EasyPerm is capable of measuring the permeability of a dry reinforcement. Evaluating permeability is important for understanding how liquid resin will behave when injected in infusion and RTM processes.
Steffan Lea, a research fellow at the AMRC Composite Centre, says: “What we get at the end is a measurement, a number which can be used in simulations that take a couple of minutes rather than several hours compared with other methods. By using sub-scale [coupons and computer simulation] testing to provide fast and accurate data, it cuts down on a trial and error approach, saving our research partners money, material and time.”
The system allows for the characterisation of resin flow in dry fibre reinforcements – crucial information for performing simulations of large and complex parts, and also for process optimisation. Used to characterise all types of fibre, including glass, carbon, aramid, flax and hemp, the system requires a minimal amount of material to perform the evaluation.
Lea says the kit is the latest addition to a diverse and growing portfolio of equipment purchased with funding from the ATI. Acquisitions include: a braiding system; Jacquard loom; tailored fibre placement system; high-temperature, high-tension filament winder; tow-spreading machine; and robotic end effectors for automated handling.
“Among the key technical capabilities of the EasyPerm is that is has two configurations for permeability measurement: in-plane and through-thickness,” says Lea. “It also has up to 5 bar injection pressure and is coupon scale, so you’re not wasting lots of material during the tests. The system also works with any kind of fibre, and the chamber is adjustable so we can vary the fibre volume fraction.”
EasyPerm has already been used in tests on GE Aviation’s Digital Propulsion project, and FabForm, a textile-based project looking at the stabilisation of thick 3D woven fabric to create composite preforms for automotive and aerospace applications.
Lea explains how it works: “Under the lid is a test chamber, inside which goes the test material – the coupon. You close the lid and inject a model fluid to replicate the resin – we use rapeseed oil – and as the pressure sensors inside the chamber are triggered, you can see how oil flows through the material.
“A key factor for us is that EasyPerm is a commercially available piece of equipment so we can compare our results to others using the same methods and have certainty that the test is being conducted in a consistent manner,” he continues. “In composites, there is a tendency for people to develop their own in-house way of testing, but with this it is standardised. So, if a university in Australia, for example, has the same equipment, we could compare our results with theirs, whereas before we would have to get our own material and do the tests in our own way.”
The new ATI-funded raft of equipment will be used to not only manufacture preforms but develop enabling technology for commercialisation, including systems for joining, automation and impregnation.