Abstract: A process is disclosed for determining tuning constants of a process control loop, the loop including a process control module, an actuator and a controlled process. The disclosed process includes making a series of changes to the target value of the actuator while measuring corresponding changes in the output of the controlled process. Certain calculations are applied to the information to determine the tuning constants, and the constants are applied to the control module.

Abstract: Density of products produced from a foam extrusion process is controlled by measuring the thickness and the basis weight. The density is calculated and is compared to a target, or desired value, to produce an error signal. The error signal is used to control the density.

Abstract: An extruding system for the production of continuously extruded elastomer, such as tread stock for the manufacture of vehicle tires, has an extruder, a first take-away conveyor belt for conveying the extrusion as it exits the extruder, a second conveyor belt for varying the thickness or weight of the extrusion after leaving the first conveyor belt, a sensor to measure the running-weigh-scale value and a targeted running-weigh-scale value. The weight or thickness of the continuously extruded elastomer is controlled by measuring the weight of the continuous extrusion at the running-weigh-scale. The measured value is compared to the target value to obtain a control signal. The control signal is used to adjust the difference in speed between the first conveyor belt and the second conveyor belt.