On the Potential to Improve Kraft Pulping and Pulp Strength Properties with a New Chipping Technique, 1997 Pulping Conference Proceedings

A new chipping technique has been developed, with which chips produced at industrial rates were all of same preset length and thickness and did not require screening before use. It applies to sawmill chipping. Chips cut to various thickness and length under a certain cutting speed have been tested by laboratory cooking and beating. Two millimeter thick veneer and hand-cut chips were chosen as the “ideal” chip reference. Mill reference chips made in a standard sawmill chipper were screened to eliminate over thick, fines and pin chip fractions. Standard cooking tests have shown that chips made with the new technique give yields and strength properties that are equal or better than pulps made of the “ideal” reference chips. New chips are superior to the screened conventional reference chips in terms of pulp yield, fibre length, viscosity and strength properties. There is an optimal chip thickness existing for ideal pulping and strength properties. Five millimeter thick or thinner chips are recommended to the practical chipping process.