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: where ∫^b_a; f(t)dt=∫^b_a; g(t)dt 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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On the assumption that the cross-section of a thread is duangle, the fabric balance of plain cloth has been defined from cloth geometry. The definition takes into considering the balance of crimps.
We have examined the relationship between the fabric balance and the anisotropy of surface friction, with the following results:
In cloths woven from continuous-filament yarns, the construction of fabrics is distinctly related to surface friction.
In this case, the differential frictional effect and fabric balance βλ indicate a negative correlation, where β is a counter-balance and λ expresses the squareness of a fabric.
Fabrics made from spun yarns show only slight variations in frictional force with the direction of rubbing, while the relationship between the differential frictional effect and βλ is indistinct.
It may seem to follow, then, that fabric balance βλ is significant as a value of fabric balance in an investigation of surface friction.

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A universal electronic testing machine has been experimentally produced and the characteristic of its control system has been analyzed with respect to the effect of nonlinear properties of transfer elements on the stability of the system.
When the input signal is sinusoidal, there is no output signal produced if the input amplitude falls in the backlash zone, but when the input signal contains some random noise in it, the stable regions are changed.
(1) Whenκ₁; is assumed the equivalent gain of the neutral zone for the sinusoidal input, a formula κ₁; =(T_A; +T_M;)[-(T²_A; +T²_M; )+√<D>]/k[(T_A; +T_M; )²-radic;<D>]T_A; T_M; is obtained where D=(T²_A; -T²_M; ) ²+4(T_A; T_M; )²(T_A; +T_M; )K
The proportional gain K of the linear part is included in the denominator and numerator of the above formula. As a result, the increase of K value results in the increase of κ₁; . So that, the increase of K extends the stable region for both sinusoidal input and random input. In other words, the increase of K has the same effect on the stability of the system as the increase of (A_z; /a).
(2) Decreasing of variance σ_n; ² of the random noise extends the stable region.
(3) Above conclusions lead us to the next method for increasing the stability of the system.
When the value of A_z; /a is large and the proportional gain K is fixed, it is recommended to place a saturation element in front of the neutral zone, and provide a filter to reduce the value of σ_z; /a.

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