The effect of pulp concentration on paper basis weight of paper machine

The effect of pulp concentration on paper basis weight of paper machine

      The instability of the slurry concentration will inevitably affect the fluctuation of the paper weight of the paper machine. In severe cases, it will cause the paper machine to break and fail to make normal papermaking. The instability of slurry concentration is affected by several factors:

1) Change in concentration of puree

The consistency of the slurry sent from the pulping workshop is changing. When concentrating, there is no necessary adjustment according to the change of the concentration, which will directly affect the change of the pulp concentration.

2) Concentration adjustment of beating process

In the beating process, the slurry has to go through the processes of concentration, beating, and mixing, etc., during which necessary concentration adjustments must be made. Some of the density adjustment methods are controlled by automatic regulators, while manual adjustment is more common. Due to unskilled technical operations, weak sense of responsibility or failure of automatic control, etc., it is easy to cause changes in slurry concentration.

3) Change in concentration of lost pulp

Generally, the broken paper that is copied back is firstly treated by a hydraulic shredder, and then through a broken paper thickener to reach a relatively stable concentration, and then diluted with water to the concentration required by the process. In this process, due to the large changes in the concentration of broken paper, during dehydration and dilution, the above reasons will also cause changes in the concentration, which will affect the entire slurry system.

4) The influence of the instability of the white water system

In order to reduce water consumption and fiber loss, the white water of general paper machines is fully utilized. One of them is used as dilution water for beating. Therefore, whether the white water system reaches equilibrium and whether the pressure and flow rate of the white water are stable will directly affect the dilution of the slurry, that is, the concentration of the slurry.