High-yield pulps are usually derived from pine wood on account of its anatomical configuration and technology used. Eucalyptus, on the other hand, is a fast-growing species, abundant in many parts of the world, and has thus emerged as an alternative source for many products in the pulp and paper industry. In this particular study, high-yield pulps of Eucalyptus grandis were used. In order to improve their properties, pulps were subjected to chemical treatments with different doses of sodium hydroxide prior to refining (0, 30, 50 and 70 kg/t), at 75ºC temperature, 3% consistency, during 1 minute. The refining process was done in a Bauer disc refiner (Regmed) using various refining times (0, 5, 10 and 15 minutes). Results showed that refining with addition of NaOH did bring significant gains to the eucalyptus fibers regarding strength properties, the dose 50 kg/t being found the most suitable. However, other variables associated with refining could also be modified to further improve the strength properties of eucalyptus pulps, including consistency and refining discs configuration.
High-yield pulp; sodium hydroxide; refining
