NOVEL ZEOLITE FILLERS FOR FRESH WATER REDUCTION IN PAPERMAKING: EFFECT ON GRADED PAPER PROPERTIES

摘要

Results showed a surprising improvement in the drainage, retention and formation characteristics using zeolite in place of PCC under alkaline condition. Zeolite was found to be very effective for Kraft dominant furnishes and efficiency decreased in the following order: Kraft > BCTMP > BTMP. A series of wet end chemicals were evaluated and their dosage was optimized. For chemical pulp retention and drainage performance improved significantly with a mixed PEO/cationic polyacrylamide system over their independent addition. The synergism in retention chemistry was more evident for cleaner furnishes system such as bleached Kraft than BTMP.rnUse of zeolite also allowed higher tolerance to white water composition. White water streams, which are rich in dissolved solid and anionic trash, demonstrated higher retention and formation characteristics when zeolite was used. Strength properties of finished paper did not change by incorporating 20 wt % of zeolite fillers and opacity, brightness and surface smoothness improved compared to PCC grade. At present the cost of commercial grade and high brightness zeolite is higher than commercial PCC. However, it is expected that true chemical value of this new additive should not be estimated based on the cost of chemical but it should also consider the savings expected from improved paper quality, fewer number of breaks and possibility to reduce waste water treatment cost.