CoolTherm® UR-388 FST encapsulant is a two-component urethane system designed for encapsulating and casting applications. CoolTherm UR-388 FST
encapsulant cures at room temperature to produce a flame retardant, semi-flexible material.

Features and Benefits:
• Low Stress – exhibits low shrinkage and stress on components as it cures.
• Low Viscosity – maintains low viscosity for complete and void-free encapsulation.
• Room Temperature Cure – suitable for curing at room temperature; may be mildly heat cured (60°C) to expedite cure.
• Low Exotherm – exhibits low exothermic heat rise during room temperature cure.
• 7Environmentally Resistant – provides excellent thermal shock resistance.
• UL Rated – provides excellent flame retardancy; UL 94 V-0 certified.

Shelf Life/Storage:
Shelf life of each component is six months when stored at 25°C in original, unopened container. CoolTherm UR-388 FST resin container must be periodically inverted to prevent settling.

After opening, protect each component from excessive moisture by using dry nitrogen as an inert cover.

If stored or shipped at cooler temperatures, CoolTherm UR-388 hardener may crystallize. If crystals appear, gently warm hardener at 30-50°C to melt crystals before mixing with resin. Limit heating period to less than three hours as excessive heating will cause dimerization.