Takao Negishi

Measurement of Torsional Rigidity of Fibers

Torsional rigidity is one of the most important mechanical properties of fibers and yarns and has considerable effects on the performance of fabrics made therefrom. A new instrument called a Torsional Rigidity Analyzer has been developed by TORAY Industries, Inc., a synthetic fiber manufacturer in Japan, for the measurement of torsional rigidity, torsional hysteresis, and residual torque of all fibers ranging from fine fiber to heavy yarn such as tire cord or carpet yarn. This analyzer utilizes a new torque balance method which is a modification of the rotary viscometer. By this analyzer the twist-torque diagram of the sample is obtained automatically in the X-Y recorder. This paper describes the analyzer and some applications to fine fibers and multifilament yarns.