High speed cable priming and heating prior to coating or sheathing - using electrostatic spraying and induction heating

摘要

Rapid application of plastics sheathing to continuous profiles is by (a) coating the profile with a liquid primer by high voltage electrostatic spraying, (b) high frequency induction heating (of the core profile) for rapid hardening of the primer coating and (c) adjusting the profile surface temp. to an optimum level for passing through a high speed coating machine, i.e. a melt extruder, prior to chilling and wind-up. Suitable for applying, e.g., PVC paste coatings to wire or cable at throughput speeds of 200 m./min.