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Volume 20, Issue 8
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Takeshi Yasuda1964 Volume 20 Issue 8 Pages 507-511
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSNylon 6 was treated by dry heat setting and wet heat setting, and abrasion resistance of its monofilament was measured. On the other hand, its density, relative viscosity, tensile strength and elongation, and birefringence were measured. As the result the following facts were observed:
(1) When nylon is treated by heat setting its abrasion resistance increases, but generally wet heat setting is more effective in this respect.
(2) The abrasion resistance increases with increased degree of crystalinity, but at higher temperatures intermolecular bond of the amorphous region is dissolved, and orientation is disturbed. Consequently, it may be considered that abrasion resistance decreases.
(3) In the case of dry heat setting, optimum temperatureis found to be about 180°C.
(4) Molecular weight has no considerable effect on abrasion resistance.View full abstractDownload PDF (297K) -
(I) SOME FACTORS AFFECTING THE HEAT RESISTANCE OF RAYON TIRE CORDEiichi Murakami1964 Volume 20 Issue 8 Pages 512-518
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSSome factors affecting the heat resistance of high tenacity rayon tire cord have been investigated for the purpose of improving it and results as following were observed:
(1) Both raw and RFL-dipped cord of high tenacity rayon suffer heat deterioration by heating in the air atmosphere, but the heat degradation of the latter is more sever than in the former.
(2) The higher the copper number of pulp is, the lower is the heat resistance of raw and dipped cord which are made using them as raw materials.
(3) By the treatment with the finishing agent containing amines, the heat resistance of the raw cord is improved, but the heat resistance of the dipped cord is not.
(4) The remarkable heat degradation of RFL-dipped cord is attributable to the low heat resistance of natural rubbre latex. The heat resistance of the cord is lowered by the adhesion of the unsaturated oil.
The heat resistance of the dipped cord is however improved by being dipped in the higher heat resistant synthetic rubber latex, such as Gentac.
From these results, it may be considered that the heat degradation of rayon cord is induced by the free radical mechanism.View full abstractDownload PDF (519K) -
(X). THE MECHANISM OF FIBER FORMATIONEiichi Murakami1964 Volume 20 Issue 8 Pages 519-524
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSAccording to our series of studies, a new theory on the spinning mechanism of modified viscose has been proposed.
In this paper, the courses of coagulation, regeneration and stretching of modified viscose were investigated in details with the following results:
(1) The degree of gel swelling of the spinning filaments lowers as the length of spin bath immersion is increased and come up to the equilibrium degree at a certain length of immersion.
(2) The residual γ-value of the spinning filaments decreases as the length of spin bath immersion is increased.
(3) At a certain point of the longer immersion length, that is, the lower residual γ-value than that of the equilibrium gel swelling, the stretchability rises to maximum and the highest tenacity is obtained.
Based on these facts, the mechanism of the fiber formation of modified viscose is discussed applying the theory of rubber elasticity.View full abstractDownload PDF (1102K) -
(3) DIMENSIONAL CHANGE ON SUCCESSIVE HEATING AND COOLING FOR HOT DRAWN P. E. T. FIBERSIsamu Kuriyama, Kan Shirakashi1964 Volume 20 Issue 8 Pages 525-534
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to investigate the phenomenon of elongation occurred in heated P. E. T. fibers under a constant length after hot drawing, the effects of draw ratio and drawing temperature on longitudial and thermal stress changes for successive heating and cooling at a constant rate were discussed. And also the fine structure of specimens, quenched at 0°C from transformation point of longitudial change-temperature curves were studied by X-ray, density and birefringence. The results obtained are as follows:
1) The low stretched specimens at 70° or 80°C in water and subsequently passed the thermal history of heating and cooling show a-axis orientation in X-ray diffraction patterns, and the length of fiber may becomes slightly longer than that of the original, because of superposing thermal creep effects on the spontaneous elongation beyond a temperature range of maximum shrinkage. On the other hand, the specimens high stretched at 70°C (draw ratio: 3.8) shows a fiber-like orientation in X-ray pattern as well as the one at 60°C (draw ratio: 2.0). Both of these show a larger thermal contractive stress, The shrinkage at a range of 85_??_90°C as well as the abnormal elongation in the vicinity of 115°C become smaller. And the specimen stretched at 70°C (draw ratio: 2.5) shows an intermediate orientation in X-ray pattern, and the orientation of its crystal may have preferentially a fiber-like orientation, On the other hand, the molecular chains in the amorphous phase do not orient so much and accordingly the maximum thermal contractive stress becomes smaller. The thermal shrinkage becomes larger, while the abnormal elongation smaller due to the unstable, structure.
2) The drawn specimen at 90°C (draw ratio: 2.0) shows negative birefringence and a-axis orientation in X-ray pattern. While both the hot shrinkage and contractive thermo-stress of this sample become smaller, the, spontaneous elongation does not occur so much.
3) The contribution of crystalline birefringence Δnc•X for a-axis oriented fiber on the temperature range of cold crystallization shows negative, and for c-axis oriented fiber strongly positive. On next heating and cooling processes, absolute values of Δnc•X may increase with closed regularity of crystals. On the other hand, the amorphous birefringence Δna shows the minimum values on the temperature range of maximum shrinkage, and on the heating and cooling processes values of Δna only increase in spite of rising and lowering temperature.View full abstractDownload PDF (1607K) -
(4) EFEECTS OF TIME-DEPENDENCE ON THE DIMENSIONAL CHANGE AT A CONSTANT TEMPERATUREIsamu Kuriyama, Hiroatsu Kaneko, Kan Shirakashi1964 Volume 20 Issue 8 Pages 534-540,526
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn the previous paper, taking notice of the temperature range of the maximum shrinkage (85°_??_90°C) and the abnormal elongation (in the vicinity of 115°C) for successive heating and coolling at a constant rate, the effects of time-dependence on the dimensional change at a constant temperature were investigated in the temperature range of 85°_??_115°C. Especially, the effects of the load on the dimensional change for lower stretched P. E. T. fibers, which were shown markedly abnormal elongation at heating, were studied. Thermal changes in the fine structure are discussed based on the X-ray diffraction patterns. The results obtained are as follows:
1) The shrinkage for most of the stretched fibers, except for higher stretched (draw ratio: 3.8), becomes larger with the time passed in silicone oil bath at 85°C under less load. The shrinkage of the intermediate oriented fiber (draw ratio: 2.5), having an unstable structure, becomes larger; the a-axis oriented (non-drawn and lower stretched fibers) are medial; next in order, the fiber-like oriented fiber (draw ratio: 3.8) becomes less so. The higher stretched fiber (draw ratio: 3.8) shows a slight elongation beyond 90min. The higher stretched fiber continues to have extension monotonously at 102°C, but other stretched ones change shrinkage for extension in a short time with increased draw ratio. The shrinkage _??_ time curves at 115°C are similar to the shrinkage behavior at 102°C.
2) Effects of the dimensional change at 102°C for lower stretched fibers are remarkable, The abnormal elongation on the shrinkage-time curve may have been superposed on the thermal creep effect due to the elongation that becomes larger with increased load over the spontaneous elongation caused by the cold-crystallization
3) When the shrinkage and logarithmic time curves under less load for the same fiber at different temperatures are compared, it is found that they may be superposed by a simple lateral shift along logarithmic time scale within the temperatures of this experiment.
4) In contrast with the time-dependence on dimensional change under tensionless condition, higher stretched fiber shows shrinkage at all times on the degree of the heat-set and logarithmic time curves under a constant length, or, intermediate stretched . fibers always show elongation. On the other hand, the lower stretched fibers may change elongation for shrinkage during the heating.View full abstractDownload PDF (1317K) -
(3) ON LIGHT LOADINGEiichi Kuze, Teruo Furushima1964 Volume 20 Issue 8 Pages 541-547
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe phenomena which are negligible on larger loading may, when the normal force or the load on sliding bodies is smaller, become subjects of problems. The following two problems have been studied.
1. The operations of surface tension.
1-1. Plain-cylinder and plain-ellipsoid are the fundamental configurations of contacts. The contact configuration of a monofilament on the smooth stainless steel cylinder seems nearly that of the plain-cylinder when the amount of added lubricant is larger. And on the mat finished cylinder and a monofilament, their contact configuration seems nearly the plain-ellipsoid type when a larger amount of lubricant is added.
1-2. It is possible to assume that the contact radius increases with the increased amount of added lubricant. This fact appears as the amount of added lubricant is smaller.
1-3. The influence of the cohesive load based on the surface tension of added lubricant to the fibre_??_or yarn tensions has been investigated. If the value R0 of the cohesive load based on the surface tension per unit length of fibre or yarn is constant, then the following equations on the belting problem are derived: Where, N is frictional index, T and T0 are final tension and initial, ρ is radius of the cylinder, θ is lapping angle of fibre or yarn against the cylinder, a is constant.
2. On the shearing of lubricant near the outside of deformed surface of asperity;
2-1. First considering the problem of the hydrodynamic lubrication of a hard ellipsoid body on a plain, the following equation is obtained: where F is frictional force, k′ the constant which contains main radii of ellipsoid a, b and c for paramenters, _??_and k the constant which contains c/a and b/a for parameters. μ and U viscosity of lubricant and sliding speed.
2-2. From the above equation and the experimental results, the following conclusion has been obtained: The problem concerning the shearing of lubricant near the outside of deformed surface of asperity need not be considered.View full abstractDownload PDF (346K) -
Ichiro Sakurada, Yasuyoshi Sakaguchi1964 Volume 20 Issue 8 Pages 548-554
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSUntreated and heat-treated (at 180°C or 225°C) polyvinyl alcohol (PVA) fibers imbibing solutions (1g/g-fiber) of various catalysts were heated with styrene (1.8g/g-fiber) in sealed tubes for graft polymerization. When potassium or ammonium persulfate were used as catalysts, the grafting generally proceeded smoothly, and the graft efficiencies of about 90% were obtained under suitable conditions. The graft efficiencies were affected only a little by catalyst concentrations (0.3_??_3%), solvents (water, water 15-methanol 85, water 30-acetone 70) of the imbibing solutions, and heating temperatures. In the cases of hydrogen peroxide, the graft efficiencies were generally lower than those in the cases of persulfates, but the efficiencies of about 80% were obtained under favorable conditions. The graft efficiencies increased with decreasing catalyst concentrations and heating tempratures, and increasing water contents of the imbibing solutions. In the cases of α, α′-azo-bisisobutyronitrile and benzoyl peroxide, the grafting did not proceed so smoothly as in the cases of persulfates; the efficiencies were only about 55% even under favorable conditions, and the efficiencies were affected considerably by catalyst concentrations and heating temperatures.
The grafting was affected only a little by previous heat treatment of the fiber so far as the water contents of imbibing solutions were high, but considerably affected when the water contents were lower.
As the other series of experiments, dry PVA fibers imbibing catalysts were heated with styrenemethanol mixtures for the grafting, and it was found that the reaction proceeded as smoothly as with fibers imbibing catalyst solutions. But, the grafting scarcely proceeded when dry fibers were heated with pure styrene.
Graft polymerization of styrene in emulsion states onto PVA fibers were also investigated, The grafting of high efficiencies could be obtained using 2% polyethylene glycol oleyl ether as an emulsifier.
The grafting behaviors of the PVA-styrene system were generally similar to those of the cellulose-styrene system, but some small differences were found between them.View full abstractDownload PDF (453K) -
Ichiro Sakurada, Yasuyoshi Sakaguchi1964 Volume 20 Issue 8 Pages 555-559
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSUntreated and heat-treated (at 180°C or 225°C) polyvinyl alcohol (PVA) fibers imbibing solutiins (1g/g-fiber) of various catalysts were heated with vinyl acetate in sealed tubes for graft polymerization. When potassium or ammonium persulfate were used as catalysts, the grafting proceeded smoothly under suitable conditions, but the efficiencies were generally lower than those in the case of styrene, and were affected by heating temperatures and solvents of the imbibing solutions. In the cases of hydrogen peroxide, the grafting proceded with some ease when water contents of the imbibing solutions were high, but the efficiencies were generally lower than those in the case of persuefates. In the cases of α, α′-azo-bisisobutylonitrile and benzoyl peroxide, the homopolymerization proceeded predominantly as the grafting scarcely occured.
The grafting was affect to a greater extent than in the case of styrene by heat treatment of raw PVA fibers.
Dry PVA fibers imbibing catalysts were also heated with vinyl acetate-methanol mixtures. The grafting proceeded slightly when fibrous structures were maintained, but proceeded considerably when fibers dissolved in monomer mixtures during the heating. In this case the droducts of about 50% increased weight dissolved almost comdletely in acetone.
The grafting of vinyl acetate in emulsion states onto PVA fibers were also examined, but no desirable results were obtained.
The difference of grafting behaviors between vinyl acetate and styrene onto PVA fibers was similar to that onto cellulose fibers.View full abstractDownload PDF (299K) -
[in Japanese]1964 Volume 20 Issue 8 Pages 560-563
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (241K) -
Haruo Sanuki1964 Volume 20 Issue 8 Pages 564-571
Published: August 10, 1964
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe author has investigated which of the removing actions are better flowing-out and the steeping methods for the yolk of greasy wool, from the results reported in Parts 2 and 3. It was found that the flowing-out method was excellent for every solvent. In the fourteen kinds of solvent used for experiment, methylene chloride was found the best solvent and the next carbon tetrachloride for removing the yolk. Kerosene was unexpectedly excellent too. Acetone, methyl ethyl ketone, anon and ethyl ether were extremely inferior.
The author has also made the experimental measurements concerning the fatigue property of liquor that was accompanied by repetition of degreasing treatment for the eight kinds of typical solvent. The fatigue property of each solvent was very remarkable in the case of the flowing-out method, but one was comparatively little in the case of the steeping method.View full abstractDownload PDF (669K)
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