Solution to Incorrect Control of Water Content in Corrugated Board (2)

After entering the dryer, first of all to ensure that the paste paste, and then according to the size of the water content, adjust the pressure reducing valve, so that it has the right temperature, so as to obtain the appropriate moisture content. Of course, the length of the cooling section of the dryer also affects the moisture content of the board. When the cooling section is too short, the water can be blown with a hair dryer if it cannot be distributed in a timely manner.

When the temperature adjustment fails to meet the desired requirements, it can be adjusted by changing the speed of the vehicle. If the water content is too high, you can slow down the car; when the water content is too low, you can increase the speed.

When the dryer is working, there is no last resort and no parking is allowed. When the front single-sided machine to replace the paper roller, before the roll change single-sided machine can be a little faster sports car, accumulating part of the single-sided cardboard on the flyover, the dryer received a paper change notification, you can run at a reduced speed, if the drying When the dryer stops, all the cardboard water on the dryer evaporates, causing the cardboard to be scrapped.

Affecting the temperature of the cardboard production line, in addition to whether the saturated steam supplied by the boiler reaches the specified pressure, the hydrophobic device of the steam piping system is also very important. Because the raw paper and single-sided paperboards pass through the preheaters, they need to take a lot of heat, and some of the saturated water vapor turns into condensed water. This part of the condensed water must be discharged in time, otherwise it will affect the preheating effect of the preheater.

Solution: If the preheating roller of the rotary steamer is used, a temperature paper or a temperature difference of more than 5°C at both ends indicates that the suction pipe is damaged or the mounting position is incorrect, and it should be disassembled for maintenance.

The trap is 2 to 3 times more hydrophobic than the condensate. If the amount of trapped water is not sufficient, the trap should be changed.

Check the drain outlet of the trap every week and clean it if it is clogged.

The quality of the paste, the size of the water, and the thickness have a great influence on the water content of the board.

If the paste has a large amount of water, a thin paste, a fast penetration, the water content of the cardboard is high. Conversely, the water content is small.

The solution is: strictly follow the times and ratio of the paste water and the mixing time to paste, master the viscosity of the paste. The viscosity of a general single-sided machine is 50 to 60 seconds, and that of a double-sided coating machine is about 100 seconds, and the double-sided coating machine should use the fresh paste made on the day. Only the production of good paste can produce qualified cardboard.

The amount of top paste affects the moisture content of the board

When the paste is the largest, the water content of the board is large, and the amount of water on the top of the board is small.

The processing method is as follows: For a single-sided machine, adjust the gap between the rubber roller and the rubber roller, the rubber roller and the main corrugating roller. Under normal circumstances, the gap between the rubber roller and the rubber roller is 0.2 to 0.25 mm, and the gap between the rubber roller and the main corrugating roller is generally 0.1 to 0.2 mm. Measured with a feeler gauge, both ends must be the same.

The gap between the squeegee and the squeegee of the double-sided gluing machine is 0.2 to 0.25 mm. The gap between the press roll and the top roll should be 0.05 to 0.1 mm lower than the height of the single-sided corrugated cardboard that is passed. The measurement method is to use a feeler gauge to measure the data at both ends. Whether it is a single-sided machine or a double-sided gluing machine, the width of the corrugated cardboard glue line produced is generally 1.5 to 2 mm.

As the rubber roller surface damage or foreign body caused uneven gluing, affecting the cardboard moisture uneven

The solution is: if the roller surface is worn or damaged, replace the rubber roller as soon as possible. If there is any foreign matter, it should be stopped immediately. All the rollers need to be cleaned every day after work, and foreign objects should be removed with a soft brush.

If the dryer conveyor belt is poor in breathability, or if water is sprayed on the conveyor belt at random, the water content of the board can be increased. The solution is: to analyze the cause of poor air permeability of the conveyor belt. If there is waste paper stuck, stop it immediately to clear it. If the big belt is used for a long time, it is necessary to replace the new belt. Do not spray water on the conveyor belt during use.

If there are too many single-sided paperboards on the single-sided conveyor belts on the flyover, the time is long and the water is distributed more, it is easy to cause the water content of the paperboard to be low.

The solution is: All operating stations across the board should always contact each other and take care of each other. The speed of operation should generally be unified. The storage capacity of the single machine board on the conveyor belts of each single-sided machine on the flyover can best account for 2/3 or 3/4 of the length of the conveyor belt.

Climate and environment will also have an effect on the moisture content of the board

In the high temperature and rainy season, the relative humidity is high, the flowability of the winter paste is poor, and the amount of upper paste is small, which will affect the moisture content of the cardboard.

The solution is: In the season with high temperature, increase the thermal area, reduce the spray, reduce the moisture content of the paste, increase the temperature, and make full use of the preheat roll to adjust the moisture content.

In short, there are many factors that affect the water content of the board, which requires the operator to strengthen their sense of responsibility. Everyone must do his or her own job. Carefully observe and carefully adjust to produce a qualified corrugated board.