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Writer's picturePrecision Finishing Inc.

Foam in your plastic media tumbling process?


Processing with plastic media can generate thick white chalky residue unless the right formula and concentration of vibratory compound is incorporated into the process.  Chemtrol 224 is specifically formulated to reduce foam when using vibratory media to the point where post-process washing may be eliminated entirely.




PLASTIC VIBRATORY MEDIA is often the ideal media to use when tumbling parts made of softer metals such as aluminum, brass, copper alloys, and non-hardened steels.  The primary reason for the choice of plastic media is due to the low density and weight of the media, which eliminates media impingement and results in parts with a planarized surfce condition and elminating the well recognized "orange peeled" surface texture.


Plastic Vibratory Media | Precision Finishing Inc

A variety of configurations are available to choose from. Shape, size, and abrasiveness are all considerations based on what critical areas of the part must be addressed. Cutting ability or "aggressiveness" is also considered, dictated by surface roughness callouts or material removal specifications. For example, high-cut, or "aggressive" media is effective and fast when requirements call for a less smooth finish such as deburring or descaling castings or saw-cut parts, whereas, more reflective and smooth finishes required in pre-plate processes or final aesthetic finishing is obtained when using a fine finishing or low cutting media.





QUALITY OF MEDIA varies from source to source and is directly correlated to the quality of materials used and the manufacturing practices.  Media is created when molten plastic polymer is mixed with abrasive particles and then molded into the final shape.  The ideal plastic media has a homogenous suspension of abrasive particles throughout, but unequal distribution can occur and compromise the quality of the plastic media.  Precision Finishing provides media wear analyses to rate performance and profitability of your finishing operations.







THE DOWNSIDES

Vibratory tumbling with plastic media and water |Precision Finishing Inc
Vibratory tumbling with plastic media and water - Notice the debris in addition to the foam

Plastic vibratory media may be the ideal choice for vibratory finishing delicate metal alloys, but there are downsides to plastic media that must be avoided to ensure optimal running conditions.  The most common problem is the thick chalky foam that develops from vibratory tumbling with plastic media from improper or lack of process comound which is not experienced with ceramic vibratory media.  The foam generated by the media breaking reduces the overall effectiveness of the finishing operation by creating a barrier between the abrasive particles within the media and the part surface.  Media foam will extend time cycles, reduce media effectivness and leave chalky depositions on part surfacesm threads and holes


In addition to being a dirty mess that reduces tumbling efficiency, the foam also acts as a conduit for dissipating the metal and plastic waste created within the process across everything it encounters.  As the foam grows it carries the waste along with it leaving a trail of plastic and metal chips, grit, dirt, etc. requiring extra time and maintenance to manage.


THE SOLUTION

Vibratory finishing with plastic media and Chemtrol 224|Precision Finishing Inc
Vibratory finishing with plastic media and Chemtrol 224

Chemtrol 224 is a liquid cleaning and deburring vibratory compound that is specially formulated to eliminate plastic media foaming problems.  Significant foam reduction is achieved when used properly at 1-4% concentration with water, and can be adjusted based on foam control needs without compromising effectiveness.


Several ancillary benefits are achieved from the elimination of foam from the surface finishing process.  For example, when the flow and concentration of the compound are properly managed, parts exit the process with a high level of cleanliness and bright surface conditions, thus eliminating the need for post-process washing.  Removing this step in the process leads to cost savings in time, energy, and equipment needs. 


analysis of foam from vibratory tumbling with plastic media| Precision Finishing Inc
Sample A - Water only | Sample B - improper compound choice | Sample C - Chemtrol 224

Further savings in processing costs such as overall improvements in time cycles, reduction in chemistry & energy consumption, and fewer maintenance requirements are also significant benefits from the elimination of foam from the finishing process.

Last, but certainly not least, is the overall benefit of a cleaner process. After all, doesn’t it make more sense for processes designed to clean and improve part surfaces to take place within a clean area?


Chemtrol offers over 150 specially formulated compounds designed, engineered, and manufactured in the USA since 1955 for optimal vibratory washing and cleaning




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