Development of a yarn evenness measurement and hairiness analysis system

Abstract

This paper presents an automatic yarn characterization system, based on capacitive sensors for evenness measurement and on capacitive sensors for hairiness analysis. This approach enables direct yarn mass determination in 1mm range for evenness, an increase by a factor of eight over the most common comercial solutions (8mm), and will also enable hairiness measurementup to 1mm with high accuracy. This system determines all parameters commonly used in textile industry, for different sensitive values defined by the operator. It also presents new parameters, not measured by commercial equipments 8 integral deviation rate-IDR, different signal processing techniques to detect error patterns (Fast Walsh-hadanard transform-FWHT) and other adapted parametrs (desviation rate-DR, Spectrograms 8Fast Fourier Transform-FFT), Coefficient of Variation-CV, Mean Deviation-U, number and lenght of faults).