Integrated compounding processes using supercritical carbon dioxide

Todays compounding technology allows flexible processing of polymer compounds and blends. Nevertheless the trend to use tailored compounds results in an increasing demand for more flexible and efficient polymer-modification processes. Integrated compounding processes using supercritical carbon dioxide (scCO2) are an interesting option to increase flexibility in the compounding process, because scCO2 has interesting properties for polymer compounding, offering solubility for additives as well as for unwanted contaminations in polymers and can therefore act as a carrier for these substances for chemical modification or cleaning processes. The combination of both, compounding and high pressure technology for supercritical carbon dioxide in a specially designed twin screw extruder offers therefore completely new ways to process polymers. First results indicate that this allows effective cleaning processes where carbon dioxide is used as an environmental friendly solvent and carrier.