Replacing manual cleaning with automated CO2 snow cleaning for precision optical mould tools

Carbon dioxide (CO 2 ) snow cleaning is now used across many industries to remove unwanted contamination from a wide range of parts and materials. CO 2 snow has become popular in replacing chemical and manual industrial cleaning processes due to its ability to remove both organic and particle contamination, reduce surface damage and reduce labour requirements. In industrial applications it can therefore be a more sustainable automated precision cleaning alternative. The technology is used by directing a CO 2 snow jet towards a surface that requires cleaning. The CO 2 snow jet is created by allowing cooled liquid carbon dioxide to expand under a reduced pressure which is directed to strike the contaminated surface creating physical and solvent interactions which removes contamination. This research provides an overview of carbon dioxide snow surface cleaning in industry as well as the key industrial advantages and challenges. This CO 2 cleaning technology is applied in the ophthalmic industry where manual isopropyl alcohol cleaning is replaced by an automated carbon dioxide snow cleaning process. The cleaning methods are assessed against each other in terms of cleanability, surface wear, cleaning cycle time, and sustainability. The research concludes that CO 2 snow cleaning can be considered a more operationally and environmentally favourable alternative to manual IPA cleaning of optical surfaces under the studied industrial conditions, providing high cleaning efficacy alongside increased cleaning throughput, reduced overall labour requirements, a safer working environment, and reduced surface damage to sensitive optical surfaces.