• Title/Summary/Keyword: 환경친화적 기계가공

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Effect of 1,3-Dioxolane on the Structure Development in Solution Casting Polycarbonate Film (1,3-Dioxolane이 용액 가공 폴리카보네이트 필름 구조 형성에 미치는 영향)

  • Kim, Jae-Hyun;Kim, Sung-Do;Han, Joon-Hee;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.32 no.5
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    • pp.478-482
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    • 2008
  • The effect of 1,3-dioxolane on the structural development in the optical polycarbonate film was studied. The 1,3-dioxolane was used as an environmental friendly solvent for manufacturing solution-cast polycarbonate film instead of methylene chloride. The evaporation rate in film drying process decreased due to the high boiling temperature of 1,3-dioxolane. This caused the crystallization in the polycarbonate film. As a result, The increase of crystallinity and roughness led to the decrease of light transmissivity. It was also found that the lowering of mechanical properties in polycarbonate film was attributed to the morphological change due to the solvent evaporation rate in film drying process.

A study on manufacturing technologies and excellence of Korean traditional paper (전통한지의 제조 기술 및 우수성에 관한 논고(論考))

  • Jeong, Seon Hwa
    • Korean Journal of Heritage: History & Science
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    • v.48 no.1
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    • pp.96-131
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    • 2015
  • Hanji(Korean traditional paper) is a valuable cultural heritage highly praised, even to this date, for its importance and technology by craftsmanship of our ancestors; it is a product of a combination of craftsmanship, well-established technologies, natural paper mulberry fiber and eco-friendly and durable natural materials and mucilages. Origin of the word 'Hanji(Korean traditional paper)' is from handmade paper made of bast part of the paper mulberry; as paper manufacturing with paper machines introduced in Japan was adopted in late Joseon, paper produced previously was called 'Hanji' and paper produced with western machines was called 'Yangji(machine made paper)'. Hanji has been called by many different names and used in various ways according to materials and production methods; and the functions varied. Hanji, from the era of three states to Joseon era, has been praised for its unique and excellent quality in three Asian countries(Korea, China and Japan); its unique excellence continues to this date in many paper-related national cultural heritages. Also total of 11 cases are registered to UNESCO Memory of the World for its importance, 8 of which are associated with traditional Korean paper: Hunminjeongeum, the Annals of the Joseon Dynasty, Jikjisimcheyojeol, Seungjeongwon Ilgi, the Royal Protocols of the Joseon Dynasty, Donguibogam, Ilseongnok and A War Diary. To examine excellent characteristics of conservation science in Hanji, many studies have been developed. By developing analysis and manufacturing technologies, the excellence of our Hanji should be re-verified scientifically and the tradition should continue as one of the representative Korean cultural heritages.