ELECTROPOLISHING: THE SMOOTHEST OF SMOOTH

Teralba Industries has recently used Electropolishing to produce some superfine, ultra shiny internally polished vessels for a biopharmaceutical manufacturer in Melbourne, Victoria Australia.  These vessels were polished until they became so smooth and so shiny you could see your face in it.

What is Electropolishing?
Electropolishing (also known as electrochemical polishing or electrolytic polishing) is a technique used to polish or refine the surface of a number of different metals, including stainless steel, resulting in the surface becoming extremely smooth and highly reflective.  It works the opposite way of electroplating – which is to add more metal on to a surface to smooth it over. Instead of adding metal, Electropolishing selectively removes common and less desirable metals, such as iron from the surface, leaving behind chromium and nickel to create an incredibly refined and beautiful finish to a microscopic level. What is so good about Electropolishing?

The process of Electropolishing is different to other techniques, and so creates different results. It creates a surface with all the peaks and valleys removed to reveal a superfine, blemish free surface because it removes the other kinds of metals. Whereas with regular mechanical polishing, it is just moved around and can leave imperfections and patterns on the surface.  

This means that Electropolishing produces more refined, smooth surfaces than the regular mechanical methods. The results are so smooth that the surface roughness can only be measured in microns – a micron is 1/1000th of a millimetre. Teralba Industries used a special instrument to measure the surface roughness of the vessels we produced and discovered that the readings were less than 1 micron! A measurement so small, you can’t see it with the naked eye. Now that is the smoothest of smooth. 

This picture shows a before (left) and after (right) of Electropolishing a piece of 304 Stainless Steel on a microscopic level

Items that have been electropolished are also much more visually appealing. The dull look of normal metal has been stripped away leaving only a beautifully polished, mirror like finish.Why is Electropolishing so important?

Electropolished items are extremely important in many fields, where it is vital that there is no microbiological contamination of substances, or bacterial growth on equipment. Electropolishing is able to achieve this because it is able to create such a smooth surface. The smoother the surface, the harder it is for anything to stick or cling to, meaning – the smoother the better!

There are many applications for the use of Electropolished metals including, hand rails, food and beverage equipment, surgical instruments, and pharmaceutical equipment like the vessels Teralba Industries has manufactured. 

The Stainless Steel vessels that Teralba Industries has produced for the biopharmaceutical manufacturer are called WFI (Water For Injection) tanks. It is vital that these tanks and other equipment of this nature experience no contamination as the water and other critical liquids they contain are absolutely pure for the purpose of being injected into people’s bodies.  

It is important to note that not all Electropolishing is created equal – Electropolishing has a number of variables and good operators combine the parameters with their experience and knowledge of the art to achieve a superb electropolished finish.

These three side by side pictures show two sides of the one piece of Stainless Steel – one that has been Electropolished and one left in its original state.

Our customer engaged us because Teralba Industries was able to offer the whole package – including the design, manufacture, electropolishing, insulating, clading, and delivery to site of their WFI Holding Tanks.Have questions about Electropolishing? Want to know how clean you could get your tanks? Contact one of our friendly staff members now! Watch this space for more on Electropolishing!

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