In order to observe the frictional properties of an Angora rabbit fibre against the same sort of fibre in water, the preliminary test was made by means of the inclined-fibre method and the following results were obtained:
1) General properties of the friction are similar to those between the fibre and metal.
2) Distribution of the measured data is larger than that between the fiber and metal, but it is sufficiently small to detect the difference between the untreated and the carroted fibres and to examine the measuring conditions such as the change of load.

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It has been generally recognized that although in the dry spinning process the length and diamenter of the spinning cell are one of the most relevant factors, in this study only a spinning cell, D₁ plant shown in Fig. 1. whose length and diameter are fixed is used.
The maximum draft, one of the measures of spinnability of dopes increased with the output of dopes up to intermediate quantities of output, beyond which the maximum draft decreased. This tendency varies with the kinds of dopes. The increase of output resulted in the increase of solvent content of undrawn filments because of the increase of diameter of extruded filaments. The maximum draw ratio of undrawn filaments also increaed with the output of dope because of the decrease of orientation of the molecules in the direction of the fiber axis introduced during the spinning. The spinning speeds as high as 500m/min could be accomplished. The increase of spinning speeds brought about the decrease of the diameter of filaments and the staying time of filaments in the spinning cell and the increse of draft. The elongation and the maximum draw ratio of undrawn filaments decreassed and the dry strength increased due to above mentioned factors. The diameter and the number of the jet holes used in the studies ranged 0. 12_??_0.20mm and 30_??_80 respectively. As the diameter and the number of extruded filaments became larger, the DMF content increased. It was recognized that the dimension of spinnerets was also one of the most important factors in dry spinning process.
The hot air intake varies up to 3 m³/min. It was found that the DMF content in undrawn filaments not largely varies with the volume of hot air, but is remarkably influenced by the effective length of spinning cell, because the volume range of hot air used in the experiments (i. e. 0.5_??_3m³/min) is larger as compared with the volume of evaporated DMF. When hot air is led into the spinning cell counter-current to the filament, evaporation of the solvent from the filaments became slower.
The spinning temperature used in the range is 140_??_220°C. The excessively high temperature in the spinning cell leads to cavit or bubble defects in the filaments due to rapid solvent evaporation. On the other hand, the lowest admissible spinning temperature could be remarkably low and in practice, it is possible to be around 140°C by choosing other spinning conditions properly. The lower spinning temperature leads to improvements in the tensile strength and elongation.
The cross-section of undrawn filaments are dumbbell or bone-shaped in most cases. The ratio of longer distance to shorter distance of dumbell-shaped cross-section and the degree of skin formation varies with the solvent evaporating velocity.

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Fibers spun from polyviny alcohol having various degrees of polymerization were heat stretched and heat treated. Solubility and shrinkage in hot water decreased and crystallinity increased for fibers of smaller degrees of polymerization. Resistance of fibers to hot water is not always proportional to its crystallinity.
The effect of heat treatment on fibers from polyvinyl alcohol obtained by the hydrolysis of polyvinyl acetate of 70% conversion of polymerization is more satisfactory than of 100% conversion.

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In mule running, it is important to adjust the conditions of carriage displacement, spindle revolution and sliver delivery. To check the suitability of these conditions, the degree and the profile of tension generated during the drafting is discussed.
A tester (Fig. 1) has been designed to draft the woollen slubbing under various conditions of draft ratio and spindle revolution, and to measure the tension generated.
By this tester, the tensions for seven samples are measured under the same condition as shown in Fig. 3. The results are shown in Fig. 4. Various profiles of tension are mainly influenced by the tensile properties of the material, and partly influenced by the counts and fiber length.

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In order to know the effect of chelate formation with Hg on the dyeing properties of wool, the energy of activation in the absorption of dyes by Hg treated wool is determined. The same process as in the case of the absorption of Hg with wool is employed. The dyeing process is considered to be divided into the following three steps (a) absorption of dyes on the surface of fiber, (b) the diffusion of the adsorbed dyes at the surface of fiber into the inner part of fiber, (c) chemical combination of dyes with metallic ions in fiber. The following relationship is found appliciable in this case:
Where, x is reaction rate (the quantity of dyes absorbed by wool in a state is divided by the quantity of dyes absorbed at equibrium), t is time.
It means that the diffusion of dyes in fiber is a rate determining step in this dyeing. From the above equation (1), (2) is obtained,
and
The energy of activation is calculated from (4) belows,
From the inclination of these straight lines and from the difference between log x_t20 and log x_t30, and between log x_t30 and log x_t50, the energy of activation is computed. Acid orange II, acidic dyes, and chrome methyl orange A, mordant dyes, are used.
The energy of activation of the absorption of these dyes with the Hg treated wool was compared with that with non treated wool. For non-treated wool, E were found to be 7570 cal/mol between 20 and 30°C, and 9830 cal/mol between 30 and 50°C, for Acid orange II and 11800 cal/mol (20_??_30°C), 11150 cal/mol (30_??_50°C) for chrome orange A. For Hg treated wool, E were 10720_??_13500 cal/mol (20_??_30°C) and 19900 cal/mol (30_??_50°C) for Acid orange II, and 26000 cal/mol (20_??_30°C) and 22000 cal/mol (30_??_50°C) for Chrome Orange A.
Using the above dyes, Hg treated wool needs much more energy than non-treated wool does.
Cross linking formed during the chelation with Hg in wool and the change of the charge in wool may have some relations to the above results.

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Absorption spectrum of triazole derivative from Congo Red were determined in solution and cellophane. The cellophane was dyed with this dye. The position of the absorption band in cellophane is displaced to longer wave lengths (7.5mμ in 3800 Â). The energy change on displacement of absorption band of triazole derivative from Congo Red in cellophane is the same as the common direct dyestuffs.

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Mainly the mixture of urea and other agents were tested for the purpose of finding the agents which have strong softening effects upon raw silk.
1) The mixture of urea and higher alcohol (emulsified with sulfuric ester of higher alcohol) had a coparativelystrong effect.
2) In the case of the mixture of urea and higher alcohol, when the temperature of the treatment had reached 70°C the weight-increase ratio and also the effect became higher and stronger.
The influence of numbers of C of higher alcohol and that of pH the solution were not clear.
3) The nature of the raw silk which is treated with the mixed solution of urea and higher alcohol approaches gradually to that of untreated one as time elapses.
4) Raw silk is not especially softened by such a method in which the raw silk is first treated with urea solution and then treated with the solution of other agents.
5) The mixture of urea and sodium cyclohexylsulfamate showes a fairly strong softening effect upon raw silk. The effect become stronger when higher alcohol is added to it. The mixture of urea and KCNS also has a comparatively strong softening effect.

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The degumming of silk cocoon fibre can be easily performed by the enzyme method at optimum pH 6_??_8 and temperature 40_??_45°C in a one-hour treatment process compared to the fermentation process which requires two-three days. Enzyme does not discolor the fibre and furthermore, observations of the fibre surface construction under the electron microscope and by the determination of the ratio of desizing sericin confirmed better and complete degumming results compared to that of by the papain and trypsin enzymes (Plate 14). Bacteria enzyme degumming (Plate 16, 17, 18) is different from the marseilles soap, sodium carbonate and ammonia water degumming (Plate 5_??_10).
The enzamine method can be safely applied on all varities of cocoon and does not affect the fibroin fibre of any part of the cocoon layer. It selectively decomposes sericin and degumming is performed uniformity.

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