The effect of water and moisture on mechanical properties and microstructures of undrawn filaments are clarified by analyzing the load-elongation curves of undrawn filaments, and the following results are obtained: 1) When immersed in water at room temperature, supherulite grows in the undrawn filament which hasΔn less than 3×10^-3. But oriented crystallization occurs for the filaments having Δn larger than 6×10^-3.2) When undrawn filaments are left in a humid chamber, they are plasticized and then crystallized. At low humidity they are only plasticized. 3) The less the water content in filaments is, the larger the calculated tenacity at break becomes. 4) When filaments adsorb moisture at 20°C×50% RH, they are plasticized but not crystallized. The change of L-E curve is almost reversible, when the adsorption-desorption behavior takes place in the lower humidity region. 5) If undrawn filaments are drawn by hot drawing in the region of natural draw ratio, super-draw phenomena are observed.

View full abstract

Sticky or clinging feeling due to perspiration is one of the important factors of uncomfortable feeling of clothes. In this study, the phenomenon of stickiness on clingingness was simulated physically by the simultaneous measurement of the absorption of a liquid drop and the sliding resistance.
The relation between the wiping off ability of the fabric and the sliding resistance was discussed, and the following results were obtained:
(1) The sliding resistance is influenced by the wiping off ability of the fabric.
(2) The absorbent fabric of bulky construction having small density and composed of thick threads of low twist has little influence on the sliding resistance or stickiness.
(3) The empirical formula for the vertical component of the interfacial tension was assumed as F=2(T/g)sin(θ+α)lN.

View full abstract

Behavior of non-ionic (disperse) dyes when dying nylon 6, polyethylene terephthalate and triacetate fibers in organic solvents has been studied, and following results are obtained.
(1) The absorption isotherm can be expressed in a formula according to Nernst's partition law.
(2) The partition coefficient, the affinity of dyeing and the heat of dyeing in organic solvents are much smaller than those in an aqueous dyeing system.
(3) The diffusion coefficients differ very much by the combination of fibers and solvents. The rate of diffusion increases largely by increasing the degrees of fiber swelling by solvents.
(4) The swelling of fibers is correlated with the solubility parameter of the solvents. The degree of maximum swelling takes place in solvents the solubility parameter of which is nearly equal to that of fibers.

View full abstract