Polyacrylamide and Polyaluminium Chloride Serve as Paper Making Chemicals
High-Purity Polyaluminium Chloride
High-purity polyaluminium chloride is often used as paper sizing chemicals in papermaking industry. It also acts as a filter aid, retention aid, or the precipitator for neutral rosin sizing. This selection of paper making chemicals can replace aluminum sulfate to serve as a neutral sizing precipitator in papermaking industry. The white one possesses the following characteristics when compared to aluminum sulfate.
1. Plenty of high-stability polynuclear hydroxyl-aluminum complexes with positive charges can effectively facilitate flocculation and sizing process.
2. White appearance and extremely low iron content can meet the needs for high-quality paper production.
3. White poly-aluminium chloride is produced from the prehydrolysis of aluminum chloride. Due to relatively low degree of hydrolysis, the pH value of paper pulp descends more slowly than that of aluminum sulfate.
4. Aluminum sulfate is only suitable for acidic sizing. However, the high-purity poly aluminum chloride in white color can be used for sizing in both acidic and neutral environments. It can significantly reduce the corrosion to a system, and also makes water treatment extremely easy.
5. The addition of cheap calcium carbonate filler can not only lower the production cost, but also improve the folding endurance and whiteness of paper. In addition, it has overcome different inevitable shortcomings of AKD and other synthetic materials, such as slipping, uncontrollable degree of sizing, etc.
6. The use of high-purity polyaluminium chloride sizing in white color helps greatly improve the filtration and retention functions of slurry.
7. Except the breaking length, all indicators of the paper have been improved to different degrees.
8. In addition, poly aluminum chloride is used to control resin barriers and also capture the anionic impurities.
In papermaking industry, polyacrylamide is commonly used as the retention aid, filter aid, and the uniformity agent, etc. It can improve the quality of paper and the dewatering performance of slurry. Also, this paper making chemical can improve the retention of filler and fiber fines. It helps reduce the consumption of raw materials and the pollution to environment.
The effect of polyacrylamide in papermaking process depends on the average molecular weight, ion property, ionic strength, and the activity of other copolymers. Anionic copolymers are mainly used as the retention aid or the wet strength agent of paper. Cationic copolymers are mostly applied in the filter acid and sewage disposal in papermaking industry. Also, they can improve the retention of filler. In addition, polyacrylamide is ideal for papermaking wastewater treatment and fiber recycling.