Masao Horio

Crimping of Wool Fibers

By employing differential staining under controlled conditions and by experiments on resist ance to chemicals, it is shown that wool possesses an inherent bilateral structure which runs the entire length of the fiber from root to tip. The similarity in behavior of wool, as shown in this study, to the formation of crimp in viscose rayon indicates that structural asymmetry may be re sponsible for the coiling and crimping nature of the wool fiber. Isolated single wool fibers show a pronounced tendency to coil; however, when movement is restricted by the proximity of other fibers in a lock or in mass, the result is the formation of crimp.

Forced Vibration of Reed as a Method of Determining Viscoelasticity

The motion of a clamp‐free reed excited by a sinusoidal displacement of the clamped end was analyzed by rigorously solving the fundamental equation for vibration. The real and imaginary parts of the modulus are given in terms of resonant frequency and band width of the frequency curves. The results are compared with those of Nolle which were obtained in an approximate manner by introducing an equivalent electric circuit. As long as the mechanical loss tangent is smaller than 10−1, as is the case in most high polymers, the practical error caused by the approximation is estimated to be insignificant. Nolles network was interpreted from a purely mechanical standpoint by means of the fundamental equation for vibration.

Dynamic Measurements of Physical Properties of Pulp and Paper by Audiofrequency Sound

The dynamic Youngs moduli of various types of paper were measured by the vibrating reed method. The Youngs modulus of paper increases statistically at a rate approximately proportional to the square of its density. The modulus and density of paper increase with the degree of beating. The sulfite and sulfate fibers behave differently during beating. The angular dependence of Youngs modulus, tensile strength, and elongation at break was analyzed mathematically; and the results were verified by experiments. According to this theory, the mean value of Youngs modulus and tensile strength of machine‐made paper should be expressed by the geometrical mean of the values of the machine and cross directions, whereas the mean value of elongation can be given by the arithmetical mean. The removal of parenchyma cells is very effective in reducing the Youngs modulus of dissolving pulp. The viscoelastic properties of paper were observed within the frequency range from 20 to 180 cps. The dynamic modulus and mechanica...

Viscoelastic Properties of Several High Polymers

The viscoelastic properties of viscose monofils differing in the degree of orientation were measured by means of the vibrating reed method within the frequency range from 20 to 100 cps. The frequency dependence as well as the orientation dependence of the modulus and viscosity coefficient were discussed and connected with the relaxation mechanism. It could be expected that the anomalous dispersion should occur at frequencies lower than 1 cps and at high frequencies such as 104∼106 cps, the former being due to the motion of secondary cross bonds permitting the chains to slip, and the latter to the motion of segments. In order to supplement the data which support this discussion, measurements were extended to Cellophane, films of cellulose acetate, and Celluloid, and also to films of synthetic high polymers such as Polycaprolactam and polyvinyl chloride. The latter two substances showed noticeably different dynamic properties from that of cellulose, and this could, assumably, be associated with the fact tha...

Theory and Morphology of Crimped Rayon Staple

ure 1) which was equal to that in the most superior Merino wool fibers. It was found that such crimps occurred whenever the acid content in the coagulating bath was reduced to a certain degree far below that previously employed in practical viscose spinning procedure. Further studies to develop this process were carried out by Suda [4]. At present, more than one-third of the rayon staple produced in Japan is crimped staple manufactured by this process, and production figures promise a rapid increase for the future. At the time of this discovery, it was sur-

Colloid-Chemical Basis for the Action of the Coagulating Bath upon Viscose

In an effort to interpret the phenomena which occur when viscose solution is extruded into the spinning bath, as in the viscose rayon process, the stability of cellulose xanthate sol in the presence of electrolytes has been studied. Coagulation values for various salts and mixtures of salts on cellulose xanthate are reported. From these values a classification of ions according to their coagulating power and mechanism of coagulation has been suggested. In similar fashion, the behavior of salt mixtures on cellulose xanthate sol has been classified as additive, sensitizing, or antagonistic in accordance with colloid-chemical theory. The rate of coagulation by different ions and the influence of the degree of sulfidity and the degree of polymerization of the cellulose xanthate on the coagulation values are discussed. These data can be corre lated with changes which take place in the course of fiber formation during viscose rayon spinning.

Injection molding of liquid‐crystalline polymer (abstract)

A liquid‐crystalline copolyester consisting of 1,4‐oxybenzoate and ethylene terephthalate groups was subjected to the injection molding using a rectangular mold 120×70×1 mm with a slot gate of 0.5‐mm gap. The structures of injection‐molded products were studied in detail by the x‐ray diffraction method and the techniques of polarizing microscope. The molecules in the outer layers contiguous to both surfaces of injection‐molded rectangular plate were highly oriented in the direction of injection and strongly birefringent, whilst the interior layer remained principally unoriented. The generation of characteristic binary structure with sharp boundaries was interpreted in terms of CAE data and the rheological behavior of the melt of liquid‐crystalline polymer. The products of usual polymer made up of flexible molecules, on the contrary, gave isotropic products. The measurements of relaxation time afforded a key to an understanding of the difference between the behavior of liquid‐crystalline polymer and that o...