
An Extruder Made to Measure
Many chemical syntheses take place in a solvent that subsequently has to be removed. This is also the case with halobutyl rubber, which is essential for the manufacture tubeless tires. Removing the solvent is especially energy-intensive, particularly in rubber production. Bayer Technology Services developed a new process step for the specialty chemicals producer Lanxess in which the solvent is carried away with the help of a twin-screw extruder. The customized extruder allows the solvent to be eliminated without the remaining, extremely viscid rubber mixture becoming to hot or decomposing. Compared with the conventional process, the new process saves on 70 percent of the energy-intensive steam.