Study on Physical-mechanical Parameters of Ring-, Rotor- and Air-jet-spun Modal and Micro Modal Yarns

Abstract

The main physical-mechanical parameters of modal yarns (unevenness, faults, hairiness and spectrograms) were compared with the parameters of micro modal yarns of the same fineness and end-use. The difference in tenacity and elongation at break of different types of modal and micro modal-spun yarns is determined by yarn structure. The highest tenacity was achieved in the oriented structure of ring-spun yarn, followed by air-jet-spun and rotor-spun yarn, in the case of both modal and micro modal fibres. All types of modal yarns differ in overall unevenness and in terms of micro modal fibres. The values of the overall unevenness of ring-, rotor- and air-jet-spun modal yarns are greater than or equal to the same values of micro modal yarns. The spinning technique, and thus the yarn structure, determine the level of overall yarn evenness. The number of faults at different levels of sensitivity measurement to detect the highest number of thin and thick places and neps (–30%, +35% and +140%) is greater in rotor- and air-jet-spun yarn than in ring-spun yarn for both levels of fibre fineness. Periodic faults of short wavelengths with significant amplitude increase the number of yarn faults to a certain extent. Rotor-spun micro modal yarn shows the highest deviation from ideal unevenness, while ring-spun modal yarn shows the lowest deviation. Yarn hairiness depends on the spinning technique. Finer fibres cause lower hairiness in all yarn types.

Keywords

• modal fibre
• micro modal fibre
• man-made cellulosic fibre
• properties