Cryogenic deflashing media is used to remove mold flash from plastic and rubber parts. By subjecting molded parts to very low temperatures, the flash becomes brittle and easy to break-off. Depending on the cryogenic deflashing process, different types of media are used. For example, cryogenic deflashing uses a cryogenic-grade polycarbonate media that’s extruded into cylinders or beads and supplied in various sizes. Cryogenic tumble deflashing and dry ice deflashing use dry ice particles instead.
Both types of media have advantages, but what’s the best choice for your molded parts?
Polycarbonate (PC) plastic is strong, impact-resistant, and naturally transparent. Cryogenic grades of this thermoplastic material are specially formulated for increased density and have a very low brittleness temperature. Nitrofreeze® uses cryogenic-grade PC media that comes in different lengths and diameters to finish part features without impacting critical surface tolerances. To clean internal dimensions, however, the media must be small enough to access part features.
Typically, cryogenic-grade polycarbonate loses its aggression below 0.015” (0.381mm). Plastic media can also become trapped in the geometries of complex parts. Although cryogenic-grade PC media can be recycled and reused, molded parts with intricate features may “trap” residual media. When this occurs, secondary cleaning is required. Cryogenic grade polycarbonate media is suitable for processing a wide range of rubber and plastic materials, but it’s not the right choice for every application.
Dry Ice Particles
Dry ice particles are made of frozen carbon dioxide. They sublimate without leaving any residual media, including harmful chemicals or pollutants. Because dry ice deflashing is effectively a media-less process, there aren’t any residues that can attach to part surfaces or become lodged in part features. This eliminates the need for secondary cleaning and supports the use of dry ice particles with molded parts that have intricate features.
Dry ice blasting is also recommended for holes and cavities with less than a 0.015” (0.381mm) opening. It can be used as standalone finishing process, or in conjunction with cryogenic deflashing. Although dry ice sublimates too quickly for reliable measurements at smaller sizes, Nitrofreeze® has cleaned cavities as small as 0.003” (0.0762mm) with dry ice blasting. Cryogenic-grade PC media can also clean inner diameter features, but it tends to lose its aggression with very small holes and cavities.
Find the Right Cryogenic Deflashing Media
What’s the right cryogenic deflashing media for your molded rubber or molded plastic parts? Contact the experts at Nitrofreeze® to review your requirements. If you 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 | firstname.lastname@example.org