According to MVP, film infusion moulding, using either infusion films or reusable films made with silicon, polyurethane or latex membranes, has slowly been gaining popularity over traditional closed mould methods. The costs and learning curve involved in mould tooling is much lower with film infusion than the traditional rigid Light RTM double mould set alternative, the company explains. However, one of the challenges in the film infusion process has been a lack of emphasis on the improvements of feeding resin under the membrane. In the past, it has been normal to pre-mix the resin in a separate container and have the vacuum ‘draw’ the resin into the mould through a number of ports strategically placed in the infusion membrane. This method produces good results, particularly with large parts such as boat hulls and large wind turbine blades, but there was still a need for a better solution to the continuous renewal of feed pipes, reservoir cleanout, waste of resin after infusion and the labour required for each moulding cycle (setting up the tubing and establishing vacuum connection security).
In answer to these challenges MVP has developed the Flex Moulding Process, a package that consists of injection systems, accessories and seals designed to optimise infusion. The company also offers a training course covering the process, accessories and systems.
Flex Moulding Process is said to offer the following advantages:
- a mix/meter infusion system provides a direct feed to the infusion membrane, eliminating the need to pre-mix resin and the use of consumable tubing and fittings;
- increased precision through the use of new accessories, including the Pneumatic Pressure Vacuum Sensor (PPVS-Infusion);
- a new ‘lockable’ reusable membrane in addition to traditional vacuum bag infusion;
- large resin reservoirs and multiple large bore feed pipes are eliminated, reducing costs and consumable wastage;
- Universal Membrane Fittings provide a secure connection for the connection valves.
MVP distributors around the world are currently being trained in this process technology.