Process could halve component weight, says Reliant Plastics

Process could halve component weight, says Reliant Plastics


Injection-moulding specialist Reliant Worldwide Plastics may be known to you as a supplier of parts for commercial aviation seating. However, the company is ready to expand its scope, with a new method to make ‘metal to plastic conversions’.


This is not some form of alchemy, it is a combination composite-thermoplastic system named Reliant-LITE. According to the company, by substituting metal seat components for plastic components, weight savings of up to 50% are possible while maintaining the strength of an aluminium part.


CEO Craig Clark was on hand at Aircraft Interiors Expo in Hamburg to explain the process. “We take a continuous carbon graphite fibre in a sheet resin that is about the thickness of a sheet of paper, with multiple continuous strands encapsulated in Polyphenylene Sulfide (PPS) resin. We then overlay the sheet in multiple layers, and through heat and a vacuum, make a plate. The plate looks a lot like a composite, but there’s no glue involved whatsoever – its all a chemical reaction through 750°C heat and pressure.”


Multiple carbon fibre components can be moulded using this process, and when they need to be joined to create a single part, a thermoplastics positioning system allows Reliant to overmould them with plastic in a repeatable way, in any colour, using what the company calls Homogeneous Connective Technology. “The overmould and the chemical reaction make it one homogenous part, with a reinforced structure inside it where needed,” explained Clark.


According to Clark, a seat leg made from Reliant-LITE will be 41% lighter than its aluminium equivalent – “the strength requirement is 150 lbs and our parts managed over 200 lbs in tests”.


So for companies looking for an alternative to metals, why not just use composites? Clark responded, “Composite parts use glue, which can fail, and when they fail they can produce a shard – ours break straight because they have the properties of a plastic part. You can’t predict where slivers of carbon fibre will go in an impact, but you can predict this material because we have a continuous carbon fibre strand resin encapsulated in an overmoulded part. Also, composites are also labour intensive and expensive, whereas the price of ours is comparable to an aluminium part.”


Reliant is currently finalising its in-house testing of the process, and will shortly be creating prototype parts for potential customers to use in their own tests. Clark is confident the process will be a success and manufacturing will begin soon: “We’ve been developing the process for over a year and a half, and know that Reliant-LITE components will pass when customers certify their seats. I think it’s going to happen quickly when we’ve proved the system works. We’ll make 200,000 parts this year with one customer. Another customer is very excited about the seat leg and now wants a spreader, and they potentially want to make a whole seat from the material, which is a 47% weight saving overall. You can save multiple hundreds of pounds over an aircraft.”

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