Exploratory kraft and NSSC pulping and production of a bleached, market - grade, kraft pulp from Colombian hardwood mixtures

FOREST SERVICE CONDUCTS EXPERIMENTAL RESEARCH TO ESTABLISH POTENTIAL USES FOR WOOD PRODUCTS NATIVE TO DEVELOPING COUNTRIES. THIS REPORT PRESENTS THE METHODS AND FINDINGS OF A PROGRAM TO EXPLORE THE MAKING OF KRAFT PULPS FROM HARDWOODS IN COLOMBIA. KRAFT PULPS WITH A QUALITY EQUAL TO OR BETTER THAN THOSE MADE WITH NORTH AMERICAN HARDWOODS WERE MADE FROM THREE MIXTURES OF 17 COLUMBIAN HARDWOOD SPECIES. IT WAS FOUND FEASIBLE TO USE A HIGH-YIELD PROCESS TO PRODUCE 25 TO 30 PERCENT SCREENINGS FOR USE IN A CORRUGATING MEDIUM, AND TO USE THE SCREENED PULP FOR LINERBOARD. SEMI-CHEMICAL KRAFT PULP, WITH A KAPPA NUMBER EQUAL TO THAT OF THE KRAFT SCREENINGS, HAD HANDSHEET PROPERTIES COMPARABLE TO THOSE OF THE KRAFT SCREENINGS. HANDSHEET TESTS INDICATED THAT A CORRUGATING MEDIUM OF ACCEPTABLE QUALITY CAN BE MADE FROM ALL THREE MIXTURES COOKED BY THE NEUTRAL SULFITE SEMI-CHEMICAL PROCESS (NSSC). IMPROVED HANDSHEET QUALITY CAN BE OBTAINED BY THE ADDING OF CAUSTIC SODA TO THE NSSC PULPING LIQUOR AND/OR BY REDUCING THE PULP YIELD. SEMI-CHEMICAL KRAFT AND GREEN LIQUOR PULPS AT 73 PERCENT YIELD ARE DEFICIENT IN THE HANDSHEET PROPERTIES WHICH ARE NEEDED TO PRODUCE A CORRUGATING MEDIUM OF ACCEPTABLE QUALITY.