The production process of corrugated cardboard is relatively complex, and its moisture content is affected by many factors, which can be summarized as follows:
1) The moisture content of the base paper used in the production of cardboard
According to the provisions of the national standard, the moisture content of the delivery state of the base paper is generally 6% ~ 10%, and whether the moisture content of the base paper is up to standard will directly affect the production process of corrugated cardboard and whether its moisture content meets the production requirements.
2) Preheat the tumble for drying
The function of the preheating drum is mainly to evaporate the moisture in the base paper put into production and make it uniform, and it plays a role in regulating the moisture of the base paper.
3) Characteristics of paper raw materials and glues
If some core paper or corrugated paper has loose fiber tissue, or the glue is poorly sticky, the paperboard has a high moisture content.
4) The impact of the drying and cooling process after cardboard bonding
When drying, the oven temperature is low, the production speed is fast, the heat absorbed by the corrugated cardboard is insufficient, and the drying is slow, the moisture content is high, so that the gelatinization and curing of the cardboard adhesive are incomplete, and the strength is reduced;
5) The impact of the production environment
It mainly includes the temperature, humidity and ventilation effect of the production workshop.
6) The impact of the circulation environment
Corrugated boxes are very susceptible to the influence of the circulation environment during use, and the moisture and temperature of the circulation environment will have a direct impact on the moisture content of the corrugated boxes, which in turn will affect the performance and service life of the corrugated boxes.
How the water content is controlled
The strength of corrugated cardboard directly affects the compressive strength of corrugated boxes. In addition to the factors affecting the strength of corrugated cardboard, the key factor is the control of moisture in the production process of corrugated cardboard.
For the control of corrugated cardboard moisture content, the following aspects should be controlled:
1. The moisture content of corrugated base paper entering the factory should be inspected in strict accordance with GB462 standard;
2. After entering the factory, the storage temperature of corrugated base paper should be controlled at room temperature, and the relative humidity should not be more than 70%;
3. The storage of corrugated base paper should be stacked vertically, and the ground should be treated with moisture-proof;
4. The storage time of corrugated base paper should not be too long.
