For engineers interested in using a lightweight aluminum in their washdown environments, components must be coated for protection against pitting and cracking. These protective measures can include anodizing, ceramic coating, or other types of coatings with PTFE or other fillers, but they will not provide the longer life resistance of stainless steel. This factor is what makes stainless steel the preferred material in most caustic chemical washdown environments.
Another popular coating is electroless nickel. These coatings are a common choice mainly because of their corrosion and wear resistance, but also their smooth polished appearance. Some of these forms include a PTFE infusion to aid in non-stick properties, and most are FDA compliant as well.
Non-metal materials such as plastics, polymers, and fillers are increasingly being used inside of mechanical drive components, guides, bearings, fasteners, and more. They are often used because of their lower cost, weight, and ease of manufacturing. The downside is that many solid plastics, such as injection molded bearing inserts, present drawbacks in washdown applications. A common issue includes liquid absorption, which can cause components to swell and subsequently increase the potential for binding and catastrophic failure.