SBR and ELT are acronyms frequently used when car tyres – and specifically worn-down car tyres – are on the agenda. But what do these acronyms actually mean?
What is SBR?
SBR stands for styrene butadiene rubber – a synthetic rubber mixture which consists of approx. 25% styrene and 75% butadiene, joined in a co-polymer to form a general-purpose, synthetic rubber.
Properties and purposes
Boasting properties like good abrasion resistance, aging stability and long-range elasticity, virgin SBR rubber has proven an excellent choice for the manufacture of numerous rubber products from gaskets to conveyor belts – and has in particular become extensively used in the car tyre industry. In fact, more than half of all tyres produced contain various types of styrene-butadiene rubber.
Car tyres are not made entirely from styrene-butadiene rubber, though. Natural rubber is an equally significant ingredient (particularly in lorry and OTR tyres), and numerous other additives are included to make high-quality rubber compounds for the manufacture of tyres.
SBR and natural rubber have different properties. Where SBR rubber hardens over time, natural rubber goes softer; and where SBR rubber performs poorly in terms of tear strength, natural rubber excels.
Different types of SBR
Styrene-butadiene rubber can be produced in two different ways. Emulsion SBR (ESBR) can be produced as either hot emulsion SBR or as cold emulsion SBR. Emulsion SBR is typically used for light-duty tyres, whereas solution SBR (SSBR) is the preferred option for high-performance tyres. Solution SBR is the most expensive of the two types – but despite the cost, it continues to be the most extensively used SBR rubber, performing better in terms of both tensile strength and elasticity.
What is ELT?
When it comes to rubber granules made from worn-down car tyres, “SBR granulate” is a commonly used term – yet “ELT granulate” is in fact a far more precise term.
ELT stands for end-of-life tyres; and as Genan only recycles tyres – and no other rubber articles – Genan rubber products are designated with the correct and precise term: ELT rubber. – Granules manufactured with nothing but end-of-life tyres as feedstock – no matter the percentage of styrene-butadiene used in the original manufacturing process.
Where SBR can refer to both virgin synthetic rubber and recycled tyre rubber, ELT refers to material from used tyres only.
Genan is a supplier of ELT rubber
At Genan, we say ELT. We recycle end-of-life tyres from passenger cars, vans, lorries and OTR vehicles. In a fully automated production process, used tyres are shredded, granulated and separated into their original components: steel, textile and rubber. We market our rubber powders, granulates and pellets as ELT rubber products – and thus tell the story of a successful and environmentally friendly recycling process, where huge amounts of car tyres, which can no longer serve their initial purpose, get a second life.
At Genan, we take what would otherwise be a waste problem and turn it into a valuable resource. Our high-quality rubber powders, granulates and pellets do indeed contain recycled SBR – but they are so much more than that. They are sustainably recycled rubber products, manufactured with nothing but tyre waste as input material.
For the benefit of the climate
Every time Genan recycles one tonne of ELT, the atmosphere is spared at least 0.7 tonnes of CO2 emission – compared to co-incineration as the alternative disposal method. This corresponds to the amount of CO2 emitted by a normal passenger car with diesel engine driving 3,800 km – e.g. from Berlin to Barcelona and back.
With six recycling plants around the world, Genan has the capacity to recycle more than 400,000 tonnes of tyres in total each year, equalling a reduction of up to 280,000 tonnes of CO2 emission. Thanks to Genan’s processing technology, considerable CO2 savings can thus be achieved – for a reduction of our carbon footprint and for the benefit of the climate.
Genan tyre recycling reduces the need for production of virgin SBR
Tyre recycling ensures the reuse of valuable raw material. When tyre rubber gets a second life in a new product, less virgin rubber will have to be produced. And if tyre manufacturers think in sustainability and substitute just a small fraction of the rubber they use with recycled ELT rubber, less virgin SBR will have to be manufactured.