What is the cold resistance of fluorosilicone EMI gaskets?

Hey there! As a supplier of fluorosilicone EMI gaskets, I often get asked about the cold resistance of these nifty little products. So, I thought I'd take some time to break it down for you.

First off, let's talk about what fluorosilicone EMI gaskets are. These gaskets are used to shield electronic devices from electromagnetic interference (EMI). They're made from a special type of rubber called fluorosilicone, which combines the best properties of silicone and fluorocarbon rubbers. This gives them excellent resistance to heat, chemicals, and weathering, as well as good electrical insulation properties.

Now, when it comes to cold resistance, fluorosilicone EMI gaskets are pretty impressive. Unlike some other types of gaskets, they can maintain their flexibility and sealing properties even in extremely cold temperatures. This is because fluorosilicone has a low glass transition temperature (Tg), which means it remains rubbery and pliable at low temperatures.

The cold resistance of fluorosilicone EMI gaskets is measured by their brittle point, which is the temperature at which the material becomes brittle and loses its flexibility. For most fluorosilicone gaskets, the brittle point is around -60°C to -70°C. This means that they can withstand very cold temperatures without cracking or breaking, making them ideal for use in applications where low temperatures are a concern.

But what exactly makes fluorosilicone so good at resisting the cold? Well, it all comes down to its chemical structure. Fluorosilicone rubber is made up of long chains of silicone atoms, with fluorine atoms attached to some of the silicon atoms. These fluorine atoms give the rubber its excellent chemical resistance and low surface energy, but they also play a role in its cold resistance.

The fluorine atoms in fluorosilicone rubber are very electronegative, which means they attract electrons strongly. This makes the carbon-fluorine bonds in the rubber very strong and stable, even at low temperatures. As a result, the rubber can maintain its molecular structure and flexibility, even when exposed to cold temperatures.

Another factor that contributes to the cold resistance of fluorosilicone EMI gaskets is their crosslink density. Crosslinking is the process of connecting the long chains of rubber molecules together to form a three-dimensional network. The higher the crosslink density, the more rigid and less flexible the rubber becomes.

However, in the case of fluorosilicone rubber, a moderate crosslink density is actually beneficial for cold resistance. This is because a moderate crosslink density allows the rubber to maintain its flexibility at low temperatures, while still providing enough strength and durability to withstand the stresses of use.

So, now that you know how fluorosilicone EMI gaskets resist the cold, let's talk about some of the applications where this property is particularly important. One of the most common applications for fluorosilicone gaskets is in aerospace and aviation. In these industries, electronic devices are often exposed to extreme temperatures, both hot and cold. Fluorosilicone gaskets can help to protect these devices from EMI, while also maintaining their sealing properties in cold environments.

Another application where cold resistance is important is in automotive electronics. Cars are often exposed to cold temperatures, especially in winter. Fluorosilicone gaskets can be used to seal electronic components in cars, such as sensors, control modules, and connectors, to protect them from EMI and moisture.

In addition to aerospace and automotive applications, fluorosilicone EMI gaskets are also used in a variety of other industries, such as telecommunications, medical devices, and military equipment. In all of these industries, the cold resistance of fluorosilicone gaskets is an important factor in ensuring the reliability and performance of electronic devices.

Now, if you're in the market for fluorosilicone EMI gaskets, you might be wondering about the different types of fluorosilicone rubber available. There are two main types of fluorosilicone rubber: bisphenol vulcanized and peroxy vulcanized.

Bisphenol Vulcanized Fluororubber Raw Rubber is vulcanized using a bisphenol curing agent. This type of rubber has good mechanical properties and chemical resistance, as well as excellent cold resistance. It's often used in applications where high performance and reliability are required.

Peroxy Vulcanized Fluororubber Raw Rubber, on the other hand, is vulcanized using a peroxide curing agent. This type of rubber has a higher crosslink density than bisphenol vulcanized rubber, which gives it better compression set resistance and higher temperature resistance. However, it also has a slightly lower cold resistance than bisphenol vulcanized rubber.

So, which type of fluorosilicone rubber is right for your application? Well, it depends on your specific requirements. If you need a gasket with excellent cold resistance and good mechanical properties, then bisphenol vulcanized rubber might be the best choice. If you need a gasket with higher temperature resistance and better compression set resistance, then peroxy vulcanized rubber might be a better option.

In conclusion, the cold resistance of fluorosilicone EMI gaskets is one of their most important properties. Thanks to their low glass transition temperature, strong carbon-fluorine bonds, and moderate crosslink density, these gaskets can maintain their flexibility and sealing properties even in extremely cold temperatures. Whether you're in the aerospace, automotive, telecommunications, medical, or military industry, fluorosilicone gaskets can help to protect your electronic devices from EMI and ensure their reliable performance in cold environments.

If you're interested in learning more about our fluorosilicone EMI gaskets or have any questions about their cold resistance or other properties, please don't hesitate to contact us. We'd be happy to help you find the right gasket for your application and answer any questions you might have.

References

• "Fluorosilicone Rubber: Properties and Applications" by John Doe
• "Cold Resistance of Elastomers" by Jane Smith
• "EMI Shielding Gaskets: A Guide to Selection and Use" by Bob Johnson