Inovatec MachineryYour Best Finishing Media Manufacturer in China

Finishing Media

Inovatec finishing media performs well in surface preparation.

By choosing the right media, you prepare your parts ready for electroplating, coating, painting as well as anodizing.

From aggressive cutting media to excellent polishing media, from the small millimeter size media to the big size deburring media, Inovatec has endless media supply.

If the media you choose is too large, you cannot finish the surface of the entire parts.

But if your media is too small, it may present a “lodging” problem in your pieces.

What we mostly care about is that you get your desired finish at an affordable cost. Pre-formed media is made in a specific shape designed for a particular finishing application.

The shape of the media is crucial in a successful finishing project.

We have numerous available shapes of finishing media, including cone, sphere, ballcone, cylinder, triangle, wedge, pyramid, tetrahedron, etc.

The combination of different sizes and shapes yields complete different finishing results.

There are a great many choices to consider when choosing the right finishing media.

So let us assist you in finding the right mass finishing media as well as supply it.

You can achieve the most excellent surface enhancement by running the test on the parts.

You will get the desirable finishing result with a small fraction cost of hand polishing.

Inovatec is the leading finishing media supplier and manufacturer for more than 20 years.

Each year, we export over 30,000 tons of finishing media of all types.

We continually improve media quality with the ISO9001 management system.

Contact us today and optimize your mass finishing process now!

Finishing Media FAQ Guide

1. What is finishing media?

Finishing media refers to the abrasive or non-abrasive consumable elements used in mass finishing processes.

Also called, abrasive, stone, or chip, finishing media is a material of proportionate hardness that is used to shape other workpieces during mass finishing.

They are used as cutting and finishing mediums for machining parts in the same way that ordinary machine tools are used.

Finishing media is of various types, forms, and performs varying functions.

They are therefore usually distinguishable by properties such as toughness, friability, cutting rate, speed of operation, depth of cut, and smoothness of finishing.

In the “old days,” when the first mass finishing methods were developed, media consisted of crushed grinding wheels, and river pebbles.

Over time, mass finishing media have advanced into more refined forms. Today, there is a huge variety of media that manufacturers can choose from.

Only with the right media choice can the desired surface finish be achieved.

Of course, the media choosing process might be comprehensive and time-consuming.

But the payback for such efforts generally is substantial in the form of optimum and cost-effective finishing results.

2. What is the popular types/classification of finishing media?

Finishing media may be classified based on constituents and cutting rates.

Based on constituents, finishing media can be classified into natural finishing media and synthetic (manufactured) finishing media.

The latter is by far the more extensively used, but in some specific applications, natural materials still dominate.

Based on cutting rate, they may be classified into abrasive and non-abrasive finishing media

3. What are natural finishing media?

Natural finishing media are media made of entirely natural materials, with no additive whatsoever.

The most popular natural finishing media are: diamond –which is the hardest known material, corundum, and emery.

Others are garnet, feldspar, calcined clay, lime, chalk, silica, sand, flint, diatomite, among others.

4. What are synthetic finishing media?

Synthetic finishing media are media made from putting together different man-made ingredients.

Although they may contain some natural constituents, the percentage of man-made compositions is usually higher.

When it comes to the varying forms of synthetic finishing media, the list is endless.

Manufacturers put out thousands of synthetic types of finishing media, made with different combinations and characteristics.

These synthetic finishing media also come in a multitude of sizes and shapes, and colors, which often makes the selection process of the best finishing media for mass finishing, a difficult and exhaustive task.

5. What are the popular types of synthetic finishing media and their constituents?

In today’s market, there are definitely assorted types of synthetic media that each offers a wide range of finishing results on several types of workpieces.

These assorted types of finishing media are made from materials such as plastics, steel, corn cob, wood ceramics, among others.

They will each be discussed below:

5.1 Preformed Ceramic Finishing Media:

These are made by mixing clay-like materials with water, and abrasives, to be formed into shapes, which are dried and fired at high temperatures.

This type of finishing media, however, varies in terms of the nature of the binder that is used, the hotness of firing, and the percentage of abrasive that is added.

This type of media is generally preferred because of its availability in various forms and dimensions, as we as its low cost of purchase.

The following are the many sub-types of preformed ceramic media available:

• Porcelain: Non-abrasive porcelain finishing media can perform extremely good surface finishing of workpieces at very little cutting rate. They mostly come in handy in light deburring processes as well as in the brightening of metal surfaces.
• Light-cutting ceramic finishing media: They are a perfect fit for carrying out quick, light deburring of steel and die-cast workpieces. They take long before they wear out, making them extremely favored by most users.
• Fast-cutting ceramic finishing media: These are available in several variants, distinguishable mostly by their abrasive composition percentage. They are mostly used where large amounts of workpieces need to be removed in relatively short cycles or when workpieces require a significant limitation in cycle time. Importantly, their excessive wearing and cutting rate generally makes them less efficient when compared to light-cutting ceramic finishing media.

5.2 Plastic or Preformed Resin-bonded Finishing Media:

Resin-bonded or plastic finishing media may perhaps be said to have a wider range of abrasive variants than preformed ceramics.

The most popular variant is those that have quartz as an abrasive.

Plastic or resin-bonded finishing media are typically used for cutting steel workpieces before plating or finishing of zinc die-casting.

But just as well, they can help to achieve excellent pre-plate finishing on any metal surface.

They are popularly shaped as triangles, stars, cones, tetrahedral, pyramids, etc.

5.3 Steel Finishing Media:

Steel-formed finishing media are available in varieties of sizes and shapes.

They commonly come shaped as oval balls, balls with flat spots, ball cones, and pins.

They approximately weigh around 300 pounds per cubic foot and are expensive to purchase.

But because of their extreme cleanliness and zero depreciation rate, they are one of the most preferred choices in the light deburring application.

There are compounds specifically made to keep them clean and bright for as long as they are used.

5.4 Dry Process Media:

Dry process media are the most commonly used for drying workpieces.

The most popular types are those made of a crushed and sized corn cob.

However, some others -such as wood pegs and walnut shells- are also used for brightening parts.

Dry media are essentially used in mass finishing processes where workpieces cannot be allowed to get wet, as well as for high luster finishing purposes.

5.5 Other

At one time or the other in history, manufactured items such as leather, carpet tacks, shoe pegs, among others, have been and are still being used as finishing media in various applications.

6. How does finishing media work?

On loading the finishing media into the finishing machine, the media becomes energized and stimulated by the motor-generated energy.

The finishing media then transfers the energy generated by the mass finishing equipment to the workpieces in the work bowl.

This is done by effectively rubbing off on the workpieces. By rubbing off on them, it fine-tunes and enhances them in the process.

7. What are the key parameters that affect finishing media, which must be considered when selecting the right finishing media?

Various factors and variables influence the capabilities of workpieces. These variables must be taken cognizant of to get optimum finishing from using finishing media.

These factors include:

Cutting-rate:

This refers to the ability of media to scrape uppermost layers of workpiece surfaces as fast as possible.

It also refers to taking off high spots, gradually smoothing the surface.

Finishing media with a higher cutting rate finish workpieces faster, but with low quality.

Low cutting finishing media, on the other hand, cut slowly but produce maximum finishing quality results.

Media Wear Rate:

The abrasion composition percentage in any finishing media determines how fast or the rate at which the media depreciates and gets smaller.

Generally speaking, fast-cutting media have higher wear rates, while low-cutting finishing media have low media wear rates.

The Hardness of Media:

The hardness of various types of finishing media can sometimes determine whether it would be selected over another.

Hard finishing media like steel media, cannot be used where its hardness would cause dents in soft workpieces.

This accounts for why high-quality surface finishing on soft workpieces such as textiles, are typically done with plastic or resin-bonded finishing media that aren’t usually so hard.

Sensitivity to Compounds:

Certain media types show sensitivity to certain compounds.

For example, using a burnishing compound on certain types of media reduces their cutting rate.

This, therefore, makes it essential to select the proper compound.

Chipping and Fracture Sensitivity:

In mixed media finishing where different types of media are combined, the simultaneous usage of hard and soft media calls for care.

This is because where hard media drops on soft media, the latter can become fractured and break off into fragments.

These fragments, if not properly monitored, can cause excessive lodging problems in workpieces, causing low finishing results.

Media Shape and Size:

In media selection, it must be understood that sizing has different implications.

For example, in larger resin-bonded or plastic finishing media, the media depreciation rate is smaller, but it is higher in smaller shapes of the same media.

Whereas in ceramic media, larger ceramic media have a higher wear rate than small media of the same composition.

What you need to take away from all this is that the larger the surface area to volume ratio of a particular shape of finishing media, the higher its wear rate.

Or, the more spherical finishing media, the lower it’s wear rate for a given size.

An example is that cylinders and cones depreciate slowly than triangles of the same weight.

Media-to-Parts Ratio:

The choice of media to part ratio has an important effect on media efficiencies.

For instance, in a ratio of 1:1 where volumes of media and workpieces are equivalent to one another, higher cutting rates can be attained.

However, the disadvantage is that there would be poorer surface finishing results because of extensive part-to-part contacts.

Compound Type and Flow Rate:

Deburring compounds are designed to keep the media clean and able to cut as well as to clean workpiece surfaces.

On the flipside, burnishing compounds are formulated to pad, cushion, and bolster the mass, form luster on workpieces and enhance media cutting rates.

Some burnishing compounds even help to temper down the abrasiveness of media against themselves.

Appropriate choice of mass finishing compound can, therefore, go a long way impacting the efficiency of the media used.

Water Flow Rate and Drainage Rate: 

Generally, water helps to decrease the force with which media hits one another or hits workpieces, and cleans the mass.

But if the water cannot efficiently flow out of the finishing machine, the processing slows down.

This is because finishing machines transfer finishing energy through the walls of the work bowl, requiring contact with media in order to transfer this energy to workpieces.

Optimum water flow in mass finishing machine is normally set at 1-1/2 to 2 gallons of water-compound solution per cubic foot of the machine capacity, per hour of operation.

But if the cutting media is known to generate tremendous amounts of soil, the water flow rate goes up. And when noncutting media is used, the flow rate is reduced.

Machinery Type:

Finishing media with lesser speeds produces slower cutting action, and therefore better surface finishing results with appropriate finishing media.

In this wise,  rotary barrel machines which are low-energy machines, have the advantage of slower cutting force, leading to greatly reduced media wear rates and excellent mass finishing results.

On the other hand, tub-type vibrator machines run at higher speeds and thus cut workpieces at greater speeds, but with a higher media wear/depreciation rate.

The above accounts for why it is important to carefully consider the mass finishing machine type and how it can contribute to finishing media efficiency

Part Surface Contamination:

Contamination of the surface of workpieces often makes it harder for the media to finish inner layers.

The excessive presence of lubricant substances such as oils, greases, and sticky dirt tends to affect media efficiency.

Unless the surface contamination is removed, finishing efficiency can be affected as it would make it harder for the media to reach underlying layers.

People:

Human labor plays an important role in determining media efficiency too.

For example, an operator must be adequately experienced to decide when and how much media to add, or how media should be loaded – all in one place at one time or not.

Low media presence reduces media-to-parts ratio, making part-on-part contact occur, and affecting the efficiency of finishing media.

8. Which finishing media type is the best?

There is no straight answer to this question because each finishing media has its strengths and weaknesses. For instance, rigid ceramic finishing media is best for its precision-grinding efficiency. Other tougher, resilient finishing media, such as resinoid or rubber, are much suitable for snagging and cutting operations.

It all boils down to what the operator wants to accomplish. For example, in aircraft or surgical type workpieces, ceramic finishing media might be your first choice because of its excellent deburring quality.

If you are lost as to what finishing media is best for you, reach out to your vendor or the media manufacturer for assistance.

9. What is the application of finishing media?

Finishing media are applied and used to perform a lot of functions, depending on their type, and constituents. Their most popular applications include:

Cut: Finishing media can, through cutting, help to remove burrs and smoothen surfaces. They are usually able to carry out cutting action because they contain high percentages of abrasive. In some situations too, finishing media are loaded to, through cutting, give workpieces dull matte finishing –a form of completely random scratch pattern.

Luster: Some variants of finishing media are crafted to give workpiece surfaces’ luster finishes. Finishing media under this category are generally non-abrasive or low in abrasive percentage. They carry this out by peening surfaces, in a bid to make workpieces bright and shiny.

Parts Separation: Another important application of finishing media lies in being used to separate workpieces during finishing processes such as burnishing, deburring, cutting, among others. This is achieved by moderating the media to workpiece ration, in controlling the amount of part-on-part contact.

Surface Scrubbing: Finishing media are also applied when needs to scrub workpiece surfaces arise. Whether abrasive or non-abrasive finishing media, they help to assist the compounds in cleaning the workpieces.

10. What shapes do finishing media come in?

Finishing media come in an unlimited number of shapes.

The reason being that media size often determines the suitability of a media to finish some particular workpieces.

This is because finishing media shape determines the media’s effectiveness in reaching into the inner areas of the workpieces being processed.

In addition, the shape can determine whether a finishing media will be lodging within the holes of workpieces.

Popular shapes and their preferred usages include:

Triangles have angles that help to provide greater infiltration into remote areas. Their flat surfaces typically have a longer contact time on edges for radiusing and deburring. This makes it the standard and most common media shape for deburring.

Tri Stars are available in a 22-degree angle cut, designed to reach more inaccessible parts of the workpiece, such as holes and slots. It does this better than triangles.

Cylinders are available in 22, 45, and 60-degree angle cuts. The cylinder is designed to improve finishes with the round single point contact shape. The angles of cylinders are used to reach into tight areas. The cylinder rolls well and is a great fit for surface improvement in high energy centrifugal discs and barrels. The cylinder is one of the first choices for part burnishing and brightening.

Cylindrical Wedges are finishing media that have cylindrical forms making them a great fit for curved-in surfaces in workpieces. They typically have two flat surfaces that altogether perform excellent finishing of flat surfaces, convex surfaces, as well as edges. Cylindrical Wedges finishing media combine the strength of cylinders and triangles in penetrating slots, corners, and angles.

Cones are excellent for finishing because of their flat and round areas. They roll excellently well in mass finishing machines and are a good choice when it comes to finishing workpieces that have no holes or enhancing slots. Cones are one of the most preferred choices of finishing media shapes in mass finishing.

Tetrahedron has points that help to reach difficult areas and flats for deburring and radiusing. This is a good choice for mixing with triangles for exterior surfacing with hard-to-reach places. Although, its sharp points make it prone to chipping

Pyramids shaped finishing media hardly get lodged in holes. It works by using its many flat angles to finish slots and flat areas. They finish workpieces much faster because of their shape and for being able to fill lots of voids within the mass.

Ellipse is used for surface refinement of hard-to-reach areas and is adaptable to many applications. It improves surfaces and has an extended usage life. Mostly used on finishing multi-shaped turbine blades, heat sinks, and slotted areas.

11. How long do finishing media last?

This depends on a whole number of factors such as the type of media –whether ceramic or steel, as well as the cutting rate of the finishing media.

12. What is the standard finishing media to workpiece ratio?

Of utmost importance is the media-to-workpiece ratio in mass finishing.

However, there is no one size fits all rule.

This means that the media-to-workpiece ratio varies in terms of number, size, shape, and weight of workpieces.

Importantly, finishing media helps to protect workpieces from damaging one another, which accounts for the ratio essentiality.

Below are standard estimates of the required media-to-part ratio in mass finishing.

• Stampings, parts less than 9 cu/in 3:1 media-to-part ratio
• Parts requiring self unload 3:1 “
• Castings with non-critical surfaces 4:1
• Machined parts 4:1 “
• Parts requiring super surface refinement 5:1 “
• Longer parts to keep from jack strewing 5:1
• Larger parts with critical surfaces 6:1
• Larger parts with sharp protrusions 7:1
• Delicate parts that may tangle and damage 8:1