Patent attributes
A casting apparatus for manufacturing polymer film includes a die for discharging a molten polymer and having discharge direction oriented at a discharge angle offset from horizontal. The apparatus includes a first chill roll having a first diameter and a second chill roll having a second greater diameter. There is a first gap between the first chill roll and the second chill roll. The discharge angle is of a predetermined magnitude to gravity assist delivery of the molten polymer to the first gap. The second chill roll is positioned to gravity support the film exiting the first gap along a first length of a first side of the film. A first polishing roll is positioned downstream first and second chill rolls. The first polishing roll engages and cools a second length of a second opposite side of the film. The first length is substantially equal to the second length.