Plastic media also called plastic tumbling media. It has superior performance for soft metals (brass and aluminum) or stringy materials smoothing and polishing. In addition, it produces a better surface finish and to prevent rolling the burr over into a hole.
Plastic media generate a smooth surface, but very little shine. Plastic media is good to use when preparing parts for pre-plating and pre-anodizing. Pyramid and cones shape is most commonly used media for parts with holes.
Typically, plastic media is 1/3 lighter compared with ceramic media.
There are three important parameters to determine the performance of plastic media.
- Size of Plastic Media
- Shape of Plastic Media
- Abrasiveness of Plastic Media
1. Plastic Media Shape
There is a variety of shape of plastic media for selections. For example, cone shape, tri-star, pyramid, tetrahedron, etc. There is still some special media shape for selection for example Nipple shape media.
Engineers select right shape media according to parts size and shape. Here are the main criteria:
- The media can polish entire surface of parts
- Media not stuck in parts slots and recess
- Parts can easily separate from media mas