"EFFECTS OF DIFFERENT RATIOS OF STARCH-CONTAINING AKD ON PAPER PROPERTIES IN INTERNAL SIZING OF VARIOUS PULP TYPES "

Abstract

The main objective of this study is to determine the effects of different ratios of starch-containing AKD emulsion in various pulp types sizing processes on paper properties. A secondary objective of the study is to evaluate the influences of starch content in AKD emulsion and AKD dosage applied to pulps. Three different pulp types were sized: unbleached kraft, bleached kraft and chemithermomechanical pulps. In preparation of AKD emulsions, three different ratios of starch were used. AKD was applied to all pulps under the same conditions at four different dosages based on oven-dried fiber weight. Test papers were produced and Cobb values (water absorptiveness), some mechanical and optical properties of the papers were determined. In addition, SEM, XRD and contact angle analyses were applied to papers produced with optimal sizing parameters. As a result of the study, it was found that the effects of AKD cause different behaviors depending on the pulp types. AKD was highly efficient in sizing chemithermomechanical pulp, decreasing the Cobb value by 90.9%. Depending on the pulp type, the starch content used in the emulsion preparation and the AKD dosage applied to the papers have various effects on the paper properties.