Electropolishing for High-Quality Stainless Steel Surfaces
Electropolishing can specifically improve stainless steel surfaces for demanding bulk material processes. Reduced micro-roughness, stable passivation, and improved cleanability make this process ideal for applications where purity is critical.
When the Surface Matters in Stainless Steel
For stainless steel containers designed for bulk materials, the surface is more than just a matter of appearance. Especially with powders and granules, it can affect how much product remains after emptying and how labor-intensive the subsequent cleaning process is.
One way to specifically treat the surface is through electropolishing. BOLZ INTEC uses this process on stainless steel containers and equipment and also performs the treatment on components and containers from other manufacturers.
During electropolishing, material is electrochemically removed from the stainless steel surface. This process reduces microscopic irregularities in particular. At the same time, it promotes the formation of a passive protective layer. The surface becomes smoother and can exhibit greater corrosion resistance.
This is of particular interest for surfaces that come into contact with the product. Product particles can become lodged in irregularities. With fine powders, this can make cleaning more difficult and lead to residues during the next product change. An electropolished surface can reduce adhesion and thus facilitate cleaning.
Where Clean Surfaces Are Essential
In the pharmaceutical industry, high standards for stainless steel surfaces are the norm. Surface quality also plays a crucial role in biotechnology, specialty chemicals, and other hygiene-sensitive sectors.
The primary concern here is not a shiny appearance. What matters most is how the surface behaves during the process: How easy is it to clean? How resistant is it to the medium being used? And how low can the risk of residues and particles be kept?
BOLZ INTEC therefore offers electropolishing for both its own stainless steel products and for components and containers from other manufacturers. We process individual components, assemblies, complete containers, and small production runs.
In addition, stainless steel surfaces can be etched and passivated. Depending on the requirements, BOLZ INTEC documents the surface quality through roughness measurements. Material certificates and GMP-compliant documentation are also available.
Don’t Just look at Ra
The Ra value is frequently used when evaluating stainless steel surfaces. While it is an important parameter, it does not fully describe a surface’s behavior. In practice, the surface texture is also a key factor. For example, two surfaces with similar roughness values may behave differently when it comes to the adhesion of product residues. That is why BOLZ INTEC considers not only the desired roughness but also the material and the specific application. Important factors include which products come into contact with the surface, under what conditions the container is used, and how it is cleaned.
Various stainless steels are suitable for electropolishing. These include, among others, 1.4301, 1.4404, 1.4435, and 1.4571. Depending on the material and composition, other stainless steels and nickel-based alloys can also be processed.
Electropolishing for Existing Containers as Well
This surface treatment is not limited to the manufacture of new containers. Existing drums, tanks, and plant components can also be reworked. BOLZ INTEC also handles the refurbishment of used tanks. Depending on their condition, repairs may be combined with renewed surface treatment and electropolishing.
This process can thus be used for both new components and existing systems—anywhere a defined, clean, and durable stainless steel surface is required.
