In the earlier papers, the authors analysed the bending of a pair of mechanically similar, rubber-covered pressure-rollers, assuming that the elastic property of the cover and the fabric were uniform over the width of the roller, and that the working width of the roller and the width of the fabric were the same.
Actually, however, a fabric has selvages, the hardness of the cover is not uniform after repeated use, and the width of the fabric is smaller than that of the rollers. The important problems concerning these factors can be solved theoretically by using the fundamental equations derived in the first paper in this series, if the spring constant of the cover and the fabric are assumed to change abruptly at some position near the edges of the roller.
As the results of calculations, the following conclusions are obtained :
(1) The effects of the selvage on the load distribution are not so predominant as the effects of roller cover elasticity. However, the change of the spring constant is not abrupt but continuous in actual practice. Hence some effect which cannot be ignored will show up in the transient zone, if the spring constants differ widely.
(2) If a fabric is small in width, it has a good effect on load distribution, as is usually expected. There still remains a chance that the lower load in the region where no fabric is pressed may reduce the load on the fabric near the edge, thus deteriorating the uniformity of the load distribution.

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The purpose of this article is to clarify the relation between the causes for setting-on areas in fabrics and their scales. We have made several experiments to grasp the tendency of scales and analyzed them by using the equations on warp tension which were established in Part 1 and the equation on bending of the race which was introduced in this report.
In the light of the results, we have tried to make clear the causes for setting-on areas and find the means to avoid them. We have reached, the following conclusions :
(1) To make setting-on areas small in scale, the moment of inertia of the tension roller system must be made as small as possible for the automatic bobbin changing cotton loom and the spring constant of the tension spring must be made as small as possible for the water jet loom.
(2) The change of the loom speed when the loom starts or stops has great influence on the scales of setting-on areas.
(3) On the automatic bobbin changing cotton loom, the scale of setting-on areas in fabrics is affected mainly by the change of the warp tension. On the water jet loom, it is affected mainly by the bending of the race.
(4) To avoid setting-on areas due to fluctuations in the beating-up tension of warp just before or after the loom starts, we should do well to equalize this tension to the tension in its stationary running state. That is, compensate for the warp tension around the beat-up point so as to satisfy the following equation :
∫^b_af(t)dt=∫^b_ag(t)dt
where
f(t) : Warp tension curve in stationary running state.
g(t) : Warp tension curve in starting or stopping state.
a, b : Beginning and end of beating-up.

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