A new electric drive system for hot-runner valve gates is said to deliver more precise control than conventional hydraulic or pneumatic actuation and is better suited for clean-room applications.
A new electric drive system for hot-runner valve gates is said to deliver more precise control than conventional hydraulic or pneumatic actuation and is better suited for clean-room applications. Said to be an industry first, the new electrical needle drive from Ewikon Hot Runner Systems of America Inc., E. Dundee, Ill., uses a stepper motor to control needle position. The needles can be moved in increments as small as 0.05 mm. Up to eight needles can be operated by one external control unit. A manual setup mode allows users to program each needle separately. The needle system is designed for use with Ewikon’s HPS III_NVE 1 and NVE 2 systems, where the needle drive is positioned in the clamping plate. It is suitable for nozzles with flow channel diam. from 3 to 9 mm. Three installation sizes are available. A fault-management and monitoring function automatically readjusts needle position within one molding cycle. An integrated PC interface allows for easy modification of the default operating parameters. Simple cable ducts for the input leads are machined into the clamping plate, eliminating the need to integrate supply bores for hydraulic fluid or air.