In order to examine the adsorption of amphoteric surface active agents (amphoteric-SAA) on a liquid paraffin, a carbon black and an albumin from eggs, an investigation has been made of the changes in ζ-potential of samples by adsorption of amphoteric-SAA and the quantity of surface adsorption of an amphoteric-SAA by calculating the surface charge density evaluated from ζ-potential.
In the solution of pH 5.4-5.5, the increase in the concentration of an amino acid type amphoteric-SAA changed the sign of the ζ-potential of these smaples from negative to positive, then it was suggested that in the solution of lower than 8.4 in pH value, i.e., isoelectric point (pI) of an amino acid type amphoteric-SAA, an amphoteric-SAA dissociated into a cationic ion was much adsorbed on the each sample by the electrostatic effect.
This was ascertained by the fact that in the case of the bath composed of the same pH value, the calculated quantities of the surface adsorption of an amino acid type amphoteric-SAA were much more than that of a betaine type amphoteric-SAA of pI 3.8 dissociated into an anionic ion. This was especially remarkable in the case of an albumin.

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The degradation of nylon-6 fibers treated with peroxide bleaching agents have been studied. Some physical properties of the nylon-6 filament yarn bleached with sodium percarbonate; the initial young's modulus, the tensile strength and the elongation at break and the decomposition rate of the peroxide bleaching agent under the various conditions, were measured. In addition, the degraded fibers owing to the bleaching were observed by an optical and a scanning electron microscopy. It was found that a metal contained in nylon-6 fibers, especially a copper metal fairly accelerated the decomposition rate of the peroxide bleaching agent in an aqueous solution. However, coexistence of a non-ionic surfactant controlled the decomposition rate. The repeated bleaching of nylon-6 filament yarns changed the configuration of a stress-strain curve of the fiber and decreased the initial yonug's modulus accompanied by the decrease of tensile strength at break.
Scanning electron micrographs of degraded nylon-6 fibers showed that the surface roughness increased with the repeated bleaching and that the characteristic crack occured perpendicular to the fiber axis.

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The oxygen index (OI) is a value indicating the degree of the flammability of polymers. This paper describes an experimental study on the oxygen index of double layered materials of different kinds of fabrics. Two kind of fabric specimen are seamed each other into a double layered material by a glass fiber thread.
The oxygen index of a cotton or an acrylic fabric layered with various fabrics follows the composite law and may be calculated as follow: (OI) _n= {V₁/ (V₁+V₂) } (OI) _a + {V₂/ (V₁+V₂) } (OI) _b
where, (OI) _n: oxygen index of double layered fabrics,
(OI) _a, (OI) _b: oxygen index of single layer fabric of a, b, V₁, V₂: volume fraction of fabric of a, b.
The measured oxygen index of a flame retardant cotton fabric layered with a various flammable fabric is lower than the oxygen index calculated by the composite law. By contrast, the measured oxygen index of a flame retardant cotton fabric layered with a flame-proofed fabric is higher than the calculated oxygen index. Hence, the synergism effect of the flame retardant treatment is recognized.

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In general, it is well known that the colour of the dyed fabric wet with water gives us more deep feeling than that of the dry fabric. But, the quantitative difference of these colour shade is not yet cleared enough.
Therefore, the relationship between the dry colour shade (C_D^*) and the wet one (C_w^*) was investigated. From the result of this investigation, the following formula was derived:
C_w^*=a (C_D^*-p) ²+q,
where, a, p and q are constant varying with the hue and the kind of fabrics.
In the case of pale shade fabrics, the change of their colour shade under wet condition occurs with the decrease of the value. As the decrease of Munsell value is approximately constant, the colour change can be estimated by determining the change of this value of wet white fabrics. However, the influence of the chroma appears as the colour becomes heavy shade.

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