For many of the custom steel wire baskets that Marlin makes, there is not much need to coat the steel in a layer of plastic polymer. In fact, it is often better to use a specialized, corrosion-resistant type of stainless steel than it is to apply a layer of plastic coating to a less-resistant basket.
This is for a number of reasons, such as the coating not being as survivable at high temperatures as the steel, the potential for gaps in the coating (particularly at hinges and joints) that compromise the basket’s corrosion resistance, and how such coatings might impact the performance of the basket.
However, there are times where a polymer coating should be used for a steel wire basket:
1: When Parts are Ultra-Delicate
Some manufacturers have a strict surface condition requirement for their parts. If a single scratch is present after the parts finishing process is done, the whole part has to be scrapped or resurfaced.
In such cases, it may be advantageous to use a polymer-based coating for the parts handling basket that holds the part through your finishing process. Many plastic coatings are soft and shock-absorbing, which means that the parts they hold aren’t as likely to get scratched or scuffed if they bounce or move in the basket—which happens a lot on the factory floor.
Of course, this varies from one coating to the next. Here a thicker, softer coating such as dipped polyvinylchloride (PVC) or ethylene chlorotrifluoroethylene (ECTFE) is usually better than a thinner, harder coating such as polytetrafluoroethylene (PTFE).
2: When the Chemicals Used Would Corrode Most Metals Too Quickly
While the chemical corrosion resistance of different steels can vary greatly from one alloy to the next, there are some chemical solutions that will quickly corrode even the most resistant metals. However, in many of these same applications, plastic baskets alone cannot be used because they lack the tensile strength to hold parts securely.
Here, using a steel basket coated in a highly-resistant, and replaceable, polymer coating can be immensely useful. Rather than having to replace the whole basket every few months, you would be able to simply strip and refresh the coating whenever it begins to wear thin—sparing the cost of a complete basket replacement.
3: To Acquire Enhanced Antimicrobial Properties
Stainless steel is often used in food and pharmaceutical production—environments where sanitation is of paramount concern. However, sometimes, even stainless steel isn’t hostile enough to microbes, despite the ease with which it can usually be sanitized.
For some food and pharmaceutical production environments, manufacturers opt to apply a specialized antimicrobial coating to their baskets and trays. These coatings can work in a number of different ways, such as using a microscopically rough surface to damage the microbes, or using an active ingredient such as silver that harms the DNA of the nucleus so it cannot reproduce.
So, if stainless steel isn’t proving to be hostile enough to bacteria, using a specially formulated polymer coating might be the answer.
These are a few of the cases where it might be better to use a plastic coating for your parts washing or handling baskets than it would be to use steel alone. However, there may be instances where polymer coatings won’t work at all—such as if the temperatures used in your process exceed the maximum temperatures that the polymer can take.
This is why Marlin Steel’s engineers always test their basket designs using virtual physics simulation software before settling on a basket material or coating. Such testing can reveal these issues before full production begins, saving time and money on physical prototypes.
Need a custom wire basket for your production line? Get a quote from Marlin Steel ASAP!