Active control of the vacuum infusion process

Through infusion experiments, fibrous preforms are shown to have an inherent heterogeneity in the permeability. This heterogeneity can lead to unforeseen, unpredictable and potentially, problematic flow patterns. A new active control system is proposed to address this issue, capable of monitoring the resin flow, identifying flow disturbances and taking an appropriate corrective action in real-time, through computer-controlled injection ports. A simple technique is also proposed for monitoring the resin flow in closed moulding processes such as Vacuum Infusion (VI), where at least one side of the mould is visible. This uses a low cost web-camera to capture images at fixed time intervals during the infusion phase and analyses them to identify flow disturbances. The control system then uses this information to take corrective action in real-time. To demonstrate the potential of the system, it has been implemented and validated through numerical simulations and infusion experiments. (c) 2006 Elsevier Ltd. All rights reserved.