What are popular fire barriers for fire resistant cable?

A fire barrier for fire-resistant cable can work in the following ways, with examples of mica glass tape and ceramic silicone rubber:

1.Mica GlassTape:

Mica tape is often used as a component in the construction of fire-resistant cables. It consists of thin layers of mica, which is a naturally occurring mineral with excellent fire-resistant properties. When exposed to fire, the mica tape acts as a thermal insulator. The layered structure of mica crystals has a high resistance to heat transfer. For example, in a cable core wrapped with mica tape, the tape prevents the heat from the external fire from quickly reaching the conductive elements of the cable.

It can withstand temperatures up to several hundred degrees Celsius without degrading or allowing the fire to penetrate through to the inner layers of the cable. This gives the cable a certain level of fire resistance and allows it to continue to function, at least for a limited time, during a fire incident. The mica tape essentially forms a protective shield around the cable, maintaining its integrity and preventing the spread of fire along the cable length.

2.Ceramic Silicone Insulation:

Ceramic silicone is another material used in fire barriers. It has unique properties that come into play during a fire. When heated, ceramic silicone undergoes a transformation. It forms a hard, ceramic-like layer that provides both physical protection and thermal insulation. For instance, in a fire resistant cable tray or conduit system, a coating or sleeve made of ceramic silicone can be applied. In the event of a fire, the ceramic silicone coating on the outside of the cable bundle or the conduit prevents the flames from directly contacting the cables.

The ceramic layer that forms is resistant to the intense heat and can prevent the cables from being damaged by the fire's high temperatures. It also helps to reduce the transfer of heat to the interior of the cable installation, giving the fire-resistant cables a better chance of maintaining their functionality and preventing the fire from spreading further along the cable route.

In both cases, mica tape and ceramic silicone contribute to the overall effectiveness of the fire barrier by either insulating the cables from heat or physically preventing the fire from reaching them, thus enhancing the fire resistance of the cable system.