The big factor in the flatness of corrugated boxes

　　The primary reason for the flatness of corrugated boxes

　　1, corrugated boxes are of different types and grades. There are imported, domestic kraft paper, imitation kraft paper, corrugated paper, teaboard 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 lining paper.

　　2, corrugated boxes The main technical parameters are different. From the carton function requirements or the user's consideration of cost reduction, the paper boxes are required to have different surface and paper, usually: corrugated boxes with different quantitative. There are corrugated paper boxes, and some have a larger basis weight than inner ones, and some have smaller ones. Corrugated boxes have different moisture content. Depending on the environmental humidity of the supplier, transportation inventory, etc., there are corrugated paper boxes that have higher moisture content than inner paper, and some have 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. The second is that the basis weight of the top paper is smaller than that of the lining paper, and the moisture content is greater than or less than that of the lining 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 between the two ends, the outer edge side and the inner side of the paper; the core side has a different moisture content.

　　4. The length of the (wrap angle) heating surface of the paper preheater is not properly selected and adjusted or the length of the (wrap angle) is heated and the length cannot be arbitrarily, which affects the preheating and drying effect.

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

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

　　7, single-sided corrugating machine and gluing machine have improper or uneven gluing amount, leading to uneven shortening of cardboard.

　　 8. The steam pressure is insufficient, unstable, the traps and other fittings are damaged, or the water in the pipeline is drained, which causes the preheater to fail to operate normally and stably.