Cardboard moisture content is the key factor affecting the carton burst line. Paper is a hydrophilic material, water absorption will become soft and tough, water loss will become hard and brittle. When the moisture content of cardboard is low, the impact of moisture on the carton burst line is mainly manifested in two aspects: on the one hand, the face of the paper folding resistance decreased, the stiffness of the cardboard increased, the possibility of carton burst line increased: on the other hand, the core of the cardboard increased compressive strength, the face of the paper toughness decreased in the line of the pressure is easy to damage the face of the paper, resulting in the burst of cardboard boxes. Test data show that a face lining paper for 250g/m2 hanging boxboard, side pressure ECT for 9000N/m five-layer cardboard, moisture below 8%, the carton began to burst. The face of the lining paper to use folding performance is very good kraft containerboard, carton burst resistance improved significantly, but if its moisture content is less than 6% of the time, the carton began to burst. Therefore, it is very important to maintain the moisture content of cardboard to prevent the bursting of cartons. Corrugated surface, the folding performance of the paper itself also has an important impact on the burst line of cardboard. Generally speaking, the kraft card is more resistant to folding some of the hanging surface, coniferous wood pulp paper is more resistant to folding than broadleaf wood pulp paper, virgin pulp copied paper is more resistant to folding than recycled pulp copied paper. Carton mills can also prevent cartons from bursting to a certain extent if they can reasonably choose the paper they use according to the changes in weather and humidity. The greater the strength of the corrugated paper sheet, the greater the resistance to tension endured by the face lining paper in the press line molding process, the more likely to cause cardboard burst line. The more layers of cardboard, the more likely to burst line. Such as three pits of cardboard than double-pit cardboard is more likely to produce burst line, double-pit cardboard than single-pit cardboard is easy to produce burst line. With A flute cardboard hardness is higher than the cardboard without A flute, which is more likely to burst line. Printing slotting operation will also cause improper carton burst line. For example, the position of the upper and lower concave and convex rollers of the press line pressure device is deviated, and the strength of the pressure line is biased, which will cause the burst line. When there is a big difference between the grammage of the corrugated cardboard and the liner, the cardboard is prone to bursting, and the bigger the difference in grammage, the more likely the bursting will occur. Therefore, when matching paper, we need to pay attention to the balance of the grammage of the face and lining paper. The best way to control the bursting of cardboard is to maintain the moisture content of the corrugated cardboard. The moisture content of the corrugated board from the tile line should be controlled at 12 to 18%, and the moisture content should be kept at 10 to 13% during printing.