How Tough-Seal Potting Compound Works
Tough-Seal has the heat resistance and service temperature of an epoxy potting compound, the flexibility common to urethanes, and the durable encapsulating protection of a silicone, all in just one potting compound. Tough-Seal is a hybrid epoxy elastomer and possesses the resilience of an elastomeric matrix.
Tough-Seal is not a urethane so it is isocyanate-free and is not moisture sensitive. It is superior to ordinary urethane and epoxy potting compounds. Thermal potting compounds & encapsulants are specified to flow over an electrical device and fill up a housing with a hardened thermoset plastic to serve as an environmental barrier.
Epoxy Potting Compounds vs. Urethanes
Epoxies are typically rigid materials with high service temperatures and urethanes are more flexible with lower heat resistance. Ideally, one would specify a flexible thermal potting compound to maintain a seal with the housing wall but urethanes are not ideal because they degrade at elevated service temperatures.
Chemistry aside, Tough-Seal is bulldog tough and grips the wall in cold when others contract to expose a gap, yet it won’t wilt under the heat. Tough-Seal picks up where urethanes leave off to guard electrical components up to 300°F.
Tough-Seal Goes from Zero to Hero
Zero embedment stress
Electrical components are subjected to stress when they are embedded in a potting compound. It is the principle cause of component failure even when an impermeable seal to the environment is attained.
Zero shrink – Zero stress
Tough-Seal avoids initial embedment stress upon cure because it has imperceptibly low shrinkage. Thermoset plastics, such as epoxies and urethanes, have a slightly larger volume in their freshly mixed liquid state than they possess in their hardened cured state.
The novel, hybridized nature of Tough-Seal has little to no shrinkage upon cure per ASTM D2256 and it cures with minimal to no exotherm even in large pours.
Thermal cycling – Zero stress
Why does Tough-Seal have superior thermal cycling characteristics? Unlike electronics suffer from the detrimental thermal cycling effects as these materials harden, embrittle and shrink more in the cold and become softer, permeable and expand as they are heated. In the graph below, the hardness of Tough-Seal is nearly constant across a wide temperature range. In this Tough-Seal “Zone of Constant Hardness” , destructive expansion and contraction forces are minimized and they do not act on embedded circuitry. Thermal cycling resistance improves.
Tough-Seal Can Save the Day
Tough-Seal forms a tough seal, but it is gentle on electrical components because it does not change as conditions do. It thermal cycles like no other and it guards electrical components.