To evaluate the effects of different levels of quaternised pyrodextrin as wet‐end and filler retention aid additives in papermaking.
The pulp furnishes used in this study were a mixture of bleached rice straw pulp with bleached sulphite softwood pulp at a ratio of 60:40. The beaten pulps (never dried) were treated with different grades of modified starch (Pyrodextrins). The results obtained were compared with those of several commercial polymers, such as Accostrength®86, cationic starch and polyacrylamide.
The results obtained from this study showed that addition of 0.3 percent of British Gum (BG) (Degree of Substitution at 0.058) grade pyrodextrin to the pulp slurry, especially in case of kaolin as paper filler gave the most significant improvement in paper properties as well as filler retention. The results obtained also showed that the filler retention and paper properties were better/higher for all pyrodextrins studied than those obtained from both Accostrength®86 and polyacrylamide.
Using quaternised pyrodextrins as wet‐end additives and filler retention aids improved all mechanical properties of treated paper, except the brightness which decreased very slightly.
The grade of pyrodextrins used in this work could be used to improve the physical and strength properties of paper sheets.
Different types of pyrodextrin namely, Dexy‐84 (D‐84), Dexy‐86 (D‐86) and British Gum (BG) could be used as paper wet‐end additives and filler retention aids in paper making processing.
