Constant pressure and low-temperature corrugated board production technology are cutting-edge and practical process technology at the current operational level. It plays a prominent role in saving energy and raw powder costs, improving the physical properties of cardboard, and improving the working environment. In the actual operation process, some corrugated paperboard manufacturers are not sure about the production technology of constant pressure and low-temperature corrugated paperboard, can’t understand it, lack confidence, and do not high or low.
Control Points in the Production Process of Constant Pressure and Low-Temperature Corrugated Board
Corrugated cardboard production enterprises belong to the second-level factories in the paper packaging industry. The upstream paper mills “are at the top of the industry chain, and the carton factories with a particular fixed downstream face the end customers, covering a wide range. But in between. The status of the cardboard production enterprises in China is embarrassing, and the living environment is worrying. Especially in recent years, the continuous implementation and tightening of domestic environmental protection policies have led to increased environmental protection costs:
- At the same time, the industry has overcapacity.
- Market supply exceeds demand.
- Profits are under significant pressure.
Facing the problematic operating situation, many domestic cardboard production companies try their best to maintain their operations. For example, they are introducing more sophisticated, high-tech, and more comprehensive production lines. Improve efficiency and reduce losses by upgrading equipment. For instance, it extends to the downstream of the industrial chain and makes up for losses by adding carton workshops. The production enterprise is in the specific cardboard production operation technology. They will also use Constant pressure and low-temperature production technology to improve efficiency and reduce costs.
Under the current situation, the constant pressure and low-temperature production technology is the most cutting-edge and most practical technology at the operational level.
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Control the balance of moisture
Facing the problematic operating situation, many domestic cardboard production companies try their best to maintain their operations. For example, they are introducing more sophisticated, high-tech, and more comprehensive production lines. Improve efficiency and reduce losses by upgrading equipment. For instance, it extends to the downstream of the industrial chain and makes up for losses by adding carton workshops. The production enterprise is in the specific cardboard production operation technology. They will also use Constant pressure and low-temperature production technology to improve efficiency and reduce costs.
Under the current situation, the constant pressure and low-temperature production technology is the most cutting-edge and most practical technology at the operational level.
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Control the paper surface temperature at the moment of lamination
The question is, how to balance the moisture balance? It involves the second key factor in cardboard production: temperature. In the cardboard production process, the weather has two effects: one is to gelatinize the paste, and the other is to dry the cardboard. The maximum temperature of the paste is 58 ± 2C. From this perspective, cardboard production does not require too high temperatures. However, it cannot ignore that the weather also needs to play a role in drying the cardboard.
What factors does the temperature required for drying depend on?
As mentioned above, it is reasonable to control the moisture content of the base paper at 8% soil two, and there is no need to increase or decrease it. Therefore, we need to control the moisture content in the paste. In the paste, 70% to 80% is water, so there is a saying that the paste is as good as the water. To some extent, as long as it can control the amount of paste, it can retain the moisture. In other words, whoever can use the least amount of paste to achieve the best bonding effect is likely to control the temperature of corrugated cardboard production to the lowest.
So this is an essential link in the production of constant pressure and low-temperature corrugated cardboard. The purple paste produced can achieve low refining temperature, good penetration, strong refining power, and quick drying. The continuous stress and low-temperature production have material protection. How strong this guarantee is, the low temperature of the constant-pressure low-temperature tile bridge board production technology can be as low as possible. Therefore, the formula for making pulp shed should include a gelatinizing agent, oxidizing agent, crosslinking agent, penetrating agent, quick-drying agent, and tackifier.
As you can see from the previous article, as long as the temperature can reach the gelatinization point, most of the colleagues think it is impossible in actual operation. That is because there is the cognition to penetrate the temperature of the fit. The bonding temperature refers to the paper surface temperature of the corrugated cardboard when several layers of base paper are bonded. As long as it reaches about 65, the paste will gelatinize, sticky, and easy to penetrate. The only problem behind it is drying.
The author emphasizes again that the keyword is “paper temperature at the moment of the fitting.”
In fact, in production, most of the temperature of the single sizeable preheating cylinder is wasted. You can measure it: What is the weather of the plain paper. When it comes out of the large preheating cylinder. What is the temperature before entering the next heating cylinder? The temperature difference in the middle is the loss.
From the size of the lost part of the temperature. We can determine that the sizeable preheating cylinder does not have too high steam pressure. When the base paper of low gram weight is used for production. The high lamination temperature will cause the water loss of the base paper to be significant. And the amount of paste will be small. The water in the paste will evaporate before it reaches a good penetration. But it is easy to bond poorly and increase Powder consumption.
Therefore, in the constant pressure and low-temperature corrugated board production process, the control of the bonding temperature must be just right. If the small hot cylinder before bonding can increase the paper surface temperature to the bonding temperature value, then the sizeable hot cylinder does not require temperature. Of course, in areas with low climate temperature and high-weight cardboard, the steam pressure of the sizeable preheating cylinder can increase according to the situation. The purpose is to increase the surface temperature of the base paper before lamination so that it can pass through the small heating cylinder before lamination when the paper surface temperature can meet the temperature requirements of the lamination.
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The tension should be a little bigger
Finally, let’s talk about tension. In the production process of corrugated board, the stress follows the principle of balance. If it doesn’t control correctly, it is easy to cause the phenomenon of collapse, skipping, shattering, and pitting. In particular, the tension control of the crossover corrugated paper and face paper during the double-layer pasting machine is easy to cause the cardboard to bend, wrinkle, to pit, and even misalignment of the paste line and poor bonding if the control is not reasonable.
In the process of constant pressure and low-temperature corrugated board production, it is recommended that the tension should be slightly larger, which is more conducive to the increase of the temperature of the paper surface and the shaping of the board. At present, the control of tension is intelligent and automatic, so it will no longer focus on it.
In short, colleagues should pay attention to control during the production process: the three significant productions of moisture, temperature, and tension must be made in exceptional teaching shed, paste the weather and the amount of paste. Keep improving on this basis. I believe there will be significant gains.
Reasons and solutions for the different lengths of corrugated cardboard when cut out
The length accuracy of corrugated cardboard is critical. If the length of the cardboard is different, it will affect the production size of the carton. At the same time, it will also affect the production cost of cardboard. So the cutting length accuracy of cardboard is critical, so what causes the varying cutting length?
Cause Analysis:
(1) The speed of the dryer is unstable;
(2) There is paper wool between the gears of the cross cutter, or the gears and bearings are damaged:
(3) The running resistance of the flyover single-sided cardboard is too large;
(4) The brake tension of the tissue paper is too large;
(5) The conveyor belt of the dryer is slipping;
(6) The meshing gap of the infinitely variable gear of the crosscutting machine is too large, or the rotating chain is aging and loose.
(7) The crosscutting control program does disorder and interfere with a strong magnetic field.
Solution:
(1) Check whether the main motor of the dryer lacks phase, whether the voltage is stable, and whether the bearing is damaged;
(2) Remove the paper scraps between the rotating gears of the root cutter and replace the gear bearings;
(3) Add lubricating oil or replace bearings for slight rotation of the paper guide rollers of the flyover, and appropriately adjust and control the vacuum suction air volume of single-sided paper:
(4) Reduce the braking force of the facial tissue;
(5) Correct the gap between the continuously variable gears, replace the new chain or adequately adjust the chain and fastening device;
(6) Eliminate magnetic solid field interference.
How do ordinary printing machines print high-quality carton products?
Printing quality is a major technical problem in the process of carton processing. How to print high-quality carton products with ordinary brushing machines mainly depends on the following three aspects.
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The selection of plates
The printing plates of corrugated boxes mainly include flexographic plates and rubber plates. Which flexographic plates and rubber plates are the most widely used. The flexo plate made soft plastic material. Which has the advantages of smooth texture, high printing resistance, clear text and graphics, and poor damage to corrugated cardboard. Therefore, after receiving an order for printed products. According to the actual situation, ordinary cartons with high requirements for small batches are generally selected for offset printing to achieve economic and practical purposes.
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The adjustment of the gap
This is a crucial issue to ensure the quality of printing. Due to improper adjustment of the holes of the printing plate, printing pressure, etc., quality defects such as thicker lines, enlarged dots, blurred writing, edge ghosting, dirty edges, solid white, overprint deviation, etc., appear. This requires the operator to adjust each gap’s size based on the plate’s actual thickness.
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The use of guide bars.
Offset strips or die-cut elastic strips play a vital role in printing, especially in applying small specifications and small printing areas. It is an effective method to solve inaccurate overprinting and misalignment of printing and cutting. The length of the guide strip should be equal to or greater than the width of the cardboard. Paste the guide strip on both sides of the printing plate and print it outside the cutting edge of the cardboard. This can make the cardboard be controlled throughout the printing process, effectively avoiding inaccurate overprinting and printing and cutting. They are not allowed to wait for the occurrence of problems.