Process for the quenching of a melt flue a polymer film and apparatus for carrying out the method

摘要

1446596 Casting polymeric film IMPERIAL CHEMICAL INDUSTRIES Ltd 7 Feb 1974 [7 Feb 1973] 6031/73 Heading B5B [Also in Division H1] A molten polymeric film 1 is quenched by passing over an electrically earthed casting surface 2 cooled by the passage of a quenching fluid flowing through inlet 3 and outlet 4 and is held to the drum electrostatically by means of a pinning wire electrode 8 connected to a source 15 of assymmetrical A.C. supply capable of applying to the electrode an alternating voltage said voltage being of symmetrical or asymmetrical wave form and exceeding 4À0 kv. peak to peak and having a frequency not exceeding that at which positive and negative electrostatic charges emitted by the electrode are unable to cross the space between the electrode and the molten film before the polarity of the voltage on the electrode changes and whereby the electrostatic charges emitted by the electrode are deposited on the molten film to cause it to adhere to the casting surface.