On the instrument side, medical manufacturers apply near-net shape strategies to generate medical tools tailored for specific surgical procedures as well as components for medical devices and minimally invasive surgical tools.
Near-net shaped medical parts and devices are closer to finished size and minimize the amount of material removed during machining to reduce waste and production costs.
Working from castings or near-net shaped parts, medical shops shorten turnaround times to increase production.
Because most near-net shaped medical parts require only finish machining passes to bring them to size, today's medical shops need machine tools, like Mazak's VARIAXIS i-700 NEO Vertical Machining Center, with higher speed spindles and full simultaneous 5-axis capability to access part features and generate smooth finishes on complex contoured surfaces.
Instead of machining implants and other medical devices from blocks of raw material, more medical shops are moving to the use of near-net shaped castings as well as near-net parts produced with additive manufacturing (AM). While doing so provides the benefits of faster part turnaround times for increased production capacity, near-net shaped parts bring with them specific requirements in terms of workholding/fixturing and, more importantly, machine tool capabilities.
Because near-net shaped parts are closer to finished size, they minimize the amount of material removed during machining to reduce waste and production costs. Most near-net shaped medical parts require only finish machining passes to bring them to size. This not only eliminates roughing operations for faster production, but it also allows shops to run at higher spindle speeds/feedrates and reduces machine wear and tear from rigorous roughing operations. It also means that today's medical shops need machine tools with higher speed spindles-such as those in the 20,000-RPM range-and with full simultaneous 5-axis capability to not only access part features during finishing, but also provide smooth finishes on complex contoured surfaces.
With 3- and 4-axis machines, medical shops often must stop production to turn or re-clamp a part into a custom-built fixture so they can handle a compound angle or diagonal part wall. With a 5-axis machine, they can simply program the machine's table to tilt or rotate for part feature access with the benefit of error-free, consistent machine-controlled movement.
As a result, what required multiple set-ups can often be finished in two, as these machines can work on five faces of a given part at once. The set-up time improvements alone contribute to much shorter lead times, while increased repeatability prevents damaged or scrapped parts from impacting productivity.
The phrase "complex contours" is commonplace with 5-axis machine technology for a reason-this type of machining makes many parts possible that could not be produced with conventional machines. Nevertheless, 5-axis machines can also expand a medical shop's capabilities in a variety of other ways. In addition to the consolidation of processes, these machines can also vastly improve the manufacturability of various products.
A given component might require multiple parts, all with tight tolerances for fit and geometric complexities necessary for final assembly. With 5-axis technology, none of this becomes necessary. Contouring, compound angles and innovative approaches to machining make it possible to produce these assemblies as single pieces. Every industry, including the medical sector, has access to this kind of streamlining, and given the costs of maintaining part families, 5-axis capabilities can result in significant savings.
Medical parts produced from near-net castings and or AM benefitting from full 5-axis machining include orthopedic implants such as hip and knee replacements, bone screws and plates as well as precision cast components for dental prosthetics and implants. Precision surgical instruments like scalpels, forceps and other intricate surgical devices are also common candidates for near-net part processes.
On the instrument side, medical manufacturers apply near-net shape strategies to generate medical tools tailored for specific surgical procedures; components for medical devices such as pacemakers, heart valves and imaging equipment; and small, precise components for minimally invasive surgical tools.
Commonly used medical part materials include titanium and cobalt-chromium alloys selected for their biocompatibility, strength and corrosion resistance. Opting for near-net shaped castings or AM produced parts also allows manufacturers to cast specialized alloys tailored for specific medical applications.
Near-net shape casting and AM are valuable processes in medical manufacturing, offering significant benefits in terms of material efficiency, precision, and cost savings. They enable the production of complex, high-quality medical components with minimal post-processing, essential for the stringent requirements of the medical industry.
As technology and materials continue to advance, near-net shape casting and parts produced with AM will likely play an increasingly important role in the manufacturing of medical devices and implants as will the use of full 5-axis machine technology. Medical manufacturers will increasingly rely on full 5-axis machines to provide the much-needed precision and agility for finish machining intricate designs. They will also depend on those machines to generate excellent surface finishes to reduce the need for additional polishing or finishing and for holding the extremely tight tolerances required for medical components.
Most importantly, today's full 5-axis machines deliver speed and repeatability. Speed is critical as the medical industry moves towards patient-specific implants designed from medical imaging data, while machine repeatability ensures quality and consistency across multiple production runs, critical for medical device reliability.
Authored by Jared Leick, Product Manager, Mazak Corporation
For more information contact:
Mazak Corporation
P.O. Box 970
Florence, KY 41022-0970
859-342-1700