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Pearl Polishing – Definitive Guide

1.  What Is Pearl Polishing?

Pearls are generally referred to as organic gemstones or jewelry due to their mode of formation.

Pearls obtained naturally are a result of mollusc irritation caused by foreign objects.

The mollusc coats the foreign objects with calcium carbonate in a concentric manner in an attempt to attenuate the penetration of its shell.

This action resulted in what we know as pearls – all in different shapes, sizes, and colors.

Pearl polishing is a common technique often used to remove unwanted materials off the surface of pearls or to attain the desired finishing.

This could be achieved manually (hand polishing) or through the use of machines (automated pearl polishing).

Generally, pearls will be tumbled alongside natural materials like corn cob, walnut shells, etc. in a gentle manner.

These natural materials, often referred to as media, offer awesome polishing properties.

To improve the efficiency of the pearl polishing process, compound agents are often utilized to ease the smoothing out of minute imperfections.

These compounds also help to enhance the luster and provide a magnificent finish.

Pearl polishing can be achieved with either a centrifugal barrel finishing machine or a centrifugal disc finishing machine.

The choice of surface finishing equipment will be informed by the use-case efficiency of either equipment and the degree of desired finish.

The use of mass finishing machines (automation) for pearl polishing helps to save cost on manual finishing (up to 80%).

Likewise, it saves time, reduces material losses, and the possibility of defects.

2.  How Is Polishing Achieved for Pearls?

Pearls could be polished manually, i.e., hand polishing, or with the use of designated polishing machines.

These machines include the Centrifugal Barrel Finishing Machine and Centrifugal Disc Finishing Machine.

A Centrifugal Disc Finishing Machine has a rotating disc at its base, and the force generated by its motor propels the disc into a spinning motion.

This action causes the pearls and the designated media to come in contact with the PU wall of the tub in a continuous manner.

The resultant effect is a quick and highly efficient pearl polishing process.

A Centrifugal Barrel Finishing Machine has four barrels affixed to a flywheel.

The pearls and the media are placed in these barrels.

The flywheel rotates in a certain direction while each barrel counterrotates in a rapid manner.

This action generates a high-intensity (G-force) centrifugal force.

Consequently, the generated force facilitates a sliding action that occurs at high pressure between the pearls, the media, and the compound agent (if any).

This action helps to create a smooth, consistent, and high-grade pearl polishing in a short cycle time.

In general, we polish pearl either in centrifugal disc finishing machine or centrifugal barrel finishing machine

3.  What Types of Pearls Are There?

Pearls are lovely pieces of jewelry obtained from the sea or freshwater – and they possess a timeless facial appeal.

Understanding pearls can be a little confusing because there are several kinds out there.

Here are some of the known pearls:

• Akoya Cultured Pearls

Akoya pearls are obtained from Akoya oysters that are artificially cultured in China, Japan, and Vietnam.

These pearls are white, shiny, perfectly rounded, have a lustrous appearance, and with sizes ranging between 2 – 9.5mm.

• Freshwater Pearls

Freshwater pearls are mainly produced in India and China and are harvested from freshwater mussels cultivated on pearl farms.

Freshwater pearls come in cream or white color, and are available in sizes ranging from 2 – 15mm.

• South Sea Pearls

Saltwater sea pearls or South Sea pearls are natural saline pearls obtained from the Pinctada maxima (the largest producer of pearl).

They are available in two distinct colors – gold and white colors – with sizes ranging from 8 – 20mm, and 13mm as a standard size.

• Tahitian Cultured Black Pearls

Tahitian pearls are mostly found in the South Sea and French Polynesia and are obtained from the black-lipped oyster.

They are renowned for their large size (from 8 – 15mm), round shape, and shiny appearance.

• Pink Natural Pearls

Pink natural pearls are very much like their freshwater variants but they are the cultured version.

They are renowned for their shiny appearance, and they offer good value for money.

4.  Which Mass Finishing Equipment Is Best for Handling Expensive Pearls?

To adequately handle expensive pearls, the centrifugal barrel finishing machine is utilized.

A centrifugal barrel finishing machine (CBFM) is a more sophisticated design of tumble barrel machines.

It harnesses (G-force) centrifugal force in the course of its operation to get rid of the unwanted layers of the pearls.

This equipment is affordable to acquire, and it operates at a high speed and high energy.

Centrifugal barrel finishers are the most ideal machine for polishing and burnishing pricey and exotic batches of pearls.

5.  What Is the Level of Precision Required in the Pearl Polishing Process?

The pearl polishing process demands high precision levels because one wrong move can destroy an entire batch of pearls.

Therefore, it is essential to be as accurate as possible when polishing pearls.

6.  How Much Will It Cost to Acquire a Pearl Polishing Machine?

The cost implication of acquiring a pearl polishing machine will be dependent on the features, capacity, and size of the machines.

If you need to know the exact fare of any of our machines at Inovatec, simply contact us by utilizing our free quote feature.

State all the information you require including machine design, option for add-ons, capacity (in liters) etc., and we will gladly respond.

7.  Centrifugal Barrel Finisher Vs Centrifugal Disc Finisher – Which Is More Suitable for Pearl Polishing?

Both the centrifugal barrel and disc finishing machines are suitable for achieving the desired pearl polishing.

Of course, depending on use cases.

Both machines can handle pink natural pearls and Tahitian cultured black pearls.

A centrifugal barrel finisher produces the best result for Akoya cultured pearls, saltwater sea pearls, and South Sea cultured pearls.

Hence, the suitability of both equipment will be based on the type of pearl to be polished.

One could never go wrong with these machines.

8.  How Long Will the Pearl Polishing Process Take?

The speed of operation of pearl polishing machine ensures that they can produce massive results in a little time.

This machine can complete each finishing cycle at a rate that is 30x quicker than conventional finishers and 90x faster than barrel tumblers.

It is possible to complete each pearl polishing cycle in 1-2 hours with the CBFM or CDFM.

Manual processing may take several hours and, in some cases, days to complete.

9.  Does Inovatec Provide After-Sales Support for Pearl Polishing Machines?

Yes, we provide after-sales support on our pearl polishing machines.

We make provision for instruction manuals alongside our products to help you through the installation and operation phase of our machine.

Provided you are in doubt, and you would like to ascertain a few things, you can reach out to us – we’ll be glad to have you.

Contact us if you require any kind of support that will enable you to utilize our pearl polishing machine to the fullest.

We will gladly support you throughout the lifetime service of the equipment.

We also provide troubleshooting videos to help you fix certain issues.

Of course, you may have to provide adequate information as to the nature of the difficulty.

If you require replacement parts, we can make them available to you regardless of your location.

Although we have specifically designed our machines with simple electronic and mechanical parts.

This is to ease the replacement of parts and the possibility of purchasing them from local stores.

10.  Is the Pearl Polishing Process Labor Intensive?

Generally, centrifugal barrel and centrifugal disc finishing machines eliminate manual labor by 95% in the mass finishing process.

The manual or hand-finishing process offers about 80% of job quality.

The surface polishing obtained through manual or hand finishing is not consistent.

Inovatec pearl polishing machines eliminate the need for hand/manual pearl polishing and other labor-intensive polishing processes.

Since all process parameters can be monitored and the polishing process automated, productivity, accuracy, consistency, and uniformity are spurred.

Instead of having to manually polish your pearls, utilizing a CBFM or a CDFM helps to save a lot of cost on labor.

The reduction of hand-polishing/labor-intensive processes to the barest minimum offers a significant boost to the pearl polishing process.

Consequently, the ROI, rate of production, and process consistency are positively influenced.

So, is the pearl polishing process labor intensive? No, it isn’t.

11.  Will the Tumbling Media Cause Any Damage to Pearls?

Media selectivity is an important criterion when polishing work-pieces like pearls and other delicate materials.

There are some factors to consider while choosing a tumbling media for the pearl polishing process.

They include the degree of desired finish, properties of the work-piece, size and shape of media, and media lodgement.

Of course, the right size and shape of media have to be chosen to avoid media lodgement or ultimately, damage to the pearls.

The media that is suitable for each type of pearl will vary depending on the type of pearl to be polished.

If for any reason, a wrong choice of media is selected for pearl polishing, damage may occur to the pearls.