Kinetic Study of Ozone Treatment on Mechanical Pulp, 2000 Pulping / Process & Product Quality Conference Proceedings

P. X. Long, J. S. Hsieh, A. A. BaOsman--Recent environmental concern, increased fiber demand and decreased wood resources have generated great interest for pulp and paper industry on bleaching thermomechanical pulp (TMP) and chemi-thermo-mechanical pulp (CTMP). Traditionally, mechanical pulp has been brightening using hydrogen peroxide and sodium hydrosulfite reaching to a required strength of 58% ISO brightness. The unbleached pulp brightness is about 56% ISO. This paper focuses on ozone application on brightening of high yield pulp. The objective is to use ozone as substitution for sodium hydrosulfite and achieve market grade brightness with better pulp properties at the same time. The experiments were conducted on TMP fiber provided by a local newsprint mill. Bleached and unbleached fiber from current mill process and had been tested for comparison. Fiber physical properties such as tensile, tear, burst, brightness and fiber length distribution were determined and compared with properties from mill pulp. The results indicate that ozone can improve pulp brightness and achieve better strength properties as well.