Massachusetts-based Synventive Molding Solutions has launched its SynFlow two-speed sequential valve gating hot runner technology, which is designed to address surface defects — such as pressure alteration marks, opposite direct gating marks, sink marks after coating and reduced adhesion of finishes — on large parts, offering improved plastic flow control.

The pin control technology, which is patent pending, is designed for cascade or sequential valve gated hot runner systems. The technology works by reducing the opening speed of the valve pin, which obstructs the rush of pressurized plastic. The valve pin then opens at top speed for the rest of the stroke to fill the part.

According to Synventive, the end result is "a smoother fill, reducing hesitations and sharp velocity changes, resulting in cleaner parts with excellent surface quality and improved process efficiency."

Other features of the SynFlow system include a hydraulic valve gate hot runner system with 12 mm, 16 mm or 22 mm diameter nozzles and actuators with position sensors; and a SynFlow flow control package including valve gates, signal lines for both valve control and position sensors, a control unit for as many as eight control zones and a hydraulic valve block.