Sustainable machining of molds for tile industry by minimum quantity lubrication

Abstract Nowadays, to reduce water pollution, soil contamination, and human health hazards, the environmental legislation is forcing manufacturing companies to avoid the use of metalworking fluids. Thus, the adoption of the dry machining and minimum quantity lubrication (MQL) techniques is becoming essential. However, small and medium companies are having difficulties and are skeptical about the adoption of these new techniques. In this study, a methodology is proposed to implement an MQL system for sustainable machining with a step-by-step procedure that facilitates its industrial application. The methodology is divided into three steps: i) MQL configuration to verify its effect on surface roughness, considering the effective flow rates and nozzle position; ii) process modeling based on the Box–Behnken design of experiments (DoE) to model surface roughness, power consumption, and tool life; and iii) process optimization for minimizing cost and environmental impact in terms of water usage and kg of CO2 equivalent. The methodology is applied in the manufacturing process of a component of a mold for the tile industry. Different alternatives are analyzed and the best alternative in both economic and environmental aspects is the use of the MQL system with optimal cutting parameters and an early tool change strategy that ensures part quality without subsequent grinding operations.