Effects of PEI as ATC on the Retention and Drainage of APMP

Abstract

The impact of highly cationic density polymers such as modified poly-ethyleneimine(PEI), as anionic trash catcher(ATC) on the drainage and retention properties of aspen alkaline hydrogen peroxide mechanical pulp(APMP) in differentCPAM(/bentonite) systems was studied. The results showed that ModifiedPEIcould improve the retention and drainage properties ofCPAM/ bentonite systems; when adding 0.02% dosage ofPEI, the drainage and retention rate were increased by 16.0% and 1.9% respectively as compared to control with 0.03% dosage of theCPAMwith 1.55 meq/g cationic charge density and 4.9 million molecular weight, which denoted byCPAM(W/W);the drainage and retention rate were increased by 28.6% and 3.0% respectively as compared to the control with 0.03% dosage ofCPAM(W/W) and 0.3% dosage of bentonite. TheCPAMwith more cationic charge density and higher molecular weight than theCPAM(W/W)is denoted byCPAM(W/O)in this paper. The microparticle system which consisted withPEIand theCPAM(W/O)(/bentonite) was slightly superior to thePEI/CPAM(W/W)/bentonite system. When 0.02% dosage ofPEIand 0.03% dosage ofCPAMwere added respectively,PEI/CPAM(W/O)made the drainage and retention rate increased by 9.5% and 1.9% respectively as compared withPEI/CPAM(W/W).