| 摘要 |
Apparatus for casting cellulose acetate film from a hot solution is described. The apparatus includes a casting wheel (12), means (13, 14) for passing heated liquid through the wheel to heat the wheel, means (15) for extruding a band of solution onto the wheel, a take-off roller (16) for taking the band, in the form of a film, off the wheel and further rollers (18, 20, 22) for leading the film (26) to a drier (24) after which, when the solvent has been largely removed from the film, the film is wound up into a roll. The take-off roller (16) and the further rollers (18, 20, 22) are concave whereby a defect in the form of surface imperfections is avoided. The imperfections take the form of short sinuous lines oriented generally parallel to the length of the film. |
