An investigation has been made to examine the effect of the stress applied to the seam, cloth construction and the stitching technique on the yarn slippage of the woolen cloth.
It was found that the amount of yarn slippage varies depending on the amount of the stress applied to the seam and the cloth construction such as the density and the yarn count. However, certain stitching techniques can prevent the yarn slippage.
In other words, top stitched seams, flat felled seams, double stitched seams which are sewn with an appropriate space between stitching can be used to prevent the yarn slippage. It seems that the top stitched seam is a very effective method, especially when the amount of the yarn slippage and the visual effect of the seam are taken into consideration.

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The fatigue phenomenon of the seam tensile strength was classified and each process was confirmed experimentally under sewing conditions of the three kinds of sewing threads and three kinds of stitches by the cyclic tension. The following results at the small range of fatigue ratio have been obtained.
1) The fatigue process by a cyclic external force was classified into four types. Three types of them were confirmed experimentally. Each fatigue process was approximately shown by the following equation:
f (X_i) =a (log X_i) ⁿ
where, X_i: cyclic times (X_i≤2×10⁴),
f (X_i) : fatigue ratio,
a, n: constant determined by sewing condition.
2) Three types of fatigue processes for log X_iwere as follows:
Type I: expressed by a linear equation (lock stitches of nylon filament thread),
Type II: expressed by a quadratic or cubic equation (three kinds of stitches of cotton thread),
Type III: expressed by composite equations (three kinds of stitches of polyester spun thread, single thread chain stitches and two thread chain stitches of nylon filament thread) .
The fatigue ratio of Type I and Type II were greater than that of Type III.

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From the result of the estimation of the colour change from dry cloths to wet ones by the colour depth value (C*), the authors introduced the next equation in the previous report.
Cw*=a (CD*-p) ²+q
where, Cw*: colour depth value in wet state,
CD*: colour depth value in dry state, and
a, p, q : constant determined by the kind of fibers.
In this report, the authors continued to investigate these colour change by means of HC*B* colourimetric system and found that, though the changes in hue (H) and brightness (B*) were very small, the change in value (V) was almost the same rate in various specimens.
HD≅Hw, BD*≅BW*
Vw≅VD-ΔVo
where, ΔVo: decrease of value by wetting the original dry white cloth.
Thus, it was found that the chroma (CW) and the colour depth value (CW*) of wet cloths could be calculated by the following equations through the measurement of the colour in dry state.
CW=BD* {10- (VD-Vo) } /10
CW*=21.72×10CW^C_w⋅^tanH/2^V_w/²
Conversely, the colour of the cloths in dry state can also be calculated from the measurement of colour of cloths in wet state. Therefore, in the case of colour mathcing in dyeing, it seemed to be possible that the colour of dry cloths is predicted with considerable accuracy from the immediate measurement of wet cloths before drying.

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