HEAT TREATMENTS INFLUENCE ON THE BREAKING TORSION OF WOOL TYPE FIBERS

• Main Authors: BORDEIANU Demetra Lăcrămioara, HRISTIAN Liliana, VÎLCU Adrian
• Format: Article
• Language: English
• Published: Editura Universităţii din Oradea 2014-05-01
• Series: Annals of the University of Oradea: Fascicle of Textiles, Leatherwork
• Subjects: wool; breaking torsion; heat treatment; frequency polygon; variation coefficient
• Online Access: http://textile.webhost.uoradea.ro/Annals/Vol%20XV-no%20II/Art.%20nr.%2038,%20pag%2017-22.pdf

In order to convert the textile fibers in yarns, these must be subjected to twisting operation which confers them a certain tensile strength. Twisting also results in certain effects, such as crepe effect. The importance of knowing the twisting behavior consists in the possibility to avoid fiber degradation as the result of an excessive twisting. The present work took for study three types of chemical fibers (wool-type rayon, wool-type polyester, wool-type polyacrylonitrile) and two types of wool fibers S11 and S12. The main characteristics of wool type chemical fibers (fiber count, nominal length, breaking length, relative elongation, brightness) and of wool fibers (diameter, almeter length, uster irregularit) have been measured. Then the fibers were subjected to thermal treatments in certain conditions. From the researches performed for the both wool blends, S11 and S21, one can notice that the torsional rigidity/stiffness increases after the thermal treatment and the wool fibers changes their handle accordingly. The rayon fibers present the biggest torsional rigidity, as compared to the other types of analyzed fibers, both untreated and heat treated. After heat treatment, the rayon fibers considerable improves their handle. The variation coefficient of breaking torsion increases in the case of heat treated polyester and poly-acrylonitrile fibers while for rayon and wool fibers this coefficient decreases.