Styrene butadiene rubber (SBR) is by far the most manufactured variant of synthetic rubber. This elastic polymer is processed in the automotive industry as the basis for vehicle tyres, seals and conveyor belts. Industrial manufacture of synthetic rubber is based on the starting substances styrene and butadiene obtained from crude oil and natural gas. These two chemicals, together with a catalyst, a soap solution as emulsifier and recovered butadiene plus styrene, end up in the reactors, where the actual polymerisation occurs. As this is typically only supposed to run up to approx. 70%, a short-stop phase is included downstream, where various additives can be removed from the polymer. Any unconverted butadiene and styrene are then recovered for recycling and pumped back into the storage tanks. In the next stage, if required, stripped latex is gathered for mixing. The latex is then coagulated, converted to granules, sieved, washed and filtered. At the end, excess water is removed and the crumbs are dried with hot air. In the follow-up process, the SBR, which is still in liquid form, is cured by vulcanisation and is thus given its final shape.

Based on its many years of expertise in the area of polymer chemistry, KROHNE offers top class measuring technology for this sector. Our Coriolis mass flowmeters for the process industry can even measure uninterruptedly with a gas content of up to 100%. The measuring systems offer various digital communication options. For example, loop-powered 2-wire sensors for conductive conductivity measurement allow the sensor to be connected directly to the process control system without the need for a separate "amplifier", i.e. signal converter. And there is electronic equipment and additional application diagnostics available to increase the process reliability of our sturdy, all-metal variable area flowmeters, for example, by identifying a float blockage caused by contaminants.