TECHSiL's High Performance Potting Silicones; Our top 6 Momentive potting materials

Silicones have a range of properties making them suitable for any environment. Below we share some of our top high-performance silicones, including FDA approved and flame retardant silicones.

Why are some silicones FDA approved and what are they used for? 

FDA (US Food and Drug Administration) approval means the silicone has been determined safe and effective, this is especially important for medical devices, food grade uses, and any product that meets the human body. Approved silicones are usually tested for chemical resistance, temperature tolerance, and longevity, providing confidence in the product.

FDA approved silicones are considered safe, stable, and versatile so are used across industries:

• FDA silicones are often used in the healthcare industry for implants, catheters, wound care and dental tools & moulds
• Silicones are non-toxic, odourless, and can handle heat, making them ideal for bakeware and kitchen tools 
• In heavy-duty settings, FDA-approved silicones are used for pharmaceutical manufacturing (tubing and seals in sterile environments), brewery and dairy equipment and water filtration systems

FDA Approved Silicones to Consider:

RTV615 Clear FDA Potting Silicone

A crystal clear, low viscosity, 2-part silicone potting compound which cures at room temperature. Provides excellent electrical insulation and shock resistance with exceptional clarity, allowing the encapsulated parts to be inspected. RTV615 can be used in food contact applications due to FDA approval.

RTV11 White FDA Silicone Rubber

 A white, 2-part silicone rubber compound, cured with a DBT catalyst agent at room temperature. The typical uses for this compound are potting and encapsulating electrical coils and connectors, making cast-in-place gaskets and moulds, and release applications. RTV11 silicone rubber compounds can also be used in food contact applications, other than with acidic food, where FDA regulations apply.

Why are Flame-Retardant Silicones Important?

Flame retardant silicones are crucial in safety critical applications where fire, heat or sparks are a risk factor. This is especially important across multiple industries to meet fire standards or prevent serious damage. Silicone is naturally insulating, and flame-retardant grades provide extra protection, key uses and benefits of flame-retardant silicones include:

• Ideal for cable insulation; jacketing, encapsulation and potting in key industry assemblies such as data centres, aircraft, and trains.
• Flame retardant silicones meet strict FAA fire safety standards so they can be used for seals and gaskets in engines and fuel systems, wire insulation and interior panels and coatings, very popular in aviation cockpit and passenger areas.
• Modern vehicles generate a lot of heat, especially electric vehicles, so flame retardant silicones are used for under-hood seals and gaskets that resist oil, heat, and flames, battery insulation, and wiring protection. 
• Public transit systems need materials that meet fire, smoke, and toxicity standards. 
• In construction they are used to slow fire spread and protect systems which includes firestop materials (seal openings around pipes or cables), HVAC seals and gaskets (where fire-rated barriers are needed) and elevator components.

Flame-Retardant Silicones to Consider

Siltrust TSE3331K-EX Silicone Rubber

A two-part material, which cures with heat to a silicone rubber with excellent adhesive properties. Other key properties include low viscosity, excellent thermal conductivity and adhesive properties. This silicone is ideal for potting electronics which require flammability and use under extreme temperatures as well as high voltage parts and motor coils. The TSE3331K EX provides excellent flammability properties being UL94 V-0 recognized.

SilCool TIA208R-HF Thermally Conductive Silicone Rubber

A 2-component, thermally conductive potting material with a low viscosity allowing it to conform to complex shapes and cavities. When cured at room temperature or with heat, it cures to a thermally conductive rubber that adheres well to most metal and plastic substrates. TIA208R-HF has good thermal conductivity and a resistance to extreme temperatures, being able to operate at a temperature range of -40 to 150c. UL 94 flame retardancy V-0 (equivalent).

Need a one component silicone? Try a heat curable option

The above high-performance silicones are all 2-part compounds which cure at room temperature but lots of industries require a 1-part solution. Heat curable silicones are a great alternative to consider; their benefits include:   

• They are preformulated and ready to use straight away which reduces user error and the need for equipment or complex production as there is no mixing involved 
• Single component silicones generally have a longer shelf life
• Heat curing is fast which is great for fast paced manufacturing
• Ideal for potting and encapsulating as heat-curable means the silicone will cure completely throughout, reducing the chance of uneven finishes
• Strong adhesion to multiple materials including glass, metal and ceramic

Single component, heat curable potting silicones to consider: 

General Purpose - TSE325 White Potting Silicone

A white, single component, heat curable silicone adhesive which has a low viscosity. This silicone was designed for potting and encapsulation but can also be used as a general adhesive for many substrates.

High Temperature Potting - TSE326M-EX Red High Temp Silicone

A one component, reddish brown, heat curable silicone adhesive, which is designed for high temperature applications.  This adhesive works for a range of materials, adhering to metals, plastics, ceramics and glass without a primer.

For more information or to speak to one of our technical team contact us on technical@techsil.co.uk.