| 摘要 |
Circuit modification for use of electrostatic attraction to cause film or sheet extruded from thermoplastic materials of high dielectric constant to adhere closely to the metal surface of a cooling/polishing drum. The film is treated in the usual fashion to high voltage electrostatic discharge prior to contacting the drum, but the drum, instead of being earthed, is maintained at a moderate potential with respect to the film. Pref. the circuit resistances are connected in a manner which is self-compensating to counteract any development of an arc-over potential. Reduction or elimination of the risk of electrical arcing as the film surface approaches the drum, and avoidance of consequent scorching/pitting/perforation of the film, or breakage of the film due to non-adherence of the prematurely discharged region of the cooling drum. |
