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Volume 31, Issue 2
Displaying 1-8 of 8 articles from this issue
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[in Japanese]1990 Volume 31 Issue 2 Pages 49-53
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
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[in Japanese]1990 Volume 31 Issue 2 Pages 54-58
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (5059K) -
[in Japanese]1990 Volume 31 Issue 2 Pages 66-71
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
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Takashi Hiramatsu, Akiko Kotani1990 Volume 31 Issue 2 Pages 72-79
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe persistence and color of afterglow on CRT display due to moving textiles are studied by using a video digitizing system of a computer. The study has shown that:
(1) It is shown theoretically that the picture size (cm or°) is equal to v (ta+tz) +1, where v is the moving velocity of the specimen (cm s1or°s-1), ta is the afterglow persistence (s), tz is the digitizing time (s), and 1 is the length of the stationary specimen in the picture (cm or°) . Accordingly, the afterglow persistence is shown as αa-αz, where αa is equal to (the picture size -1) v1and αzis equal to (no afterglow picture size -1) v-1.
(2) The afterglow is rather easily observed, when the back ground is dark, with bright fibers than with dull fibers, with filament yarns than with spun yarns, with satin weave than with plain weave, and with bright colors than with dark colors. The afterglow persistence may amount to 0.02 seconds even under ordinary conditions.
(3) There are some conditions that the color of afterglow is different from that of the camera subject. The different color is almost red, because of the longer afterglow persistence of red elements than that of other colors.View full abstractDownload PDF (1656K) -
Junko Akashi, Toshio Masuda, Osamu Yuge1990 Volume 31 Issue 2 Pages 80-86
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe effect of the needle eye edge on the needle thread during sewing operation has been investigated by using a model which consists of sliding wire on the thread fixed at its both ends.
The results obtained were as follows.
(1) The principle of the displacement of the thread twist is as same as the false twist of the thread.
(2) Twisting or untwisting the thread depends on the twist angle, the cross angle between wire and thread, and the direction of sliding.
(3) The amount of the displacement of the twist is largest when the cross angle β is twist angle a, and is least when βis α+90°.View full abstractDownload PDF (2160K) -
Nobuaki Kuwabara, Tomoko Sue, Noriko Obata, Seibei Yoshikawa1990 Volume 31 Issue 2 Pages 87-94
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe effects of. moisture on the sorption of formaldehyde (HCHO) vapor by various fibers were investigated under various atmospheres having different HCHO concentration and relative humidities. The results obtained are as follows: (1) The amounts of HCHO sorbed by fibers increased with increasing the moisture content. The closer the solubility parameter of fiber to that of HCHO, the amount of HCHO sorbed by the fiber became larger. (2) The amount of HCHO sorbed was constant between 30 and 70% in relative humidity, and abruptly increased with relative humidity over 85%. These are attributed to different sorption mechanisms. (3) In the former case (30-70%), the sorption can be described by Langmuir's sorption mechanisms. (4) In the latter case (>85%), the amounts of HCHO sorbed increased with increasing HCHO concentration. This increase may be caused by dissolution of HCHO molecules in water sorbed by fiber molecules. (5) The dissolution was evidenced by the fact that there was obeyed the Henry'law between the amount of monohydrated product of HCHO and the HCHO concentration in vapor phase.View full abstractDownload PDF (896K) -
Nobuaki Kuwabara, Tomoko Sue, Noriko Obata, Seibei Yoshikawa1990 Volume 31 Issue 2 Pages 95-101
Published: February 25, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSFor wool and polyester fiber on which formaldehyde (HCHO) vapor was absorbed, desorption of HCHO vapor was measured under various atmospheres with different temperatures and relative humilities. The results obtained are as follows: (1) The desorption of HCHO vapor could be described by a diffusion equation which is based upon Fick's second law. Using its equation, the diffusion coefficient (D) could be obtained. (2) D of HCHO in wool increased at all the atmospheres with increasing the concentration of HCHO sorption, but D in polyester decreased at low temperatures and high relative humilities. (3) Apparent activation energy of HCHO diffusion (Ed) in wool at 50% RH was higher than that in polyester, but the former at 85% RH was a little lower than that in the latter. (4) The variation of D0with the relative humidity can be well understood for wool particularly at high relative humidities, by the free volume theory. This conclution does not contradict with previous ones which have been obtained from permeation and sorption measurements, but does support the previous conclusion.View full abstractDownload PDF (760K) -
1990 Volume 31 Issue 2 Pages 103
Published: 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (16K)
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