Towards a fully integrated resin infusion process

The importance of Resin Infusion dramatically increased in ship and boat industries for the last two decades. Infusion gradually replaces traditional manufacturing techniques, such as hand and spray lay-up. Resin Infusion has mostly been developed with trial and error from the industry. The level of reliability and reproducibility is limited. Furthermore, the range of application of Resin Infusion is limited by the current moulding techniques. This piece of research focuses on Resin Infusion with a layer of porous mesh, also called Vacuum Assisted Resin Infusion Moulding, which is widely used in the marine industry. The overall aim of this thesis is to demonstrate that VARIM can become a reliable process to manufacture large structural FRP components. Therefore, a part of this work is dedicated to improve the scientific knowledge of the process. The mechanical properties of panels manufactured with VARIM are investigated and compared to samples produced with RTM in order to validate the quality of infused components. The influence of the fibre type, the laminate thickness and the gravity on the flow propagation is studied. The curing properties of the tested resins are measured. Moreover, real-time flow and cure monitoring techniques are investigated that can be used in an industrial environment. A flow monitoring system based on the resin conductive properties is designed, built and validated. Finally, an innovative moulding system using a flexible mould and adapted to the infusion set-up is realised and tested. Its ability to keep a constant shape during the infusion is demonstrated. The benefits and issues of combining both real-time monitoring systems and flexible moulds with the VARM set-up are evaluated. The possibilities to transform such an integrated process to a controlled one are discussed.