Paperboard soft is a common problem of paper cotton thread, mainly including materials, starch paste degree, temperature, environmental humidity and other factors.
The quality of the material is the main reason. As the market competition becomes more and more intense, each manufacturer drives down the price to seize the market. Some factories use inferior raw materials to reduce the production cost. These low grams of raw paper are characterized by uneven thickness, minimal sizing, high sand content, and minimal toughness fibers. Instead of making high-quality cardboard, this material accelerates the wear of corrugated rolls.
2. Many people think that the starch paste is too thick and is very sticky, which is wrong. On the contrary, too thick or single, double-sided machine slurry is too large to cause the paper to be soft.
3. The production temperature of cardboard includes steam temperature and ambient temperature. Cardboard line usually steamed soup temperature in 165 ℃ ~ 185 ℃
When the speed is high, the temperature should be raised and the temperature should be lowered to avoid high temperature and low speed production. The temperature difference between the cardboard and the environment will cause the cardboard to absorb the moisture easily and become soft, especially the use of the uncoated paper.
4. Improper adjustment of pressure will also cause the cardboard to be soft. Attention should be paid to the clearance adjustment of the rubber roller and pressure roller and the high and low control of the hot bed pressure roller. When the pressure roll is set too low, it will cause the corrugated peak deformation to cause the paperboard to resist the pressure.