Lean and Environmentally Friendly Manufacturing – Minimum Quantity Lubrication (MQL) is a Key Technology for Driving the Paradigm Shift in Machining Operations 2008-01-1128

These are challenging times, not only for the manufacturing industry but for our planet and its inhabitants. The markets are changing rapidly, and there is fierce competition everywhere in the automotive business and in the manufacturing world. We face global sustainability challenges, including climate change, depletion of natural resources, poverty, population growth, urbanization and congestion. Consumers are increasingly concerned about rising fuel prices, energy security (see Figure 1: “Increased demand for energy”) and climate change.

With these great challenges comes great opportunity. As the pace of change accelerates, innovation is more important than ever [2]. The reduction of CO₂ emissions, initiatives for vehicle weight reduction, fuel economy improvements, hybrid vehicle technologies, hydrogen fuel cell powertrains or bio-fueled automobiles only represent some of the latest product related innovations, benefiting the environment and the customer.

However, it is as important for the manufacturing sciences to also contribute to the overall environmental tasks and help meet competitive cost targets. Nature and the environment are our greatest asset. Many everyday products, especially in the automotive world are manufactured using conventional wet machining processes. To support the various kinds of metal cutting operations, constant temperature coolant is permanently flooding both machinery and workpieces (see Figure 2).

But maintaining and operating such coolant supplies is a huge cost driver and an environmental challenge [3].

Besides the work intensive daily preparation of coolants, it is the equipment investment, the potential safety hazards and the high energy consumption to run pumps and chillers that forces the manufacturing industry to look into other, more suitable alternatives [2]! Near Dry Machining (NDM), also known as Minimum Quantity Lubrication (MQL), eliminates conventional flood coolant from the machining processes. In doing so, MQL reduces oil mist generation, biological contamination of coolant, waste water volume, costs for capital equipment and regulatory permitting. MQL also improves recycling and transport of coolant contaminated chips [5]. Although MQL machining technology has several advantages compared to wet machining, widespread implementation will require a paradigm shift among end-users, machine suppliers, and cutting tool suppliers. Successful implementation of MQL machining requires a high technical understanding and a solid infrastructure to support maintenance and on-going continuous improvement [6].