An Evaluation of the Current Status of Automated Process Control for Thermosetting Composites Available to Purchase

Automated process control for thermosetting composite cure is used to ensure part quality while reducing the energy required to manufacture parts. This study summarizes the techniques used in automated process control and evaluates the progress toward implementing these methods in production. An ideal transducer must provide information about the physical state of the resin while the part is in the processing tool. It must also be able to survive the hostile environment of processing equipment, be simple to install, not interfere with the mechanical properties if it is left behind in the part, and, of course, be economical. Promising transducers based on dielectric, acoustic, and fluorescent signals are detailed in this study. When the physical state is known, the control algorithm acts on the information to vary the cure parameters (temperature, pressure). A number of different strategies for controlling the cure have been proposed. All are developed by trial and error and are part-specific. As more is understood about the physical mechanisms of resins during processing, algorithm development will be easier.