Overcoming Challenges of Medical Device Machining with Metalworking Fluids

Strict cleanliness regulations for machining medical components is one aspect of that industry that sets it apart from others. Machine shops that manufacture any kind of medical parts must be cautious about the type and quality of the materials they use, as well as their manufacturing processes, to ensure it is high quality before these machined devices come into contact with human cells. This includes using a coolant that is designed especially for medical machining.

These metalworking fluids are designed to be compatible with the high-end materials commonly used for medical applications. They also are designed to provide long tool and sump life, high-quality surface finishes and are free of substances that are typically restricted by medical manufacturers. These high-lubricity cutting fluids, such as Master Fluid Solutions’ Trim MicroSol 642RX, are formulated to be clean running, provide excellent tool life, are easy to remove and are low foaming.

While using advanced coolant formulated for medical applications can boost productivity and help a shop comply with chemical regulations, other factors besides coolant come into play to keep up with medical restrictions, according to Justin Geach, business development manager, North America at Master Fluid Solutions.

“In today’s age of continuously changing and increased chemical restrictions, medical manufacturers need to be sure they select the right (cutting fluid) products for their manufacturing, have the right cleaning processes in place, and complete all the proper testing — which may include cytotoxicity testing — especially for implantable devices,” Geach says.

Sustainable Substances

Machined medical parts are often subject to several process chemical restrictions that are frequently updated. For example, REACH (registration, evaluation, authorization and restriction of chemicals) compliance as well as SVHC (substances of very high concern) became even more stringent with revisions made in January 2022. There are also CMR (carcinogenic, mutagenic, reprotoxic) substances, Toxics Release Inventory chemicals (SARA 313), animal-derived raw materials and chlorine and other halogens that may be restricted by medical OEMs.

Because of these regulations, Master Fluid Solutions is only using sustainable substances in its medical coolant formulation.

“There has been a push for sustainability in both the chemical and medical industries,” Geach explains. “So, we have developed our medical-focused coolant with plant-based raw materials versus animal-based derivatives. Some medical manufacturers prohibit the use the of animal-based products, even if they meet rigorous processing restrictions.”

He adds that Master Fluid Solutions’ medical coolant will outlive the changing chemical requirements of the future because it is created without the use of harmful or often restricted chemicals. Yet, it can still provide excellent machining performance on medical-grade materials such as titanium, various aluminum alloys, stainless steel and nickel-based alloys that are commonly used in the industry.

Maintenance and Recycling

For any coolant, necessary preventive maintenance and recycling is important. However, it is especially crucial to ensure a clean medical machining application.

Concentration control, keeping coolant levels full on machine tools and removing tramp oil and other contaminants from coolant are all necessary aspects of regular maintenance. A coolant manufacturer can help with these procedures, Geach says. For example, a good supplier will provide lab testing for elemental and particle count analysis to determine if machine oils or metal fines are contaminating the coolant.

Recycling coolant is another way to pull tramp oil and fines out of the fluid to ensure the cleanliness necessary for medical machining. Starting with the best coolant possible and keeping it at peak performance by implementing recycling equipment leads to an easier parts cleaning process and results in the best tool life and finishes on machined parts while reducing fluid disposal Geach adds.

Not only does recycling clean the coolant but it reduces coolant usage and a manufacturer’s waste stream. It also lowers environmental impact and carbon footprint.

Master Fluid Solutions | masterfluids.com