Description of standard and advanced driving modes
Adaptive control of the thermoplastics injection process

Standard mode (BFH)

On a standard injection molding machine, the maintenance phase, designed to compensate for shrinkage due to polymer solidification at the start of cooling, consists of applying a constant hydraulic pressure to the injection cylinder (BFH mode: closed loop on hydraulic pressure, figure 1 a). Since the pressure of the polymer in the cavity is not directly taken into account, and since the hydraulic pressure/material pressure transfer function can be significantly affected by a large number of parameters, such as cylinder oil temperature, tool geometry and/or local flow conditions (pressures, temperatures, speeds), this control is sensitive to various process disturbances. These include, for example, thermal disturbances (linked to production start-ups) or...