Saint-Gobain Seals Group develops a new generation, exhaust gas recirculation (EGR) sealing solution, Rulon® E2, for the latest and future European engine emission control standards (Euro 6 & 7), which required a significant investment in sophisticated test equipment to validate the performance of the new designs to meet the strict leakage limits for EGR valves and environmental requirements.
Currently, emissions of nitrogen oxides (NOx), total hydrocarbon (THC), non-methane hydrocarbons (NMHC), carbon monoxide (CO) and particulate matter (PM) are regulated by the European Commission for most vehicle types and for each vehicle type, different standards apply.
The Seals Group made the preemptive decision to invest in the Rulon® E2 emission control project (the new sealing material becomes part of their fluoropolymer product line) due to Euro 6 coming into force starting September 2014 for the approval of passenger vehicles and from January 2015 for the registration and sale of new cars. The limit for nitrogen oxide emissions from diesel engines decreases in comparison to the Euro 5 emission standard (2010-2015) from 180 g/km to 80 g/km (a reduction of 55%). Prior to this, the NOx limit was 250. NOx and PM limits for gasoline engines will remain the same. The next major step for Europe will occur in 2021 with a reduction for CO2 emission to 95 g/km, recently agreed by the European Union. Currently, most OEMs are above 120 g/km and it is estimated that they will have to invest up to € 12 billion to achieve the set target.
Due to the more stringent legislation, the standards for exhausted emissions will be reduced further in order to limit pollutants caused by passenger vehicles and heavy duty trucks. The requirements for new sealing solutions for exhausted gas recirculation valves will also become stricter. European engine makers have invested heavily in developing new technology to reduce the levels of NOx and PM and improve air-quality. Furthermore, car manufacturers and Tier 1 suppliers are requiring pre-validated sealing solutions in order to reduce development time and cost. In response to these critical demands, the Seals Group developed new sealing solutions for emission control applications at high temperature, using sophisticated test equipment to validate the performance of these new designs. The low leakage requirement of the new generation EGR Seals required a reengineered sealing design and a superior Rulon® sealing material developed for emission control seals. The Rulon® E2 material operates extremely well against soft mating surfaces, has excellent wear resistance, is non-abrasive and has one of the lowest coefficient of friction of reinforced PTFE materials. In particular, the material has excellent chemical resistance against sulphuric oxide, which transforms to acid sulfur in reaction with water and becomes one of the most aggressive and harmful substances emerging from the burning process from diesel engines.
The Rulon® brand consists of a family of proprietary, homogeneous materials that are mostly composed of PTFE based resins, and products include bearings, rings, tapes, formed parts, basic shapes and wear components. Primarily used in mechanical, electrical and chemical applications, Rulon® material withstands a variety of harsh environments such as extreme dryness, cryogenic temperatures, water, steam and hydrocarbon fuel. Rulon® bearings were recently selected for use in high-performance clinical chemical analyzer systems, and Rulon® J was recently certified for mass transit applications such as in trains and aircraft in regards to specific safety requirements for flammability, smoke and toxicity (FST).