Rubber mixing. (Literature: hardware/software).

The MixCont industrial control system for the rubber mixing process is featured in company literature. Most industrial control systems for rubber mixers are said to control the mixing process in predetermined repetitive sequence according to downloaded mixing parameters such as time, temperature and energy. MixCont uses the same idea as an oscillating disk rheometer supplemented by the ability to estimate changing rubber compound properties during the mixing by evaluation of torque dynamics in real time. Based on the model of the mixing process, MixCont makes on-line analysis and prediction of mixing process behavior by on-line mathematical evaluation of mixing process variables such as electrical power (torque), temperature of the compound, ram position (if it is available), ram pressure (if it is variable) and rotational rotor speed (if it is variable). Based on the processed information about the mixing process, MixCont makes mathematically motivated optimal control decisions in real time. Namely, MixCont determines total mixing time, time between feedings, number of lifts within one mixing cycle, duration of every ram down, and rotor speed and ram pressure (if they are variable) at different parts of the mixing cycle, according to the literature. (MixCont AB, Henry Dunkers Gata 2, 231 81, Trelleborg, Sweden)

Circle 136 on card