The Evolution of Cryogenic MachiningSeptember 20, 2019
It takes more than a good idea to create a truly transformative product or process. Inspiration’s only part of the story: To bring a good idea to life, it takes the right combination of technology, capability, and economic incentive—not to mention the drive to make it happen.
Using cryogenic liquid rather than toxic wet coolants to control tool temperatures was always a good idea, but it took innovation and commitment to make it a practical one. As with most innovative concepts, it took a lengthy period of refinement to resolve the many challenges standing between this breakthrough concept and its presence on the factory floor. 5ME® tackled these challenges head on, and devised the solutions needed to make it practically and commercially viable.
Taking Cryo from the Lab to the Shop Floor
Initial attempts at cryogenic machining were conducted within research labs, using delivery methods that were only suitable for a laboratory setting (and therefore impractical for use in a production facility). To make the technology viable, the 5ME® team needed to address some significant challenges:
- Difficulty in efficiently directing cryogen to cut zones using external spray systems
- Overcooling and work-hardening of work piece material, making it more difficult to cut
- Excessive cryogen wastage and associated additional cost from inefficient overflow systems
- Inefficient insulation in delivery systems, resulting in heat gain and inadequate cooling in the cut zone
- Difficulty in maintaining continuous flow of cold cryogen to the cut zone
- Difficulty in maintaining efficiency and environmental sustainability when using flawed cooling mediums (i.e. CO2)
- Difficulty in maintaining system reliability within production environment conditions and/or high production rates
As 5ME® worked to overcome these challenges, it also identified other key characteristics needed for a viable, high-performing cryogenic cooling system. 5ME® saw that an optimal cryogenic cooling system would be designed to work effectively across different machine types or brands, and would be readily integrated into the machine for ease of use and maintenance.
Applying Coolant Where It Counts
The 5ME® Cryogenic System succeeded in addressing all of these issues, beginning by rethinking what needed to be cooled and how. 5ME®’s engineers recognized that by internally cooling cutting tools, rather than relying on external spray nozzles, they could efficiently direct cooling power where it was needed. The internal cooling system delays or even prevents heat activated tool wear and extends tool life without unnecessarily cooling—and hardening—machined material. The result was an exponential increase in cooling efficiency, coupled with a dramatic reduction in cryogen usage.
Better for the Environment and the Bottom Line
5ME® also selected environmentally-friendly—and extremely abundant—liquid nitrogen (LN2) for use in its system, rather than carbon dioxide or other cryogens. Besides being unquestionably safe for both the environment and human beings, liquid nitrogen’s lower temperature delivered increased cooling capability while using less cryogen by volume. Controlled, metered internal flow allows continual adjustment of flow rates to achieve optimal tool temperature, and vacuum-jacketed insulated components prevent thermal impact to critical machine components while preventing heat gain. A patented Subcooler ensures consistent liquid flow to the cutting edge without gas interruption.
Maximum Flexibility for Maximum Benefit
Versatility and suitability for purpose were also key considerations for the 5ME® engineering team. The 5ME® system is designed to be brand and machine agnostic, enabling usage with nearly any machine tool, and is provided as both a new machine option or as a retrofit to machines already in the field. The system is also designed for full integration into a machine’s CNC for ease of use and maximum controllability.
5ME® succeeded in bringing cryogenic machining from the test lab to the shop floor—and, in so doing, has helped businesses machine parts more accurately, efficiently and cost-effectively while eliminating the hazards created by traditional chemical coolants. For the company, it’s a technological and business success; for the wider world, it is an important step towards more efficient, sustainable manufacturing.