process for cleaning metal machine parts caked with thermoplastic polymers and apparatus for carrying out said process . the process consists in placing the parts caked with polymers inside an autoclave and in striking them with a stream of overheated steam . the stream mixes with the vaporized polymer residues produced by the thermal decomposition and hydrolysis of the polymers that are initially present on the parts and is conveyed outside the autoclave together with the vaporized residues . the stream containing vaporized polymer residues that leaves the autoclave is then subjected to condensation and the pollutants elimination .