An acetone bath will smooth the edges of your 3D printed object. Typically, it is said to do this you must heat the chamber containing the acetone to achieve results, but it is quite dangerous to do this if not done by trained professionals, as acetone becomes volatile at high temperatures. It is worth noting that acetone evaporates at room temperature, it just takes longer. Therefore, this procedure should be carried out with room temperature acetone. While it may take longer, the danger is much lesser this way.It is also worth noting that not all PLA plastics will be effected by an acetone bath. It depends on the quality of the filament, with better quality PLA working best. This is because PLA itself is not effected by acetone. Instead, what happens is that certain filament manufacturers add materials to the PLA which do react to acetone, such as PHA plastic. Plastics like ABS respond much better to an acetone bath.