The principle of dispersant is to distribute solid tiny particles as evenly as possible in another incompatible material. It refers to a coarse dispersion system composed of insoluble particles distributed in the outer phase of liquid or semi-solid. Dispersant can make the solid dispersed particles in the suspension fully wetted and evenly dispersed by the liquid phase, and reduce the separation, aggregation and sedimentation rate of solid particles in the system to a minimum to maintain the maximum dynamic stability of the suspension. Commonly used dispersants are surfactants.
In the papermaking process, paper fibers and fillers in the pulp are hydrophobic and tend to flocculate into agglomerates, and it is often difficult to produce paper with uniform performance and strength that meets the requirements. An additive needs to be added to increase the viscosity of the pulp to facilitate the uniform dispersion of fibers and fillers, so that the paper is uniform, smooth, flexible and without holes, so that the papermaking performance is stable, and it is not easy to break the paper and powder during papermaking. At the same time, it can improve the tensile strength and dry and wet strength of paper products and save pulp. This additive is called a papermaking dispersant.
Papermaking dispersant is an economical and effective additive to improve paper uniformity. In the paper production process of the papermaking industry, the fibers and fillers in the pulp suspension are hydrophobic and tend to flocculate into agglomerates, reducing the uniformity of the paper and increasing losses. Adding papermaking dispersant can form an electric double layer on the surface of solid fibers. The outer layer of dispersant and water form a thick hydration layer, which increases the charge repulsion between solids, improves the solid phase dispersion effect, effectively prevents the agglomeration of fibers, and improves the quality of paper. Uniformity. Papermaking dispersants can show good fiber dispersion effects with a very small amount of addition (less than 1kg per ton of absolute dry pulp).
The characteristics of papermaking dispersants are explained as follows:
- When used in papermaking coatings, papermaking dispersants have high dispersion efficiency, stable coating viscosity, less foam, non-toxic and non-corrosive, can increase the solid content of coatings, have good fluidity and scrub resistance, and can maintain paper High quality gloss, not easy to get moldy.
- Papermaking dispersants can also increase papermaking speed, save beating time, reduce energy consumption, and have significant economic benefits.
- Papermaking dispersants have fast dissolution speed, high viscosity, low water-insoluble content, and are easily degraded at high temperatures. They promote the dispersion of fibers, especially long fibers, and are suitable for high-speed paper machine production to ensure low paper basis weight, thin paper pages, soft and uniform paper, etc. .