Fiberglass Deflashing - Alternative

Removing the flash off various types of molded parts (see last post) can be done in a wet or try process. Vibratory tumbling with a Plastic or Ceramic media in a wet process can be a quick and easy method to achieve the desired results. After the deflashing step, the parts will generally need to be rinsed and dried.

A traditional dry tumbling process involves the use of Hardwood media that have been treated with an appropriate cream compound. The selection of this compound depends on the needed aggressiveness and required surface finish. The challenge with these compounds isthat sometimes the cream can transfer from the media and become deposited in holes, slots or corners of the part. This then requires cleaning prior to further processing of the part.

An alternative to using creams is a similar previously described process for dry tumbling of wood parts. Depending on the type of part and the amount of flashing that needs to be removed, simply tumbling the parts with Hardwood media and an abrasive grit such as White Aluminum Oxide will provide excellent results with only a light dust on the parts. Because the abrasive material is not 'attached' to the media, a barrel tumbler is typically a much better process than vibratory tumbling.

Choosing Tumbling Media (2)

In addition to choosing the proper type of tumbling media, the shape and size of media is also critical to achieving the proper finish. Given the multitude of tumbling media options, the size and geometry of the parts being tumbled will narrow down the choices considerably. Optimizing a process requires using a good quality media that is appropriate for the job at hand.

The most popular Ceramic Media shapes are Angle Cut Cylinders and Angle Cut Triangles. The angled edges help the media to produce a uniform finish across the entire part including inside corners, holes and slots. Cone shapes are popular choices when using Plastic and Synthetic Media. Generally, larger media will work better with larger parts. Smaller media will have a tendency to impact surface finish more than edges.

Aggressive media (whether large or small) will shorter the cycle time to deburr or round edges - and even for polishing (aggressive = dense) operations. Aggressive, abrasive media will break down more quickly than general purpose type media so replacement cost and the waste stream are an additional consideration.

The high quality tumbling media manufactured by Vibra Finish provides the balance between options (size, shape and type), cost (economical) and quality (uniform bonds, even break-down).