The pressent article discusses the optimum drawing condition of undrawn filaments of poly-xylyleneadipamide. The relatioship between the moisture regain of undrawn filaments and the optimum hot-pin temperature is also discussed.
The results obtained are: 1. Undrawn filaments do not crystallize at 20°C and below 65% RH. But they crystallize at 20°C and over 70% RH. 2. When tenacity and breaking elongation of drawn filaments and drawing tension are plotted agaist the reduced pin-temperature, smooth curves are obtained, only when the moisture regain of undrawn filaments is between 2.2 and 3.6wt%.
If the moisture regain of undrawn filaments increases by 1%, the pin-temperature should be lowered by 12°C. Consequently the following equation is established: T_M; =115-12M T_M; : optimum pin-temperature (°C) M: moisture regain of undrawn filaments (wt%)

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In the previous paper, the structure of helical coil assemblies was presented as a yarn model, and basing upon this structure, the distribution of the phase angles of fibers was discussed.
In this paper, a method to measure the phase angles is discribed, and it is made clear that the phase difference can be calculated by mutual correlation function R(τ) between two crimp waves. This R(τ) takes the maximum value at the position where two phase angles are coincident. The experimental results agree with the phase distributions which can be estimated from the theoretical analysis.

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In this paper, drape coefficients and mechanical properties of 138 samples of woven fabrics are measured, and the relation between them is analyzed by means of residual-regression method. A linear equation by which the drape coefficient can be calculated from the mechanical properties is presented.
As a result, it is shown that the value given by ³√<B/W> is most related with the drape coefficient, where B is bending rigidity (g•cm²/cm), W weight per unit area of fabric (mg/cm²).
Next, the anisotropy in the bending property of fabric is examined, and we get an equation for the drape coefficient, by means of multiple regression method; D_n; =5.1+115.0³√<B₉₀; /W>+131.1³√<B₀; /W>+1.2³√<B₄₅; /W> where B₉₀; is bending rigidity (g•cm²/cm) along warps, B₀; along wefts, and B₄₅; in bias directions.
Finally, the stability of the drape shape is examined. It is found that as the hysteresis in fabric shearing and bending is large, the instability in the drape coefficient increases. From this fact, the experimental technique of drape testing is also discussed.

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