What are the factors that affect the paper humidity in the drying section of a paper machine?

Vacuum dryer is mainly used in high-speed paper machine. The main function of 1 and VAC cylinder is to change the drying part from the original upper and lower blankets to a bed. When running between two dryers, the dryer paper arranged in two layers is in an open state without any support. When the paper is wet, the strength of the paper is relatively small and it is easy to break. After arranging the vacuum rollers, the paper will always run with the blanket. Through entrustment, paper damage and paper diseases can be reduced. Generally speaking, when the speed of the cultural paper machine exceeds 400 meters, a vacuum cylinder will be set in front of the drying cadres. 2. Another advantage of the vacuum drum is that the paper is easy to handle when it is damaged. If paper breaks, the damaged paper of the two-layer dryer will fall between the blanket and the dryer, and sometimes it will be wound on the guide roller, thus damaging the blanket and being difficult to handle. After arranging the vacuum drum, the damaged paper directly falls to the ground, or can be directly transported to the pulper through the conveyor belt. Therefore, high-speed paper machines generally use single-row vacuum dryers.