In order to obtain knowledge of interlacers generating a high number of tangles, the yarn motion was observed in slit-type interlacers with various sizes with high-speed video cameras. Results obtained are as follows: (1) Interlaced yarn is generated by the iteration of closed, dispersion and twisting states of running yarn independent of size of interlacer. (2) Interlacers generating a high number of tangles are supposed to have the following characteristics: Yarn passage region, where the airflow velocity is low, is small. In addition, the twin vortex has high dynamic pressure, filaments disperse to the whole yarn passage, plural twists generate in a yarn cross-section by the twisting action of the twin vortex, and a series of entanglements with different twist types occurs in the direction of yarn axis. Hence, strong entanglements between filaments are formed.

In this study, the effective thermal conductivity of Cupra, Polyester and Polytrimethyleneterephthalate (PTT) fiber assemblies in low fiber volume fraction is measured using KES-F7 Thermo Labo II apparatus. In order to eliminate thermal perturbation by external heat, the radiation shielding board is set up between samples and operator. Heat flux to calculate thermal conductivity is measured including heat leakage from the side wall of sample and is calibrated in the analysis. The results are analyzed using non-linear regression method. The results are obtained as follows. Thermal conductivity curve is convex downward within the range of fiber volume fraction measured. The effective thermal conductivity, λ is expressed as following equation, λ = Aφ + B/φ + C where, φ: fiber volume fraction, A, B: coefficients and C: constant determined by non-linear regression analysis. Based on this equation, the effective thermal conductivity is divided into three parts, i.e. Aφ: heat conduction within fiber, B/φ: radiative heat transfer and C: heat conduction within air. Component of conduction in air, C plays a most important role in thermal conductivity of fiber assembly, and component of heat conduction in fiber, Aφ follows in higher fiber volume fraction.

This paper shows the experimental results about the dynamic compression durability of a textile sensor. Results obtained are as follows; (1) There were few changes of the detective pressure of the textile sensor in one million repetitive compression numbers or less. (2) The repetitive compressions caused the deformation of electrically conductive yarn. And then, the detective pressure of the textile sensor increased with the compression number greater than two million. In addition, the non-detecting points also increased with the compression number greater than two million because of breakage of electrically conductive yarn by dynamic compression. (3) Pressure detection characteristics of the textile sensor before loading the dynamic compression were maintained in one million repetitive compression numbers or less.