How to Prevent Common Epoxy Potting Issues
If you work in an industry that relies on epoxy potting to protect elements of your product, you’ll understand how important it is that these materials cure properly. By using adhesive dispensing systems, you’ll automatically improve the quality of your epoxy mix (and therefore, the quality of your products). But if you don’t currently use an epoxy dispenser — or you fail to use one as directed — you may run into certain issues. We’re discussing a few of those issues, as well as the ways to prevent them, in today’s post.
When epoxy potting doesn’t perform the way you expect, you may want to consider the possibility of contamination first. Any impurity — be it oil, grease, dirt, silicone, or air — that interacts with the epoxy mix can lead to poor cure. Preventative maintenance of your epoxy dispensing systems, including your dispensing valves and other important components, is key in avoiding off ratio/load mix. The same goes for surface preparation and cleaning. You must also take care to avoid cross contamination from certain release agents or silicones, in addition to being precise with mix ratios. Finally, you may need to remove air prior to meter/mix/dispense as air gaps can prevent on ratio mixing from taking place. Humidity can create early cure failure of components. Vacuum degassing can ensure that no air is left within the epoxy, ensuring lasting protection of your product.
For instance, the EXACT 1450 SA epoxy dispenser and metering system has the option for both vacuum degas of the resin and dispense into your part under vacuum. The vacuum chamber is large enough to accommodate dozens of work pieces at once. After the vacuum degassing is complete, the potting process can be completed without risk of air bubbles.
It’s vital to achieve the correct temperature for a given epoxy. An improper temperature can lead to cure that is to fast and sub-par performance. Using too high a temperature on a given adhesive can cause incorrect polymerization, change the epoxy’s viscosity, and degrade the quality of the final product. One of the benefits of using adhesive dispensing systems, of course, is the precision they provide. There are many situations where EXACT may recommend heating the part to be potted versus any heat applied to the epoxy.
When you use automated epoxy dispensing systems, you’ll be able to achieve better consistency. However, you may still need to maintain good house keeping. Even if you properly clean the equipment prior to use, blockages can still occur during the curing process if epoxies cure in the equipment itself. Should this occur, the material will not be able to be applied consistently, leading to off ratio product mix and other issues. Be sure to check the nozzles, valves, and other components regularly for blockages to ensure your adhesive will cure as it should. For these reasons, it’s essential to work only with rugged epoxy dispensers that were built for high performance.
While automatic dispensing systems should significantly decrease many of the most common epoxy issues, problems can still occur if this equipment is used improperly. Likewise, by using fixed ratios systems, you won’t have to worry about incorrect settings. An operator who adjusts equipment settings, for instance, may inadvertently cause off ratio curing problems. Make sure that the mix ratio settings, air pressure gauge, and other settings remain consistent. You’ll also want to check that all attachments are functional and that necessary components are plugged in, switched on, and working properly.
Manual epoxy applications can result in issues that compromise the quality of your product. Many of these issues can be prevented by switching to a meter/mix/dispense that’s customized for your needs. To find out more about our systems, please contact EXACT Dispensing today.
For more information checkout this webinar on Potting and Encapsulation – Application Problems – Practical Solutions.