Modification of the cover type vacuum adsorption o

  • Detail

The transformation of cover type vacuum adsorption of corrugated board single-sided machine

China's corrugated box industry is entering a stage of rapid development and adjustment. On the one hand, the production capacity is constantly expanding, and the equipment is continuously updated, so that a large number of low-speed guide claw single-sided machine production lines are facing the situation of complete elimination or technical transformation. At the same time, most of the small and micro corrugated boards, such as E-board, F and G, are mainly produced in the form of single-sided machine and two-layer board, and most of them are guided claw type. On the other hand, many small carton factories mainly produce guide claw single-sided machines

the guide claw single-sided machine generally runs at a speed of only about 30 ~ 40m/min, with low production efficiency, high cardboard scrap rate and high energy consumption, so the production cost is high (especially for the production of micro cardboard). However, due to its small investment and fast production, there is still a considerable number of guide claw single-sided machines in China. The outer cover vacuum adsorption transformation of the guide claw single-sided machine is being more and more widely used, and has become one of the preferred schemes with low cost and quick effect adopted by carton factories to improve quality, efficiency and benefit

next, through the analysis of the working principle of the corrugated paper single-sided machine, we can understand the different structural characteristics and performance advantages and disadvantages between the cover type vacuum adsorption and the guide claw type

the general structure of corrugated board single-sided machine is composed of paper guide roller, preheating roller and outlet guide vane (OGV), which have been widely used on the cold end parts of foreign advanced aircraft engines. The forming composite device composed of upper and lower corrugated rollers, pressure rollers, pressurizing cylinders, lower preheating roller 1 and lower preheating roller 2 and the gluing mechanism including gluing roller, homogenizing roller, pulp tray, etc

the corrugated base paper is adjusted by the paper guide roller, the upper preheating roller controls the humidity, slides over the top of the upper corrugating roller and enters the corrugated channel between the heated upper and lower corrugating rollers. After being pressed and ironed at the meshing point on the central line of the two rollers, it runs close to the lower corrugating roller to the central line between the gluing roller and the lower corrugating roller, After the excess glue is scraped off by the leveling roller, a layer of uniform glue film is formed on the surface, and the glue is evenly applied to the top of the corrugated paper. The corrugated paper after sizing continues to operate with the lower corrugated roll, during which the glue is gradually gelatinized by heating. At the connecting line between the lower corrugated roll and the pressure roll center, it is hot pressed and combined with the surface paper that reaches the pressure roll after passing through two preheating rolls to control the humidity, so as to produce various corrugated types of two-layer corrugated board

the above process includes a complete process of two-layer corrugated board production including preheating, ironing, sizing, gelatinization and composite drying. One of the key technological conditions is that the corrugated paper after ironing and forming must be close to the lower corrugating roller to accurately complete the sizing of the corrugated top part and the compounding with facial paper. Any displacement of the pressed corrugated paper on the lower corrugated roller will cause the formed corrugated deformation, resulting in quality defects such as degumming, high and low corrugated, jumping corrugated, broken paper, ear edge, inverted corrugated and so on

with the rapid progress of corrugated board production technology, in order to meet the above process conditions and adapt to the production of wide width, high speed and various corrugated conditions, the structural improvement of corrugated board single-sided machine is constantly innovating. The positioning method of corrugated paper on the lower corrugated roller has developed from the mechanical guide claw type to the commonly used vacuum internal suction type, cover type vacuum adsorption type, air cushion positive pressure type, etc. And the cover vacuum adsorption (also known as external suction) is widely used because of its simple structure, strong adaptability, light manufacturing cost and reliable operation. It is easy to refit and the transformation cycle is short, so it has become the preferred scheme for the transformation of single-sided machine

II. Working principle of guide claw type

the old-fashioned single-sided machine uses a guide claw plate made of copper (also known as copper knife and paper guide, see Figure 1). The upper part of the guide claw plate is inserted into the groove of the upper corrugating roller, close to the central line of the upper and lower corrugating rollers, and the back is embedded in the groove of the rubber coating roller. The circular arc surface of the abdomen is concentric with the lower corrugating roller and maintains a suitable gap greater than the paper thickness, The lower part extends close to the center line between the lower corrugating roll and the pressure roll. The formed corrugated paper is separated from the upper corrugated roller through the guide claw plate, and the corrugated paper is held in the corrugated shape of the lower corrugated roller to complete the gluing and compounding process

because there must be a running gap between the guide claw plate and the paper, when the lower corrugating roller runs fast, centrifugal force and gravity always make the formed corrugated paper throw away from the lower corrugating roller, and continuous friction with the guide claw plate causes the guide claw plate to wear. The faster the running speed is, the more serious the wear is. When the guide claw plate is worn to a certain extent, the corrugated paper cannot be accurately positioned on the lower corrugating roller for gluing and compounding processes, which directly affects the product quality. At the same time, the installation and debugging of the guide claw plate is highly demanding and difficult. The axial extension after the heating of the upper corrugating roll will also cause the guide claw plate to collide with its groove wall and deform and wear, so the wear consumption of the guide claw plate is large, the production and operation is unstable, the replacement and adjustment are frequent, and it costs money and trouble. The gluing roller will also accumulate hardened glue on both sides of the guide claw plate, affecting the quality of paperboard, etc., all of which limit the running speed of the guide claw single-sided machine and affect the product quality

III. working principle of cover type vacuum adsorption

cover type vacuum adsorption is composed of suction hood, paper guide copper sheet, suction pipe, damper, high-pressure suction fan and muffler. There are suction grooves evenly distributed on the surface of the lower corrugating roll of the outer cover vacuum adsorption. The high-pressure fan exhausts strongly through the suction pipe to form a negative pressure between the inner cavity of the suction cover and the lower corrugating roll. Through the suction groove on the lower corrugating roll to ensure the safety of medication, the formed corrugated paper clings to the lower corrugating roll, and the gluing composite process is accurately completed. Then, the paper guide copper sheet installed on the suction cover and stretched into the suction groove of the lower corrugating roll, Guide the composite dried polybutylene 2-benzoate two-layer corrugated board out of the lower corrugated roller. During this period, the air door can adjust and control the air suction volume, and the muffler can reduce the noise of the air suction flow. Changing the corrugating rollers of different corrugating types can produce two-layer corrugated cardboard of various corrugating types

because the vacuum negative pressure principle is used to locate the formed corrugated paper, the positioning instability caused by mechanical wear of the guide claw structure is eliminated, which is enough to adapt to high-speed operation. In particular, the micro corrugated board, after forming, has low strength, easy deformation and is not suitable for positioning. At present, the world can only adapt to high-speed operation by vacuum adsorption or air cushion positive pressure. We have successfully transformed the first domestic 1.6m F-shape (height 0.75) and 1.25m g-shape (height 0.55) micro corrugated external suction single-sided machine, providing high-quality micro corrugated board for high-end color box packaging, and achieved good results, which is difficult to achieve by the guide claw plate single-sided machine. When the paper size of the product is only 50% of the rated size of the corrugating roller, it can operate normally and stably, which fully reflects the good working performance of the cover vacuum adsorption

IV. transformation content of cover type vacuum adsorption of corrugated board single-sided machine

1 New external suction corrugated roll. The external suction hood is installed on the lower corrugating roll. The roll surface of the lower corrugating roll is processed with suction grooves distributed at a certain distance. The upper corrugating roll has no groove, and the original corrugating roll is eliminated

2. The groove of the guide claw plate on the new glue roller will affect the composite quality, and the new glue roller has no groove

3. Design and manufacture the suction hood device, paper guide copper plate device and installation and fixing device according to the specifications of single-sided machine and corrugating roller

4. According to the actual structural location and surrounding environment of the single-sided machine, design the direction of the suction pipe, determine the location of the high-pressure fan, and manufacture the suction pipe system and the high-pressure fan support

5. Select the matching high-pressure fan and muffler according to the specifications of the corrugating roll. Design electrical control

v. modification procedure of cover type vacuum adsorption of corrugated board single-sided machine

1 The relevant dimensions and technical parameters of the single-sided machine and the corrugating roller are checked by on-site mapping

2. Pipeline route and high-pressure fan location are designed on site

3. Determine other transformation and repair items that must be added

4. Made by a professional company (generally, the production time does not exceed the production cycle of the new corrugated roll)

5. On site reconstruction, installation and commissioning (generally 2 days, some new repair items can be removed at the same time and sent to professional companies for emergency repair)

the whole transformation process only needs to be shut down for a few hours during on-site mapping and 2 days during installation and commissioning, which has little impact on production. If the supplier and the demander arrange carefully and cooperate tacitly, the downtime can also be shortened

VI. other transformation and repair items that must be added

because most of the single-sided machines that need to be transformed are old machines, many parts have been worn, and need to be repaired, supplemented and updated, other transformation and repair items may have to be added. (checked and determined by the engineering and technical personnel of the professional company)

1 Repair the worn pressure roller

2. Repair the worn rubber roller

3. A pair of transmission gears on the lower corrugating roll and pressure roll need to be newly made after wear (this item is not available for transmission by gearbox and universal joint)

4. Repair, replace and supplement bearings, oil seals, sprockets, cylinders and other transmission, pneumatic, sealing and mechanical parts

5. Reform, supplement, replacement and repair of electrical control part

the outer cover vacuum adsorption transformation of corrugated board single-sided machine is economical, mature and reliable technology, short transformation cycle and small impact of shutdown. It is being widely promoted and applied in the carton industry. However, at present, the domestic transformation technology is mixed, some of which are rough, Jerry built, copper plate is replaced by aluminum plate, aluminum plate is replaced by iron plate, high-pressure fan is not made by professional manufacturers, and so on. There are hidden dangers in stability and safety performance, which directly damage the interests of users. Therefore, carton manufacturers should choose professional manufacturers, consult professional manufacturers based on many foam will also disillusion manufacturers on relevant transformation matters, and conduct a comprehensive and serious detailed investigation on the use of professional manufacturers and their product users, the after-sales service network and quality of professional manufacturers, and identify the technical level of products. It is better to choose carefully. (dujianchun, Wujin Haili roller Co., Ltd.)

Copyright © 2011 JIN SHI