4 factors to consider for perfect potting

Potting compounds are vital components that protect sensitive electronic circuits from shocks and vibrations. For reliable protection, it is important that the potting compounds are perfectly mixed. A slight mistake in potting could lead to issues such as the emergence of air bubbles. Such issues sometimes become apparent only after curation and reduce the quality of protection available to the electronic parts. This could also have severe consequences for businesses on the cost front, and affect the brand’s reputation.

Potting is more than just pouring a liquid into an enclosure and waiting for it to cure. A number of essential factors need to be considered when undertaking mixing and pouring of epoxy potting compounds.

Consider these 5 factors to achieve the best potting results

Resin and hardener ratio

The ratio of hardener and resin determines properties such as flexibility and hardness of the epoxy compound. The mixing ratio can be fixed, or it can be varied as per the needs of the application.

A cylinder-piston mechanism can be used in instances where the ratio is fixed. This mechanism involves containers/cylinders that are sized for resin and hardener, and the correct proportion of resin and hardener is introduced into the containers by the pistons.

Alternatively, using a gear pump allows for more variation in the ratio. The gear pump comprises electronically controlled motors turning a set of screws to dispense the resin and hardener in specified proportions.

It is advised to consult with the epoxy compound manufacturer to determine whether your application requires a fixed or varying ratio. Running a number of trials could help arrive at the right ratio.

The temperature of the resin

To ensure the proper flow of the resin during the mixing and potting process, it is heated to a specific temperature. Various resins have their own temperature ranges, and it is important to consult the compound manufacturer to understand and achieve the right temperature for the resin.

Mixing

Proper mixing of the resin and hardener is the crux of the entire potting process. Detachable mixing nozzles are used to ensure proper mixing of resin and the hardener. These nozzles typically have a short lifespan and need to be frequently replaced. The mixing nozzles homogenize the compound stream. The longer the nozzle, the better the compound is mixed.

Do note that the mixing should also happen at the right pressure. Consult with the compound manufacturer to learn of the right pressure required for mixing the compound.

Dispensation

The final properties of the curated compound are influenced not only by the ratio and mixing of ingredients but also by the way the compound is dispensed into the enclosure. Dispensation can be conducted in a single shot or in multiple shots, and it is dependent on the size of the electronic circuit being potted. A cylinder-piston mechanism allows less control over the volume of dispensing. Hence, multiple shots need to be taken with this method. In contrast, the gear-pump mechanism allows the user to take one continuous shot.

Additionally, the speed of the dispensation should be adequate so that the epoxy compound is dispensed completely before it begins to cure. The compound should be dispensed at the rate at which it is able to cope with the electronic circuit being potted.

In recent years, smart machines have brought a certain degree of automation to the mixing and dispensing process. Automating the mixing and dispensing process also helps avoid human errors and saves time in the case of fast-curating compounds.

Conclusion

Even though the action of pouring the ingredients for a quality epoxy resin looks simple, it involves a number of subtle considerations. Alongside the considerations mentioned above, the quality and reliability of the ingredients and epoxy compounds is vital for reliable protection. Here, working closely with a long-term partner in epoxy compounds could ensure the right quality of protection for your circuits throughout.

Veeyor Polymers has over 30+ years of experience in manufacturing epoxy resins. Over the years we have developed a deep focus on R&D to offer customized resin solutions to our customers