• 펄프종이기술
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• 제36권2호
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• pp.39-46
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• 2004

In this paper, the effects of roll diameter and storage time in roll form, bending method and relative humidity on curl in copy paper and inkjet coated papers are investigated. In copy paper, more MD curl is showed at smaller roll diameter and the extension of bending time. However CD curl is hardly influenced by roll diameter and bending time. At high relative humidity, especially CD curl largely reduces. All inkjet coated papers without the primary or the secondary back coating during papermaking show the increase in MD curl and slight decrease in CD curl by MD bending regardless of the winding methods(TSO, TSI). The water spray as back coating results in the remarkable reduction of CD curl regardless of the winding methods. Drying on flat dryer after spraying the moisture on back side display the most excellent effect on the reduction of CD curl.

• 펄프종이기술
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• 제36권3호
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• pp.60-66
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• 2004

The effects of roll diameter, winding time, winding methods and relative humidity on curl In newsprints(46$g/m^2$, 54 $g/m^2$, and 54 $g/m^2$ SNC) are examined. The larger MD curl appears at smaller roll diameter, with the extension of winding time, and at the treat ment of soft nip calendering. The MD curl shows the back side curl at winding methods with top side as outer side(TSO), and the top side curl with top side as inner side(TSI). While the CD curl in newsprints( 46 $g/m^2$, and 54 $g/m^2$ SNC) treated with calender is hardly influenced by the storage times, roll diameter, and winding methods. However the CD curl in newsprint(54 $g/m^2$) gradually increases to a two weeks, and then hold constant regardless of roll diameter and winding methods.. The CD curl shows always the top side curl regardless of winding methods. At high relative humidity, the CD curl largely reduces, but the MD curl is not nearly changed. Especially, the CD curl in news-prints(54 $g/m^2$ SNC) is little affected by the changes of relative humidity.

• 한국정밀공학회지
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• 제21권1호
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• pp.46-50
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• 2004

The curing characteristics of a liquid photopolymer during microstereolithography and the shape accuracy of thereby fabricated microstructures were investigated experimentally. A He-Cd laser with a wavelength of 442nm and a photopolymer consisted of a commercial resin from SK chemical and a photoinitiat or were used for the experiment. By varying the laser beam power and scanning speed of the focused laser beam, minimum curing thickness of 50 ${\mu}ㅡ$ was obtained. The distortion of solidified structure due to adhesion force was measured and the optimum fabrication conditions were determined. Also, the feasibility of direct fabrication of three-dimensional microstructures by Super IH process was examined.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2000년도 춘계학술발표논문집
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• pp.55-55
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• 2000

환망초지기는 장망초지기와 달리 섬유배향성이 심할 뿐만 아니라, 초지속도를 높일 경우 실린더 회전에 따라 생긴 원심력으로 인하여 지필 파괴(wash-off)가 발생하기 때문에 속도에 제한을 받게 된다. 본 연구는 이런 점을 개선하기 위하여 forming zone과 탈수시간이 중요한 인자임을 인식하고 vat 인입부에 apron을 설치하고 mould head의 변화를 통하여 종이의 품질향상과 생산성 향상을 도모하고자 하였다. 그 결과 wash-off 의 감소로 인하여 퍼짐새(formation)의 향상은 물론 생산속도을 증가시킬 수 있어 생산성 향상을 도모할 수 있었다. 섬유 배향성 개선으로 인한 CD의 치수안정성 도모, 종이의 양면성 감소로 인한 컬 발생을 방지 할 수 있으며, 내부수위의 적절한 변경은 종이의 퍼짐새는 물론 종이구조 개선의 중요한 인자로 확인되었다.