Why is the Ra value important for products in cleanroom environments?

For operations with high demands on sanitary environments, such as those in the pharmaceutical and food industries, it is imperative to be able to minimize the risk of bacterial growth, cross-contamination and the spread of hazardous substances. Products and machines used in daily work therefore need to be designed to be easily cleaned and cared for. This is done, among other things, by ensuring that the surface of the products, i.e. what we actually see with the naked eye and can touch, needs to be smooth, easy to clean and able to withstand various acids and substances.

In order to meet the requirements and regulations set by the responsible authorities, the companies concerned often choose to use stainless steel products. This is because the material itself has high corrosion resistance and good durability, but also because they are easy to clean, a characteristic of products with a low Ra value.

So, what is Ra value?

Ra value refers to the surface fineness of a material or product, which is a measure of the smoothness or roughness of a surface. Like sandpaper, it can be divided into very coarse, coarse, medium and fine, and the Ra value is determined by how much the product’s surface deviates from a perfectly smooth surface. A low Ra value is indicative of a smooth surface, while a high Ra value equals a rougher surface.

 

 

It is easy to think that the lower the Ra value the better, but this is a false claim. In fact, the best conditions for sterilizing and cleaning products occur when the surface has an Ra value between 0.25 and 0.60 µm. In other words, this is the sweet spot of the Ra value.

Fumex PSS has an Ra value of ≤ 0.6

Fumex PSS is one of our stainless steel spot extractors and it has an Ra value of ≤ 0.6. With such a smooth surface, it is easy to clean, which contributes to a safe and sterile working environment free of dirt, bacteria and toxic substances. The Fumex PSS is also the very first extraction unit on the market to have a hermetically sealed profile, further contributing to easy maintenance and efficient cleaning.

The spot extractor is also equipped with our Fumex Q-MaiD™ quick disconnect system, which makes it easy to disconnect the product and clean the areas around the hose and hood.

If you want to switch to an extractor that meets the highest sanitary requirements, download the product brochure or contact us to learn more.