The Effects of anionic polyacrylamide on fines retention in newsprint manufacturing

The Effects of Anionic Polyacrylamide on Fines Retention in Newsprint Manufacturing In this study, the unbleached mechanical pulp and bleached sulfate pulp provided from SEK A- Aksu mill were used as raw material. Fines retention levels of furnishes prepared by mixing these pulps at various rates were determined by using dynamic drainage jar with different anionic polyacrylamide (APAM) addition levels. When amount of APAM increased from 0% to 1% in furnish prepared by mixing of 80% unbleached mechanical pulp and 20% bleached sulfate pulp, ratios of first pass fines retention increased from 34.02% to 96.97% without filler addition. However, in the same furnish in which 10% filler was added, increasing of amount of APAM from0% to 1% resulted in increasing in first pass fines retention from 39.39% to 97.28%. It was determined that the physical and optical properties of paper decreased when amount of APAM addition increased in furnish. Since APAM values above 0.2% added in furnish decreased the physical and optical properties of papers made from this furnish extremely, the optimum amount of APAM addition was determined to be 0.2%. These decreased properties restrict manufacture of various paper grades. However, increase in amount of APAM addition in furnish causes to increase in paper manufacturing cost and it interferes with costsaving provided from fines retention. Key Words: Fines Material, Retention, Dynamic Drainage Jar, Drainage Time, Coagulation, Flocculation X