Optimize the selection and maintenance of press felt
Select suitable press felt, considering factors such as the compression, moisture content, and air permeability of the press felt to meet the needs of paper production. Regular cleaning and maintenance of the press felt to maintain good water filtration and air permeability can effectively extend the service life. (It should be noted that the needle punched press felt is thick and flat, and not easy to bend. The tension of the new press felt should not be too tight after it is put on the machine. The press felt should be evenly moistened first and then allowed to shrink naturally. It should be idle for 10 minutes to allow the press felt to be fully hydrophilic and remove a small amount of floating hair. In addition, before paper making and pulping, the press felt should be appropriately tensioned and kept loose. The cutting machine should not be tensioned, otherwise the lateral contraction of the felt will cause the mesh of the base cloth to deform and the water filtering effect will be poor.)
Adjust the pressing device and parameters
(1) According to the quantitative, pulp ratio, beating degree and other factors of the paper, select a suitable pressing device, such as ordinary pressing, vacuum pressing or groove pressing; ensure that the number, type, structure and other types of the pressing device meet the production requirements to improve the pressing dehydration efficiency.
(2) Dehydration control is performed by changing the line pressure and vehicle speed to achieve the best pressing effect. According to the equipment and paper characteristics of the pressing section, the pressure distribution of the pressing section is adjusted to ensure uniform pressing process.
Control the water temperature and paper temperature of the press section
Appropriately increase the water temperature and paper temperature of the press section to reduce water viscosity, improve water fluidity, and facilitate pressing and dehydration. (Note that the water temperature should not be too high, otherwise it will lead to a decrease in paper quality and even damage to the press section equipment)
Reduce the rewetting effect
During the pressing process, minimize the contact time between the paper and the press felt to prevent water from returning to the paper through capillary action or internal vacuum of the paper. Separate the paper from the press felt as soon as possible at the press outlet to reduce the rewetting effect.
Optimize the dehydration stage of the press section
According to the dehydration principle of the press section, reasonably divide the dehydration stages, and take corresponding measures to improve the dehydration efficiency of each stage. (Example: In the air exhaust stage, it is necessary to ensure that the paper sheet and the press felt exhaust air together. Until the paper sheet reaches saturation, in the dehydration stage, gradually increase the pressure to further remove moisture)
Measures to improve the dehydration of the paper machine involve optimization of the structure and operation of the press section, improvement of the dehydration efficiency of the press section, and strengthening of the operation management of the paper machine. The implementation of these measures can effectively improve the dehydration efficiency of the press, reduce the evaporation load of the drying section, and thus improve paper quality and production efficiency.