Comprehensive Evaluation of Strength and Cohesiveness of Fibers as Elements of Cellulose Materials Structure
At present, pulp production is controlled mainly by means of the Kappa number measurement and viscosity analysis of cellulose samples using various methods. It should be noted that methods for assessing structural and morphological properties of fibers both at individual stages and on the whole are rarely applied, and so far there has not been developed any definite correlations between the geometric parameters of individual fibers and the finished product parameters. A new trend in ​ assessment of cellulose fiber properties, which is based on measuring the characteristics of individual fibers in the material structure, allows us to exercise a rather prompt control of quality of semi-finished products and their response to technological impact. Basic fiber characteristics, such as strength directly in the material structure, geometrical dimensions and interfiber interactions, can be determined using Pulmac Zero-Span testers. The authors carried out a comprehensive study to establish such correlations in the real process of bleached hardwood pulp production. For this purpose, we tested fiber samples at workflow points, including such operations as cooking, washing, sorting, all stages of bleaching and production of a marketable semi-finished product. The correlation analysis also includes measurement data of structural and morphological parameters of fibers, obtained by an independent analysis method using Fiber Tester. First of all, statistically significant linear pair correlation was established between the Kappa number on the one hand, and parameters of the fiber structure in the samples on the other. 9* We found high coefficients ​​of pair correlation between the fiber parameters measured by Pulmac Zero-Span and Fiber Tester. The correlation analysis shows that the strength of individual fibers in the structure of hardwood pulp samples depends on the mean fiber length and width, increasing with fiber straightening and, conversely, declining with the growing number of sharp bends and fine fractions in the sample, i.e. with a higher degree of damage. Hence, in the first approximation we solved the problem of monitoring the changes in the properties formation of a semi-product during the manufacturing process.