Obertec Limited

In any mass finishing operation, choosing the right combination of media, compound and equipment is the first step to achieving quality results economically. Ceramic, plastic and steel media is available in a wide variety of shapes, sizes, colors and compositions. The composition of the abrasive media determines its grinding performance and the surface finish effect. The shape of the media must fit the shape of the component to ensure all contours can be reached and lodging is avoided. The shape of the media also has an effect on the performance. Larger heavier media cuts more aggressively and leaves a more textured surface. Ceramic Media and Plastic Media grades range from media with no abrasive, recommended for very fine burnishing and polishing, to extremely heavy, high-density media that can replace steel media in certain applications. There are grades which contain silicon carbide abrasive. These are recommend for use on parts that can have no aluminum oxide impregnation (usually on parts that are to be welded, brazed or soldered). The availability of large sizes of plastic media lends itself for use with complex aluminum and zinc die cast parts.

Steel media imparts compressive stress, causing the surface of the part to become work-hardened. Parts processed with steel media have longer cycle lives and greater resistance to wear as a result of this compressive stress action. When parts are finished with steel media, a compacting action helps eliminate porosity and can increase the corrosion resistance after plating and painting.

The difference in size between the component and the media must be sufficient to allow for separation. Usually media is smaller than the parts to allow the media to pass through a screen if the process involves automatic separation.

Let our experience guide you in selecting the most appropriate media for your application. Contact us to determine the best possible process for your finishing.