Advanced stainless steel structure. All the parts touching with solvent such as inner cylinder,external cylinder,air channel,filter all the collectors,oil-water seperator.solvent case, distillation tank etc.are made of advanced stainless steel.Hot Dip Galvanizing is adopted. the least concentration of gas C2Cl4 in the roller is 1500PPM after the temperature is decreased and the bad smell is released for the 7 generation dry cleaning machine. However for the 9 generation, it has the active carbon reclaiming device outside. It may treat the air in the roller again after normal drying program. new type environmental friendly ecological filter and high-precision carbon core filter,no need of addition of dry cleaning filtrating powder and carbon powder.