In order to provide a basis for parameter setting during the process of making man-made fiber fabrics as imitations of natural fibers fabrics, to understand characteris tics of natural fiber fabrics and to establish discriminant methods for such characteristics have become important subjects in the textile industry nowadays. By applying discriminant analysis and neural network, I have successfully used fabric physical properties measured by KES-FB system and FAST system to establish discriminant models for fabric characteristics of cotton, linen, wool and silk. KES-FB discriminant model that applied fabric mechanical properties appeared to have a better classification ability than FAST discriminant model. On the other hand, the discriminant model established by applying neural network appeared to have a better classification ability than that by applying discriminant analysis. While only 9 and 5 physical properties of fabrics measured by KES-FB system and FAST system, respectively, needed to be applied, the discriminant model established by applying stepwise method should possess the characteristics of simplicity, convenience and effectiveness.

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This paper presents an analysis of the fiber dynamics in the twist draft spinning, and an application of the derived theory from the analysis to TCTDS (Tension Control type Twist Draft Spinning), a kind of the twist draft spinning that is being developed by the authors.
Through the analysis, we specially have regard for linear density and twist rate of the twist draft spinning yarn those are deeply concerned with the quality and structure of the yarn. And we found that the twist multiplier of the twist draft spinning yarn spun in steady state of the spinning process is formulated by a function of properties of raw materials, e.g., fiber length, fiber diameter, and the coefficient of inter-fiber friction.
The theoretical result shows good agreement with the practical data of yarn properties given by the related experiments, and it proves to be a valuable tool in designing of yarns spun with TCTDS.

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An air jet loom equipped with a profile reed and sub-nozzles is able to weave wider fabrics at higher speed than other types. A study on the characteristics of airflow and behavior of the weft yam in the weft passage area of the profile reed during inserting the weft yam is very important. The velocity distributions of airflow issued from a sub-nozzle in the weft passage were measured in detail by a hot-wire anemometer. The motion of a weft yarn in the weft passage was also observed by photography.
The experimental results indicate that the shape of the lower jaw part of the profile reed affects positions of the maximum velocity of the air jet in a cross-section until the air jet runs into the bottom of the reed. When the front side of the profile reed is closed, the value of the maximum velocity in the weft passage is smaller than that under the normal condition because of increasing of flow leakage behind the profile reed. The position of the maximum velocity in the weft passage is found to coincide with the position of the maximum leakage from the profile reed. It is confirmed by photograph that a yam tip is led through the weft passage by the jet issued from a sub-nozzle.

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The effects of pre-elongation ratio, stress relaxation time and recovery time on the hysteresis behavior of the stress-strain curve are discussed for segmented Poly(urethane-urea).
The loss of stress and extension energy was found to be much larger than unrecovered strain with pre-elongation. In the range of low extension ratio of α<2, the large loss in shear modulus was shown for unloading and re-elongation curves. However the breaking energy of the linkages was lower than 0.75kJ/mol. As for the range of 2<α<3.5, the linkage having the bond energy of 20 kJ/mol were broken by pre-elongation. The pre-elongation of α>4 led to break the linkages having the strong bond energy of 75kJ/mol. This energy corresponds to the break down of intermolecular hydrogen bond of hard segment. The molecular weight between cross-link points(Mc) estimated by shear modulus of unloading or re-elongation curves was almost the same as that of the prepolymer. The strong hydrogen bond of 75kJ/mol between hard segments re-bonded and recovered faster than other weaker linkages.
The Moony-Rivlin plots of unloading and re-elongation curves had much smaller values of C₂ than those of the pre-elongation curves. This suggests that the strain softening effect decreased by preelongation. It is especially interesting that the unloading curve for elongation of α>4 had the value of C₂_??_0 and showed ideal rubber elasticity.

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