How to control the water content in corrugated board production process?
In the production process of corrugated board, the moisture content not only seriously affects the hardness and level up degree of the board, but also affects the subsequent printing, tile mounting and die cutting. Therefore, if the control of corrugated board moisture content, is a very important and technical content is quite high things.
Main Factors Affecting Water Content
Corrugated board production process is relatively complex, its water content is affected by many factors, can be summarized as the following:
1) Moisture content of base paper used in the production of paperboard Corrugated Cardboard Line
According to the provisions of national standards, the delivery of the water content of the base paper is generally 6% ~ 10%, the moisture content of base paper will directly affect the production process of corrugated cardboard and its moisture content is in line with the production requirements.
2) Drying at the preheating drum
The role of preheating drum is mainly to make the water in the production of the base paper evaporation, and make its water uniform, it played a role in regulating the water base paper.
3) Properties of paper materials and glue
If some of the core paper or corrugated fiber organization loose, or poor adhesive glue, the high moisture content of cardboard.
4) the influence of the drying and Corrugated Packaging Machine cooling process after the paperboard bonding
Drying oven temperature is low, production speed, corrugated board heat absorption is insufficient, drying slow, moisture content is high, so that the paperboard adhesive gelatinization and curing incomplete, reduce strength; Otherwise, the moisture content is low.
5) Impact of the production environment
Mainly including the production workshop temperature, humidity and ventilation effect.
6) Impact of the circulation environment
Corrugated box in the use of the process is very easy to be affected by the circulation of environmental moisture and temperature will be a direct impact on the water content of corrugated box, and then affect the performance and service life of corrugated boxes.
Water Content Control Methods
The intensity of corrugated board Corrugated Machine directly affects the compressive strength of corrugated box. Excluding the factors that influence the strength of corrugated base paper, the key factor is the control of moisture in the production of corrugated board.
For corrugated board water content control, should focus on the following aspects of control:
1. Corrugated base paper into the plant when the water content should be strictly in accordance with the standard GB462 inspection;
2. The storage temperature of corrugated base paper should be controlled at room temperature, the relative humidity is not more than 70%.
3. Corrugated base paper should be stored vertically stacking, the ground should be moisture-proof treatment;
4. Corrugated medium storage time should not be too long.
Note
1. If the cardboard moisture is too high, preheating roller temperature can not meet the requirements, to increase the boiler steam pressure, so that the steam supplied to the saturated steam, under normal circumstances, the steam pressure should be maintained at 1.1Mpa ± 0.2Mp;
2. If the water is low, it is necessary to adjust the paper guide roller, reduce the preheating area, while making full use of the single-side machine spray device (wet roller), spray on the base paper, increase the moisture of the base to meet the standard requirements;
3. Flat dryer at work, less than a last resort, can not stop. Single-sided confidential before the replacement of the original paper should speed up, increase the amount of accumulation on the bridge; After receiving the signal, the composite machine should slow down and wait for the single-sided machine to finish the paper. If the equipment failure must stop, the Conveyor Belt should be lifted to prevent excessive moisture loss of cardboard on the flat dryer;
4. For single-sided machine, to adjust the cots and scraping cots gap. Under normal circumstances, on the cots and scraping cots gap of 0.2mm a 0.25mm, coated cots with the main corrugating roller in the thermal state of the gap should be 0.02mm greater than the thickness of corrugated paper used. For the double-sided machine, the gap between the scraping cots and the cots is 0.2mm to 0.25mm, The gap between the roller and the cots should be smaller than the height of the single-sided corrugated board by 0.05mm a 0.1mm, and the gap at both ends of the roller should be consistent, can be measured with feeler gauge.
