“Cat Reman restores parts at the end their lives to like-new condition, providing you with a cost-effective alternative solution to new Cat parts.” This is how the construction machinery and equipment company Caterpillar is attempting to convince its customers about the quality of the parts and components that get a second chance of life through the company’s remanufacturing exchange system. Like Caterpillar, many other companies who have initiated remanufacturing programs are emphasizing on the “like-new” condition of their products besides their environmental benefits to pave the way for their adoption in the market.

As a circular economy strategy and a tendency for future manufacturing, remanufacturing can be regarded as an environmentally favorable end-of-life treatment method during which a product is rebuilt to the quality of the original manufactured product using a combination of reused, repaired and new parts. Remanufacturing can offer much greater energy reduction and materials conservation, and has therefore being encouraged through the circular economy framework.

Remanufacturing involves a series of processes such as disassembly, cleaning, inspection, recondition, reassembly, test and packing. Among these, cleaning processes play critical roles and must be executed at different stages along the entire remanufacturing procedure. The cleaning process typically gets rid of paint, carbon deposit, grease, rust on the surface of used components. It is not only important for the physical appearance of the final product, but more importantly facilitates the examining of the wear pattern and microcracks and determining the remanufacturability of parts.

Cleaning technologies are usually not used alone but in succession based on material, complexity, and accessibility of parts. For example, a typical remanufacturing facility combines two conventional methods of high temperature decomposition and shot blasting: firstly, organic chemicals on recovered parts get evaporated and decomposed by heat, and secondly, solid residues on surfaces are eliminated by blasting with hard beads. The removed waste residues after cleaning are typically disposed in the landfill. In an advanced cleaning system, a supercritical fluid (SCF), commonly supercritical CO2, is used to remove contaminants. SCF is a substance with intermediate state between liquid and gas whose low surface tension makes it a good solvent that can infiltrate into details of parts to perform cleaning.

The growth in remanufacturing practices calls for systems that are more effective and efficient in cleaning while being environmentally friendly. The latter requires a detailed life cycle and environmental analysis to ensure that the remanufacturing procedure in overall is improving the sustainability performance of the final product. The opportunities to reduce the environmental footprint of cleaning processes are abundant, for example by relying on renewable energies, by replacing volatile organic compounds with less harmful chemicals and solvents, and by managing the waste water produced during the process.

The Caterpillar’s Cat Reman program relies on a continuous and long-term relationship with its customers to enable an efficient take-back scheme to support its remanufacturing program. Therefore, similar to many other circular economy strategies, technology and operations must work together effectively to achieve a successful circular practice.