MECHANICAL PULP CHARACTERIZATION - A NEW AND RAPID METHOD TO EVALUATE FIBER FLEXIBILITY

A new method of measuring the flexibility of high-yield pulp fibres was developed in order to characterize two different types of mechanical pulp: CTMP and TMP. This method is based on the Bauer McNett classification and the average fibre lengths obtained with a Kajaani FS100 apparatus. The determination of the average fibre length of each fraction from the Bauer McNett classifier and the correlation between the Kajaani lengths and the theoretical McNett lengths allows a dynamic and a static flexibility coefficient to be defined. This flexibility measurement is applicable to all sorts of lignocellulosic fibres. Flexibility coefficients are affected by refining, bleaching, the wood species and the mechanical pulping process. Flexibility is an important parameter in the development of the optical characteristics and strengths of the pulps. This method is rapid and can be used for laboratory control purposes in pulp production. It is one way to characterize high-yield pulp fibres and to better understand the way the fibre evolves during the production process.