A closed loop injection control system is available on the larger Techmire machines – Models 44 and up. The system permits real time control of the injection process from start to finish, resulting in stable system performance and premium part quality.
The main elements of the system are a special manifold, a fast response time servo valve, displacement and pressure transducers, and proprietary software.
Three (3) variable velocity profiles can be programmed for use during the cavity filling phase, and two (2) variable pressure profiles for use during the compaction phase. The switch-over point from velocity mode to pressure mode is pre-selected based on displacement of the injection cylinder and pressure.
All settings of the real time control system for any given mold can be saved on the hard disk of the PC that controls the machine, along with mold sequence and PPCS settings. This greatly reduces the time required for a repeat set-up of the mold.
In addition to improving part quality, the closed loop system significantly reduces the “hammer effect” at the end of the injection, thereby minimizing flash.