medical device deburring | medical plastics machining

Why Medical Plastics Machining Needs Cryogenic Deburring

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Medical plastics machining can produce complex parts with excellent dimensional stability. During CNC machining operations, however, milling and drilling can stretch part surfaces. If the workpiece material contains a crack, this stretching may cause the crack to grow and fracture. This creates burrs, raised areas that can interfere with part seating, sealing, or assembly.

Nitrofreeze® cryogenic deburring can remove burrs without affecting the part geometry or surface finish that medial plastics machining achieves. Our patented process is especially effective at removing burrs from blind holes, through holes, and other challenging features. Edges are maintained without rounding and critical dimensions are preserved. There are other benefits as well.

Medical Deburring That’s Safe, Clean, and Cost-Effective

Cryogenic deburring is a computer-controlled, machine-based process that puts batches of parts in a chamber and cools them to cold temperatures so that the burrs become brittle. When the part material reaches its glass transition (Tg) temperature, the parts are impacted with non-abrasive polycarbonate media. This removes burrs quickly and cleanly.

The cylindrical polycarbonate media that Nitrofreeze® uses comes in sizes from 0.015” (smallest) to 0.060” (largest) to accommodate specific deburring requirements. This non-toxic media won’t leave dust or residue behind, and it won’t affect the structural integrity of components. Applications include PEEK implants, polypropylene surgical caddies, and rotary valve seals for ventilators.

Compared to manual deburring, Nitrofreeze® cryogenic deburring is cost-effective. This automated batch process can deburr more than one part at a time, and with greater part-to-part consistency than hand tools. For example, a PEEK spinal cage can take 15 to 20 minutes to deburr by hand. There’s also a risk that workers will damage the small cross-holes used by implant fasteners.

Cryogenic Deburring vs. Other Burr Removal Processes

For parts made with medical plastics machining, Nitrofreeze® cryogenic technology also offers advantages over other burr removal processes. For example, thermal deburring feeds gases into a chamber and ignites this mixture with a spark. The process can remove multiple burrs from a machined medical part, but there’s a risk of heat distortion and surface discoloration.

Punch deburring is another machine-based process, and one that can remove burrs from holes or corners. It’s not recommended for complex part geometries, however, and punch deburring uses metal tooling that can damage surfaces. Tumbling is also an option, but it alters the surface finish of the part and may leave abrasive residues behind. Vibratory finishing can deburr smaller parts, but often provides inconsistent results.

With each of these other processes, there’s a risk that parts deburring will affect critical tolerances or surface finish. Since medical plastics machining often uses specialty polymers, it’s essential to minimize the costs associated with material waste.

Choose Nitrofreeze® Cryogenic Deburring for Medical Plastics Machining

Nitrofreeze® cryogenic deburring can process tens of hundreds of parts at the same time, and our standard turnaround time is just two days after receipt. We can also save your deburring recipe for future batches of the same part. Our process works on a wide range of plastics that have medical applications, including ABS, PET, PTFE (Teflon®), acetal (Delrin®), nylon, and HDPE.

The consultation with Nitrofreeze® Cryogenic Solutions is free of charge, so contact us at the phone number or email listed below to get started.

(508) 459-7447 x105 | info@nitrofreeze.com