All metal machining operations create oil mist and oil smoke to some extent. Both oil mist from emulsions and oil smoke from neat oils normally contain a number of undisclosed additives that will affect the human being. Removing oil mist is therefore essential to grant safety and cleanliness in the work place.
Oil mist is the aerosol defined as droplet particles mainly above 1 micrometer in size, which is often formed when oil emulsions is used as a coolant/lubricant during the machining of metal and ceramic materials. Even vaporising from swarf-handling can also be an issue. Emulsions normally contain 90-95% water and the remaining is soluble. The mist consists of aerosols from mainly oil/water emulsion. Mineral oil-based metalworking fluids, known as neat cutting oils or straight oils, creates oil smoke, defined as droplet particles typically below 1 micrometer in size. Both oil mist from emulsions and oil smoke from neat oils normally contain a number of undisclosed additives that will affect human health if not taken care of.
Problems surrounding oil mist
It is well known that prolonged and repeated exposure to oil products can be harmful to health, which means that good ventilation must be ensured under all working conditions. Oil mist usually results in oily premises, equipment and products. Oily floors are usually slippery and therefore a safety risk.
Modern machine tools are controlled by sensitive electronics and productivity can decrease by unplanned disruptions – caused by contaminated circuit boards. Production equipment coated in a thin film of oil is not acceptable working practice and definitely not production-friendly.
Oil mist released free in the outer environment without control is not a good solution for a sustainable world and does not correlate with neither company nor most countries environmental standards. Removing oil mist is therefore essential for workplaces to grant safety and cleanliness and to protect the outdoor environment.
How to identify if there is an oil mist problem
In many cases, the presence of oil mist is quite evident. In severe cases, the oil residues are clearly visible on the floor, walls, lights and on the machinery. There is also a distinguishing odor wherever there is oil mist present. Very often, the oil mist in a workshop is visual under the ceiling and especially in backlight increasing particle visibility.
To properly measure the amount of oil mist in the air, a device such as TSI DustTrak™ can be used. This is a common practice for Nederman to identify and make site inspections and tests to support our customers, showing the actual oil mist content in different areas in the workshop.
The process solution
The Nederman oil mist filtration solutions should be used in processes wherever oil mist is generated, from traditional machines to the latest highspeed CNC equipment. We offer highly efficient filter and extraction solutions for numerous operations, such as grinding, turning, drilling, milling, hardening, lathing, cold heading etc.
High-speed machining is a growing trend and the equipment used creates even finer oil mists, more and more often to a limit designated as oil smoke. Thanks to our latest developments in filter technology, contamination problems can be effectively dealt with, for instance in modern CNC lathes.
These machines operate at speeds of > 20,000 rpm or more and use high pressure > (145 to 580 psi/10 to 40 bar) coolants. In situations like these, Nederman FibreDrain™ oil mist filters OMF/OSF are the ultimate choice for oil smoke and oil mist filtration.
New process technologies
Many users strive to lower the consumption of oil and water in their process, due to costs and environmental issues, and therefore work with the latest developments within machining. The machining process that reduce the quantity of lubricants to a minimum has compressed air to combine the coolant lubricants with. This process is defined as MQL – Minimum Quantity Lubrication.
There are plenty of different filtration methods for MQL on the market but as this is a process in between wet and dry, the filter unit needs to be effective for all type of processes in between. These new application areas are, by Nederman, defined as “medium wet” (MW) and “semi dry” (SD) processing.
Nederman has excellent filtration solutions for MQL processes. Please talk to your local Nederman Sales Company for further information on how to identify an oil mist problem and about Nederman FibreDrain™ MQL solutions.