Water-soluble cutting fluid enabling cost reduction, environmental sustainability, and improved workplace conditions

Abstract: In recent years, manufacturing sites in Japan have faced significant changes driven by a declining labor population, increased automation, and growing environmental requirements based on ESG and SDGs initiatives. As a result, cutting fluids are now expected not only to provide high machining performance and long tool life, but also to contribute to improved workplace conditions and reduced operating costs. In particular, water-soluble cutting fluids often present challenges such as microbial degradation, unpleasant odors, and sticky residues, as well as increased running costs caused by higher concentrate consumption and waste fluid disposal. This presentation reports the development concept and performance evaluation of a newly developed water-soluble cutting fluid, the Daphne Alphacool NV Series, which was designed from a new perspective of suppressing the consumption of active components and maintaining a favorable coolant cycle over extended periods. The NV Series is based on two core technologies: (1) reduction of coolant carry-off through the formation of a dense adsorption film on metal surfaces using specially designed fatty acids, and (2) improved thermal stability and pH retention achieved by employing low-volatility amines. These technologies aim to simultaneously extend coolant service life, reduce concentrate replenishment, and suppress odor and sticky residue formation. Evaluation results obtained from a customer survey of 100 users and from actual machining lines covering non-ferrous metals, steels, alloy steels, stainless steels, and cast irons demonstrated that the NV Series significantly improves environmental performance and cost efficiency. In addition, stable machining performance comparable to or superior to conventional water-soluble cutting fluids was confirmed across a wide range of machining operations, including high-load processes. These results indicate that the NV Series is an effective solution for achieving a balance among environmental improvement, cost reduction, and machining performance in modern manufacturing environments.