EVALUATION OF 2-STAGE AND 3-STAGE REFINING PROCESSES FOR PRODUCTION OF TMP PULP FOR SCA- SIMILAR TOTAL SPECIFIC ENERGY-LEVELS GIVE SIMILAR CHARACTERISTICS( PAPER )

Two- and three-stage mainline refined RTS TMP pulps were produced to e valuate potential benefits from either process using a northeastern wo od furnish supplied by STORA SFI. The three-stage process applied more energy to the mainline pulp and operated with a lower system reject r ate (35%). The two-stage process operated at a higher system reject ra te (49%) and applied more energy to the fractionated pulp using series reject refining. Compared at a similar total specific energy both pro cesses demonstrated equivalent freeness, bonding strength, tear index and shive content. The three-stage pulps had a higher surface strength and scattering coefficient.