COMPOSITES
Material world T
he drive to lighten materials across a variety of industries is fuelling research into composites. Professor Kevin Potter of the Bristol Composites Institute (ACCIS) at the University of Bristol is a 40-year research
veteran who is currently managing an array of projects designed to push the material’s boundaries. Starting with automation and advances in
manufacturing, Potter says, “Take, for example, large placement machines for a wing skin or spar, putting strips cured. The moment you want to make something more complicated – such as sandwich panels for the wing surfaces – these will be laid up by hand in the traditional way. automation but it largely failed because of an underlying incorrect assumption, that hand lay-up is unskilled.” To remedy this the university is investigating the hand
lay-up process in much greater detail. Potter continues, levels of the operators, how to support them, put tools in place to predict material behaviour and examined their tools more thoroughly, and so we can use VR to aid in training, as it seems unlikely that any geometry you can With conventional additive manufacturing as with
composites, one is making the material and the structure simultaneously, unlike machining an item from a block of metal where its properties are known in advance. Potter believes this limits additive manufacture’s use to less critical tackled. “You can buy additive layer manufacturing the moment they are fairly limited in both properties and
Composites are increasingly finding their way onto a variety of industrial applications previously thought unsuitable. Professor Kevin Potter reveals the latest trends
ALL IMAGES courtesy of The University of Bristol
geometry capability. We’re doing work studying whether it and also recyclability,” he observes. In fact, overcoming problems with recycling is another area the university is examining. For in-process reuse, Potter cites the BMW i3 as one
woven cloth material wasted when the side panels are created go back to the supplier, and are shredded into a loose mat which is then used in the roof panels. “For end-of-life recycling, it’s not so straightforward,”
Potter notes. “Of course you can chop it up, burn out applications. The problem is that without an alignment process a lot of the value is lost. What’s more, for certain applications, such as aerospace, the resin is more expensive The alignment issue is something else currently being
matrix designed to be easily removed can then be put on loop recycling, but he doesn’t see it happening soon. “It will have to happen one day though,” he observes.
A shattered laminate tested by students to
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HEALING TOUCH One interesting property of composites is the potential to include a self-healing ability. It is possible to generate a matrix that can heal damage, but the bad news is that these matrices have had relatively poor properties to start
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