Application of Dispersant in Paper Industry

There are many problems encountered in the process of paper processing. Fibers, fillers, resins, and some additives are all water-insoluble, and they have a tendency to self-assemble in aqueous solutions; often due to incompatibility between different chemicals In this way, it is difficult to obtain a paper with uniform properties and ideal strength. The economical, reliable, and easy-to-operate method to achieve this goal is adding dispersants to the papermaking process.

dispersant is to distribute of fine solid particles in another incompatible material as evenly as possible. The dispersant can make the solid dispersed particles in the suspension fully wetted and evenly dispersed by the liquid carrier, and minimize the separation, aggregation, and settling speed of the solid particles in the system, to maintain the maximum dynamic stability of the suspension.

For the papermaking process, fibers, fillers, and some additives are all water-insoluble, and they have a tendency to self-assemble in an aqueous solution, and different materials are often kept as far away as possible due to incompatibility, so it is difficult to obtain performance Uniform, ideal strength paper. Adding a dispersant can make the surface of the solid particles form a bimolecular layer structure, and the polar end of the outer layer of the dispersant has a strong affinity with water, which increases the degree of wetting of the solid particles by water. The solid particles are far from each other due to the electrostatic repulsion to achieve a good dispersant effect. A good fiber dispersant requires certain pyrolysis, that is, it will gradually decompose with the increase in temperature, and the viscosity will decrease accordingly so that it will not stay on the dried paper and will not be damaged by the use of fiber dispersant. affect the original performance of the fiber.

The mechanism of action of the dispersant:

1. Give the surface charge of the fiber, making it almost repulsive

2. Cover the fiber surface and play the role of protective colloid

3. Form a high-viscosity state around the fiber to prevent fiber collision and aggregation

4. The surfactant has good adsorption and suspension characteristics and is adsorbed on the surface of the fiber.

5. The change in fiber surface wettability also reduces the friction between fibers and reduces the chance of fibers sticking to each other.