STG unveils lighter, biodegradable floor path safety glow stripRunway Girl

CWMBRAN and HAMBURG — Cabin interiors pose complicated end-of-life recycling issues, driven by multiple factors, from the location (often at remote boneyards or MRO locations) to the materials (especially those attached with certain glues or adhesives, and recyclability problems with flame retardant materials) and intellectual property concerns around labelling. Deep within one niche — floor path safety lighting — sits STG Aerospace, which is reaping the rewards of serious materials science work to develop a bio-additive, which means the polycarbonate in its new saf-Tglo eco E1 photoluminescent products will now biodegrade even if they’re sent to landfill.

The key problem for sustainability within this part of the market, STG product manager Rhian Bache says, is that “from a disposal point of view, at the end of their life, we don’t have control over how an airline gets rid of it. How would you risk-mitigate against that?”

Around a tour of the laboratory and a chat with the scientists responsible for these advances, Bache explains to Runway Girl Network that “polycarbonate is really difficult to recycle. We’ve added this bio-additive into the polycarbonate of the casing, so that the microbes — the microorganisms — really want to eat that bio-additive. While they’re chomping away on it, they excrete enzymes that break down the bonds between the polycarbonate atoms, so that it turns into organic compounds and water, essentially.”

At the front end of the lifecycle, STG has also changed the resin in which the photoluminescent elements are contained from a solvent-based resin to a water-based resin, reducing the local environmental impact and making production substantially easier and more comfortable for staff, who no longer have to deal with potentially dangerous volatile organic compounds.

STG Aerospace has done impressive materials science work to improve its products environmental credentials. Image: STG Aerospace

STG is also changing its plastic feedstocks so that the new eco E1 product is made up of a majority of recycled material. “Across the lifecycle, we have managed the sustainability to the greatest point that we can. From a resources point of view, we’ve reduced the amount of virgin material that we’re using,” Bache says.

Safety glow strips are made up of two key elements: the floor track and the plastic insert. The former is now made with 50 percent recycled polycarbonate, while the latter is now 80 percent post-consumer recycled waste.

“To do that, we’ve had to increase our traceability, working with our supply chain very closely to ensure that they understand the importance of that traceability,” Bache tells RGN. “We’re down to an 80% reduction in virgin material use, which is quite considerable. It’s 50% recycled, 50% not recycled, on the polycarbonate sleeve. We’ve kept that virgin material in there, to make sure you’ve got the structural integrity: it has to withstand a galley cart constantly going over it, so you need to be confident!”

In person, the new eco E1 product is very comparable to what it replaces. Image: John Walton

In addition, eco E1 is also lighter than a comparable previous generation saf-Tglo SuperSeal product — some 79 percent of weight reduction on an example Boeing 737-800.

Repeatability of production is a key hurdle when it comes to certification of materials, and here STG has made strong progress with its suppliers.

“We are very careful who we work with,” Bache says. “We make sure that they are people we can have that degree of confidence in. They are used to dealing with aerospace suppliers. I think we were the first, if not one of the first, to ask them to do something of this nature, so there were definitely learning curves there. It’s definitely been a collaborative process, but they’ve been very positive — very open to it.”

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Featured image credited to STG Aerospace