Paper tension insufficient is divided into lengthways and crosswise, it is related to pulp speed ratio, fiber process ratio, and the binding force of the fiber.
1. The slurry speed ratio is the ratio of cylinder speed and pulp pump speed. The normal pulp ratio of paper machine is between 1:1.0-1:1.2, if the speed ratio is too large then longitudinal tension is big, transverse decrease, on the contrary, transverse tension is big and longitudinal is small, but can’t beyond certain range, or will get opposite effect.
2. The fiber orientation is the standard which decide the longitudinal and transverse tension, to control the fiber orientation through adjusting the reflux valve of headbox, maximum open degree and big transverse tension, small open degree and big longitudinal tension.
3. The binding force of fiber itself: The reasons to influence fiber’s binding force including hemicellulose, cellulose, lignin, the length of fiber, the use of chemical additives and auxiliaries, pressure from press part, dryer temperature and strength from fiber itself, fiber distribution and alignment in wet paper, etc.