Train passengers take for granted the heating, ventilating, and air-conditioning (HVAC) units in train cars. These systems channel air from outside and remove odors, moisture, and pollution while maintaining temperatures comfortable to the passengers. The HVAC units must hold up under a wide range of environmental conditions, including high and low temperatures, rain, dust and pollution. Unfortunately, a polyvinyl chlorine and nitrile rubber blend gasket material used to seal train HVAC units was collapsing overtime, allowing dirt and pollution into the HVAC units, and causing HVAC units to malfunction due to clogged condenser coils and blocked ductwork. For train passengers, the end result was an uncomfortable ride, with poor air quality and widely fluctuating temperaturesinsidethetraincars.
The original gasket material was collapsing over time due to poor compression set. The solution for reliable, long-lifetime train HVAC gaskets was to replace the original gasket material with Rogers BISCO® BF-2000 ultra-soft silicone material. HVAC gaskets formed of 19 mm (0.75") thick BISCO® BF-2000 blocked out dust, dirt, and pollution while maintaining a tight seal under wide temperature ranges (-5°C to 200°C). BISCO® BF-2000 features low closure force to achieve reliable and sure seals, filling gaps around the HVAC unit’s perimeter. The foam material is available with a pressure-sensitive adhesive on one or both sides to simplify bonding to different surfaces and make installation easier and quicker.
With its high compression set resistance (see description), BISCO® BF-2000 foams can maintain a gasket seal on the train HVAC units for a long period of time. The material meets ASTM E162, ASTM E662, and SMP 800-C requirements for trains for flame, smoke, and toxicity. In addition, it is resistant to UV light, has high flame resistance per UL 94 requirements and provides isolation from vibration, all important for good performance in the varying weather environment.
The use of Rogers’ BISCO® BF-2000 silicone foam reduces the amount of money and time lost when cars are out of service. Cars in need of repair can be out of service up to three days, costing car owners $4,000-$8,000. Most train car warranties are about ten years. During the life of the car, this problem could occur twice, for a total cost to the owner of $8,000-$16,000. Rogers’ BISCO® BF-2000 is the smart choice to maintain the integrity of the HVAC unit through even the most severe weather exposure.