All-electric cold runner maximises LSR injection moulding flexibility and precision

ELMET’s new all-electric SMARTshot E valve gate cold runner system has servo-driven nozzle needles to maximise flexibility, precision and controllability when injecting two-component liquid silicone rubbers (LSR) into multi-cavity moulds.

It complements ELMET’s range of SMARTshot Liquid Injection Molding (LIM) cold runners which also includes a pneumatic version, the model P, and a hybrid version with pneumatic needle movement and electrical stroke adjustment, the model PE.

Compact brushless DC servomotors used in the high-end SMARTshot E move and position the needles during nozzle opening and closing, while the 18.5” colour display allows needle position to be set very quickly and uniformly to an accuracy of 0.002mm and provides constant feedback about instantaneous position. Due to opening and closing times of the order of hundredths of a second, needle movements can be perfectly synchronised and precisely balanced during injection into up to 16 cavities.

In comparison with alternative solutions, the servomotors with their low waste-heat output and small space requirements also enable compact mould design due to a significantly reduced nozzle spacing of as little as 44mm.

One time-saving advantage of the SMARTshot E is that it is connected via virtually wear-free miniature industrial connectors capable of withstanding even frequent assembly and disassembly. Optimised cable management with a cable harness can be removed as an assembly without requiring a qualified electrician. The harness also prevents incorrect connection on reassembly. Clear recipe management with import and export options as well an integrated authorisation system with user management further maximises operating reliability.

All SMARTshot models allow each nozzle to be calibrated and filling behaviour to be defined. They boast a particularly long needle guide and complete protection from twisting, the tip of which is part of the moulding cavity contour. The cooling system and thermal isolation of the cold runner from the mould side ensure process stability. The moulding principle used ensures almost complete elimination of production waste such as sprues and runner scrap.