TRB Lightweight Structures has developed a carbon fiber reinforced plastic (CFRP) sandwich panel door with bio-based resin and a 100% recycled foam core.
The design and fire protection of this new biocomposite door leaf product is suitable for use on above ground and underground railways. The composite system is BS 6853 and BS 476 and complies with the EN 45545 HL3 standard.
According to TRB, it now offers the rail industry a sustainable composite option for door blades that is as cost-effective as aluminum door and window blades and weighs 35%. The product expands its offerings to customers in the rail industry to meet the growing demand for more energy efficient products in the global marketplace.
TRB's design and engineering team worked closely with resin partners to develop new proprietary carbon fiber compatible prepreg resins. The new system must be highly sustainable, enabling TRB to cost-effectively produce lighter composite parts to meet even the most demanding fire, smoke and toxic fumes (FST) specifications in underground railway applications. This new "biopreg", which is non-toxic and does not use volatile organic solvents, is based on a polymeric sterol (PFA) resin made from renewable alcohol produced from natural waste by-products of refined sugar production.
TRB's new prepreg is the first sustainable fire protection material on the market, specifically for TRB to produce components for FST rail applications. In addition to the carriage door, prepregs can be used for other vehicle components. The foam core used in the rail door composite structure is made of 100% recycled consumer plastic. Recycled foam cores meet TRB's “High Sustainability” specification and, when used with double woven carbon fiber fabrics and bioresin prepregs, provide the overall material properties required for sandwich panels. Matrix design options for other applications of fiberglass, natural or aramid fiber can be customized by TRB upon request. According to the needs of railway customers,
According to independent data, the sandwich panel system reached Level 1a in BS 476 Part 7: Test 'Flame Spread' in 1977, and recorded a flame spread of only 30% of 50 mm during the 1.5 minute test period. The maximum allowable value for level 1a is 165 mm.
“We are very pleased with the overall performance data of the new biocomposite carbon fiber prepreg sandwich panel system, especially the FST specification,” said TRB chief engineer Lyndon Newman. “In the 30 years of this industry, I have never seen The impressive fire resistance test results for non-phenolic based thermoset systems make the BS standard so comfortable. Our PFA bioresin prepregs have higher flame retardancy than phenolic resins, as well as excellent temperature and chemical resistance. "
“We originally developed this biocomposite product for railway door fans, but it can be used for other internal applications of mass transit,” he added. “We have brought aviation prepreg technology to our rail customers. They can now offer them a true 'green' material design option that is 35% lighter than an aluminum alloy door of the same price."
The data provided by TRB compares a 40 kg aluminum door leaf, excluding any fittings or door furniture, and the same size door weight as the new biocomposite CFRP prepreg sandwich panel produced by TRB is only 26 kg. .
The TRB biocomposite CFRP door leaf product is reported to have a 40-year life cycle, is more durable than aluminum equivalent materials, and has excellent fatigue resistance and low maintenance costs. Due to the significant weight reduction, composite door fans require less heavy-duty door operating systems and offer railroad operators many cost-saving benefits such as reduced energy consumption per track and less track wear. In addition, they offer the opportunity to have shorter station dwell times because lighter doors open and close for a few seconds. For London traffic, this is a way of calculating the daily underground service during installation and running additional pipeline trains every day on routes that need to ease peak hours.
