Remaking Train Interiors
Forecasters agree that train interiors are the area to watch for new uses of composites. Lucintel predicts that the interior segment will remain the largest market segment by volume, with growth driven by the increase of options in fire-retardant materials with improved aesthetic properties.
Because fire resistance remains an issue for broader use, Kapadia sees resin suppliers exploring the use of next-generation fire-resistant resins. For example, the global chemical company Scott Bader teamed with Shanghai Cedar Composites Technology Co. Ltd. to provide luxury cabin chairs for high-speed trains operated by China Railway, the national railway operator. The CFRP chairs, produced via vacuum assisted resin transfer molding (VARTM), feature Scott Bader’s Crestapol® 1212, a low-viscosity, fire-retardant urethane acrylate closed mold resin. The resin meets several international performance standards, including Germany’s DIN-5510 fire test for railway components, France’s NFF 16-101-F0 fire test for railway components and NFP 92-501-M1 building materials combustion test, and the European Commission’s EN/TS 45545-2: 2009 on fire testing materials and components for trains.
In addition to fire-resistance, cost remains another issue that composite suppliers need to address. “You have to balance the upfront costs with the ongoing costs,” Kapadia says. “If something costs a little bit more upfront but saves you money throughout its life – because composites don’t corrode, they’re lighter so they save you on fuel, etc. – that is an equation that people are increasingly going to consider.”
Opening Doors to Innovation
Achieving cost savings by providing lighter weight components was top of mind for U.K.-based Penso Group when it unveiled its CFRP train door last year. The press-formed phenolic prepreg door, with an integrated core sandwich panel, reportedly provides a 30 percent reduction in weight compared to standard aluminum doors.
Train doors are a critical area in need of innovation, according to Shift2Rail, a European initiative supporting improved trains and more durable and cost-effective rail infrastructure. The group encourages the development of doors that move away from current solutions based on honeycomb, aluminum or steel sheets, which have drawbacks around energy consumption, as well as noise and thermal transmission.
The organization is pushing manufacturers to use composites as the foundation of train door systems that open and close more quickly than today’s systems, while meeting necessary safety and reliability levels. An uptick in door speed could reduce people’s time spent on the platform and increase overall line capacity.
Penso reports that by using processes such as hot compression molding and high-pressure resin transfer molding (HP-RTM), the company is able to achieve process cycle times of four to 15 minutes, respectively. This production speed is key to making the use of CFRP more competitive against traditional materials. The company has recently invested in a new plant and equipment with support from Great Britain’s recently launched Rail Supply Growth Fund aimed at helping businesses grow their capabilities and capacity to meet need in the expanding rail supply sector.