Fiber Quality Analysis: OpTest Fiber Quality Analyzer versus L&W Fiber Tester

Abstract

In this paper, the measurements from OpTest FQA (fiber quality analyzer) and L&W Fiber Tester were compared on 95 TMP (thermomechanical pulp) samples from a TMP-based newsprint mill in Eastern Canada that uses mixed black spruce and balsam fir as raw material. It was found that both FQA and L&W Fiber Tester provide repeatable measurements for fiber length, fines, coarseness, curl, and kink index. However, there were significant differences in the results obtained from the two instruments. Compared to FQA, the L&W Fiber Tester measurements were on average 59% higher for the arithmetic mean fiber length and arithmetic fines content, about 6% higher for the length weighted mean fiber length, approximately 44% lower for the coarseness, and about 37% lower for the kink index.