“Glazing” occurs when the surface of the media becomes contaminated with metal fines and other debris from the work pieces. As a result, the media becomes very shiny and frequently looks like a piece of aluminum, brass, steel, zinc, etc.
Because glazed media completely loses its original surface properties, it no longer has any grinding effect. Instead, glazed media creates a sort of uncontrolled burnishing. It also retains dirt and other particles which are then deposited on the work pieces.
The image above depicts (from left) media states include clean, heavily glazed, partially cleaned, and fully cleaned.
Rosler has more than 60 years of media production experience. In that time we’ve seen—and corrected—countless examples of ineffective surface finishing as a result of media glazing.
As a result, media wears down over time, losing its shape, size, and effectiveness. Known as undersized media, this worn media must be discharged and replaced with fresh media to ensure proper processing and safety.
Whether a process uses ceramic, plastic, or polishing and drying media, Rosler stresses the importance of monitoring media levels and the mix of new and worn media for precise and safe mass finishing results.
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.
True to our mantra of “finding a better way…” Rosler Metal Finishing is constantly working to optimize our consumables. These improvements and additions to our offerings improve process stability, cost efficiency, and productivity of surface finishing processes.
From media composition and compounds to wastewater handling, Rosler is dedicated to constant enhancement in the area of consumables as well as our mass finishing and shot blasting technology.
One such example is Rosler’s development of a plastic media with the grinding and non-chip characteristics of ceramic media. Minimizing the risk of work piece damage, this range of high-density plastic media exactly achieves this frequently requested combination.
At Rosler, we believe in helping our clients in unique markets find a better way to finish and process their products. According to Grand View Research, Inc., the global structural steel market is expected to reach USD 140.4 billion by 2025. It is projected to expand at a CAGR of 5.6% during the forecast period. Increasing construction spending in emerging economies is projected to drive the demand for structural steel. Maybe that’s why our top posts this year included a series on Structural Steel. Enjoy the following recap.
5. Optimal Media Mix, Part 1 – Identifying and Maintaining Proper Levels
The best mass finishing equipment is useless without the proper media. That’s why the experienced engineers at Rosler Metal Finishing pair their quality equipment with the right type and amount of media to achieve consistent results.
Understanding how your machine, the work pieces it
is finishing, and the selected media will interact is key to delivering an
optimal finish each cycle. Doing so requires understanding why media levels are
important, determining and tracking levels, and evaluating media consumption to
Machinery and media are nothing in the mass finishing world without the right compound.
A manufactured object can be designed to specifications, but if it doesn’t look and feel finished, it may be rejected. A metal alloy can be structurally perfect, but surface corrosion may make it less presentable. Process water may work well for initial cycles before contaminants wear down its effectiveness over time.
The right compound for a given mass finishing process can solve each of these problems and more.
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: