The flatness of corrugated cardboard is one of the important indicators in carton production technology, and it is directly related to the quality of product printing, die cutting or slotting. So what is the reason for the flatness of corrugated board? Xiaobian analyzes this problem.

The main reason affecting the flatness of cardboard

1. Different types and grades of lining paper. There are imported, domestic kraft paper, imitation kraft paper, corrugated paper, tea board paper, high-strength corrugated paper, etc., and are divided into A, B, C, D, E, and grades. According to the poor quality of the paper, the surface paper is generally better than the inner paper.

2. The main technical parameters of lining paper are different. From the perspective of carton performance requirements or the user's consideration of cost reduction, it is required that the surface of the carton is different, usually:

The paper has different basis weights. There are papers with a larger basis weight than the inner paper, and some smaller ones.

The moisture content of the paper in the tissue is different. Depending on the environmental humidity of the supplier, transportation inventory, etc., some tissues have a higher moisture content than a lining paper, and some have a lower moisture content.

The basis weight and moisture content of the paper are different. One is that the basis weight of the tissue paper is greater than that of the lining paper, and the moisture content is greater than or less than that of the lining paper. Second, the basis weight of the top paper is smaller than that of the inner paper, and the moisture content is greater than or less than that of the inner paper.

3. The moisture content of the same batch of paper is different. The moisture content of one part of the paper is greater than that of the other part of the paper or roll paper. The moisture content of the core side is different.

4. Improper selection and adjustment of the length of the heating surface of the (wrapped angle) of the paper preheater or the length of the (wrapped corner) cannot be arbitrarily heated, which affects the preheating drying effect.

5. The steam spray device cannot be used correctly or there is no spray device on the equipment, so the humidity of the paper cannot be increased arbitrarily.

6. After the paper has been preheated, the time for dissipating moisture is insufficient or the environmental humidity is high, the ventilation is poor, and the production line speed is inappropriate.

7. Inappropriate and uneven glue application of single-sided corrugator and gluing machine leads to uneven shrinkage of imported cardboard.

8. Insufficient and unstable steam pressure, damage to accessories such as traps, or draining of water in the pipeline causes the preheater to fail to work normally and stably.