Maintaining the right ratio of media to work pieces is essential to achieving precise, repeatable results in mass finishing processes where work pieces and media loosely tumble in the processing bowl.
Ensuring that the work pieces are properly embedded in the media allows the media to perform its designated grinding or polishing function as well as cushioning the work pieces from damage caused by part-on-part impingement.
The standard ratio of media to work pieces is around 3-to-1 by volume – meaning that the mix is 3 parts media to 1 part of work pieces – but the exact ratio varies based on the aggressiveness of finishing required as well as the work piece’s material, shape, size, weight, and delicacy or lack thereof.
The importance of the media selection in any surface finishing process cannot be emphasized enough. These consumables are essential “precision tools” for achieving the specified finishing results.
Selecting the right media is a complex task. That’s why you should consult an expert such as Rosler for guidance.
Even after a mass finishing process has been established, the media status must be constantly monitored and, if necessary, corrected. When different work pieces are processed or finishing tasks are altered, exchanging the currently used media type with another may be required.
Careful and collaborative media selection is crucial to a mass finishing success.
Whether it be a process for polishing, surface cut down, grinding, deburring, cosmetic finishing, or just cleaning, an appropriate media is available. Choosing the media can seem daunting at first, with over 1700 various media and compounds available. Therefore, sample trials are of significant importance. Here are three considerations to think about when choosing the right media: Read more about media purchasing considerations
The quality of consumables used in mass finishing is a key factor in surface processing. Using consumables with a consistent high quality is crucial to attain set surface specifications, process times, costs and to manage considerations to any environmental impact.
There are in excess of 1700 types of vibratory media consisting of various shapes, sizes and incorporating a percentage of abrasive. These are divided typically between ceramic and plastic families.
Ceramic Media Production
A ceramic media has a higher density than that of plastic media. Ceramic chips of various shapes and sizes are formed, fired and held at certain temperatures and durations; providing an infinite range of variation and capability.
A consistent, supreme quality media is extremely important for the user to obtain a uniquely stable and reproducible surface finishing result.
Ceramic media is manufactured to exacting standards, controlled in a fully-automated way.
Plastic Media Production
The manufacture of the plastic media is also totally automated.
The plastic media is of a lower density than that of the ceramic media, therefore it is suitable for a more gentle treatment of critical component parts and softer metals.
The process involves mixing, forming and curing of the media and the whole process is computer controlled and continuously monitored. This quality standard ensures a consistent wear and cutting performance, and repetitive results during the finishing process.
Surface Finishing Compounds
Compounds can be added to the vibratory process, optimising the surface specification for: degreasing, brightening, polishing, corrosion protection and producing surfaces free of stains.
Another important function is keeping the process clean. The compound continuously flushes tiny metal particulates from the chip media and other contaminants out of the mass finishing system, keeping the media active and the parts free from contamination.
Depending on the specific process, compounds will provide various options of acidity and alkalinity as a pH factor.
Despite compounds being used for many years in mass finishing applications research and development constantly progress new formulations for special applications.
The range of different compounds is broadly diversified: