The roller drafting process of the blended sliver composed of long and short fibers was studied in order to clarify the mechanism that causes the blend irregularity. The relationship between several factors was formulated. By using this formula, delivery sliver thickness was calculated from the feed sliver thickness. Experimentally the blended sliver was drafted and sliver thickness was measured. Experimental results agreed well with calculated results. It was clear that the velocity-change-point of short fibers was different from that of long fibers and variation in the velocity-change-point of short fibers was larger than that of long fiber during the roller drafting process of the blended sliver composed of long and short fibers.

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The fiber leading end density in the blended sliver composed of long and short fibers was measured and cross-sectional number of fibers was obtained by using sliver diagram. The sliver structure was analyzed along the sliver axis. Subsequently, the influence of various drafting conditions on the sliver structure was also examined. The results obtained are as follows: (1) Variations in the fiber leading end density of short and long fibers in the blended sliver showed a similar tendency along the sliver axis. In all regions along the he sliver sliver axis, variation in the fiber leading end density of the short fiber component is larger than that of the long fiber component. (2) In the blended sliver composed of long and short fibers, there are a large number of short fibers in the region where the sliver gets thicker. On the other hand, there are a large number of long fibers in the region where it gets thinner. This tendency gets more and more noticeable with an increase in draft ratio and roller gauge. (3) The correlation coefficient of the cross-sectional number of long and short fibers increases in accordance with draft ratio and roller gauge. The phase of short fibers advances a little more than that of long fibers.

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It is established that in sewing operation, a needle could be deflected by factor such as sewn fabric structure. Empirically, however, this deflection is considered to be closely related to sewability, but without defining the proper correlation they may have. A series of studies are, therefore, undertaken to find out the correlation between sewabiliity and needle deflection in sewing operation. The present paper is aimed at a proposed method for evaluating the needle deflection. In the method, the deflect-ing force is measured by two gauges attached to the lateral surfaces of a needle shank, and then the deflection is estimated by using a simple needle model. Some model studies are carried out on synthetic paper and cotton fabrics, and their results are presented,

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