This small polyamide, thermoplastic resin, hardened part had a rough surface finish as well as flashing that needed to be removed. The challenge in deflashing and polishing plastic parts is to choose a media that will be aggressive enough to remove enough material to create a smooth finish without scratching or etching the surface too much so that the part can be polished successfully.
A two-step process was used to first de-flash the part and then polish the surface. The first step involved vibratory tumbling with a Precision Ceramic Fast Cutting Sphere to remove the flash and smooth the surface. This shape and bond (formulation) of media provided good cutting action (deflashing and edge rounding) but not the rough, ‘tumbled’ finish normally associated with angular shaped media. The part was then polished with a Precision Ceramic Polishing Sphere. Again, this shape provided the best polishing action and left the part with a near-mirror surface.