On-line Fiber Orientation Measuring System for Papers

Abstract

It is well known that fiber orientation of paper has influence on the anisotropy of mechanical breaking strength and hygroexpansion coefficients. Therefore, the development of on-line measuring system will contribute a lot in improving stability in paper quality as well as paper quality itself, because the on-line measuring system simplifies influence analyses of fiber orientation under varying conditions of a paper machine.
In our laboratory, we have developed methods for measuring the fiber orientation of paper by employing linear dichroism in the near-infrared range. Test results obtained with the off-line device using these methods showed a good correlation with results obtained under other methods, such as Microwave Molecular Orientation Analyzer and Sonic Sheet Tester. In this paper, we report test results and discuss the development of the on-line system under our methods in comparison with the On-line Retardation Measuring System. The On-line Retardation Measuring System is a device that measures the optical anisotropy of polymer film.