WEB EXCLUSIVE A new hot-runner flow controller based on pressure rather than temperature was introduced recently by Mold-Masters Ltd., Georgetown, Ont. Its new Proportional Flow Control is designed to minimize melt imbalances and eliminate the need for a pressure or temperature transducer in thermal gating applications. It is an open-loop controller with two self-regulating valve pins. The system relies on the force of the melt (driven by the injection screw) to open and close the valve, with the controller used to set the percentage that the valve will open