High resolution yarn measurement

Abstract

Yarn structure is subject to periodic or random irregularities. In order to be able to quantify the yarn evenness, the principle often applied is based on 8mm capacitive sensors. The capacitance variations enable the automatic indication of the mass deviation and the coefficient of variation. Knowledge of the yarn mass in 1mm range is of most importance to evaluate properly the yarn evenness; furthermore several irregularities can only be properly detected if this mass evaluation is possible in this range. We present a methodology to extract yarn mass in 1mm range with signal processing techniques and statistical analysis. However, the ultimate goal is the direct measurement of mass in the 1mm range. To achieve this goal, a solution with cylinder sensors with different diameters is under test.