Textile dry cleaning in high pressure CO$_{2}$

High-pressure carbon dioxide (CO$_{2})$ is one of the most suitable replacements for perchloroethylene (PER), a common but harmful textile dry cleaning solvent. Previous studies have indicated that the particulate soil removal with CO$_{2}$ is lower compared to that with PER, because of the lesser amount of mechanical action in CO$_{2}$. Furthermore, there is a lack of understanding of textile-dirt-CO$_{2}$ interaction. It is the objective of this study to get an insight in the mechanical forces that play a role in CO$_{2}$ dry cleaning and to use this information to improve the CO$_{2}$ washing performance. Various mechanical actions were investigated with the experiments in an \textit{in-situ} high pressure observation cell. Textiles stained with different kinds of particulate soils were washed in CO$_{2}$. The washing results show that the combination of rotating and vertical action gives the highest cleaning performance and liquid CO$_{2}$ spray may be a suitable additional mechanism to increase the cleaning performance.