• Title/Summary/Keyword: fiber drawing

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The fine structure and physical properties of Nylon6/AgO bicomponent fiber on drawing and annealing (Nylon6 / AgO복합섬유의 연신 및 열처리에 따른 미세구조와 물성)

  • 김동환;이선희;정호규;조현혹
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.04a
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    • pp.239-242
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    • 2003
  • 고분자 물질은 여러 가지 물질과 복합체를 형성하여 물리적 성질을 향상시켜왔다. 특히 유ㆍ무기물질의 복합체는 의류용, 산업용 차원에서 관심이 증대되고 있으며, 유ㆍ무기 입자가 첨가된 고분자 복합소재는 고분자 매트릭스에 기계적, 열적 특성을 향상시킬 뿐만 아니라 이들의 다양한 기능성을 부여할 수 있다.[1] 최근 수 십 년 동안 자연 오염문제로 인하여 섬유분야에서도 항균 처리가 관심이 증대되고 있다. (중략)

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Mechanism of Fiber Structure Development in High-Speed In-Line Drawing Process of Poly(ethylene Terephthalate) (II) -Studies on Structure Evolution and Property of Obtained Fibers- (폴리에틸렌테레프탈레이트의 고속 In-Line 연신공정내에서의 섬유형성 메커니즘에 대한 연구 (II) -구조물성분석에 의한 섬유내 고유 고차구조형성기구 해석 -)

  • Hahm, Wan-Gyu;Ito, Hiroshi;Kikutani, Takeshi
    • Proceedings of the Korean Fiber Society Conference
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    • 2007.11a
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    • pp.147-150
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    • 2007
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Effects of Air-Gap Distances on Properties of Cellulose Fiber Spun (셀룰로오스 섬유의 방사시 공기층 거리가 물성에 미치는 영향)

  • 홍영근;조성무;이화섭
    • Textile Coloration and Finishing
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    • v.5 no.2
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    • pp.139-143
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    • 1993
  • The effects of air-gap distance on properties of cellulose fiber spun from the 6 wt% solution of cellulose in monohydrate N-methylmorpholine N-oxide (NMMO) were investigated. The diameter of fiber spun was drastically reduced in 10 cm of air-gap distance at fixed drawing speed, however, no great change was observed beyond 40 cm. As the distance lengthened, the Cellulose II structure was first appeared and followed by Cellulose II and IV mixed morphology. Also the degree of crystallinity and the size of crystals were tending to decrease.

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Physical Properties of Ultrahigh Molecular Weight Polyethylene(UHMWPE) Tape Yarns Produced by the Compaction/Drawing Method

  • Jo Hwan;Lee, Seung-Gu;Hwan, Ju-Chang
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.410-413
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    • 1998
  • Since early of 1980's, high. performance fiber has been developed by processing of ultrahigh molecular weight polyethylene(UHMWPE). UHMWPE fibers have high strength high modulus and excellent impact properties due to the strong C-C bond. Furthermore, the specific gravity of UHMWPE fibers is less than 1.0g/$\textrm{cm}^2$, which makes it possible to produce composites that combine good mechanical properties with low specific mass. (omitted)

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Preparation of hollow fiber membrane for degassing by melt spinning and drawing method. (용융방사와 연신에 의한 용존기체 제거용 중공사 분리막의 제조)

  • 김승일;이의소
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.185-186
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    • 2003
  • 막을 이용한 분리기술은 다양한 종류의 혼합물에서 원하는 물질을 분리 정제하는 기술로 여기에는 고-액, 액-액, 기-액분리가 모두 포함된다 현재까지 분리공정은 주로 여과, 증류, 추출, 흡착등 방법이 있으나 에너지소비가 많고, 설비투자비가 많이 들며 효율이 낮아 비경제적이라는 문제점을 가지고 있고 이와 같은 문제점을 해결하기 위하여 최근 주목받고 있는 기술이 막을 이용한 분리기술이다. 막을 이용한 분리기술의 장점은 앞서 언급한 바와 같이 에너지소비와 설비비를 최소화하면서도 고효율의 분리효과를 얻을 수 있다는 점에 있다. (중략)

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Change on Fine Structure of PTT Fiber with Vibrating Drawing and Annealing (진동 연신.열처리에 따른 PTT 섬유의 미세구조 변화)

  • 박은영;김경효;이양헌;조현혹
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.213-214
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    • 2003
  • 1950년 Poly(ethylene terephthalate)(이하 PET)의 상업화 이후 Poly(trimethylene terephthalate)(이하 PTT)는 동종의 Poly(methylene terephthalate)계열의 고분자 중에서 Poly(butylene terephthalate) (이하 PBT)와 함께 최근 가장 주목받는 섬유 중의 하나이다. PTT 섬유는 얼마 전까지만 해도 주원료인 1,3-propanediol(이하 PDO)의 가격이 너무 높아 지난 60년 간 상업화 및 학문적 연구가 거의 이루어지지 않다가 최근 미국의 Shell사와 독일의 Degussa(미국의 Dupont)에 의해 PDO가 대량 생산되면서 상업화에 대한 연구가 활발히 이루어지고 있다. (중략)

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Evaluation of Quantitative Effectiveness of MR-DTI Analysis with and without Functional MRI (기능적 자기공명영상 사용유무에 따른 확산텐서영상 분석의 유효성 평가)

  • Lee, Dong-Hoon;Park, Ji-Won;Hong, Cheol-Pyo
    • The Journal of Korean Physical Therapy
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    • v.25 no.5
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    • pp.260-265
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    • 2013
  • Purpose: This study was conducted in order to evaluate the quantitative effectiveness of region of interest (ROI) setting in MR-DTI analysis with and without fMRI activation results. Methods: Ten right-handed normal volunteers participated in this study. DTI and fMRI datasets for each subject were obtained using a 1.5T MRI system. For neural fiber tracking, ROIs were drawn using two methods: The drawing points were located in the fMRI activation areas or areas randomly selected by users. In this study, the neural fiber tract targeted the corticospinal tract (CST) Quantitative analyses were performed and compared. The pixel numbers passing through the fiber tract in the individual brain volume were counted. The ratios between the ROI pixel numbers and the extracted fiber pixel numbers, and the ratios between the fiber pixel numbers and the whole-brain pixel numbers were also calculated. Results: According to our results, extracted CST fiber tract in which the ROI was drawn with fMRI activation areas showed higher distribution than drawing the ROI by users' hands. In addition, the quantitatively measured values represented higher pixel distribution: The counted average pixel numbers were 4553.8 and 1943.3. The average ratios of the ROI areas were 33.87 and 22.52. The average percentages of the individual whole-brain volume numbers were 2.06 and 0.87. Conclusion: Results of this study appear to indicate that use of this method can allow for more objectives and significant for study of the recovery of neural fiber mechanisms and brain rehabilitation.

Selenide Glass Optical Fiber Doped with $Pr^{3+}$ for U-Band Optical Amplifier

  • Chung, Woon-Jin;Seo, Hong-Seok;Park, Bong-Je;Ahn, Joon-Tae;Choi, Yong-Gyu
    • ETRI Journal
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    • v.27 no.4
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    • pp.411-417
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    • 2005
  • $Pr^{3+}-doped$ selenide glass optical fiber, which guarantees single-mode propagation of above at least 1310 nm, has been successfully fabricated using a Ge-Ga-Sb-Se glass system. Thermal properties such as glass transition temperature and viscosity of the glasses have been analyzed to find optimum conditions for fiber drawing. Attenuation loss incorporating the effects of an electronic band gap transition, Rayleigh scattering, and multiphonon absorption has also been theoretically estimated for the Ge-Ga-Sb-Se fiber. A conventional double crucible technique has been applied to fabricate the selenide fiber. The background loss of the fiber was estimated to be approximately 0.64 dB/m at 1650 nm, which can be considered fairly good. When excited at approximately 1470 nm, $Pr^{3+}-doped$ selenide fiber resulted in amplified spontaneous emission and saturation behavior with increasing pump power in a U-band wavelength range of 1625 to 1675 nm.

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