Elkem LSR-4305 Silicone Elastomer (A-221-05)

A-221-05 (LSR 4305) Liquid Silicone Rubber – Shore A 05

A-221-05 is part of the Elkem LSR 4300 Series, a platinum-cure liquid silicone rubber designed for liquid injection molding (LIM) and precision applications requiring very soft, flexible, and durable elastomers. With a Shore A 05 durometer, it offers a balance of extreme softness with improved strength compared to lower durometer options.

This two-part, 100% solids system is supplied as a pumpable, colorless, translucent paste. When Parts A and B are mixed in a 1:1 ratio, the material cures via addition-cure (platinum) chemistry to form a tough, optically clear elastomer with excellent physical properties.

Product Features

• Shore A 05 very soft silicone elastomer

• Elkem LSR 4300 Series (LSR 4305)

• 1:1 mix ratio (Part A : Part B)

• Platinum (addition-cure), solvent-free system

• High clarity / translucent appearance

• Long working time

• Designed for liquid injection molding (LIM)

• Produces flexible, durable finished parts

Processing Notes

• Non-pourable – designed for pump/injection systems

• Supplied as a paste-like material

• Requires heat curing for full vulcanization

Cartridge Options

• Available in 50 mL, 200 mL, and 400 mL cartridge systems

• Can be pigmented for custom color matching

Applications

• Injection molded silicone components

• Applications requiring very soft, flexible materials

• High-clarity, precision molded parts

A versatile LSR material offering exceptional softness, clarity, and performance for advanced molding applications.