Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering


Na2CO3/NaOH cooking liquors were evaluated as possible pulping agents for the production of semichemical pulp for use in corrugating medium. Optimum ratios of Na2CO3/NaOH were found to be 2/1 to 4/1. Pulp produced with ratios within these figures were equal to tensile and concora and higher in yield when compared to NSSC pulp made at the same temperature, time and Na2O/chip ratio. By increasing either the time or the Na2O, higher tensile and concora tests were obtained but with a slight sacrifice in yield. Na2CO3/NaOH pulps are more resistant to refining than NSSC pulps made under comparable conditions and in some cases required more than twice the beating time to reach target Canadian Standard Freeness tests.