Safer, Better, Closer

Shanghai Tianliu looks back cooperation with LANXESS in the past ten years

Safe urban environments and transportation

Urbanization is one of the most defining trends of the 21st century – both worldwide and in China. In 10 years, China will have 221 cities with at least one million residents. By 2030, the total number of urban dwellers is expected to reach one billion, which would translate to an urbanization rate of 70%. Creating safe and eco-friendly urban environments represents a key challenge for today’s society.

The 2003 subway fire in South Korea, which caused the death of 192 people, was a tragic wake-up call to enhance safety measures and fire prevention in urban transportation systems. In case of a fire, smoke – often containing poisonous substances – is the most dangerous element and can lead to death by suffocation. Additionally, smoke containing corrosive substances can cause dysfunctions of technical facilities and control systems.

China soon realized the danger of fires in transportation systems and launched stricter regulations requiring the use of ethylene-vinyl acetate copolymer (EVM) products in trains. High-quality EVM such as LANXESS Levapren® does not only have the advantage of high flame retardancy, but is also halogen-free and burns without corrosive or poisonous emissions. Flame retardance is achieved by adding high amounts of specialized fillers, such as aluminium hydroxide or magnesium hydroxide. Based on laboratory flame tests, properly compounded EVM material such as LANXESS Levapren® displays lower smoke development than competitive materials, and thus considerably increases the safety of urban transportation systems. “Actually, the material is not only safe, but also eco-friendly”, Gang Xu, General Manager from Shanghai Tianliu Cable Materials points out. “Besides fire retardance, decreased smoke development and zero halogen, LANXESS Levapren® is also well known for its usage of environment-harmless materials. LANXESS’ EVM products do not contain any heavy metals such as lead.”

In China, LANXESS and Tianliu Applicance collaborate since 10 years in order to provide trains and urban transportation systems with safe and eco-friendly cables and other technical solutions. LANXESS Levapren® is relevant for more than 90% of technical products developed by Tianliu. Being considered a strong contributor to public safety, the products of LANXESS and Tianliu are already applied in many national-level programs. No matter if it’s the OIympic ceremony in Beijing 2008, China’s first aircraft carrier PLAN Liaoning or subway systems all over China – LANXESS and Tianliu offering their expertise and technological know-how to a wide range of applications and projects in China.

Setting new industry standards

Besides flame-retardancy and oil resistance, heat resistance is a further key strength of LANXESS’ EVM solutions. “Back in the 1990s, the common standard was 100⁰C, but LANXESS helped us to reach 125⁰C”, says Xu. Traditionally, requiring a higher service temperature by just 10⁰C would mean to cut its service life by 50%. However, LANXESS helped to achieve a heat resistance of 125⁰C without sacrificing efficiency and material service life-time. “The superior heat resistance and durability in combination with low smoke development and zero halogen represents a qualitative leap”, Xu acknowledges. “Cables with heat resistance between 100 -150⁰C and a sufficient durability are difficult to realize. Some cable systems only withstand temperatures in the range of 70 - 100⁰C, other very exotic extreme heat cables start at 180⁰C. LANXESS helped us successfully to cover the technically important temperature range between these two extremes.”

Fire is not the only element which requires advanced technical solutions – further ones are ice and snow. Ordinary cables have a cold resistance of -25⁰C. This limit is usually sufficient, but in regions such as Russia or Tibet it is not nearly enough, as LANXESS and Tianliu have learned. In 2006, Tianliu supplied material for the Qinghai–Tibet Railway. Currently, the company is involved in several subway programs in Russia as well as the new Beijing-Xinjiang-Moscow high-speed train project. There is one common factor among all projects: a required low temperature flexibility of -50⁰C. This demand initially represented a major challenge, but after a development phase of three years, Tianliu and LANXESS achieved a new technical milestone in the EVM field by developing cables which resist temperatures from -50⁰C to +125⁰C. The cables are not only highly temperature-resistant, but also have a life time of 20,000 hours in line with international standards.

Driving global wind energy

In recent years, LANXESS and Tianliu worked closely together in improving Hydrogenated Nitrile Butadiene Rubber (HNBR) components, which are mainly applied in wind power facilities. Besides HNBR, Tianliu also uses Levapren® for its wind energy solutions. “In the last four years, we saw significant demand from the wind energy sector. The yearly volume increase was around 100%. Last year, we supplied more than 300 tons of rubber for wind power programs”, Gang Xu summarizes Tianliu’s recent success in the wind sector. Wind energy is not only rapidly developing in China, but also in other regions around the globe – driven by government efforts and an increasing need for sustainable energy. Due to its advanced technical solutions, Tianliu is able to support wind energy facilities around the world, be it in collaboration with foreign companies such as Siemens or with Chinese partners, which also increasingly seek opportunities abroad.

Continuous efforts to achieve global standards

The previous 10 years can be characterized as a successful partnership between LANXESS and Tianliu. “LANXESS is the only company to achieve a VA content of more than 40%. Additionally, the company applies the Mooney index, which enables it to produce softer rubber than its competitors. But LANXESS does not only stand out when it comes to technical properties, they also helped us to reduce production costs and always ensure a fast and steady supply – not to mention the technical cooperation”, Xu says.

No matter if fire retardance or heat resistance, LANXESS’ R&D team and Tianliu cooperate closely in order to enhance technical properties and to meet international standards. Xu from Tianliu confirms: “Before our cooperation started, we only had a limited understanding of European standards. LANXESS went a long way in helping us to adjust our products to these requirements.” Another major challenge set by European regulations was the required degree of oil resistance for cables in trains, which can be difficult to realize, but is absolutely necessary for modern urban transportation. Despite their electric engines, modern trains still require a wide range of oils (e. g. lubricants). Today, all cables which are installed based on Tianliu’s compounds are produced according to European standards.

For the future, Tianliu is eager to successively increase its technical capabilities and know-how. “We must be aware of the gap between us and international producers. But we want to play an even stronger role in international wind energy and high-speed train projects by continuously improving our technical capabilities”, Xu summarizes the coming challenges and goals.

One challenge will be to provide cables with increased electrical properties including improved cable covering and insulation – an often sought-after requirement. Reducing material weight is a further key criteria, as engineers seek to make high-speed trains as light as possible. Xu states: “We are eager to co-develop new materials together with LANXESS. Materials which are flame-retardant and oil-resistant, have low smoke development properties, zero halogen and strong weather resistance, but which are also lighter, very flexible and can cope with high electrical requirements.” The ongoing R&D efforts already generated additional tangible results. One of Tianliu’s new cable solutions can resist 6,000 torsions – and is absolutely free of halogen.