When the vacuum pressing roller absorbs moisture from the paper, the relatively high humidity reduces the lubrication effect of the bearing

(1) The operating temperature at the bearing position of the press roll is high; during normal production, the bearings operate in a sealed environment at relatively high temperatures, Consequently, all bearing components undergo thermal expansion, making them more susceptible to the ingress and adhesion of material. This increases the running resistance of the rolling elements, causing small pitting or pitted spalling on their surfaces; the spalled metal then adheres to the raceway surface, leading to surface roughening.
(2) When vacuum press rollers absorb moisture from the paper, the humidity is high. If the seals are not tight, paper fibres splashed during production can penetrate the bearings and cannot be removed. These fibres enter the ball bearings, reducing lubrication effectiveness and increasing rolling resistance, which causes friction against the inner ring. This leads to thermal expansion of the inner ring, creating gaps and resulting in wear.
(3) During prolonged operation, the bearings and bearing seats undergo a certain degree of fatigue deformation due to the inherent properties of the metal. This prevents the required interference fit from being maintained during installation, resulting in insufficient preload. Consequently, the inner ring rotates relative to the housing, causing wear to the bearing seat.
The above outlines some of the causes of wear on vacuum press rolls. We trust that you now have a better understanding of the issue. Therefore, when using vacuum press rolls, it is essential not to neglect routine maintenance and care. This will help extend the service life of the vacuum press rolls, improve dewatering efficiency, enhance sheet quality, and minimise the adverse effects of pressing on the paper sheets.