Date of Award
Master of Science
Paper Engineering, Chemical Engineering and Imaging (to 2013)
Dr. Ellsworth H. Shriver
Dr. Raymond L. Janes
Dr. Raja Aravamuthan
Masters Thesis-Open Access
The main objective of this study was to investigate the effect of refining on the brightness of softwood chemithermomechanical (CTMP) and thermomechanical (TMP) pulps. Seven different pulps were refined using a laboratory Valley beater. Brightness, opacity, tensile index, TEA, and fines content of these pulps were determined at four different freeness levels. Scattering (s) and absorption (k) coefficients of these pulps were calculated. One-way analyses of variance (ANOVA) were applied to determine the significance of change in brightness.
Changes in s-values were significantly affected by fiber morphology of different wood species. Refining increased the k-values of the pulps. When the increase in s-value outweighed the increase in k-value, the result was an increase in brightness. Southern pine unbleached TMP showed increases, while bleached CTMP pulps showed decreases in brightness with refining. Other pulps did not exhibit a definite trend. Opacity and tensile strength generally increased with refining.
Mishra, Ashok Kumar, "Effect of Refining on the Brightness of Softwood CTMP and TMP Pulps" (1990). Master's Theses. 1092.