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Volume 53, Issue 7
Displaying 1-11 of 11 articles from this issue
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Kiyohiro Inoue, Sinoaki Masato, Shigeo Asai, Masao Sumita, Seigo O-oya1997 Volume 53 Issue 7 Pages 265-271
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDegradation of biodegradable poly L-lactic acid was studied with alkaline hydrolysis and hot water. In the alkaline hydolysis, the sample shows a remarkable weight loss and at the same time the shape is changed with time. Koch curve was applied as a model of surface boundary for the degraded material. In the degradation with hot water, cracking and fragmentation occurs preferentially in the initial stage of weight loss. The change in shape of the degraded PLLA was analyzed by measuring box counting dimension and comparing the dimension with fractal image. The spider tree model of fractal figure is useful for cracking of PLLA. The overall cracks has a dimension of about 1.5. At the dimension of 1.7, the cracks form network and samples are pulverized. In conclusion, this treatment is useful for plastic garbage of PLLA.View full abstractDownload PDF (1949K) -
Kiyohiro Inoue, Shigeo Asai, Masao Sumita, Kumiko Inoue, Seigo O-oya1997 Volume 53 Issue 7 Pages 272-280
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSTextile fibers have long been used as a medium to record, preserve and transmit information. Jacquard invented Jacquard fabrics with optional patterns that are produced by using punch cards. Punch card corresponds to a pattern with the position of small punched holes. The form of information is regarded as the regular mass of information element or the so-called “systematized form”. There are three patterns in systmatized forms of information elements on textiles. They are linear form, branched form, and grouping form. Gestalists attempted to classfy the types of interaction in the visual system and called them laws of perception. Their lows of grouping includes proximity, similarity, good continuation, and closure. The laws of “grouping” may be seen in a “systematized form” of the information element for the spaces in lace. The box-counting dimensions of string part, space part of lace and fractal images were measured to discuss the relationship between box-counting dimension and “grouping (law of perception)”.View full abstractDownload PDF (2567K) -
Yasuhisa Nagata, Katsumi Nakama1997 Volume 53 Issue 7 Pages 281-288
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThree Kinds of aromatic polyimides, pyromellitic dianhydride (PMDA)/p-phenylenediamine (PPD)/3, 3', 4, 4'-biphenylene tetraamine (TAB), 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride (BPDA)/PPD and PMDA/4, 4'-diaminodiphenyl ether (DPE), were heat-treated at about 1000°C and further heat-treated at 2300°C under inert gas atmosphere and carbon films were prepared. It was confirmed by X-ray analysis and scanning electron microscopic measurements that the amount of graphite carbon of PMDA/PPD/TAB films was higher than that of BPDA/PPD and PMDA/DPE. This is due to the fact that the molecular chain of PMDA/PPD/TAB forms a coplanar structure. Preheat-treated films were unidirectionaly drawn and then carbonized. PMDA/PPD/TAB films, which showed the highest orientation of polymer chains, exhibited the highest values of dynamic modulus and electric conductivity. During carbonization, the oriented carbon layers grew along the drawn direction. The results indicates that the ordered structure of precursor polyimide films affects the properties of carbonized polyimide films.View full abstractDownload PDF (4706K) -
Miyuki Morita, Emiko Komatsu, Tamio Kamidate, Hiroto Watanabe1997 Volume 53 Issue 7 Pages 289-293
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe transfer of dissolved Orange II to various fabrics was measured at pH9.0 and 20°C in the presence of horseradish peroxidase (HRP) and hydrogen peroxide. HRP inhibited the transfer of dissolved Orange II to wool, polyester, acryl and modacryl. On the other hand, Orange II transfered to cotton, silk and nylon. The amount of transfered Orange II to no-dyed nylon decreased with increasing decoloration rate of Orange II. The color differences observed in no-dyed cotton, silk and nylon with HRP was about 2-3 times lower than those observed with percarbonate at pH11.5 and 20°C . The color difference of no-dyed nylon with percarbonate was about the same as that with HRP, when percarbonate was used at pH11.5 and 70°C. No decoloration of Orange II-dyed nylon occurred during washing in the presence of HRP and hydrogen peroxide. However, the Orange II-dyed nylon was decolored using percarbonate at pH11.5 and 70°C. These results indicate that HRP is more useful than percarbonate for inhibition of dye transfer.View full abstractDownload PDF (352K) -
Miyuki Mori, Masako Niwa1997 Volume 53 Issue 7 Pages 294-304
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSWe investigated the thread tension of sewing machines in practical conditions by interviewing several sewing engineering experts. Of those interviewed, 80% replied that they rely on their experience and intuition, when they adjust the needle and bobbin thread tension of a sewing machine in order to obtain a well balanced stitch. Bobbin thread tension changes during a pulley rotation and also reeling amount of bobbin thread, even if the other condition is the same. In this study, we tried to clarify the effect of needle and bobbin thread tension on stitch balance and seam puckering. The seamed samples were prepared using the fabrics and sewing machine threads having different mechanical properties. We postulate the following the criteria that when the length of the needle and bobbin thread per unit fabric length are the same, a stitch is well balanced. Needle thread tension should increase if bobbin thread tension raises to obtain a balanced stitch. To achieve a pucker free seam, the thread tension must be maintained as low as possidle. In the above conditions, a large amount of thread is necessary to obtain a good seam. We established the relationship among needle and bobbin thread tension, stitch balance and seam puckering. The effect of physical properties of fabric and sewing thread on the above relationship was also studied.View full abstractDownload PDF (1320K) -
Wan-Ling Chen, Ryoko Yamamoto, Noriko Kawasaki, Hisaaki Kanetsuna, Sho ...1997 Volume 53 Issue 7 Pages 305-309
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSTaking into account of an effect of optical density to enhance the cross-sectional views of fibrous materials, a new preparative technique was applied to detect the skin-core structure of Cupra and Tencel filaments. The same sample species were also examined to determine the characteristic concentration gradient of dye molecules along the fiber axis starting from the sliced section. Microphotospectroscopic observation of a Cupra and Tencel filaments shows that the diffusion rate is predominant factor at the initial stage of dyeing and then an equilibrium state is attained depending on the fine structure of fibrous materials.View full abstractDownload PDF (1797K) -
JUNJI WATANABE1997 Volume 53 Issue 7 Pages P197-P201
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
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Low Energy and Super Spinning (Spider)JUN MAGOSHI, YOSHIKO MAGOSHI, TAMAKO HATA1997 Volume 53 Issue 7 Pages P202-P211
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
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David M. Lewis, [in Japanese]1997 Volume 53 Issue 7 Pages P213-P219
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
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KUNIHIRO MORIMOTO1997 Volume 53 Issue 7 Pages P220-P223
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
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TAKEYUKI MATSUO1997 Volume 53 Issue 7 Pages P227-P228
Published: July 10, 1997
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (1831K)
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