Date of Award


Degree Name

Master of Science


Chemical and Paper Engineering


Paper Engineering, Chemical Engineering and Imaging

First Advisor

Dr. Brian Scheller

Access Setting

Masters Thesis-Open Access


Over the years, various attempts have been made to develop methods to measure fiber flexibility. In the course of developing test methods for fiber flexibility, various studies have been performed that measure the flexibilities of different wood pulps.

In this study, never-dried individual thermomechanical pulp (TMP) and bleached kraft fibers were mounted on the tip of a glass tube submerged in water and deflected by water flow. The deflection of the individual fibers was measured using a microscope and image analysis software. The fibers were then dried, rewetted, and the deflection was measured_again. This drying and rewetting cycle was repeated three times until a total of four deflection measurements had been made for each individual fiber.

This study offers evidence, on a single fiber level, t}lat repeated drying and rewetting decreases bleached kraft fiber flexibility. Six of eight fibers showed consistent trends of decreasing deflection as the number of drying and rewetting cycles increased. Statistical analysis showed the first drying cycle to be significant, the second and third drying cycles to be insignificant.

For TMP fibers, as the number of drying and rewetting cycles increased, deflection values were too inconsistent to establish any trends. Analysis of variance did not show any of the drying cycles to be significant.