Working principle of the hottest single corrugated

2022-07-24
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Working principle of single corrugated board production line

decision makers of enterprises should pay attention to the following issues when selecting medium and high speed corrugated board production lines

first, good product market research is the basis for equipment selection.

corrugated box products are a kind of large-scale import and export products. Considering the increased cost of freight and the timeliness of delivery, the market area of such products is doomed not to cover a large range. The market scope is usually locked within a radius of 200 km. Therefore, the decision-makers must investigate and investigate the main specifications and ridge types of the products of major potential customers around, so as to know well and provide a basis for the next decision

in addition, it is necessary to understand the equipment status, management status and customer status of surrounding competitors, so as to provide basis for the formulation of next marketing measures

second, consider the matching of the overall coordination of the corrugated board production line

the selection principle for the medium and high-speed corrugated board production line is to consider the automation level of each single machine, and pay more attention to the overall matching and coordination of the corrugated board production line. Since you choose a high-speed production line, you should choose a configuration that matches the whole line with a high degree of automation

for example, it needs to be equipped with an automatic paper feeder (select a paper feeder with appropriate speed according to the whole line speed, and the number of paper receivers depends on your own economic situation), a positive pressure cassette type single-sided corrugating machine (easy roll change, stable operation and fast speed), a production management system, an internal expansion chuck (for safety, multi-point brake must be selected), a full-automatic thin knife Slitter (2 sets are required for quick order change) The slitting machine shall be equipped with three kinds of line pressing wheels (convex to concave, concave to convex, convex to flat), spiral cross cutting machine, automatic glue making system, glue applicator (using pressure regulating pressure contact rod instead of pressure roller), and the number of hot plates of the double-sided machine shall match the speed (the drying cadre adopts spring hot pressing plate, of course, the advantages and disadvantages of condensate drain valve must be paid attention to), etc

third, focus on the key selection of core components

several important technical points of corrugating roller

for high-speed machines, the diameter of single-sided machines usually cannot be less than 320mm, otherwise, it is difficult to improve the speed. Generally, the diameter of corrugating roll is above 375mm

the most commonly used single-sided machines in the market are mostly non paste fork type external suction vacuum single-sided machines or positive pressure cassette type single-sided machines. In actual operation, it is necessary to control the fitting pressure (fitting gap), parallelism, surface temperature of the corrugating roll, and select the appropriate medium and high

of course, the control of the surface temperature of the corrugating roller (usually 160 180 ℃) is closely related to the saturated vapor pressure and the discharge of condensate. As we know, the saturated water vapor in jg/t5103 (1) 998 of mast column aerial work platform will release latent heat and condense into condensate after passing into the corrugating roller. Due to the low thermal conductivity of condensate, if it is not eliminated smoothly and accumulates in the roller, the thermal resistance of the roller will be greatly increased, resulting in the decrease of the surface temperature of the roller and the failure to work at normal speed

when the condensed water in the roll accumulates to a certain extent, it covers the outlet of the drain pipe. Since the saturated steam pressure in the roll is greater than the pressure at the end of the drain pipe, the pressure difference at both ends makes the condensed water continuously discharged. Therefore, the port of the condensed water discharge pipe must be installed downward, and the end should be as close to the inner wall at the lower part of the roll body as possible, so as to discharge the condensed water as much as possible. Of course, the pipe orifice cannot contact the inner wall, because the roller is rotating, and the condensate drain pipe and steam rotary joint are fixed, otherwise noise will be generated and the drain pipe will be damaged. The fixed straw is usually made at an angle of 45 to the lower bottom surface

during the meshing process of the corrugating roll, pressurization at both ends of the upper corrugating roll will produce a certain deflection, which will increase the gap in the middle part of the corrugating roll. Therefore, during the manufacturing of the corrugating roll, the central diameter should be slightly larger than that at both ends, and the difference is medium high. According to the industry standard QB/t2498--2000 corrugated board production line, the corrugated roll on the high-speed machine is medium high, which is usually 4 times the roll deflection

preheating cylinder

the diameter of the preheating cylinder shall not be less than 900mm. It shall have the maximum wrapping angle adjustment ability to adjust the humidity of the base paper and ensure the flatness of the paperboard

glue applicator touch bar

we know that the traditional glue applicator uses the gravity pressure roller to apply glue. If a small range of paperboard is produced for a long time, the middle part of the paste roller and the gravity pressure roller is seriously worn. When the large-scale paperboard is produced, the middle part is worn, so the middle part will not be well glued, resulting in problems such as degumming, blistering and poor fitting of the paperboard. However, where there is no wear on both sides, due to pressure, It will flatten and deform the corrugated board shape to varying degrees, and too much glue will soften the board and reduce the strength

it is necessary to adjust the gap of the paper pressing gravity roller when changing the paper material (the transformation between high gram weight paper and low gram weight paper) and changing the corrugated shape. This is a difficult task. Therefore, it is necessary to ensure that the oil pump is in a vibration free condition. If the oil pump is good, the cardboard will be flattened or will not be glued, resulting in the scrapping of the cardboard. If the operator uses a minimum clearance for any corrugated type in order to save trouble, the strength of the paperboard will be greatly damaged. For example, the height of corrugated board B is 2.7mm. Only when the gap between the rubber roller and the gravity pressing roller is 2.6mm according to the normal standard can the paste be evenly applied. That is to say, the corrugated board must be flattened by 0.1mm according to the normal adjustment, and the flattened board will use a lot of glue. Of course, the hardness and compressive strength of the flattened and the paperboard with a large amount of glue will be greatly reduced

the contact pressure bar of the glue applicator is installed on the glue applicator to replace the traditional gravity pressure roller, and is composed of a group of elastic tablets with balanced pressure. The contact bar is made by connecting many wear-resistant arc-shaped sheets and springs. The spring force always makes the arc-shaped sheets adhere to the upper pasting roller evenly. Even if the upper pasting roller is worn and dented, the spring sheets will also be dented, which always makes the corrugated core paper adhere to the upper pasting roller evenly, making the corrugated core paper paste evenly

the tablet pressing design of the contact pressure bar has the same radian as that of the upper rubber roller to ensure stable pressure, uniform pasting and easy control of the glue amount. There is an independently controlled elastic device on the tablet, which can automatically adjust the irregular runout, avoid flattening the ridge shape, and ensure the strength of the paperboard

at present, there are two types of elastic devices for tablet pressing in the market: mechanical spring and automatic pressure adjustment

due to the unadjustable spring pressure, the spring elasticity of ordinary spring type pressure bar is prone to fatigue, resulting in a series of problems. For example, the spring pressure will flatten the corrugated, which will affect the compression resistance and excessive sizing, resulting in slower speed and softer paperboard; Small spring pressure will lead to uneven sizing, paper board degumming, foaming, etc

the pneumatic pressure regulating system of the pressure regulating touch bar adopts a stable and reliable cylinder type push rod design, coupled with high-quality precision machining and imported wear-resistant pneumatic materials to ensure that the touch bar can operate stably and reliably for a long time. The device can pass through various paper materials without adjusting the height. There is no need to adjust the gap when the material thickness and the edge shape of the paper change. In this way, when the corrugated core paper enters the gluing machine for gluing, the corrugating height and the corrugating height when it comes out of the gluing machine after gluing are basically guaranteed to remain the same, so as to avoid the occurrence of inverted corrugating or flattening of the corrugating tip, maintain the intact corrugating shape, apply the glue evenly, and save a lot of corn starch glue. The final paperboard is close to the ideal standard, making the compressive strength high, ensuring the process requirements and the thickness and strength of the paperboard

the number of hot plates for drying and hot pressing of the double-sided machine should match the number of hot plates for drying with the high-speed production line. Otherwise, the pasted paperboard will not be fully dried, the adhesive will not gelatinize well, and too fast will cause a large number of paperboards to be degummed and too soft. Generally, the number of hot plates should not be less than 18

the hot pressing plate of the double-sided machine is installed on the hot plate of the dryer. It is a new product to replace the traditional gravity pressing roller and make the corrugated board heat transfer and dry quickly on the hot plate. The dryer hot pressing plate is composed of a special wear-resistant stainless steel sheet and a special spring. Each hot pressing plate is divided into a group. Each group of hot pressing plates can automatically select the rise and fall according to different speeds and temperatures, which is easy to operate

we know that any substance has the characteristics of thermal expansion and cold contraction. When the corrugated board is dried by the hot plate, it will take away a lot of heat, making the temperature of the bottom and surface of the hot plate inconsistent. When the temperature above is low, the hot baking plate will be concave and deformed. In particular, the first to fifth pieces are the most active for international cooperation and exchange. The faster the speed is, the more heat is taken away and the greater the deformation is. In addition, the traditional gravity roller is a straight line, which is in line contact and will not bend with the deformation of the hot plate. In this way, the middle part cannot be pressed, and the two sides are pressed too heavily, resulting in degumming, foaming and poor fitting in the middle of the paperboard. Of course, the corrugated shapes on both sides are flattened. In addition, its heat transfer efficiency is low. If the vehicle speed is too fast, it will degumm due to insufficient heat of the paperboard, resulting in poor fitting. As the roller bearing is a high-speed linear reciprocating friction and wear testing machine (vibration friction and wear testing machine) which is installed dispersedly, the weight is not easy to adjust, so it is easy to flatten the corrugated board shape and appear the phenomenon of corrugation, and the produced cardboard will also be bent and uneven, especially when the single corrugated board and the double corrugated board are changed, it is more difficult to adjust

the hot plate contact plate is specially designed for the above problems. Its working principle is the same as that of the spring type contact bar on the glue applicator. It is assembled by springs and grouped wear-resistant stainless steel sheets. The spring with constant elastic force can ensure the stable pressure required to be applied to the hot plate at any time, so that the corrugated core paper can be completely attached to the hot drying plate, so that every place of the corrugated paper can be heated evenly. Whether the hot plate is deformed, sunken or protruded, the spring with balanced elasticity always sticks the pressing plates to the hot plate along with the sunken or protruded hot plate. Even if the core paper with poor quality is used, it will not flatten the ridge shape, and has high heating efficiency, fast gelatinization speed, no degumming, no foaming and good fitting of the paper plate. The produced paperboard is flat, hard and has good compressive strength. According to the test, the heat transfer efficiency of the hot plate after refitting the hot plate is much higher than that of the traditional roller type. Of course, the speed of the paperboard after entering the drying plate section is also greatly improved. In addition, each hot plate is provided with a group of hot pressing plates that can control the lifting and lowering independently, and each group of hot pressing plates can be controlled independently. It can freely choose to rise or fall according to different vehicle speeds and temperatures. It can automatically (PLC control) or manually control the lifting and lowering, which is very simple and convenient to use

several equipment configurations to reduce waste of base paper

for the medium and low speed production lines manufactured before, the collet of the base paper rack is generally a hexagonal cone collet, which will break the base paper tube and inner paper edge during use, making the paper tail difficult to use, resulting in waste of raw materials. However, most of the current medium and high-speed lines use the internal expansion collet, which has a simple structure and does not need power assistance. The collet convex strip shrinks or relaxes with the horizontal movement of the base paper frame, and expands automatically in the paper cylinder to fix the base paper. In this way, the disadvantage of the conical collet supporting the tail paper is solved, and the utilization rate of the tail paper is improved

for the high-speed production line now manufactured, it is equipped with stable performance and high speed

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