Film casting apparatus, protective film of polarizing plate, and polarizing plate

필름 캐스팅 장치, 편광판 보호필름, 및 편광판


A film casting device, a polarizing plate protection film and a polarizing plate are provided to prevent bubbles collected in a dope supply pipe from being infiltrated into discharged dope, and to restrict stripe on the manufactured film by completely closing a discharge valve after discharging air. A film casting device(10) is composed of a co-casting die(12) having a feed block(11) and a casting belt(15) supporting a multilayer web(14) discharged from a die lip(13) by moving continuously under the die lip of the co-casting die. The casting belt is made of stainless steel and rotated between rollers(17,18). An intermediate pipe is composed of a curved pipe part connected to the feed block and a straight pipe part extended between the curved pipe part and a three-way valve to supply intermediate dope. The radius of curvature of the curved pipe part is 50 to 200 mm, and the length of the straight pipe part is about 0.5 to 3 m. Three air discharge valves are formed in the curved pipe part, and the straight pipe part is inclined to a horizontal plane at 0 to 20 angular degrees.
도프를 코-캐스팅 다이에 공급하는 파이프가 코-캐스팅 다이의 피드블록에 접속된 곡관부와 곡관부에 접속된 직관부로 구성된다. 곡관부의 곡률반경은 50㎜∼400㎜이고, 직관부는 수평면에 대해 0°∼25°의 각을 이룬다. 도프 공급을 시작할 때 배출밸브가 열리고, 도프가 나올수록 조금씩 닫힌다. 공기가 완전히 배출된 후, 배출밸브가 완전히 닫힌다. 그로 인해, 갇힌 공기가 파이프로부터 완전히 빠져나가서, 코-캐스팅 다이의 다이 립으로부터 방출된 플라스틱 웹이 기포를 전혀 포함하지 않게 되어, 웹이 다이 립에 튀어 제조된 필름의 줄무늬를 야기하는 것이 방지된다.




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Cited By (4)

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    US-8784725-B2July 22, 2014Sk Innovation Co., Ltd.Wide casting belt, method for manufacturing a wide film, and wide film
    US-9428624-B2August 30, 2016Sk Innovation Co., Ltd.Method for manufacturing a wide film, and wide film
    US-9884461-B2February 06, 2018Berndorf Band GmbhWide casting belt, method for manufacturing a wide film, and wide film
    WO-2010140721-A1December 09, 2010에스케이에너지 주식회사Wide casting belt, method for manufacturing a wide film, and wide film