Influence of Fibe Length of the Fractionated Pulp and its Fiber Swelling Capacity on Compressive Resistance and Other Strength Properties of Corrugating Medium Handsheet

Abstract

The objective of this research work was to understand the influence of length and swelling capacity of fractionated pulp fibers on compressive resistance of corrugating medium handsheet and its other strength properties. In this work, the three length fractions of pulp fibers with various degrees of fiber swelling, which was measured with the water retention value (WRV) test, in the range of 1.20-1.70 g/g were used as the fiber samples for making the handsheet with a grammage of 90 g/m2. These fibers were prepared by fiber fractionating three samples of unbleached softwood kraft pulp with the different freeness levels with the Bauer-McNett classifier. The results showed that compressive resistance of the handsheet, which was measured with the Concora test (CMT), was not increased with an increase in the fiber length of fractionated pulp, but increased significantly with increasing the fiber swelling capacity. On the other hand, the tear strength seems not to be affected by the fiber swelling capacity, but to be significantly affected by the fiber length of fractionated pulp. Other strength properties of the handsheet such as tensile and burst strength were found to be significantly related to the length and swelling capacity of the fibers.