1）Quality of raw materials
Base paper is the decisive factor to determine the compression strength of cartons, which can be seen from the kellicutt formula. However, the influence of other conditions in the production process of corrugated board can not be ignored, such as the amount of adhesive, the change of corrugated height, impregnation, coating, composite processing and so on.
2) Moisture content
If the carton is made of corrugated board with high water content, or stored in humid environment for a long time, its compressive strength will be reduced. Fiber is a kind of water absorbent, in the rainy season and when the humidity in the air is high, the moisture balance between the paperboard and the atmospheric environment is very important.
3) Box type
Box type refers to the type of box and the size ratio of the same type of box, which has a significant impact on the compressive strength. Some cartons are made of double-layer corrugated board, and their compressive strength is significantly higher than that of single-layer cartons of the same specifications; under the same conditions, the higher the box is, the worse the stability is, and the lower the compressive strength is.
4) Printing and opening
Printing will reduce the compressive strength of the carton. For goods with air permeability requirements, opening holes on the box surface or punching handle holes on the side of the box will reduce the strength of the carton, especially when the opening area is large and tends to one side.
5) Process deviation
In the process of box making, improper line pressing, too deep slotting and loose combination will also reduce the pressure strength of the box.