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Volume 53, Issue 3
Displaying 1-10 of 10 articles from this issue
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Kazuyuki Murakami, Hiroshi Toshima, Masaharu Yamamoto1997 Volume 53 Issue 3 Pages 73-78
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSSeveral kinds of pitch-based carbon fibers were prepared from various mesophase pitches derived from naphthalene, petroleum and coal with a single filament spinning apparatus. The relationships between the dependence of Young's modulus of carbon fibers on spinning viscosity and average molecular structural parameters of mesophase pitches were examined. Aromaticity and compactness factor of pitch were found to be closely related to the dependence of Young's modulus of carbon fibers on spinning viscostiy. The experimental results suggest that the control of average molecular structure of mesophase pitch, as well as bulk properties such as viscosity, is required in order to prepare the precursors for carbon fiber manufacturing.View full abstractDownload PDF (466K) -
Yuji Matsuda, Fumihiko Onabe1997 Volume 53 Issue 3 Pages 79-85
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSMicrofibrillated Cellulose (MFC) consists of remarkably fibrillated fine fiber. The unique structure of MFC swollen in aqueous suspension was characterized by arithmetic average fiber length and water retention values. Dranage behavior of pulp suspention on wire was controlled by controlling MFC addition to paper stock at wet-end. Furthermore, pigment retention, dye retention and tensile strength were improved by the MFC addition. These advantages of MFC as a wet-end additive for papermaking seem to be due to its large specific surface area and its micro-network formation between pulp fibers in papersheet.View full abstractDownload PDF (1707K) -
Toshiharu Enomae, Fumihiko Onabe1997 Volume 53 Issue 3 Pages 86-95
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSWhat Parker Print-Surf (PPS) roughness means was discussed by comparing the theoretical equation to that of Bekk smoothness and by determining the wavelength range which PPS represents by the spectral analysis applied to the stylus profiles of paper. As a model of air flow through channels between paper surface and the metal measuring head of an air-leak type smoothness tester, the PPS model is more comprehensible than the Oken type (Bekk) model. However, what the testers survey is fundamentally common to the two methods. Thus, the two equations standing for the models are convertible and the conversion equation was led to be G3=18.65_??_, where G3 is PPS roughness; TB Oken type smoothess. The empirical data exhibited that the conversion equation applies to many papers except those with different compressibility. The correlation between PPS roughness and centerline average (Ra) at several cut-off wavelengths calculated from stylus surface profiles showed that PPS tester presses out paper surface so that the surface shape agrees with roughness at a cut-off wavelength of 234μm for calendered handsheets. This cut-off wavelength gave the least sum of squared deviations from the theoretical conversion equation, G3=2.13×Ra. Oken type smoothness was considered to survey the longer wavelength components than PPS roughness. However, the best-fitting cut-off wavelength was greatly dependent on the surface deformability of paper at a testing pressure in view of papermaking history and converting processes.View full abstractDownload PDF (617K) -
Akira Isogai1997 Volume 53 Issue 3 Pages 96-100
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSMicrocrystalline cellulose was dissolved in aqueous NaOH by the freezing-defrosting-diluting procedure, and its never-dried regenerated cellulose gel was prepared from the aqueous NaOH solution. Handsheets were then prepared from mixtures of bleached kraft pulp and the regenerated cellulose gel. Mechanical, optical and sizing properties of the handsheets thus prepared were studied in terms of the regenerated cellulose content. Young's modulus and tensile and tearing indices of the handsheets increased with the regenerated cellulose content from 0 to 10%. Especially, folding endurance drastically increased by the addition of the regenerated cellulose. On the other hand, opacity and sizing degrees decreased with the regenerated cellulose content.View full abstractDownload PDF (1095K) -
Shigeyuki Nakano, Kazuhiko Komurasaki, Yoshiharu Kimura1997 Volume 53 Issue 3 Pages 101-106
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSCotton fibers were shattered by a rotor mill with different sieve meshes and then treated with cellulase to obtain cotton cellulosic powder which could be potentially new material resource. In the initial stage of the enzymatic treatment, the nap formed on the fiber surface during the mechanical shattering was exclusively hydrolyzed. Therefore, the fiber surface of the shattered fiber became smooth, and the weight loss became much larger in the treatment of the shattered fibers than in the treatment of the original cotton fiber. When the treatment time was increased, the fiber length became shorter with many cracks formed inside the fiber. Wide angle X-ray scattering of the enzyme-treated fibers revealed that the crystallinity increased in the initial stage of the treatment, but became constant in the later stage. The specific surfacc area and micropore volume of the fibers sharply decreased in the beginning of the enzymatic treatment, while they increased in the later stage with increasing treatment time. The specific surface area reached a plateau after 50h of treatment with the micropore volume decreasing.View full abstractDownload PDF (1540K) -
Hatsuyo Ohyanagi, Miki Inamoto, Fujiharu Nagoya, Sigenobu Matsuda, Kun ...1997 Volume 53 Issue 3 Pages 107-110
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe polyethylene / dialkylphthalate system was found to exibit liquid-liquid phase separation thermodynamically and microporous membrane consisting of independent spherical-like pore could be prepared by gradual cooling of this system. The addition of styrene hydrogenated butadiene di-block copolymer (SHB) to the above system resulted in the very homogeneous pore structure by spinodal decomposition. For the purpose of clarifying the role of SHB on the pore-structure formation, a preferential staining of SHB by rutenium tetraoxide was made and the membrane was observed by TEM. SHB exists as if encapsulating the pore composed of HDPE backbone and works as a polymeric surfactant between polyethylene-rich and -poor phases and hinders the coarsening of the phase-separated structure.View full abstractDownload PDF (2323K) -
Isao Ikeda, Takayuki Hirose, Kimihiro Suzuki1997 Volume 53 Issue 3 Pages 111-114
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSCellulosic azo-initiators (CAI) were prepared from cellulose and cellulose acetate (CAc) by treating with a reactive azo-initiator, 4, 4'-azobis(4-cyanopentanoyl chloride) (ACPC) and polymerization of vinyl monomers such as styrene, methyl methacrylate (MMA) and acrylamide was studied with CAI yielding graft copolymers of cellulosics. The rate of polymerization of styrene with CAI from CAc was larger than that with ACPC. Azo groups were found to remain in the CAI after polymerization with styrene and could be used for further polymerization with MMA. In this case, as the grafting of polystyrene of the CAI samples increased, the grafting of poly(MMA) at the second polymerization lowered.View full abstractDownload PDF (256K) -
YASUKO OGAWA1997 Volume 53 Issue 3 Pages P81-P86
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (1051K) -
Multiple Spinning of Bombyx moriJUN MAGOSHI, YOSHIKO MAGOSHI, SHIGEO NAKAMURA1997 Volume 53 Issue 3 Pages P87-P97
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (5426K) -
SUSUMU YAMAGUCHI1997 Volume 53 Issue 3 Pages P98-P103
Published: March 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (502K)
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