Technical Info - Closed Loop

The Loomis Closed Loop Process Control system is an extremely precise method for maintaining extrusion speed, which results in a more uniform density in green parts. This precise control is possible by using the latest motion control and linear positioning technology combined with servo- positioning and velocity control devices.

Linear positioning is accurate to .0010”, and velocity control is accurate to .0010” /sec.



At the heart of the Loomis closed loop extrusion control system is the closed loop hydraulic module; a multi-axis, closed loop process controller with process times below 2 milliseconds per loop cycle.

The Loomis Closed Loop Process controller can make adjustments in milliseconds rather than tenths of seconds (or even seconds) which is often the case with an open or single loop controller. The result is a process that can quickly reach and maintain the velocity set point.

Motion control modules are connected directly to the PLC (programmable logic controller) I/O Bus, allowing commands to be executed almost instantaneously. This is in contrast to external closed loop systems in which the commands must negotiate communications protocols before sending executable commands to the controller. In addition to the benefits of sharing a bus, instructions and parameters can be incorporated into the PLC Logic Program which allows for smoother and more complete system integration.