The surface smoothness of corrugated cardboard is poor, which can be roughly divided into three types: horizontal arch, longitudinal arch and arbitrary arch.
The transverse arch refers to the arch formed along the wave direction. Longitudinal arch refers to the arch formed by the cardboard in the direction of the production line speed. Arbitrary arches are arches that undulate in any direction. The following Suzhou carton manufacturers will introduce the main reasons that affect the flatness of cardboard:
1. Different paper types and grades. Carton packaging includes imported, domestic kraft paper, imitation kraft paper, corrugated paper, tea board paper, high-strength corrugated paper, etc., and is also divided into A, B, C, D, E, grades. Face paper is better than backing paper due to poor paper quality.
2. The main technical parameters of the backing paper are different. Considering the performance requirements of the carton or the cost reduction of the user, the paper in the carton is required to be different. usually:
There are different amounts of paper in the flour. The face paper is larger than the backing paper, but also smaller. The moisture content of the backing paper varies. Due to the different humidity levels in supplier and shipping stocks, face paper has a higher moisture content than backing paper, and it is also less. The amount and moisture content inside the paper vary. First of all, the quantity of the face paper is larger than that of the backing paper, and the moisture content is larger than that of the backing paper or less than that of the backing paper. The second is that the quantity of the surface paper is smaller than that of the lining paper, and the moisture content is larger than that of the lining paper or smaller than that of the lining paper.
3. The moisture content of the same batch of paper is different. The moisture content of a part of the paper is higher than that of another part of the paper or the carton packaging. The outer edge and inner core have different water content.
4. The length of the heating surface of the paper heater cannot be adjusted arbitrarily. The former is improperly operated, and the latter is limited by the equipment, which affects the preheating and drying effect.
5. It is impossible to use a steam spray device or equipment, and there is no spray device, so that the humidity of the paper cannot be increased arbitrarily.
6. After preheating, the moisture from the paper is not enough or the ambient humidity is high, the ventilation is poor, and the production line speed is improper.
7. The uneven shrinkage of the cardboard is caused by the improper and uneven glue loading of the single-sided corrugating machine and the gluing machine.
8. Insufficient steam pressure, instability, damage to parts such as water traps, and lack of drainage in the pipeline cause the preheater to not work normally and stably.