Plastic media is known by its bonding agent. The two primary bonding agents of plastic are:

• Polyester

• Synthetic

The polyester is the original formulation of plastic media. It is produced from an oil derivative, therefore, non biodegradable. The polyester breakdown is a white chalky sediment that's difficult to clean off of parts if not rinsed properly.

The synthetic plastic is a recent development and runs cleaner than polyester. The synthetic is softer and lighter than polyester achieving superior finishes. Synthetic is also biodegradable.

The cutting element in plastic media is usually quartz. The cutting element is limited to a given percentage because the manufacturers process starts with a liquid and like adding sugar to water and mixing it, if too much sugar is added it will drop out. Plastic media are processed in a variety of different cuts:

• Fine Cut (Pre Plate)

• Medium Cut

• Fast Cut

• Extra Fast Cut

Plastic media in most cases does not cut as fast as ceramic.

Below are a number of advantages of plastic media:

• Light weight and soft bonding agents allow it to wear a burr off with out rolling the burr onto the part.

• Certain plastic shapes, particularly a wedge, will sharpen as it wears allowing points to get into inside radius of parts.

• In large mass finishing systems with large parts, hard media compressed between the machines sidewall and the rotating part can gouge and damage the part. Softer plastic media tends to eliminate this type of damage.

In summary plastic media have many advantages. Your parts should be run in a lab to determine the proper media to use.