Application of PEO in paper industry
PEO is increasingly used as a multifunctional additive in the papermaking industry. It can be used as a fiber dispersant, paper softener, water-soluble functional paper binder, retention and filtration aid, and resin control agent.
Dispersant for Long Fibers
In the papermaking process, fibers, fillers, and some additives are water-insoluble and tend to aggregate in water, making it difficult to obtain paper with uniform properties and ideal strength. Using polyethylene oxide can shorten beating time and produce paper with good uniformity using pulp with lower freeness.
Retention and Filtration Aid
In newsprint papermaking, fillers are often added to reduce costs and improve paper whiteness.
However, a considerable proportion of fillers and fine fibers are lost during the papermaking process. Adding 0.025~0.05 kg of high molecular weight PEO per ton of oven-dry fiber can significantly reduce the loss of fillers and fine fibers. PEO is a high molecular weight nonionic polymer.Its retention mechanism is through bridging and bonding. It works by forming a network, interacting with suspended solids present in the pulp. PEO resin also shows a synergistic effect with commonly used flocculants. It not only improves the retention of fillers and fibers but also enhances the drying efficiency of the paper sheet in the paper machine's drying section.
Water-soluble Paper Adhesives
Due to its high viscosity and excellent water solubility, even low-concentration aqueous solutions of PEO have high viscosity, and the viscosity disappears after drying. Furthermore, its good chemical stability makes it suitable for formulating water-soluble adhesives. In the paper industry, PEO is used as an adhesive during paper winding, allowing the paper tube to be opened without tearing the paper.
Paper Softeners
The softening and lubricating effect of paper can be expressed by the difference between the static coefficient of friction and the dynamic coefficient of friction; the smaller the difference, the greater the softness. PEO is generally used as a dispersant, enabling the production of thin, uniform paper with good absorbency at low beating degrees from long fibers; it has also been found that the produced paper has good softness and strength. PEO plays a vital role in the production of household paper products such as toilet paper and napkins. Its mechanism of action is that PEO can form hydrophobic groups on the fiber surface, causing outward adsorption and reducing the dynamic and static friction factors of the fiber material, thus resulting in a smooth and soft feel.
