Carton compressive strength is the most important quality index required for many commodity packaging. During the test, the corrugated carton is placed between two pressure plates, and the pressure when the carton is crushed is the compressive strength of the carton, expressed in KN.

1) Quality of raw materials

The base paper is the decisive factor in determining the compressive strength of the carton, which can be seen from the kellicutt formula. However, the influence of other conditions in the production process of corrugated board cannot be ignored, such as the amount of adhesive, the change of flute height, impregnation, coating, and composite processing.

2) Moisture

carton made of corrugated cardboard with too high moisture content, or stored in a humid environment for a long time, will reduce its compressive strength. Fiber is a kind of strong water absorption. In the rainy season and when the humidity in the air is high, the moisture balance between the moisture in the cardboard 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, they have a significant impact on the compressive strength. Some cartons are made of double-layer corrugated cardboard, and their compressive strength is significantly higher than that of single-layer boxes of the same specification; under the same conditions, the higher the box, the worse the stability and the lower the compressive strength.

4) Printing and perforation

Printing will reduce the compressive strength of the carton. For products that require ventilation, opening holes on the surface of the box or punching the handle holes on the side of the box will reduce the strength of the carton, especially when the opening area is large, and the effect is more obvious.

5) Process deviation

In the process of box making, improper wire crimping, deep grooves, weak bonding, etc. will also reduce the compressive strength of the box.