Shin-Etsu KE-347-W/B Electronic Grade RTV Silicone Sealant

Shin-Etsu KE-347 Electronic Grade RTV Silicone Sealant Performance

Shin-Etsu describes KE-347 as a low-odor, non-corrosive, self-leveling adhesive that develops strong unprimed adhesion to many metals, plastics, glass, and ceramic surfaces. Its neutral condensation-cure system is designed to reduce corrosion risk around metal and electronic parts compared with acidic silicone technologies. The medium-flow consistency helps the sealant spread into seams, around component bases, and across uneven interfaces while remaining controllable during manual or automated dispensing.

Typical uncured properties include a density of approximately 1.04 g/cm³ and viscosity of about 55 Pa·s. At 23°C and 50% relative humidity, the published tack-free time is approximately four minutes, while the reference full-cure condition is seven days. Actual cure speed depends on temperature, humidity, bead thickness, joint depth, and access to atmospheric moisture. Thick sections and deeply enclosed joints require additional time because moisture must diffuse through the material.

Electrical, Electronic, and Communication Equipment Applications

Shin-Etsu KE-347 Electronic Grade RTV Silicone Sealant is suitable for sealing and reinforcing printed circuit board components, connectors, cable exits, sensors, relays, coils, transformers, terminals, housings, display modules, communication equipment, and precision instruments. It can also be used for form-in-place gasketing and flexible sealing between compatible metal, plastic, glass, and ceramic parts.

The cured elastomer helps absorb vibration, mechanical shock, and differences in thermal expansion between dissimilar substrates. This flexibility can reduce stress concentration around delicate components and maintain sealing performance during temperature cycling. The white KE-347-W version provides visible coverage for inspection, while the black KE-347-B version can provide a dark, unobtrusive finish in housings and exterior-facing assemblies.

7 Benefits of Shin-Etsu KE-347 Electronic Grade RTV Silicone Sealant

• One-component processing: Requires no weighing, mixing, or separate hardener.
• Neutral non-corrosive cure: Designed for electrical, electronic, and metal-containing assemblies.
• Fast surface curing: Provides a typical tack-free time of approximately four minutes.
• Flexible protection: Helps absorb vibration, impact, movement, and thermal expansion.
• Broad adhesion: Bonds many compatible metals, plastics, glass, and ceramic surfaces.
• Electrical insulation: Supports sealing and protection around powered components.
• Wide service range: Suitable for validated use from approximately -40°C to 180°C.

Mechanical, Electrical, and Thermal Properties

After the reference cure, KE-347 provides typical Shore A hardness of 30, tensile strength of approximately 1.97 MPa, elongation of about 300%, and shear strength near 0.80 MPa. These properties create a balance of flexibility and durability for assemblies that experience movement or vibration. The material is not intended to replace a rigid structural adhesive where very high load-bearing strength is the primary requirement.

Published electrical values include volume resistivity of approximately 10 TΩ·m, dielectric strength of 20 kV/mm, dielectric constant of 2.5 at 50 Hz, and dielectric dissipation factor of 1 × 10^-3 at 50 Hz. Typical thermal conductivity is approximately 0.21 W/m·K. These values support electrical insulation and environmental sealing rather than high-performance heat dissipation.

Application and Curing Guidance

Clean all surfaces thoroughly and remove oil, grease, dust, moisture, oxidation, release agents, and old sealant. Apply a continuous bead to one surface and assemble, tool, or position the parts before skin formation. Provide access to atmospheric moisture and avoid disturbing the joint until sufficient handling strength develops. Adhesion, cure depth, electrical performance, and long-term durability should be validated on representative production parts.

Review the official Shin-Etsu KE-347 product page and the official Shin-Etsu SDS and TDS download center for current specifications, regional safety documents, and handling guidance.

Explore our electronic-grade RTV silicone sealants for additional non-corrosive bonding and sealing products. Browse our electronic component protection materials for vibration damping, moisture sealing, electrical insulation, and component reinforcement. Contact our sales team for quotations, KE-347-W white and KE-347-B black availability, package options, technical documents, bulk orders, and export support.