This title can have a few meanings. We could be reviewing ways to keep producing at your current rate or sustain market share, or we could be addressing the issue of creating a more sustainable production environment. As it turns out the second option will keep the first option possible, or even improve upon it. While the focus in most machine shops is reducing production time and extending machine life, there are direct and indirect resource savings that can be realized when sustainable CNC manufacturing looks at the whole operation.
The topic of energy savings is important, and the need to address it will become even more important as countries try to reach climate reduction goals. Climate protection through management of energy consumption, raw materials, and waste production and handling can be realized in CNC manufacturing. Many advantages are being seen already as by-products of more precise engineering of part design. And machine upgrades, such as automated tool exchangers allow one machine to produce a whole part rather than the time, energy, resources, and labour to move the production between machines. These specific insights into sustainability are good ways to move forward.
The recycling of chaff has long been in practice in CNC machining. The value of steel and its retained strength and performance through recycling makes this an easy solution. New ideas around recycling are beginning to emerge.
Running coolant through centrifuge equipment is a new step in raw material handling that saves both water use and the cost of coolant. Through coolant delivered at the tip of the cutting tool provides both longer tool life and more even wear on the tool flutes. This coolant delivery method is more expensive, but uses less coolant and realizes cost savings in production time and tool replacement.
A new theory put into practice is also the minimum amount of oil used in lubrication as opposed to over-spraying the area. This, again, reduces the input of raw materials.
There may be a need in the future to address the carbon footprint of supply chain materials in your operation. Canada has already implemented a carbon tax for some industries. It’s a good time to start documenting that information now and working on ways to reduce overall CO2 emissions in manufacturing.
Many steps in production, like regular maintenance, extend tool life and, thus, save on raw material use. Remanufacturing is another method to save tools, rather than replace them.
In a study, it was determined that the number of flutes in a cutting tool has a sweet spot for tool wear balanced with efficiency. It makes sense that more flutes will remove material faster on each revolution of a cutting tool, but too many flutes make it difficult to evacuate chaff, resulting in tool wear. The increased cost of the more intricate tool design must, of course, be weighed against improved production.
The quality of metal to produce the tool should also be considered. Longer life of tools, clamps, and other devices will result from parts made with higher tensile steel, carbide, or ceramics.
Just as it is important to maximize the tool flute for more material contract per revolution, it is equally important to program the toolpath and feed rate to keep the tool in contact with the workpiece as much as possible. New technology like the Mastercam Dynamic Motion software provides the needed confidence for programmers when pushing the limits of cutting tools.
Artificial intelligence will improve the production process even more, allowing for real-time adjustments in a production run with input from cameras and sensors to change speed or alter the cutting path. This programming will allow for tool wear, heat, or chaff build-up to make necessary changes to maintain product quality without shutting down the machine and resetting parameters.
In some ways, CNC machining has been a leader in resource management. Sustainable CNC manufacturing will continue to advance naturally through the fourth industrial revolution. But other considerations, like air conditioning in machining operations, are becoming a more common approach to overall building design, for example, saving energy or improving machine performance through temperature control. Looking at roof space to add solar panels is another example where CNC manufacturers can look beyond the tip of their drill for productivity and energy management.