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Volume 23, Issue 8
Displaying 1-8 of 8 articles from this issue
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1. ON THE SHAPES OF COAGULATED FIBERS AT THE STAGE OF EXTRUSIONHideo Ohe, Shuichiro Isaka, Masao Ishiwara1967 Volume 23 Issue 8 Pages 355-362
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn the spinning of acrylic fiber from the dope of copolymer of 10% conc., using NaCNS as solvent and NaCNS aqueous solution as coagulation solution, the dope column expands in an onionlike side-view immediately after extrusion.
In this experiment, the maximum diameter of extruded fiber and the distance to the maximum expansion point from spinneret holes were measured, in varying spinning velocity and the diameter of spinneret holes.
It was observed that spinning velocity has effects on the maximum diameter of extruded fiber, the distance and time to reach the maximum expansion point from spinneret holes, and that, when the velocity exceeded a certain value, the shape and the position of the onion changes depending on the tension. The critical spinning velocity was estimated as 175cm per min. in relation to the distannce to the maximum expansion point.
When the diameter of aspinneret hole is 0.09mm, the value of the maximum diameter of extruded fiber and the calculated diameter of extruded dope column are the same, and apparently no diffusion was noticed between coagulation solution and dope column. As the spinneret holes became finer, the maximum diameter became smaller than the calculated diameter of extruded dope column. This is due to the extruded dope column that attains the critical concentration of coagulation faster as the amount of NaCNS per unit length of the extruded dope column become less.
As the spinning velocity becomes larger in the non-tension spinning, the maximum diameter of extruded fiber and the distance to the maximum expansion point from spinneret holes became smaller, but, they could not become smaller than the diameter of spinneret holes. The time to reach the maximum expansion point was 10-3 sec.View full abstractDownload PDF (507K) -
(2) ON THE COAGULATION VALUE AND THE CRITICAL CONCENTRATION OF ACRYLIC AN-MA COPOLYMER IN SOLUTIONHideo Oe, Kunihiko Kawamura, Masao Ishiwara1967 Volume 23 Issue 8 Pages 363-367
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSAcrylonitrill (AN)-methyl acrylate (MA) co-polymers in which contents of MA varied from 0 to 15, wt. %, were dissolved in 50 wt. % NaCNS aqueous solution to make 1% polymer solution at 30°C. 10cc. of them were titrated with 0, 6, 11, 16, wt. % NaCNS aqueous solution at 5-10°C or 18-20°C. In this report, the amount of precipitant just to make polymer precipitated is called coagulation value or the point of turbidity. The critical concentration is expressed with the concentration of NaCNS, wt. % based on liquid phase at the point of turbidity.
It was found that the coagulation value increases as the concentration of NaCNS in the precipitants and the MA content in the copolymer increase. The critical concentration of NaCNS in liquid phase is reversely proportional to the MA content in polymer. That is, each copolymer has its own critical concentration, depending on the MA concentration.
Data of critical concentration shows that water is the most powerful precipitant. 6% NaCNS conc. aqueous solution is the second. 11 and 16% aqueous solution are mild.
It is noticed that the measuring temperature affects on the critical concentration.View full abstractDownload PDF (317K) -
(3) ON THE PHYSICAL PROPERTIES OF NaCNS AQUEOUS SOLUTIONHideo Oe, Yoshio Ichikawa, Kunihiko Kawamura, Ikuo Kajima, Masao Ishiw ...1967 Volume 23 Issue 8 Pages 368-373
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESS1. Specific gravity -Specific gravity of NaCNS aqueous solution of concentration from 10.35wt % to 57.62% was measured at the temperature of 0°C to 40°C. y=-0.0003585z+0.00001344x2+0.0055x+0.9999 was the result. y=specific gravity z=measuring temperature °C x=NaCNS concentration in weight percentage.
2. Refractive Index -Refractive index of NaCNS aqueous solution of concentration from of wt 0% to 60% was measured at 30°C, using Abbe Refractometer.
3. Freezing point -Freezing point of NaCNS aqueous solutions of which concentration ranged from 0% to 58% were measured. Up to the 20% NaCNS concentration, the degree of depression of freezing point was about 0.67°C/1% NaCNS
4. Specific heat -A formula, c (specific heat)=-0.000579x+0.988 was obtained in the range 10% to 58% NaCNS concentration.
5. Viscosity -The relative viscosity of NaCNS aqueous solution against water was measured at 30°C. The values of relative viscosity at the NaCNS concentration of 10.8% and 58.2% were 1.055 and 6.453 respectively. In the temperature range from 9°C to 60°C, the relative viscosity of NaCNS aqueous solution of 10%, 35% and 60% concentration was measured. The relative viscosity of NaCNS aqueous solution at 9°C was 9.801, while at 60°C it became 4.155.
6. Boiling point and latent heat of evaporation -Boiling points of NaCNS aqueous solution of 35% and 58% weignt concentration were measured at the pressure of 760 to 240mm Hg. For instance, the boiling points of the above solutions at 240mm Hg were 78.8°C and 96.7°C. Latent heat of evaporation was calculated in relation with pressure and boiling point.
7. Solubility of alkali metal salts into concentrated NaCNS aqueous solution -Various alkali metal salts were tested. The result proved that nitrate should be noticed for its higher soluble nature.View full abstractDownload PDF (332K) -
EFFECTS OF MOLECULAR WEIGHT AND MOLECULAR WEIGHT DISTRIBUTION ON FIBER SPINNABILITY OF POLYPROPYLENE(PART II) EFFECTS OF MOLECULAR WEIGHT DISTRIBUTIONKenji Kamide, Yoshihiko Inamoto1967 Volume 23 Issue 8 Pages 374-378
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThis paper is concerned with the effects of melecular weight distribution (MWD) on fiber spinnability of polypropylene. Five kinds of polypropylene were melt-spun using the straight die of 1.00mm diameter with 5mm length in temperature range of 190_??_350°C at the rate of output 0.765cc/min. Details of the sample are following: Three blends (I) having nearly same viscosityaverage molecular weight _??_=1.8×105, ranging in breadth of MWD represented by the ratio of weight-to number-average molecular weight _??_ from 1.2 to 2.0 which were prepared from fractions by mixing in solution, a whole polymer (II) having _??_=3.2×105 and _??_=3_??_4, whole polymer (_??_=1.97×105) (III) from which about 10% of the lower and higher molecular weight portions were removed, respectively, a fraction (IV) having _??_=2.5×105, a fraction (V) added as much as 10% of lower molecular weight fraction (_??_=2.4×104) to (IV). According to the method described in the preceeding paper (Kamide, Inamoto; This journal, 23, 79 (1967)), maximum draft ratio (MDR), i.e. the ratio of the linear velocity at the die-wall to that at the winding wall, at which the continuous melt spinning becomes abruptly impossible, was determined as the parameter of spinnability. Spinning temperature, at which MDR>103 holds, increases with _??_ On the other hand breadth in the range of the spinning temperature corresponding to MDR>103 is independent of _??_. The optimum temperature of melt spinning (OST) is defined as the temperature at which MDR reaches maximum. OST is found to be a kind of material parameter depending on molecular weight and MWD and independent of the spinning conditions. (MDR)max of (I) is qualitatively identical with that of (IV), however, (MDR)max of (II) is by far smaller in comparison with (I) and (IV). Removal of both lower and higher molecular weight portions from the whole polymer makes (MDR)max larger and addition of lower molecular weight portion to fraction makes (MDR)max smaller. (MDR)max of the former ((IV)) is almost the same as that of (I) and (MDR)max of the latter ((V)) is almost the same as that of (II). It became evident from the experimental results described above that the contamination of the lower molecular weight portion which has no spinnability if it were melt-spun by itself is remarkably responsible for the spinnability of polypropylene.View full abstractDownload PDF (335K) -
(4) CONVERTING TO ELASTOMERIC FIBER OF WOOL BY GRAFATING WITH ETHYL ACRYLATEKozo Arai, Michiharu Negishi, Sadayuki Okada1967 Volume 23 Issue 8 Pages 379-385
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSEA-grafting for unreduced and reduced wool fibers was performed in aqueous Br--S2O82- redox system at 0-15°C. The rate of garfting increases very rapidly as soon as the grafting are starts and it proceeds until almost all the monomers converted to the graft polymers and homopolymers. Thus, EA-grafting was reached to about 3000% graft-on. Judging from the aspects of the grafting, this graft reaction seems to be a popcorn polymerization.
It was found that the breaking elongation of high grafted fibers iecreases to 400-900% and the elastic recovery was excellent. The tensile strength, initial modulus of elasticity and average toughness decreased to about 1/40, 1/3000 and 1/2 of original wool fibers respectively. These grafted fibers revealed the typical rubber elastic behaviors in the range of over 1200% graft-on for reduced fibers and 1500% for unreduced fibers.
A considerable stress softening (Mullins effect) occurs in grafted fibers for both unreduced and reduced wool fibers. The grafted fibers for unreduced wool fibers were treated with thioglycollic acid and recrosslinked by H2O2. The modulus of elasticity and energy-loss decreased by the reduction and recovered nearly to that of the grafted fibers before reduction by the oxidation.
It seems that the -S-S- crosslinks in wool parts are responsible for the formation of a network strutucre and for the reinforcement of PEA as fillers.View full abstractDownload PDF (510K) -
(I) DISTRIBUTION OF RADIUS OF SPHERICAL CELLSKazuo Mihira, Tadashi Osawa, Akira Nakayama1967 Volume 23 Issue 8 Pages 386-391
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESS(1) In order to investigate the geometrical structure of polymeric foam or cellular substances, the statistical relation between the distribution of radius of spherical cells and that of the circles of a cross section is discussed theoretically. The expression relating these two distributions may be expressed as: where s is radius of sectional circles of any cross section, F(s) cumulative distribution function of radius of sectional circles s, r; radius of spherical cells, f(r) density function and r the mean value of radius of spherical cells.
(2) Five types of simple distribution function of f(r) were postulated and the corresponding distribution curves f(s) were obtained and shown diagrammatically. Mean, variances and coefficients of variation are evaluated from the formula of f(s) obtained and tabulated for comparison.
(3) In order to estimate the mean, variance, etc. of the actual spherical cells from the distribution of radius of circle on the cross section of isolated foam substance, it is necessary to estimate f(r) from the experimental values of f(s). If the distribution types such as discussed in the present paper were not taken into consideration, probable error of 10_??_20% can not be avoided in the values of mean and variance when r and σϒ2 are calculated from the experimental values of s and σ2sView full abstractDownload PDF (1399K) -
(I) EFFECTS OF AMOUNT OF LUBRICANT ON THE FRICTION AT VARIOUS SLIDING SPEEDSEiichi Kuze, Teruo Furushima1967 Volume 23 Issue 8 Pages 392-397
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe friction of fibres with the different amount of lubricant has been studied.
(1) When a liquid lubricant is applyied the effects of the increased amount of lubricant on the friction of fibre can be classified into the following three types:
1) simple increase 2) the increased and then decreased 3) simple decrease
(2) When the amount of the lubricant decreases, the friction changes from constant to increased value at a specific amount of lubricant. This amount is large in higher sliding speed. This phenomena can be explained qualitatively by the theory of hydrodynamic lubrication of fibres.
(3) When liquid lubricant is applied the decreased friction due to the decreased amount of lubricant is accountable by slip of lubricant.View full abstractDownload PDF (404K) -
(2) EFFETS OF THE AMOUNT OF SOLID PARAFFIN ON THE FRICTION ON LIGHT LOADINGEiichi Kuze, Teruo Furushima1967 Volume 23 Issue 8 Pages 398-401
Published: August 10, 1967
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe friction of fibre lubricated with different amounts of solid paraffine has been studied on light loading. It was found that solid paraffine has qualitatively the same effect on the friction as that of liquid lubricant.
1) The adhesive force can not be neglected at light loading, however small it may be.
2) When the large amount of lubricant is applied, the shearing of lubricant needs to be taken into consideration outside of deformed surface of asperity.View full abstractDownload PDF (205K)
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