The term “wet end chemistry” is a special term in the papermaking process. It is usually used to describe the various components (such as fibers, water, etc.) , fillers, chemical additives, etc.) the law of interaction and action.
On the one hand, wet-end chemistry can be used to enhance drainage, reduce air ingress and eliminate foam, keep paper machines clean, and keep white water low in solids; on the other hand, if these factors get out of control, the same wet-end chemistry can Make the paper machine run abnormally, produce spots and air bubbles on the paper, reduce water drainage, make the paper machine unclean, and reduce production efficiency.
It is mainly manifested in the following aspects:
1) Drainability of slurry
Drainability is an important performance in paper machine operation. The degree of water drainage of the paper web will be affected by the flocculation between fibers and fibers and between fine fibers and fine fibers. If the flocs formed are large and porous, the pulp will become viscous and hinder the passage of water, thereby reducing water drainage.
2) Precipitation and scaling
Sedimentation and fouling often occur when wet end chemistry is out of control, excessive use of common chemical additives, charge imbalance, chemical incompatibility, and unstable chemical balance, etc., all of which can lead to sedimentation and fouling in paper machines. Dirt, there are many ways to clean up sediment and dirt, but the best way is to find out the cause of the out of control and correct it.
3) Foam formation
Wood fibers contain substances that stabilize air into the pulp (and certain chemical additives do the same), reducing the drainage of the pulp, causing stickiness and foam. If it occurs, the best way is to find the root cause and eliminate it. If this is not possible, mechanical and chemical methods can generally be used to eliminate it. At this time, the role of wet end chemistry is less.
Post time: Mar-15-2023