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Volume 40, Issue 6
Displaying 1-12 of 12 articles from this issue
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Koukichi Yoshida, Nobuo Ogata1984 Volume 40 Issue 6 Pages T163-T170
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIt is important to investigate the tensile properties of the yarn consisting of parallel filaments, since these features may provide some basic insight into the breaking mechanism of the actual twisted and spun yarns. For convenience sake, we will refer to the bundle of parallel filaments as multi-filament yarn. The tensile properties of the multi-filament yarn is considered to be markedly influenced by that of filaments consisting of the yarn.
Therefore, this influence is analytically investigated in this paper. As a result, we obtain the following conclusions:
1. The specific stress of multi-filament yarn is proportional to that of the fiber in the yarn;
2. The coefficient of variation of the specific stress of multi-filament yarn is inversely proportional to that of the fiber in the yarn;
3. The stress-strain curve and the features of the tensile properties of multi-filament yarn are scarcely influenced by the coefficient of variation and the correlation coefficient of the specific stress of the fiber;
4. The ratio of the specific stress to elongation of the multi-filament yarn and the fiber at breaking point is inversely proportional to the coefficient of variation of the elongation of the fiber.View full abstractDownload PDF (577K) -
Toshimasa Hashimoto, Chengchu Tai, Akira Takaku, Jiro Shimizu1984 Volume 40 Issue 6 Pages T171-T176
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThermally stimulated current (TSC) of polyacrylonitrile (PAN) films heat-treated at elevated temperatures in air and in vacuum has been investigated. In the TSC spectra of solvent cast PAN films, the current peak due to residual solvent was observed. The residual solvent could be removed by heat treatment in vacuum at 200°C for 60min. The TSC spectrum obtained for a solvent free PAN film was characterized by two current peaks observed at 110°C (αII peak) and 150°C (αI peak) due to the dipolar relaxations in the paracrystalline and amorphous phases, respectively. The amount of polarization calculated from TSC was in good agreement with theoretical value calculated from the dipolar orientation of nitril groups.
The αII peak increased in the early stage of heat treatment at 230°C, while the αI peak decreased rapidly. The total polarization calculated from the both peaks decreased linearly with decreasing amount of nitril groups in a PAN film. It was found that a PAN film heat-treated at 230°C in air for longer times than about 200min did not show a significant TSC, although it was confirmed by infrared analysis that about 20% of nitril groups in PAN still remained after the heat treatment. This fact indicates that the pendant nitril groups of PAN heat-treated for prolonged time were immobilized by neighboring cyclized rigid segments and could not contribute to polarization.View full abstractDownload PDF (479K) -
CHARACTERIZATION OF FIBER STRUCTURE BY CONSIDERING ORIENTED MESOPHASEJiro Shimizu, Takeshi Kikutani, Akira Takaku, Norimasa Okui1984 Volume 40 Issue 6 Pages T177-T184
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSOriented fine structures of high speed melt spun PET filaments obtained at 1000-9000m/min were investigated by Wide-angle X-ray analysis. WAXS pattern for the filaments spun at 4000m/min shows diffuse reflection on the equator which suggests that the polymer is in an amorphous state, in spite of considerable degree of molecular orientation. In other words, this might be called an “oriented mesophase”. The amount of three phases in the filament; crystalline phase, oriented mesophase and amorphous phase, was estimated through the X-ray intensity separation procedures. In the range of take-up velocity from 1000 to 4000m/min, the amount of oriented mesophase increases remarkably and shows the maximum at 4000m/min. The orientation induced crystallization starts from 5000m/min. The amount of the oriented mesophase decreases as the crystallization proceeds, whereas the sum of the amount of crystalline phase and oriented mesophase increases continuously from 1000 to 7000m/min. These results suggest that oriented molecules in the mesophase selectively aggregate and then initiate the nucleation of crystals.
Resolution of the azimuthal intensity curves into the crystalline and the oriented mesophase components yield the higher crystalline orientation factors than those obtained without resolving procedures. The crystalline orientation factor increases with increasing take-up velocity from 5000 to 8000m/min. It is known that c-axes of PET crystals in the drawn fibers are not aligned exactly parallel to the fiber axis, but they are all tilted with about the same amount and in the same direction with respect to the fiber axis. For the high speed spun PET filaments, the tilt angle decreases and the degree of preferential molecular orientation toward the tilt direction becomes higher with increasing take-up velocity.View full abstractDownload PDF (715K) -
Jia Hui Liu, Tetsuya Danno, Toshimasa Hashimoto, Keizo Miyasaka, Yukio ...1984 Volume 40 Issue 6 Pages T185-T192
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSCommercial PET fibers for tire-cord use were characterized by Thermoluminescence method (TL). TL experiments were performed separately at low and high temperatures: In the low temperature experiment, samples were irradiated by x-ray from a Copper-tube at -180°C for 1 hour and then heated up to room temperature at a rate of 3°C/min. to measure the TL intensity as a function of temperature. In the high temperature experiment, the x-ray irradiation was made at room temperature and heated up at the same rate of heating as in the low temperature experiment. In the Low temperature TL, asymmetric-shaped intensity curves with the maxima between -150°C and -130°C were observed commonly for all specimens. However, big difference was observed in the magnitude of the low temperature TL intensity among the specimens: the intensity of a specimen with the strongest TL was one order of magnitude larger than that of the specimen with the weakest TL. The high temperature TL curves had maxima at about 80°C corresponding to the Tg, and the specimens with very weak low temperature TL had another maxima at 160°C as well as at 80°C. The fibers were repeatedly extended to a fixed strain at a rate of 105 rep./min. at room temperature, and the change of TL with the extension was measured. The high temperature TL intensity increased with extension but decreased with time after the stop of the repeated extension: the intensity measured after long time was weaker than before extension, with an exception of the specimen from FII company. In this fiber the increase in the TL intensity with the extension was much larger than in other specimens, and the intensity did not become weaker than before extension even after a long time. Low temperature TL intensity remarkably increased in the specimens with weak low temperature TL before extension, while it almost remained as before in the specimens with strong TL intensity before extension. The results obtained in the study suggested that TL method may be effectively used for the characterization of PET tire-cord fiber and also the study on the fatigue properties of the fibers.View full abstractDownload PDF (637K) -
Koichiro Toriumi, Atsuo Konda1984 Volume 40 Issue 6 Pages T193-T201
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn a previous paper, novel numerical method for solving the equations governing the unsteady-state melt spinning process was reported. The method based on orthogonal collocation was found to be very suitable in numerically solving nonlinear differential equations.
In this paper we discuss the simulation of draw resonance in unsteady melt spinning process which are described by nonlinear partial differential equations. Both isothermal and non isothermal conditions were simulated, and in the latter case results were compared with experimental data.
Following results were obtained;
(1) In the case of isothermal spinning, sufficient accuracy was obtained by selecting a proper collocation number with results in close agreement with those of other investigators.
(2) In nonisothermal conditions, two factors governing the cooling of thread line, cooling air velocity and air temperature strongly influence the resonance wave shape especially the peak level. Since cooling affects draw resonance indirectly through increasing elongational viscosity. Temperature dependence of viscosity also influence its wave shape.
(3) Results of simulation agreed with experiments best when elongational viscosity had the expression;
η=η0exp _??_5300/(T+273)_??_View full abstractDownload PDF (659K) -
Akira Nakayama, Katsuhiko Inagaki1984 Volume 40 Issue 6 Pages T202-T208
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn this study, the anisotropy of bending rigidities of cloths with stitched seams were examined.
The results are as follows:
(1) When specimens (length; L, width; W) were cut at an angle θ for warp direction from cloths with parallel seam lines stitched (stitch pitch; p) at an angle α (0_??_α<90°) for warp direction, the domains were classified into two parts (A and B) by the number of seam lines contained in the width direction. If the angle between seam lines and specimen length direction was β, bending rigidities El of domain A and B and their fractions ∅ were given by the following equations. where k indicates [(W/p) cosβ] ([ ]; Gauss' notation), s, the size of seam line, (EI)cl, θ, bending rigidity of base cloth and (EI)s, β, bending rigidity of seam lines. There were given by applying the anisotropy theory by Shinohara et al.2)
(2) Bending rigidity of cloths in the conditions above mentioned was given by the following equation by applying the complex law of series model shown in another paper4) and the result shown in preceding paragraph.
(3) In the case of cloths with parallel seam lines (stitch pitch; p) crossing each other, (EI)θ was calculated by using the following equation with the length and contents of each domain changing in the direction of length of specimens obtained by the flow chart (Fig. 3) as well as with the bending rigidity (EI)θ i, calculated by applying eq. (10).View full abstractDownload PDF (472K) -
Shigeo Kobayashi1984 Volume 40 Issue 6 Pages T209-T215
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe purpose of this paper is to discuss the effect of mechanical properties on the handle of knitted fabrics. In this paper, the handle is regarded as a tactual evaluation judged from physical stimuli of fabric mechanical properties. The KES-Handle Testers were used to measure factors of mechanical properties, such as tensile, compression, bending, shear and surface characteristics. Also, the technique of factor analysis was applied to investigate relations among these mechanical factors.
As the result of factor analysis, six factors, namely, bending resistance, shear resistance, tensile resistance, tensile resilience, surface friction and surface roughness, were selected. But the factors of bending and share resistance were most important for the handle of knitted fabrics. The relation among samples are shown on the orthogonal coordinates with values of factor score. The feature of handle can be catched by the degrees of contribution of each factor to the individual sample.View full abstractDownload PDF (473K) -
Yong-Jin Lim, Mitsuru Tahara, Toru Takagishi, Nobuhiko Kuroki, Tomiji ...1984 Volume 40 Issue 6 Pages T216-T220
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPolyester fiber was treated with the strongly-interacting solvents such as dimethylformamide, benzyl alcohol, and butanol. The pretreated fibers were dyed with seven kinds of disperse dyes (C. I. Disperse Yellow 7, Orange 1, Orange 3, Red 17, Violet 1, Blue 3, and Blue 7) in water and the saturation dye-uptake values were determined. The solvent-induced structural changes led to changes in dyeability. At the same time, the dyeing behaviors were found to be greatly different with the dyes investigated. The relationship between dyeability and structure of the dyes has been briefly discussed.View full abstractDownload PDF (331K) -
Jiro Seta, Mina Takeno, Taisuke Ito1984 Volume 40 Issue 6 Pages T221-T225
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSUnder high hydrostatic pressures up to 1500 bar, the diffusion coefficients, D, were measured at 80°C for p-aminoazobenzene (pAAB) in cellulose diacetate swollen with water and benzene. From the pressure dependence of D, the activation volume, ΔV_??_, for the diffusion was found to be 20.9cm3/mol for the water and 39.5cm3/mol for the benzene swollen system. The degree of swelling, S, of the polymer was more than twice as large in benzene (S=19.8%) as in water (S=7.5%). The observed ΔV_??_ values as combined with those of S were not in accordance with the expectation that ΔV_??_ decrease with increasing degree of swelling which supplies the larger free volume. It was proposed that the solvation of pAAB by benzene gives the reason for the unexpectedly larger ΔV_??_ value observed.View full abstractDownload PDF (922K) -
TOSHIHIKO OHTA1984 Volume 40 Issue 6 Pages P407-P418
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (1300K) -
Visit to Laboratories of Universities in U.S.A and EuropeTOSHIO KUNUGI1984 Volume 40 Issue 6 Pages P419-P424
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (3268K) -
HIROSHI MITOMO1984 Volume 40 Issue 6 Pages P425-P432
Published: June 10, 1984
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (1661K)
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