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Volume 48, Issue 10
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Susumu Kase1992 Volume 48 Issue 10 Pages 511-520
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSUsing thin filament equations, it was shown that the cross-sectional area of spinline immediately below the spinneret decreases with increasing spinline tension, in the spinning of upper convected Maxwell fluids. The decrease obeys the equation of rubberlike elasticity. It was found that the filament thickness at upstream end must decrease with increasing tension when the flow within the spinneret hole is kept constant and that the well known unattainable region in draw ratio does not in fact exist in this case.View full abstractDownload PDF (693K) -
Katsufumi Tanaka, Kiyohito Koyama, Tadashi Nagahara, Takashi Ota, Masa ...1992 Volume 48 Issue 10 Pages 521-526
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSElongational viscosity was measured at constant strain rates and at the temperature of 160°C for the melt samples of low density polyethylene (LDPE), high density polyethylene (HDPE), and their blends, which showed almost same curves in the frequency dependence of complex viscosity ranging from 10-2 to 102 rad/sec at the same temperature. Non-linearity of the elongational viscosity of the samples was evaluated by non-linearity parameter, defined as the ratio of the measured elongational viscosity to the expected viscosity assuming the linear viscoelasticity. Elongational viscosity at linear viscoelastic region and intensity of non-linearity of the elongational viscosity, defined as the slope of the linear relationship between natural logarithm of the non-linearity parameter and total strain, showed deviation from the additivity rule of the weight content of LDPE component at 10, 20 and 80wt%. These three blends were considered to be immiscible in the melt state. Dependence of the intensity of non-linearity upon the weight fraction of LDPE showed qualitative consistency with that of relaxation moduli upon the weight fraction of LDPE at relaxation times as long as 103 and 104 sec, which was calculated by a constitutive equation with Lodge model from the time dependence of the elongational viscosity of the samples.View full abstractDownload PDF (445K) -
Hiroyuki Makino, Yoshihiko Inamoto1992 Volume 48 Issue 10 Pages 527-533
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe air drag on about 1 to 4 denier poly (ethylene terephthalate) monofilaments, which were spun in the high take-up velocities ranging from 6, 000m/min to 10, 000m/min, was investigated. The spinning stress was measured along the spinline below the oiling nozzle that was located at 20cm below the neck-like deformation point. The air drag coefficient (CD) on the monofilament can be expressed as a function of the radius Reynolds number (Rea): CD=0.26Rea-0.61. This obtained function agreed well with the functions obtained in other works which employed take-up velocities up to 6, 000m/min. This fact suggests that the air drag under the condition of this study is caused by the transitional flow from the laminar to turbulent flow.
The air drag on the multifilaments that were bundled by the oiling nozzle was markedly reduced. The value of measured air drag agreed well with the calculated values based on the assumption that the bundled filaments were close-packed and behaved like a monofilament along the spinline.View full abstractDownload PDF (463K) -
Yuhei Maeda, Ken-ichiro Oka, Masatoshi Mineo1992 Volume 48 Issue 10 Pages 534-540
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe velocity profile in high-speed spinning process was measured by using a laser-Doppler velocimeter. Melt spinning of poly (ethylene terephthalate) was carried out at spinning speed of 4000 to 7000m/min, output of 0.44 to 2.67g/min, and quenching air speed of 7.2 to 25m/min. The abrupt changes on the velocity profiles, the so-called necking, were observed at spinning speed of more than 5000m/min. The necking completes within a few milimeters and is estimated to similar in profile to the necking in the drawing of undrawn filament. The stress and the temperature just above the necking were estimated from the velocity profile. The stress just above the necking becomes lower, when the spinning speed increases or the quenching air speed decreases. The necking seems to occur when the filament has a stressstrain curve satisfying the Vincent condition and the applied stress on the filament exceeds the yield stress. The important factors for the yield stress is the orientation and the temperature just above the necking.View full abstractDownload PDF (484K) -
Seishu Hayashi, Katsuya Tani, Hideki Ishihara, Hiroshi Yasuda1992 Volume 48 Issue 10 Pages 541-548
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn a polymer processing system using Spinline Heating Spinning (SHS) technique, the conventional drawing process can be omitted. The SHS process is characterized by the presence of a heating device located between the spinneret point and the take-up point. Drawing was conducted in the heating zone at lower spinning tension and higher temperature in comparison with the conventional spin-draw process. Unlike the conventional drawing system, the draw ratio can be regarded as an out-put variable in this process. Along with the experimental clarification of the behavior of SHS, the basic equations including the drawing behavior in the heating device were introduced for the numerical analysis. The agreement between calculated and experimental results for various take-up velocities and heating conditions were sufficient The physical properties of fibers obtained by SHS were intermediate between those of high-speed spun fibers and conventionally drawn fibers. The structural characteristics of SHS fibers were also clarified.View full abstractDownload PDF (863K) -
Takeshi Kikutani, Keiichi Wakayama, Masashi Sato, Akira Takaku1992 Volume 48 Issue 10 Pages 549-556
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSHigh-speed melt spinning of linear type poly (p-phenylene sulfide) (PPS) was performed up to the take-up velocity of 7km/min, and the effect of the take-up velocity on the structure and properties of as-spun filaments were investigated. The filaments obtained at the lower take-up velocities were in an amorphous state, whereas the highly oriented and crystallized filaments were obtained at the higher take-up velocities. The molecular orientation, crystallinity and mechanical properties of the high-speed spun filaments, however, were not sufficiently high compared with those of the PPS filaments produced with the conventional melt spinning, drawing and annealing method. This is due to a significant degree of radial distribution of molecular orientation and crystallinity in the cross-section of the high-speed spun filaments. The structure near the surface of the filaments spun above 6km/min was comparable to the structure of the filaments from the conventional method. A diameter profile measurement along the high-speed spinline was conducted. The reduction of the diameter became steeper at a certain distance from the spinneret as the take-up velocity was increased. Immediately after the steep diameter reduction, the solidification of the spinline was observed above 5km/min, and the solidification temperature appeared to be higher than the glass transition temperature of PPS. The mechanisms of the formation of fiber structure and its radial distribution were discussed based on the result of diameter profile measurement.View full abstractDownload PDF (1203K) -
Kazue Ueda, Toshiro Takahashi, Kazushige Kudo1992 Volume 48 Issue 10 Pages 557-562
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSLateral order distributions were measured for amorphous region of high stress spun industrial poly (ethylene terephthalate) (PET) fibers by using a phenol adsorption method with which cohesion energy distribution could be obtained. Relationship between amorphous microstructure of fibers and spinning stress as well as fiber properties was obtained. In the measurement of lateral order distribution, the mobility of molecules was estimated by changing the concentration of phenol solution, and the amorphous region was separated into several phases, from the one with extremely high mobility to the one with extremely low mobility. According to the multi phase model which represents the fine structure of PET fibers, low thermal shrinkage of the treated cords from high stress spun PET yarns was attributed to high content of the amorphous region with extremely low mobility which was transformed from the large amount of high mobility amorphous region in the drawn yarns through the treatment process.View full abstractDownload PDF (914K) -
STRUCTURE AND MECHANICAL PROPERTIES OF POLY (BUTYLENE TEREPHTHALATE)/POLYCARBONATE MELT BLEND FIBERSYutaka Ohkoshi, Atsuo Konda, Shinji Mieda, Toshihiko Ide, Koichiro Tor ...1992 Volume 48 Issue 10 Pages 563-568
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPoly (Butylene Terephthalate) (PBT)/Polycarbonate (PC) blends prepared in a molten state were melt spun into PBT/PC blend fibers. Structure and mechanical properties of these fibers were investigated. It was revealed that the orientation induced crystallization of PBT component occured in the spinline above a certain take-up velocity if the blend fibers contained less than 10wt% of PC. The onset of crystallization lead to the increase in density, the appearance of crystalline reflections in the Wide-angle X-ray diffraction patterns and the abrupt increase in birefringence. The velocity above which crystallization took place increased with the increase in PC content, and if PC content was higher than 20wt%, crystallization was not observed up to the experimentally attainable highest velocity, 3500m/min. Birefringence of blend fibers obtained at the same take-up velocities showed minima at PC content between 60 and 80wt%. The additivity of specific volume was observed for the blend fibers unless those were crystallized. Young's modulus increased with increasing take-up velocity, however, there was no dependence of Young's modulus on PC content. Tensile strength increased and elongation at break decreased with take-up velocity for the blend fibers of each PC content, whereas both properties for each take-up velocity showed minima with the increase in PC content.View full abstractDownload PDF (823K) -
Masayoshi Ito, Yoshihide Wakayama, Tetsuo Kanamoto1992 Volume 48 Issue 10 Pages 569-575
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe preparation of ultra high molecular weight poly (ethylene terephthalate) (U-PET) and the drawing behavior of solution spun fibers from U-PET were investigated. U-PET was prepared by solidstate polymerization of porous and fibrous aggregates which were prepared from commercially available PET. As-spun fibers from U-PET (intrinsic viscosity, IV=3.6dL/g) were prepared by the solution spinning method using a mixed solvent of hexafluoro-2-propanol and dichloromethane (50/50, v/v). The polymer solution (8wt%) was extruded at room temperature through a conical capillary die with a diameter of 0.2mm. As-spun fibers were drawn at room temperature, followed by a tensile drawing at 210°C in an air. By this draw technique, the fibers could be drawn up to draw ratio of 12. Such highly drawn fibers exhibited tensile modulus and strength of 270 and 17g/d, respectively. However, the IV retention after the hot-drawing was only 67% primarily due to hydrolysis and/or oxidative degradation during processing.View full abstractDownload PDF (943K) -
Seishiu Yamamoto, Shigeyoshi Ebihara, Fukuno Sakairi, Takeshi Kitano, ...1992 Volume 48 Issue 10 Pages 576-582
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPorous hollow fibers of polysulfone (PS) were spun by the wet or dry-wet spinning technique by using four-hole tube-in-orifice spinneret, polymer dope consisting of PS/Dimethylformamide (DMF)=20/80wt%, and water as bore precipitant and coagulant. Contacting solvent (DMF) to dope from bore precipitant side (inside) and coagulant side (outside), water (inside)-solvent (DMF)-dope-solvent (DMF) extruded from the four-hole spinnineret were drawn into a coagulation water bath. The coagulation rate was controlled by solvent onto the dope. Performance of the porous hollow fibers, i.e., water content, density, stress-strain property, air flux and morphology were investgated. The surface and internal structures of porous hollow fibers could easily be controled by the time of contacting solvent with dope.View full abstractDownload PDF (2549K) -
Shinji Ohwaki, Ryouichi Yamasaki, Masato Yoshimoto1992 Volume 48 Issue 10 Pages 583-589
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIt is known that the flat fiber of high aspect ratio shows the complexed crimp structure in which the wavy crimp is formed at the edge of the flat fiber as found in sea-weed. The mechanism for the formation of crimp structure in the flat fiber of poly (ethylene terephthalate) was studied in this work. The degree of crimp increased with increasing aspect ratio and spinning speed. The birefringence of this complexed wavy crimped yarn showed the large distribution along the long axis of the fiber cross section. When the fiber shrank by heat treatment, the structural heterogeneity caused the irregularity of shrinkage which developed the wavy crimp.View full abstractDownload PDF (1935K) -
1992 Volume 48 Issue 10 Pages 593
Published: 1992
Released on J-STAGE: November 28, 2008
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KATSUMI KUBOSHIMA1992 Volume 48 Issue 10 Pages P527-P536
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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RYOJI ITO1992 Volume 48 Issue 10 Pages P537-P540
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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AKIRA SENTO1992 Volume 48 Issue 10 Pages P541-P544
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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TOSHIHIKO KURATA1992 Volume 48 Issue 10 Pages P545-P552
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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A Viewpoint from Paper Science ResearchFUMIHIKO ONABE1992 Volume 48 Issue 10 Pages P553-P556
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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HAJIME OKAMURA, KAZUMASA OZAWA1992 Volume 48 Issue 10 Pages P557-P560
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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AKIHIRO SAKAMOTO1992 Volume 48 Issue 10 Pages P561-P565
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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AKIRA MIYAGAWA1992 Volume 48 Issue 10 Pages P566-P569
Published: October 10, 1992
Released on J-STAGE: November 28, 2008
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