electronic Silicone encapsulants components

There are a variety of materials on offer including polyurethanes, epoxies, silicones and many other polymers. It is important to fully understand the chemical and physical properties of each system.

Why do we use silicone encapsulants?

Silicone polymers and elastomers have excellent properties including:

1. Wide operating temperature range.

2. Excellent electrical properties.

3. Good Flexibility.

4. Good chemical resistance.

5. Resistant to humidity and water.

6. No or low toxicity.

Through the selection of polymers and fillers it is possible to adjust viscosity and the final hardness and modulus of the cured rubber. Silicone encapsulants are very versatile and provide engineers with a wide product choice.

Systems that cure or change from a liquid to a solid cured rubber at room temperature are also referred to as RTV. Silicone encapsulants generally fall into two categories: condensation cure systems and addition cure systems. Understanding the differences between the two different silicone systems is very important.

Condensation Cure system Silicone:

Condensation cure systems function with moisture present in the atmosphere and it can not be accelerated through heated (applying excessive heat whilst curing will be bad for the curing process). There are some small amounts of by-product produced. This is generally used for 1-Part sealants, coatings and 1 & 2 Part encapsulants.

Addition Cure system silicone:

Addition cure systems adopt platinum catalyst to initiate the cure process and do not produce any by-products. Once catalysed, they will fully complete the cure process, even in a sealed enclosure and do not need to be kept open to the atmosphere. Heat can be used to accelerate the cure if required.