| 摘要 |
1312263 Quenching films AGFA-GEVAERT 19 Oct 1970 [30 Oct 1969] 53306/69 Heading B5B In a process for producing thermoplastic films molten polymeric material is extruded from extruder 10 via filter 11 and slot die-head 12 on to the surface of a rotating quench drum 13 and is electrostatically pinned to the drum 13 by depositing electrostatic charges on that surface of the film which contacts the quench drum from electrode (or electrodes) 16 mounted (on machine frame 15 and insulating support(s) 18) between the die-head and the quenching surface. In the preferred embodiment the electrode 16 is a wire electrode spanning the width of the cooling drum and connected through lead 19 to the positive terminal of output source 20 (Fig. 2, not shown). The film may additionally be urged against the drum 13 by an air blower head 23. The drum surface may be covered by, for example, a thin coating of an electrically insulating material, P.T.F.E., to prevent direct electrical contact between the drum and the film. |
