Stycast S 5225

Stycast S 5225 is a two-component, silicone encapsulant developed for small electronic devices with tightly packed components. Its very low mixed viscosity of approximately 2,420 mPa·s allows it to flow easily throughout complex assemblies, ensuring complete coverage and void-free encapsulation for sensors, relays, transformers, and power supplies. A standout feature is its 1:1 mix ratio by both weight and volume, which simplifies processing and reduces the risk of mixing errors. Additionally, it offers primer less adhesion when heat cured, eliminating the need for surface primers and streamlining the production workflow.

The material is engineered for reliable performance in extreme environments, featuring a wide operating temperature range of -60°C to +220°C. It is particularly well-suited for fragile components like ferrite cores because it can be used in large castings without adverse exotherm or shrinkage limitations. In terms of safety and compliance, Stycast S 5225 meets UL 94 V-0 flammability requirements at a thickness of 6.35 mm. It remains manageable on the line with a working life of approximately 4 hours at room temperature, providing ample time for degassing and precision dispensing.

Once cured, the encapsulant provides a robust balance of physical and electrical properties, reaching a Shore A hardness of 53. Its electrical stability is further evidenced by a dielectric constant of 3.0 and a dissipation factor of 0.01 at 1 MHz. To accommodate different manufacturing speeds, the system supports multiple cure schedules: 16 hours at 25°C, 1 hour at 100°C, or 30 minutes at 150°C, with an optional post-cure at 100°C to optimise final performance.