Pactur’s shrink tunnels are designed so as not to lose the heated air into the atmosphere, thanks to a system of turbines developed by us to create an internal recirculation of the air and, at the same time, to blow air all over the product.
Temperature control is made through a PID system (proportional-derivative-integrative), which activates solid-state relays. The PID controller is a control algorithm with a predefined structure, which is tuned (calibrated) by choosing the value of some parameters. Correction factors are calculated by comparing the output value with the set value and applying gains that minimize overshoot and oscillation, while implementing the change as quickly as possible. PID control on a shrink tunnel heating system grants a constant and continuous variation of the output within a feedback mechanism of the control loop, in order to verify the process and ensure the absence of oscillations and, therefore, maximum saving.