TRB Lightweight Structures Ltd, based in the UK, has reportedly developed a new biocomposite resin based carbon fiber reinforced (CFRP) sandwich panel door leaf with a 100% recycled foam core. This new biocomposite door leaf product has been designed and fire rated for both overground and underground rail use, passes BS 6853 and BS 476 and is EN 45545 HL3 compliant. According to independent data sourced by the company, the sandwich panel system when tested to BS 476 Part 7: 1977 for ‘Spread of Flame’ easily achieved a Class 1 Category 1a rating, with a 30% less recorded flame spread of only 50mm in the 1.5 minute test time.
Manufacture of the leaf included the development of a new, proprietary carbon fiber compatible bio prepreg resin, the company said. The new system had to be sustainable to make composite parts that could meet even the fire, smoke and toxic fumes (FST) specifications in subterranean rail applications. The new ‘bio’ prepreg, which is non-toxic and does not use volatile organic solvents, is based on a polyfurfuryl alcohol (PFA) resin derived from a renewable alcohol produced from a natural waste bi-product from refined sugar production.
According to TRB, this means that a ‘green’ composite material option for carriage door leaves is available at a comparable cost to aluminum bonded door leaves, with a 35% weight saving from 40 kg to 26 kg.
The foam core used in the rail door leaf composite structure is also produced from 100% recycled consumer plastic, TRB said. Other matrix design options for other applications using glass fibers, natural fibers, or aramid fibers can be custom made by TRB on request. As well as carriage door leaves, the TRB bio prepreg based system can be used for other rolling stock parts.
Chemical resistance
’We are extremely pleased with the overall performance data for the new biocomposite carbon fiber prepreg sandwich panel system, in particular the FST specifications achieved,’ said Lyndon Newman, chief engineer for TRB. ‘In the 30 years I have been in the industry I have never seen such impressive fire performance test results for a non-phenolic based thermoset system, achieving the BS standard so comfortably. Our PFA bio resin prepreg has fire retardant properties greater than phenolics, plus excellent temperature and chemical resistance.’
’We initially developed this biocomposite product for rail door leaves, but it could be used for other mass transport interior applications. We have brought aerospace prepreg technology to our rail customers and can now offer them a truly ‘green’ material design option that is 35% lighter than a bonded aluminum door at a comparable cost.’
This story uses material from TRB with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
