monsoon climate, the area experiences high humidity year-round. During the production of corrugated cardboard, the new adhesive absorbs moisture from the factory environment, reducing its tackiness.

[0004] To solve the above technical problems, our company reduced the water content in its self-produced new adhesive to improve its adhesion. However, every time we conduct small-scale production of corrugated cardboard of different specifications, we need to repeatedly adjust the water content in the new adhesive, which increases the company's labor costs.

[0005] Meanwhile, because our company is located in the Chongqing area with high humidity, the daily temperature and humidity vary. When producing corrugated cardboard of the same specifications on the same day, the moisture content of the new adhesive used to match the same specifications of corrugated cardboard remains unchanged. However, in the actual production process, the corrugated cardboard itself absorbs moisture from the surrounding environment. If the humidity is too high on a given day, not only will the corrugated core board absorb moisture from the surrounding environment, resulting in a decrease in the hardness of the corrugated core board itself, but the new adhesive will also absorb moisture from the surrounding environment, resulting in a low dynamic solids content in the new adhesive and poor adhesion. Moreover, in the process of bonding multi-layer corrugated core boards, segmental delamination is prone to occur in the middle layer of the multi-layer corrugated core board, as well as delamination at the edges of the multi-layer corrugated core board. Summary of the Invention

[0006] This invention aims to provide a method for controlling the quality of corrugated cardboard, addressing the technical problems encountered during the production process. Due to geographical factors in Chongqing, not only does the corrugated core board absorb moisture from the surrounding environment, leading to a decrease in its hardness, but the new adhesive also absorbs moisture, resulting in a low dynamic solids content and poor adhesion. Furthermore, during the bonding of multi-layer corrugated core boards, segmental delamination and edge delamination are common issues.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: 1) A method for controlling the quality of paperboard, comprising the following steps: Step 1: A multi-stage corrugating machine is evenly set up along the paperboard conveying direction. Each stage of the corrugating machine has at least one set of corrugating heating rollers that bite and heat the original paper surface to form corrugations. The outer surface of the corrugating heating roller of each stage forms a baking angle with the surface of the original paper. The temperature and humidity of the environment are collected on the same day to adjust the inner paper wrapping angle of each stage of corrugating heating roller. The baking angle between the corrugating heating roller and the original paper surface is adjusted in real time based on the inner paper wrapping angle, the thickness of the original paper surface, and the moisture content of the original paper surface. Step two: The corrugated sheets of the original paper are folded into corrugated core boards by multi-stage corrugating machines. The amount of adhesive sprayed is adjusted based on the moisture content of the corrugated core boards collected on the same day. After passing through the corresponding corrugating machines, the corrugated core boards are conveyed to the corrugated paper paste drying assembly. The corrugated paper paste drying assembly has at least one set of heating plates for bonding and heating the corrugated paper and linerboard to form multi-layer corrugated cardboard. The heating plates apply pressure to the multi-layer corrugated paper to generate air pressure, so that the air pressure of the heating plates continuously applies different stages of temperature to the multi-layer corrugated cardboard, so that the corrugated top of the corrugated core board inside the corrugated cardboard gradually forms and is pressed and dried with the original paper to form multi-layer corrugated cardboard.

[0008] This invention collects the temperature and humidity of the surrounding environment during the daily corrugated cardboard production process. Based on the ambient temperature and humidity, it adjusts the linerboard wrap angle of the corrugating heating roller inside the corrugating machine. This adjustment of the linerboard wrap angle can improve the edge crush strength of the corrugated base paper. During production, the baking angle between the corrugating heating roller and the base paper is adjusted in real time based on the linerboard wrap angle, the thickness of the base paper, and the moisture content of the base paper. When the ambient temperature is low and the humidity is high, the linerboard wrap angle of the corrugating heating roller is increased, thereby extending the bonding time between the corrugated core board and the base paper. Combined with the heat from the arc-shaped section of the corrugating heating roller facing the adhesive, the initial bonding between the corrugated core board and the base paper is baked, making the bonding between the corrugated core board and the base paper more stable in a short time after passing through the corrugating machine, thus improving the quality of the corrugated cardboard.

[0009] In addition, after the original paper is folded by the corrugating machine to form the corrugated core board, the moisture content inside the corrugated core board is collected to determine whether the moisture content inside the corrugated core board after the baking angle is adjusted meets the production standard. This allows for control of the amount of adhesive sprayed, ensuring that the adhesive is applied in conjunction with the adjustment of the inner paper wrapping angle to prevent the corrugated board edge from bending upwards or downwards. Effectively, under the air pressure of the heated pressure plate, the corrugated core paper and the original paper are continuously subjected to different stages of temperature on the multi-layer corrugated board through the adhesive under air pressure. This allows the corrugated top of the corrugated core board inside the corrugated board to gradually form and be pressed and dried with the original paper to form the multi-layer corrugated board.

[0010] 2) According to the control method for controlling the quality of cardboard described in 1), the temperature and humidity of the environment collected on the same day are used to adjust the wrapping angle of the inner paper of each corrugated heating roller, and the baking angle between the corrugated heating roller and the original paper surface is adjusted in real time based on the wrapping angle of the inner paper, the thickness of the original paper surface, and the moisture content of the original paper surface, including: The baking angle between the corrugated heating roller and the original paper surface is adjusted according to the tightness of the original paper surface. The calculation formula is as follows: D=(m 1 -m 2 ) / h …… Formula (1) X=

(m 1 -m 2 ) / m 1

[0011] By combining formulas (1) and (2), the initial mass m of the original paper surface is determined. 1 Then, the orientation mass m of the original paper surface is obtained by passing the original paper surface through the corrugated heating roller. 2 By combining these two values ​​with the thickness h of the original paper surface, the tightness of the original paper surface can be calculated. The tightness indicates the tension of the corrugated paper surface after passing through the corrugated heating roller. At the same time, the moisture content X of the orientation mass of the original paper surface is calculated. The moisture content X is used to determine whether the moisture content of the corrugated paper surface exceeds the standard, and the baking angle of the corrugated heating roller is adjusted accordingly.

[0012] 3) A method for controlling the quality of cardboard according to 1), wherein: In step one, adjacent corrugating machines are equipped with a glue applicator along the conveying direction. The glue applicator has a glue applicator box facing the corrugating heating roller. The glue applicator box is located at the starting position of the corrugating heating roller in the rotation direction. The distance between the glue applicator box and the corrugating heating roller is the glue amount of the glue applicator box. The glue amount is adjusted according to the ambient temperature and humidity of the day. The adjustment range of the glue amount is 0.19g / ㎡-0.25g / ㎡.

[0013] During this process, adjacent corrugating machines, along the conveying direction, jointly apply glue to the corrugated core paper. The glue applicator within the applicator is positioned at the starting point of the corrugating heating roller's rotation direction, enabling the application of glue to the corrugated core paper. This ensures that the top and sides of the corrugated core paper are adhered to the adhesive. Simultaneously, the amount of adhesive applied in the glue applicator is controlled within a range of 0.19 g / m² to 0.25 g / m², effectively controlling the amount of adhesive. Even after the adhesive absorbs moisture from the factory environment, this controlled amount effectively controls the adhesive's viscosity, mitigating the reduction in adhesive viscosity compared to existing technologies.

[0014] 4) A method for controlling the quality of cardboard according to 1), wherein: In step one, the pressure control of the corrugated heating roller on the original paper surface includes a corrugated heating roller pressure operating side and a corrugated heating roller pressure driving side. The corrugated heating roller pressure operating side is the side of the corrugated heating roller facing the operator to adjust or monitor its pressure, and the adjustment range of the corrugated heating roller pressure operating side is 16%-20.4%. The corrugated heating roller pressure driving side is the side of the corrugated heating roller to drive its rotation, and the adjustment range of the corrugated heating roller driving side is 16.3%-22%.

[0015] By adjusting the pressure of the corrugated heating roller on the operating side, which is the side of the roller facing the operator for pressure adjustment or monitoring, and setting the adjustment range of the pressure operating side to 16%-20.4%, combined with the adjustment range of the drive side to 16.3%-22%, the uniform and stable operation of the corrugated heating roller can be ensured. Furthermore, when both the pressure operating side and drive side are adjusted within this range, the shape of the corrugated core paper remains consistent during corrugation caused by the rollers engaging and heating, thus guaranteeing the forming quality and strength of the corrugated core paper.

[0016] 5) A method for controlling the quality of cardboard according to 1), wherein in step two, the corresponding original paper corrugated sheets are folded into corrugated core boards by a multi-stage corrugating machine, and the amount of adhesive sprayed is adjusted based on the daily moisture content of the corrugated core board, including: Periodic corrections are made during the corrugating machine folding process. The original paper is folded at an angle of 80°-100° to form corrugated paper in multiple folding cycles. In each corrugating cycle, sensors set in the conveying direction monitor the changes in the original paper folding angle, folding position, and folding pressure in real time. The changes in folding angle, folding position, and folding pressure are transmitted to the central control system. The central control system compares the changes in folding angle, folding position, and folding pressure with the preset target values. Based on the deviation, the folding angle, folding position, and folding pressure of the original paper in the corrugating machine are adjusted in real time, and the corrugated core board is output. The moisture content in the corrugated core board is collected to obtain the folding moisture content. The folding moisture content is combined with the ambient moisture content to determine the amount of adhesive to be sprayed.

[0017] During each folding cycle, sensors monitor the changes in folding angle, folding position, and folding pressure of the original paper surface in real time, and feed the real-time data back to the central control system. The central control system compares the changes in folding angle, folding position, and folding pressure with preset target values, and adjusts the folding angle, folding position, and folding pressure of the original paper surface in the corrugating machine in real time according to the deviation, and outputs the corrugated core board. The moisture content in the corrugated core board is collected to obtain the folding moisture content. The amount of adhesive sprayed is adjusted based on the folding moisture content and the ambient moisture content until the deviation is reduced to an acceptable range, ensuring that the geometry and strength of the cardboard meet the requirements during the forming process.

[0018] 6) A method for controlling the quality of cardboard according to 1), wherein: The wrapping angle of the corrugated heating roller to the inner paper of the original paper is 40%-48%, and the wrapping angle of the corrugated heating roller to the corrugated paper of the original paper is 30%.

[0019] The wrap angle refers to the contact angle between the base paper and the corrugated heating roller. A 40%-48% wrap angle between the corrugated heating roller and the base paper increases the contact area, thus improving preheating. This helps to better control the moisture and temperature of the corrugated paper in subsequent processing, ensuring the bonding quality. Conversely, a 30% wrap angle reduces the contact area, thus decreasing preheating. This helps to better control the moisture content of the corrugated paper during corrugating, preventing excessive drying or wetting.

[0020] 7) A method for controlling the quality of cardboard according to 1), wherein: In step two, the corrugated paper pasting and drying assembly includes a pasting machine and a dryer. The multi-stage corrugating machine feeds corrugated paper to the pasting machine, and the pasting machine applies adhesive to each corrugated paper and bonds them together to form multi-layer corrugated paper. The pasting machine feeds multi-layer corrugated paper to the dryer, and the heated platen in the dryer presses down the multi-layer corrugated paper to form multi-layer corrugated board. The air pressure is adjusted to 2.5 Pa according to the ambient temperature and humidity of the day. The temperature of the heated platen is set as a first stage temperature, a second stage temperature, and a third stage temperature. The first stage temperature is 2.5 J / (kg·K), and the second stage temperature and the third stage temperature are both 5 J / (kg·K). This allows the air pressure of the heated platen to continuously apply different stages of temperature to the corrugated board, so that the corrugated core board inside the corrugated board gradually forms and dries with the original paper surface to form multi-layer corrugated paper.

[0021] Based on the ambient temperature and humidity, the air pressure was adjusted to 2.5 Pa. The heating plate was set to three temperatures: the first temperature, the second temperature, and the third temperature. The first temperature was 2.5 J / (kg·K), and the second and third temperatures were both 5 J / (kg·K). This allowed the air pressure of the heating plate to continuously apply different stages of temperature to the corrugated cardboard, gradually shaping the corrugated core board. Combined with the air pressure generated by the heating plate, this quickly forced the moisture in the adhesive to evaporate and solidify, thus preventing the corrugated core board from being deformed and wrinkled by pressing against the original paper surface, which could lead to missing corrugations in the corrugated paper.

[0022] 8) A method for controlling the quality of cardboard according to 1), wherein: The baking angle of the corrugated heating roller in the corrugating machine is reduced, and the downward pressure of the heating plate in the dryer is increased.

[0023] In the actual production process, the baking angle of the corrugated heating roller in the corrugating machine is reduced to meet the production temperature of the corrugated paper. In order to ensure the moisture content of the produced carton, the downward pressure of the heating plate in the dryer is appropriately increased. The downward pressure applied by the heating plate causes the corrugated cardboard formed by the bonding and heating of multiple layers of corrugated paper to evaporate moisture quickly due to the downward pressure, thereby ensuring the moisture content of the corrugated cardboard.

[0024] 9) A method for controlling the quality of paperboard according to 8), wherein: The baking angle is determined by the production carton conveying speed and the weight of the original paper surface, with the conveying speed being 110-130 m / min and the weight of the original paper surface being 120-200 g / m. 2 The baking angle is the angle formed by connecting the two sides of the contact surface between the outer surface of the corrugated heating roller and the surface of the original paper with the center point of the corrugated heating roller.

[0025] This invention adjusts the temperature of the corrugated paper output from the corrugating machine by controlling the production carton conveying speed and the weight of the original paper surface. When the weight of the original paper surface is a fixed value, the temperature of the output corrugated paper is adjusted by controlling the production carton conveying speed and the baking angle. When the production carton conveying speed is too fast, the contact time between the outer surface of the corrugated heating roller and the surface of the original paper surface is shorter, thereby increasing the baking angle. Conversely, the baking angle is reduced. Therefore, this invention adjusts the moisture content of the corrugated paper by controlling the temperature of the output corrugated paper, thus ensuring the quality of the corrugated paper.

[0026] 10) A method for controlling the quality of paperboard according to 1), wherein: The corrugated paper paste drying assembly is equipped with an exhaust fan along the conveying direction, and the exhaust fan vents the corrugated paper for 15 seconds.

[0027] An exhaust fan, positioned along the conveyor direction in the corrugated paper drying assembly, draws air from the periphery of the corrugated paper, promoting airflow and accelerating the drying process. The exhaust fan improves drying efficiency, ensuring the corrugated paper dries quickly as it passes through the drying zone. The exhaust time is controlled to 15 seconds to rapidly evaporate moisture from the adhesive and allow it to solidify, preventing the corrugated core from pressing against the linerboard and causing deformation and wrinkling, thus avoiding gaps in the corrugated paper.

[0028] Compared with the prior art, the present invention also has the following technical effects: Compared to existing technologies, this invention utilizes the baking angle of the corrugated heating roller, the amount of adhesive applied, the air pressure of the heating plate, and the temperature of the heating plate at different stages. This allows the air pressure of the heating plate to continuously apply different stages of temperature to the corrugated cardboard, enabling the corrugated core board inside the cardboard to gradually form its corrugated top. Combined with the air pressure generated by the heating plate, this rapidly forces the moisture in the adhesive to evaporate and solidify, thereby avoiding segmental delamination in the middle layer of the multi-layer corrugated core board and the phenomenon of delamination at the edges of the multi-layer corrugated core board during the bonding process. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for controlling the quality of cardboard according to the present invention. Detailed Implementation

[0030] The following detailed description illustrates the specific implementation method: See the example. Figure 1 As shown, this embodiment of a method for controlling the quality of cardboard includes the following steps: Step 1: A multi-stage corrugating machine is evenly set up along the paperboard conveying direction. Each stage of the corrugating machine has at least one set of corrugating heating rollers that bite and heat the original paper surface to form corrugations. The outer surface of the corrugating heating roller of each stage forms a baking angle with the surface of the original paper. The temperature and humidity of the environment are collected on the same day to adjust the inner paper wrapping angle of each stage of corrugating heating roller. The baking angle between the corrugating heating roller and the original paper surface is adjusted in real time based on the inner paper wrapping angle, the thickness of the original paper surface, and the moisture content of the original paper surface. Step two: The corrugated sheets of the original paper are folded into corrugated core boards by multi-stage corrugating machines. The amount of adhesive sprayed is adjusted based on the moisture content of the corrugated core boards collected on the same day. After passing through the corresponding corrugating machines, the corrugated core boards are conveyed to the corrugated paper paste drying assembly. The corrugated paper paste drying assembly has at least one set of heating plates that bond and heat the corrugated paper and linerboard to form multi-layer corrugated cardboard. The heating plates apply pressure to the multi-layer corrugated paper to generate air pressure, so that the air pressure of the heating plates continuously applies different stages of temperature to the multi-layer corrugated cardboard, so that the corrugated top of the corrugated core board inside the corrugated cardboard gradually takes shape and is pressed and dried with the original paper to form multi-layer corrugated cardboard.

[0031] This embodiment collects the temperature and humidity of the surrounding environment during the corrugated cardboard production process on the same day. Based on the temperature and humidity of the surrounding environment, the wrap angle of the inner linerboard of the corrugating heating roller in the corrugating machine is adjusted. The adjustment of the inner linerboard wrap angle can improve the edge crush strength of the corrugated base paper. During production, the baking angle between the corrugating heating roller and the base paper is adjusted in real time based on the inner linerboard wrap angle, the thickness of the base paper, and the moisture content of the base paper. When the ambient temperature is low and the humidity is high, the inner linerboard wrap angle of the corrugating heating roller is increased, thereby prolonging the bonding time between the corrugated core board and the base paper. Combined with the heat from the arc-shaped section of the corrugating heating roller facing the adhesive, the initial bonding between the corrugated core board and the base paper is baked, making the bonding between the corrugated core board and the base paper more stable in a short time after passing through the corrugating machine, thereby improving the quality of the corrugated cardboard.

[0032] In addition, after the original paper is folded by the corrugating machine to form the corrugated core board, the moisture content inside the corrugated core board is collected to determine whether the moisture content inside the corrugated core board after the baking angle is adjusted meets the production standard. This allows for control of the amount of adhesive sprayed, ensuring that the adhesive is applied in conjunction with the adjustment of the inner paper wrapping angle to prevent the corrugated board edge from bending upwards or downwards. Effectively, under the air pressure of the heated pressure plate, the corrugated core paper and the original paper are continuously subjected to different stages of temperature on the multi-layer corrugated board through the adhesive under air pressure. This allows the corrugated top of the corrugated core board inside the corrugated board to gradually form and be pressed and dried with the original paper to form the multi-layer corrugated board.

[0033] In this embodiment, the wrap angle of the corrugated heating roller to the inner liner of the base paper is 40%-48%, and the wrap angle of the corrugated paper to the base paper is 30%. The wrap angle refers to the contact angle between the base paper and the corrugated heating roller. A 40%-48% wrap angle increases the contact area between the base paper and the heating roller, thus improving the preheating effect. This helps to better control the moisture and temperature of the corrugated paper in subsequent processing, ensuring the bonding quality of the corrugated paper. A 30% wrap angle reduces the contact area between the base paper and the heating roller, thus reducing the preheating effect. This helps to better control the moisture content of the corrugated paper during corrugating, preventing excessive drying or wetting.

[0034] The temperature and humidity of the environment collected on the same day are used to control the inner paper wrapping angle of each corrugated heating roller. The baking angle between the corrugated heating roller and the original paper surface is adjusted in real time based on the inner paper wrapping angle, the thickness of the original paper surface, and the moisture content of the original paper surface. This includes: The baking angle between the corrugated heating roller and the original paper surface is adjusted according to the tightness of the original paper surface. The calculation formula is as follows: D=(m 1 -m 2 ) / h …… Formula (1) X=

(m 1 -m 2 ) / m 1

[0035] By combining formulas (1) and (2), the initial mass m of the original paper surface is determined. 1 Then, the orientation mass m of the original paper surface is obtained by passing the original paper surface through the corrugated heating roller. 2 By combining these two values ​​with the thickness h of the original paper surface, the tightness of the original paper surface can be calculated. The tightness indicates the tension of the corrugated paper surface after passing through the corrugated heating roller. At the same time, the moisture content X of the orientation mass of the original paper surface is calculated. The moisture content X is used to determine whether the moisture content of the corrugated paper surface exceeds the standard, and the baking angle of the corrugated heating roller is adjusted accordingly.

[0036] Meanwhile, in step one, the pressure control of the corrugated heating roller on the original paper surface includes the corrugated heating roller pressure operation side and the corrugated heating roller pressure drive side. The corrugated heating roller pressure operation side is the side of the corrugated heating roller facing the operator to adjust or monitor its pressure, and the adjustment range of the corrugated heating roller pressure operation side is 16%-20.4%. The corrugated heating roller pressure drive side is the side of the corrugated heating roller to drive its rotation, and the adjustment range of the corrugated heating roller drive side is 16.3%-22%.

[0037] By adjusting the pressure of the corrugated heating roller on the operating side, which is the side of the roller facing the operator for pressure adjustment or monitoring, and setting the adjustment range of the pressure operating side to 16%-20.4%, combined with the adjustment range of the drive side to 16.3%-22%, the uniform and stable operation of the corrugated heating roller can be ensured. Furthermore, when both the pressure operating side and drive side are adjusted within this range, the shape of the corrugated core paper remains consistent during corrugation caused by the rollers engaging and heating, thus guaranteeing the forming quality and strength of the corrugated core paper.

[0038] In addition, in step two, the corresponding original paper corrugated sheets are folded into corrugated core boards by a multi-stage corrugating machine. The amount of adhesive sprayed is adjusted based on the daily moisture content of the corrugated core board, taking into account environmental factors. Periodic corrections are made during the corrugating machine folding process. The original paper is folded at an angle of 80°-100° to form corrugated paper in multiple folding cycles. In each corrugating cycle, sensors set in the conveying direction monitor the changes in the original paper folding angle, folding position, and folding pressure in real time. The changes in folding angle, folding position, and folding pressure are transmitted to the central control system. The central control system compares the changes in folding angle, folding position, and folding pressure with the preset target values. Based on the deviation, the folding angle, folding position, and folding pressure of the original paper in the corrugating machine are adjusted in real time, and the corrugated core board is output. The moisture content in the corrugated core board is collected to obtain the folding moisture content. The folding moisture content is combined with the ambient moisture content to determine the amount of adhesive to be sprayed.

[0039] During each folding cycle, sensors monitor the changes in folding angle, folding position, and folding pressure of the original paper surface in real time, and feed the real-time data back to the central control system. The central control system compares the changes in folding angle, folding position, and folding pressure with preset target values, and adjusts the folding angle, folding position, and folding pressure of the original paper surface in the corrugating machine in real time according to the deviation, and outputs the corrugated core board. The moisture content in the corrugated core board is collected to obtain the folding moisture content. The amount of adhesive sprayed is adjusted based on the folding moisture content and the ambient moisture content until the deviation is reduced to an acceptable range, ensuring that the geometry and strength of the cardboard meet the requirements during the forming process.

[0040] Meanwhile, adjacent corrugating machines are equipped with glue applicators along the conveying direction. The glue applicator has a glue applicator box facing the corrugating heating roller. The glue applicator box is located at the starting position of the corrugating heating roller rotation direction. The distance between the glue applicator box and the corrugating heating roller is the glue amount of the glue applicator box. The glue amount is adjusted according to the ambient temperature and humidity of the day. The adjustment range of the glue amount is 0.19g / ㎡-0.25g / ㎡.

[0041] During this process, adjacent corrugating machines, along the conveying direction, jointly apply glue to the corrugated core paper. The glue applicator within the applicator is positioned at the starting point of the corrugating heating roller's rotation direction, enabling the application of glue to the corrugated core paper. This ensures that the top and sides of the corrugated core paper are adhered to the adhesive. Simultaneously, the amount of adhesive applied in the glue applicator is controlled within a range of 0.19 g / m² to 0.25 g / m², effectively controlling the amount of adhesive. Even after the adhesive absorbs moisture from the factory environment, this controlled amount effectively controls the adhesive's viscosity, mitigating the reduction in adhesive viscosity compared to existing technologies.

[0042] In step two, the corrugated paper pasting and drying assembly includes a pasting machine and a dryer. The multi-stage corrugating machine feeds corrugated paper to the pasting machine, which applies adhesive to each piece of corrugated paper and bonds them together to form multi-layer corrugated paper. The pasting machine feeds the multi-layer corrugated paper to the dryer, where a heating platen in the dryer presses down the multi-layer corrugated paper to form multi-layer corrugated board. The air pressure is adjusted to 2.5 Pa according to the ambient temperature and humidity. The temperature of the heating platen is set as a first stage temperature, a second stage temperature, and a third stage temperature. The first stage temperature is 2.5 J / (kg·K), and the second and third stage temperatures are both 5 J / (kg·K). This allows the air pressure of the heating platen to continuously apply different stages of temperature to the corrugated board, allowing the corrugated core board inside the corrugated board to gradually form and dry with the original paper surface to form multi-layer corrugated paper.

[0043] Based on the ambient temperature and humidity, the air pressure was adjusted to 2.5 Pa. The heating plate was set to three temperatures: the first temperature, the second temperature, and the third temperature. The first temperature was 2.5 J / (kg·K), and the second and third temperatures were both 5 J / (kg·K). This allowed the air pressure of the heating plate to continuously apply different stages of temperature to the corrugated cardboard, gradually shaping the corrugated core board. Combined with the air pressure generated by the heating plate, this quickly forced the moisture in the adhesive to evaporate and solidify, thus preventing the corrugated core board from being deformed and wrinkled by pressing against the original paper surface, which could lead to missing corrugations in the corrugated paper.

[0044] Meanwhile, the baking angle of the corrugated heating rollers in the corrugating machine is reduced, while the downward pressure of the heating platen in the dryer is increased. In this embodiment, during actual production, the baking angle of the corrugated heating rollers in the corrugating machine is reduced to meet the production temperature of the corrugated paper. To ensure the moisture content of the produced cartons, the downward pressure of the heating platen in the dryer is appropriately increased. The downward pressure applied by the heating platen causes the corrugated cardboard formed by the bonding and heating of multiple layers of corrugated paper to evaporate moisture quickly, thereby ensuring the moisture content of the corrugated cardboard.

[0045] The baking angle is determined by the production carton conveyor speed and the weight of the raw paper, with an adjustment range of 110-130 m / min and a raw paper weight of 120-200 g / m. 2 The baking angle is the angle formed by connecting the two sides of the contact surface between the outer surface of the corrugated heating roller and the surface of the original paper with the center point of the corrugated heating roller.

[0046] This embodiment adjusts the temperature of the corrugated paper output from the corrugating machine by controlling the production carton conveying speed and the weight of the original paper surface. When the weight of the original paper surface is a fixed value, the temperature of the output corrugated paper is adjusted by controlling the production carton conveying speed and the baking angle. When the production carton conveying speed is too fast, the contact time between the outer surface of the corrugated heating roller and the surface of the original paper surface is shorter, thereby increasing the baking angle. Conversely, the baking angle is reduced. Therefore, this embodiment controls the temperature of the output corrugated paper to adjust the moisture content of the corrugated paper and ensure the quality of the corrugated paper.

[0047] In addition, in step two, an exhaust fan is installed along the conveying direction of the corrugated paper drying assembly. The exhaust fan evacuates the corrugated paper for 15 seconds. The exhaust fan, located along the conveying direction of the corrugated paper drying assembly, draws air from the periphery of the corrugated paper, thereby promoting air circulation and accelerating the drying speed. The use of the exhaust fan improves drying efficiency, ensuring that the corrugated paper dries quickly as it passes through the drying area. The 15-second exhaust time quickly forces the moisture in the adhesive to evaporate and solidify, thus preventing the corrugated core board from being pressed against the linerboard, causing deformation and wrinkling, and preventing gaps in the corrugated paper.

[0048] In this embodiment, the baking angle of the corrugated heating roller, the amount of adhesive applied, the air pressure of the heating plate, and the temperature of the heating plate at different stages are used to continuously apply different stages of temperature to the corrugated cardboard with the air pressure of the heating plate. This allows the corrugated core board inside the corrugated cardboard to gradually form at the top, and the air pressure generated by the heating plate quickly forces the moisture in the adhesive to evaporate and solidify. This avoids the phenomenon of segmental delamination in the middle layer of the multi-layer corrugated core board and delamination at the edges of the multi-layer corrugated core board during the bonding process.

[0049] The above are merely embodiments of the present invention. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for controlling the quality of cardboard, characterized in that, Includes the following steps: Step 1: A multi-stage corrugating machine is evenly set up along the paperboard conveying direction. Each stage of the corrugating machine has at least one set of corrugating heating rollers that bite and heat the original paper surface to form corrugations. The outer surface of the corrugating heating roller of each stage forms a baking angle with the surface of the original paper. The temperature and humidity of the environment are collected on the same day to adjust the inner paper wrapping angle of each stage of corrugating heating roller. The baking angle between the corrugating heating roller and the original paper surface is adjusted in real time based on the inner paper wrapping angle, the thickness of the original paper surface, and the moisture content of the original paper surface. Step two: The corrugated sheets of the original paper are folded into corrugated core boards by multi-stage corrugating machines. The amount of adhesive sprayed is adjusted based on the moisture content of the corrugated core boards collected on the same day. After passing through the corresponding corrugating machines, the corrugated core boards are conveyed to the corrugated paper paste drying assembly. The corrugated paper paste drying assembly has at least one set of heating plates for bonding and heating the corrugated paper and linerboard to form multi-layer corrugated cardboard. The heating plates apply pressure to the multi-layer corrugated paper to generate air pressure, so that the air pressure of the heating plates continuously applies different stages of temperature to the multi-layer corrugated cardboard, so that the corrugated top of the corrugated core board inside the corrugated cardboard gradually forms and is pressed and dried with the original paper to form multi-layer corrugated cardboard.

2. The method for controlling the quality of cardboard according to claim 1, characterized in that: The temperature and humidity of the environment collected on the same day are used to control the inner paper wrapping angle of each corrugated heating roller. The baking angle between the corrugated heating roller and the original paper surface is adjusted in real time based on the inner paper wrapping angle, the thickness of the original paper surface, and the moisture content of the original paper surface. This includes: The baking angle between the corrugated heating roller and the original paper surface is adjusted according to the tightness of the original paper surface. The calculation formula is as follows: D=(m 1 -m 2 ) / h …… Formula (1) X=【(m 1 -m 2 ) / m 1 】x100%...Formula (2) in: D represents the density of the original paper surface, measured in g / m³. -3 ; m 1 The initial mass of the original paper surface is expressed in grams. m 2 The orientation mass of the original paper surface after passing through the corrugated heating rollers is expressed in grams. h represents the thickness of the original paper surface, in mm; X represents the moisture content of the original paper surface.

3. The method for controlling the quality of cardboard according to claim 1, characterized in that: In step one, adjacent corrugating machines are equipped with a glue applicator along the conveying direction. The glue applicator has a glue applicator box facing the corrugating heating roller. The glue applicator box is located at the starting position of the corrugating heating roller in the rotation direction. The distance between the glue applicator box and the corrugating heating roller is the glue amount of the glue applicator box. The glue amount is adjusted according to the ambient temperature and humidity of the day. The adjustment range of the glue amount is 0.19g / ㎡-0.25g / ㎡.

4. The method for controlling the quality of cardboard according to claim 1, characterized in that: In step one, the pressure control of the corrugated heating roller on the original paper surface includes a corrugated heating roller pressure operating side and a corrugated heating roller pressure driving side. The corrugated heating roller pressure operating side is the side of the corrugated heating roller facing the operator to adjust or monitor its pressure, and the adjustment range of the corrugated heating roller pressure operating side is 16%-20.4%. The corrugated heating roller pressure driving side is the side of the corrugated heating roller to drive its rotation, and the adjustment range of the corrugated heating roller driving side is 16.3%-22%.

5. The method for controlling the quality of cardboard according to claim 1, characterized in that: Among them In step two, the corresponding original paper corrugated sheets are folded into corrugated core boards by multi-stage corrugating machines. The amount of adhesive sprayed is adjusted based on the daily moisture content of the corrugated core boards, taking into account environmental factors. This includes: Periodic corrections are made during the corrugating machine folding process. The original paper is folded at an angle of 80°-100° to form corrugated paper in multiple folding cycles. In each corrugating cycle, sensors set in the conveying direction monitor the changes in the original paper folding angle, folding position, and folding pressure in real time. The changes in folding angle, folding position, and folding pressure are transmitted to the central control system. The central control system compares the changes in folding angle, folding position, and folding pressure with the preset target values. Based on the deviation, the folding angle, folding position, and folding pressure of the original paper in the corrugating machine are adjusted in real time, and the corrugated core board is output. The moisture content in the corrugated core board is collected to obtain the folding moisture content. The folding moisture content is combined with the ambient moisture content to determine the amount of adhesive to be sprayed.

6. The method for controlling the quality of cardboard according to claim 1, characterized in that: The wrapping angle of the corrugated heating roller to the inner paper of the original paper is 40%-48%, and the wrapping angle of the corrugated heating roller to the corrugated paper of the original paper is 30%.

7. The method for controlling the quality of cardboard according to claim 1, characterized in that: In step two, the corrugated paper pasting and drying assembly includes a pasting machine and a dryer. The multi-stage corrugating machine feeds corrugated paper to the pasting machine, and the pasting machine applies adhesive to each corrugated paper and bonds them together to form multi-layer corrugated paper. The pasting machine feeds multi-layer corrugated paper to the dryer, and the heated platen in the dryer presses down the multi-layer corrugated paper to form multi-layer corrugated board. The air pressure is adjusted to 2.5 Pa according to the ambient temperature and humidity of the day. The temperature of the heated platen is set as a first stage temperature, a second stage temperature, and a third stage temperature. The first stage temperature is 2.5 J / (kg·K), and the second stage temperature and the third stage temperature are both 5 J / (kg·K). This allows the air pressure of the heated platen to continuously apply different stages of temperature to the corrugated board, so that the corrugated core board inside the corrugated board gradually forms and dries with the original paper surface to form multi-layer corrugated paper.

8. The method for controlling the quality of cardboard according to claim 1, characterized in that: The baking angle of the corrugated heating roller in the corrugating machine is reduced, and the downward pressure of the heating plate in the dryer is increased.

9. The method for controlling the quality of cardboard according to claim 8, characterized in that: The baking angle is determined by the production carton conveying speed and the weight of the original paper surface, with the conveying speed being 110-130 m / min and the weight of the original paper surface being 120-200 g / m. 2 The baking angle is the angle formed by connecting the two sides of the contact surface between the outer surface of the corrugated heating roller and the surface of the original paper with the center point of the corrugated heating roller.

10. The method for controlling the quality of paperboard according to claim 1, characterized in that: The corrugated paper paste drying assembly is equipped with an exhaust fan along the conveying direction, and the exhaust fan vents the corrugated paper for 15 seconds.

Images