MICA SHEETS FOR THE SEALING INDUSTRY

Mica is a mineral that is to be found in scraps. Mica is not dangerous to health and shows a good resistance to temperature (up to 1000°C) and mechanical stress. The latter properties enable mica to replace asbestos in many applications where the temperature does not exceed 1000°C.

There are several types of mica. However, the most commonly used are phlogopite mica (withstanding up to 1000°C) and muscovite mica (withstanding up to 750°C). Both mica paper types are impregnated with a silicon resin that can resist high temperature levels. The resin also gives more flexibility to the mica, which is a key characteristic in the making of mica gaskets.

When compressed between two parts, mica gasket material avoids leaks by closing up gaps. They are cost-effective: they make up for irregular surfaces. Therefore there is no need for parts to be machined in order for them to perfectly slot together. Mica gaskets are often milled in mother sheets.

Among their features in the sealing industry, mica gaskets’ high resistance to mechanical stress is a major one. The main use of industrial gaskets involves the compression of a bolt that may exceed 14 MPa (2000 psi). This explains why mica is so largely utilized for industrial gaskets.

Use

Here are two common applications for mica gasket material: exhaust systems and boilers. In fact, both require the use of gaskets that can provide long-term impermeability to temperature sometimes exceeding 500°C. Conventional gaskets deteriorate considerably faster than mica gaskets at this elevated temperature.

Mica properties

· High flame resistance – mica can withstand up to 1000°C

· High dielectric strength: up to 20 KV/mm

· Good tensile strength

· Asbestos-free

· Environmentally friendly, non-toxic and infusible

· High resistance to mechanical stress

Water-repellent; mica is stable and does not react to chemical agents, acids, solvents, oils