Cryogenic deburring and cryogenic deflashing are versatile processes that improve the surface quality of plastic or rubber parts that have been machined or molded. Because parts differ by physical properties and geometry, Nitrofreeze® optimizes the processing parameters for each project during our pre-production engineering evaluation (PPEE) program.
To determine the right recipe, Nitrofreeze® evaluates your parts for five parameters or process variables.
- Type of Media
- Throw Wheel Speed
- Tumble Speed
The following sections describe these five T’s for cryogenic deburring and deflashing. For an overview of how these Nitrofreeze® processes work, see our cryogenic deburring and cryogenic deflashing pages.
Time or cycle time refers to how long parts need to be tumbled and blasted at cryogenic temperature. It does not include the time spent staging batches, cooling the chamber, or loading and unloading the basket. Depending on the parts, cycle times may range from a few minutes to 30 minutes or longer. The main drivers of time are batch volume and the accessibility of burrs or flash. Crowded batches and hard-to-reach surface imperfections often require longer-duration tumbling and blasting.
Temperature refers to the atmospheric temperature of the chamber during cryogenic treatment. Liquid nitrogen is flashed into the chamber as gaseous nitrogen, which cools the chamber to the desired temperature. Often, cooling is performed to the glass transition temperature of the part material; however, Nitrofreeze® also processes parts at temperatures as cold as -200° F. This cryogenic treatment embrittles the burrs or flash but does not change the physical or mechanical properties of parts.
Type of Media
Type of media refers to the dimensions of the non-abrasive media that’s used. This parameter is often the most significant driver of processing aggression. All of the blast media used in cryogenic deburring and deflashing is a cylindrical, cryogenic-grade polycarbonate (PC). These beads are available in different lengths and diameters, which allows Nitrofreeze® to process parts without impacting critical surface tolerances. To clean internal dimensions, the media must be small enough to access part feature.
Tumble speed is the number of rotations per minute (RPM) at which the parts basket tumbles inside of the chamber. The part material, robustness, and burr location determine the tumble speed that’s used. Slower tumbles are used to flip parts and simply expose all of a part’s surfaces to media blasting. Faster tumbles are required for the more aggressive removal of external flash and burrs.
Throw Wheel Speed
Throw wheel speed is the RPMs for the throw wheel, which determines the velocity at which media are broadcast to parts. For optimum processing, Nitrofreze® uses throw wheel speeds up to 20,000 RPMs. To see cyrogenic deburring and cryogenic deflashing in action, watch our Nitrofreeze® Cryogenic Deburring and Nitrofreeze® Cryogenic Deflashing videos on YouTube.
Cryogenic Deburring and Cryogenic Deflashing for Your Parts
What are the five T’s for your machined or molded parts? Contact the experts at Nitrofreeze® to review your requirements and, if your part is a viable candidate, we can perform sampling to demonstrate the process. The consultation is free of charge. To learn more, contact us at the phone number and email listed below.
(508) 459-7447 x109