QSIL573 (44KG Kit)

Reference: QSIL573 44 KG

QSIL™ 573 – (Grey) Thermally Conductive, Repairable Addition-Cure Silicone for Electronics Potting

QSIL 573 is a two-component, 100% solids, addition-cure silicone elastomer engineered for high-performance potting and encapsulation of sensitive electronic assemblies. With a 1:1 mix ratio by weight, it delivers excellent thermal conductivity (~0.9–1.19 W/m·K), robust mechanical protection, and reliable environmental sealing while remaining fully repairable for rework or component replacement.

Curing rapidly at elevated temperatures (e.g., 15 minutes at 150°C) or fully at room temperature in 24 hours, QSIL 573 forms a hard, durable elastomer (Shore A 55) with low modulus to minimise stress on delicate components. Its grey cured appearance and non-corrosive, platinum-cure chemistry make it ideal for power electronics, LED systems, automotive control units, and other applications requiring thermal management and long-term reliability.

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Key Features

High thermal conductivity: 0.9–1.19 W/m·K
1:1 mix ratio by weight – simplifies dispensing and ensures consistent performance
Addition-cure system – no by-products, non-corrosive, and fully repairable
UL 94 V-0 rated at 3.0 mm thickness (meets flammability requirements)
Wide service temperature range: –55°C to 204°C (–67°F to 400°F)
Excellent protection against moisture, dust, vibration, and mechanical shock
Low mixed viscosity (5,500 cP) – enables easy mixing, degassing, and flow into complex geometries

Typical Applications

Potting of power modules, LED drivers, and high-brightness LED arrays
Encapsulation of automotive sensors, battery management systems, and inverters
Protection of industrial control boards in harsh environments
Applications requiring thermal dissipation and future rework capability

Technical Notes

Pot life: 60–155 minutes at 25°C (depending on batch and handling)
Tensile strength: 1.1 MPa (160 psi)
Elongation: 40% – provides rigidity with minimal flexibility
Dielectric strength: Not explicitly listed, but suitable for standard electronic insulation
Self-bonding: No adhesion to substrates may require surface preparation or priming
Inhibition sensitivity: Avoid contact with sulphur, nitrogen, tin, or PVC-based materials that can inhibit cure
Cure options:
Fast cure: 15 min at 150°C
Room-temperature cure: 24 hours at 25°C / 50% RH

Processing Recommendations

Mix Components A (white) and B (grey) 1:1 by weight in a clean container (3× material volume)
Degassing under 29 in. Hg vacuum is recommended for hand-mixed batches
For automated dispensing, use static mixers and ensure equipment is free of contaminants (especially from condensation-cure silicones or sulphur-containing rubbers)
Store components below 25–38°C (77–100°F) in sealed containers to maintain shelf life

Storage & Shelf Life

Shelf life: 24 months in original, unopened containers
Storage temperature: ≤ 38°C (100°F), protected from frost and moisture

Packaging Options

Available in matched A/B kits in various sizes for manual or automated meter-mix-dispense systems. Ideal for both prototyping and high-volume production.