When it comes to the topic of utilizing elastomeric seals, it’s stereotypical to consider environmental sealing as one of the simpler categories of applications. Near-ambient pressure and temperature conditions and a lack of exotic or aggressive chemistries are the kinds of details that typically come to mind. However, throw in a curveball or two and suddenly the challenges posed can make finding a solution seem reasonably more intricate.
Unique conditions call for custom design expertise
For instance, consider the potential challenges of sealing off a battery enclosure or other kind of electrical component. While this may seem like a simple issue of finding a material that seals against moisture or fluids found in open-air conditions, manufacturability also needs to be taken into consideration. Many electrical enclosures have particular spatial requirements, including those which involve seal housings that require low closure force or those with sharp corners that could damage more conventional seal designs like solid-profile O-rings. These kinds of conditions are becoming more and more frequent, especially considering the automotive market and its increasing share of electric vehicles, which involve a larger proportion of electrical components in a more compact arrangement for reduced weight. Add to this the fact that these batteries and other electrical components are becoming more elaborate and more expensive as a result, and the need for highly-effective protective sealing design becomes imperative. This is where Parker engineers can design products like picture frames gaskets and hollow profiles that are customized to unique requirements.
Industry standards can get complicated
There are also industry standards for electrical enclosures that help ensure a seal material meets relevant requirements that might not be taken into consideration or well-understood by those outside the elastomer industry. For instance, the UL 50E standard evaluates the physical properties and volume swell requirements deemed necessary for a seal material to withstand the conditions in these applications. Parker has materials from the EPDM, nitrile, and silicone compound families that are certified under this standard.
Another set of industry standards that reveal the specialization of environmental sealing requirements are Ingress Protection (IP) Ratings, which rate sealing performance against both solid contaminates and various forms of water (the most strenuous ratings for sealing against solid contaminates - those most relevant for elastomeric seals - indicate prevention of dust contamination). These ratings apply to the effectiveness of an entire assembly and not the material of a component specifically – this means each assembly must be assigned a rating on a case-by-case basis.
One example of an IP rating is IP65, which uses a special set of test requirements to evaluate designs for resistance to blasts from standard-pressure water jets. Another example is IP67, which rates sealing performance under water submersion conditions. Parker engineers can provide the design support necessary to ensure a system earns either of these two ratings in particular, as well as those that verify an assembly’s ability to prevent dust contamination from inhibiting performance.
This article was contributed by Nathaniel Reis, applications engineer, Parker O-Ring & Engineered Seals Division.