The major advantages of mica sheet and roll material properties for industrial insulation

The major advantages of mica sheet and roll material properties for industrial insulation

Mica is a group of minerals that form in multiple tightly packed layers. This two-dimensional sheet structure is the reason for mica being known as silicate sheets. They are found in all three major rock varieties and have certain chemical properties which lends mica to being incredibly useful for industrial insulation. 

Due to the layering of the minerals, mica is suited to being produced as mica papers which can be converted into sheets and flexible roll materials. Two of the key properties of mica rolls and mica sheets is the resistance to high temperatures and its inability to conduct electricity. Mica sheets and rolls use these properties, as well as its chemical resistance and durability, in order to work as a highly efficient insulating and reinforcing agent

Mica can also be rigid or flexible, with flexible being used mainly for furnace insulation and automotive gasket application due to its fantastic electrical resistance under high temperatures. Rigid  mica  sheets  are used for sheathing passive fire protection and dielectric barriers within multiple applications.

There are two types of mica mineral used by Elmelin, Muscovite and Phlogopite. Muscovite mica has a higher dielectric strength, therefore having greater insulating properties, while also being a very poor conductor of electrical currents. Because of this, muscovite is widely recognised as the best mica type for electrical applications and devices. As well as this, muscovite mica can be highly durable and both flexible or rigid depending on resin composition.

Phlogopite mica is similar to muscovite mica; it is more heat resistant than muscovite, and as well a poor electrical conductor and can be manufactured  flexible or rigid depending on use. They are the only two mica minerals that are used commercially, 

Here we discuss the major advantages of mica’s thermal, electrical and physical properties for industrial insulation.


Heat resistance

Sheet mica or roll mica is highly resistant to heat, due to the chemical properties of the minerals. This heat resistance is unsurprisingly ideal for industrial applications, specifically insulation. Phlogopite Mica can resist temperatures up to 1200°C due to its low thermal conductivity, yet high thermal stability. In industrial applications, temperatures can reach incredibly high levels and insulating the machinery and equipment is vital for safe operation. Flexible mica sheet in the foundry and steel industry for example, is essential for containing the high temperatures. Elmelin have been working with the foundry and steel industry for over a century. 

Combining experience and expertise with mica’s excellent chemical properties for thermal protection, Elmelin have created solutions that increase the productivity of a foundry, reduce costs and maintain safety. Muscovite mica and phlogopite mica are both used by Elmelin, as they both offer great thermal qualities while being flexible and easy to cut into shape. Muscovite mica is stable up to 700 °C however phlogopite mica remains stable at higher temperatures (up to 1000 °C). Therefore phlogopite mica can be used when dealing with higher temperatures that require stability. Mica continues to offer industrial insulation solutions as new innovations are tested, whether it’s mica sheets, mica tubes or mica roll laminates.


Electrical insulator

Mica is a dielectric and therefore has very low electrical conductivity. Because of this, mica sheets can be used as electrical insulators in electronic devices. From intricate circuit boards to large-scale industrial machinery, mica sheets can be implemented within their components in order to improve their insulation. Circuit boards as an example, can have thin mica sheets layered across the boards. Due to being able to withstand such high temperatures, sheet mica is ideal for providing the structure to electrical heating wire.

These electrical properties combined with mica’s versatility prove to be a hugely beneficial combination for electronic applications. The different grades of mica sheets will determine its use; for example the highest quality mica sheets are used to manufacture capacitors for calibration standards. The next lower grade is used in transmitting capacitors. Specialised applications for sheet mica are found in automotive components, laser devices, medical electronics and radar systems.



Whilst previously mentioned, it’s worth highlighting the flexibility of mica sheets and just how advantageous it is. With any form of manufacturing, using materials that are flexible and versatile is a major benefit. Flexibility allows for easier application to components, less wasted resources and being able to adapt to design changes when required. 

Flexible mica sheets are able to sheathe, cover and wrap around pieces in fairly complex shapes. It can be of different grades, or thickness, depending on how it’s required for use. When impregnated with a heat-resistant binder, flexible mica sheets can perform as an insulation foil. Suitable for deflecting heat, these insulation foils can be used in many different applications such as BEV automotive.

Phlogopite mica as a flexible Material , for example, can be combined with other high performance insulation materials which can be used as passive fire protection for passenger safety or as compression pad/spacer material to insulate the thermal propagation in case of a thermal runaway.

Flexible mica sheets also help to extend the life of furnace linings. This is due to the outstanding slip plane characteristics, which withstand the contraction and expansion of linings when presented with intense heat. Because of this, the amount of relining required by a furnace will be lessened therefore saving money.



Mica is a group of minerals that have excellent thermal and physical properties which together allow for effective, versatile insulation. The number of applications for mica insulation is vast, from aerospace to toasters, and Elmelin work with these industries to ensure their products are as efficient and safe as possible. Whether rigid or flexible, mica are essential to application safety Elmelin are here to help you decide which is best for your business and provide you with the best possible mica insulation products, so don’t hesitate to get in touch and find out more.