The function and classification of the roll of Fourdrinier paper machine

The top roll of the paper machine is the last dewatering device in the Fourdrinier section. After the wet paper web passes through the vacuum suction box, it is further dehydrated on the flat roll to reach a certain degree of dryness and has sufficient wet strength to be smoothly peeled from the surface of the forming wire and transferred to the press section. The dryness of the paper web reaching the flat roller is generally 12%-18%, and the flat roller can increase its dryness to 18%-25%.

The flat roller is also a main driving point of the Fourdrinier section. This is the only driving point in a paper machine without a screen drive. When there is a screen drive roller, the drive is allocated to two parts: the flat roller and the screen drive roller, the flat roller is the auxiliary drive, and the screen drive roller is the main drive.

In terms of structure, the flat rollers are mainly divided into two categories: ordinary flat rollers and vacuum flat rollers. The old low-speed paper machine is equipped with an ordinary volt roller, and the wet paper web is pressed to reach a dryness of 15%-18% by mechanical pressing. In newly designed paper machines, vacuum rolls are commonly used. In recent years, a double-sided dewatering roll press has appeared in foreign countries.