How Silicone Foam Products Can Protect from Fire Spread, Enhancing Passenger Comfort and Safety
Public transport is becoming more popular as we seek to limit our CO2 footprint. According to estimates derived from the Department of Energy, train travel is approximately 34% more energy efficient than taking a flight and about 46% more energy efficient than driving.
Today, within the US alone, the goal appears to be doubling the number of rail journeys and expanding rail routes in most major cities. Worldwide, there are absolutely no signs of rail transport slowing down. Global governments are investing heavily in rail infrastructure and digitalisation projects.
Revitalizing next‑generation rail equipment will not come without challenges. In addition to improving the travel experience for passengers, rail manufacturers must ensure they can meet enhanced safety standards by investing in innovative solutions, particularly silicone foam products, silicone gasketing, and advanced silicone materials that prioritize safety, durability, and performance in demanding rail environments.
To discover the ways that silicone foam products are emerging as small yet crucial materials for safeguarding modern-day rail travel, we spoke with Diana Buckley, Sr. Product Manager, Silicone & CHR® Tapes.
Diana, could you explain why the use of Norseal® products in applications such as rail can help to ensure enhanced fire protection and safety?
Within the rail industry, dangers such as electrical malfunctions, friction between moving parts, and external factors like debris or exposure to heat and flames could result in fire risks and potentially catastrophic consequences.
By integrating silicone gasketing materials in critical sections of railway carriages, such as engine compartments or passenger cabins, fires can be effectively contained, and the risk of spreading can be minimised. However, these solutions need to meet certain standards and have flame retardancy ratings that can withstand the challenges.
With low outgassing and high flame retardancy, Saint-Gobain® Norseal Silicone products such as F-12, F-15 or F-20 have a lower likelihood of spreading toxic, dark smoke and flames if ignited. They have an exceptional ability to withstand wide temperature ranges (-51°C to 204°C). Furthermore, they offer an excellent compression set value.
While these products differ slightly in cell structure and density, all three products are a good solution for interior and exterior sealing. Norseal F-12 and F-20 meet the highest hazard classification of HL3 per EN 45545-2. Meeting the highest classification ensures that these products can be trusted to help enhance passenger safety.
When exposed to heat higher than 200°C, a product that can expand into a fire-resistant char and seal gaps, further blocking fire, smoke and gases, is our Norseal FS1000 Series. This is a fire-blocking polyurethane foam tape that meets EN 45545-2 classification and is specially designed to be airtight, thermally insulating and watertight. Due to its protective features, it can be used to protect seats, freight compartments, fuel tanks, HVAC systems and more across rail and multiple other industries.
Could you share more about the differences in cell structure and density of the products mentioned?
Norseal F-15 is a medium-low density silicone designed to deliver environmentally stable, flame-retardant performance for gasketing, insulation and dampening applications, offering non-toxic, low smoke generation and low flame spread. F-15 is the newest member of the Silicone product family and serves as a great in-between option where both lightweight features and smoke resistance are needed.
Norseal F-12 has a modified cell structure and low density for gasketing and thermal insulation applications. These features make F-12 lightweight and very easy to process. It is often used as a fire-blocking foam for gaskets, seals and cushioning. Due to its lightweight nature, it can help with increasing fuel efficiency and, because of this, it is also used in aircraft and aerospace applications.
Norseal F-20 has a finer closed-cell structure with a medium density for excellent sealing attributes. The closed-cell structure of F-20 ensures high water resistance to protect electronic components of the exterior lighting systems of the rail carriages.
What does it mean when the products have a low compression set?
This means that a low percentage of permanent deformation occurs under pressure. The low compression set ensures long-lasting seals, while reducing overall maintenance costs.
In addition to overall fire safety, could you please address the important aspect of comfort within rail applications?
Absolutely! Norseal Silicone products are vital contributors to enhancing comfort within different areas of the train. They can ensure that the interior environment of the train cabin is not susceptible to noise and rattling because of their ability to offer acoustic insulation and noise dampening. Vibrations can be reduced, and comfort can be enhanced when these foams cushion floor panels and seats.
With the ability to withstand multiple types of temperature extremes, products such as Norseal Silicone Sponge R10400 and R10460 are often used in applications such as thermal/acoustic insulation and HVAC sealing. Meeting rating specification HL2 EN 45545-2 makes them another great choice for rail applications. They are good candidates due to their excellent weatherability and non-stick properties.
As rail transport continues to evolve and expand, the integration of advanced silicone foam solutions represents a significant step forward in enhancing safety standards and passenger comfort. By leveraging innovative technologies and materials, rail manufacturers can ensure railway transport meets rigorous safety regulations while providing a superior travel experience.