Pre-treatment of remanufacturing cleaning by use of supercritical CO₂ in comparison with thermal cleaning

With the development of manufacturing industry, environmental issues have grown increasingly important; remanufacturing has thus been proposed as a means of improving manufacturing sustainability. Cleaning of the used product is one of the most demanding steps of remanufacturing and is usually taken to be the main polluting stage. Traditionally, the cleaning of engines has included thermal cleaning as the pre-treatment, followed by physical cleaning such as abrasive blast cleaning or ultrasonic cleaning. In this paper, a novel and environmentally friendly method of remanufacturing cleaning is proposed, using supercritical carbon dioxide (SCCO₂) to remove oily contamination on discarded engine components. A comparison is conducted between this method and thermal cleaning, as pre-treatments, followed by abrasive water jet cleaning and ultrasonic cleaning to remove the pre-treatment residues. The results demonstrate that supercritical fluid cleaning is an ideal alternative to thermal cleaning when remanufacturing aluminium parts with low melting points.