Insulation material is a material possessing good dielectric properties used on wire components in cable usually as direct covering on conductors. It is composed of a pile of thin metal sheets, each sheet being covered by insulation. This insulation is constituted by a refractory material in a fibrous or pulverulent state.

Properties
General properties of insulation materials are:

• Voltage dielectric for higher voltage charge at the conductor surface.
• Low loss material for higher frequency signal
• Heat resistance in high temperature environments.
• Low temperature flexibility.
• Toughness for cut-through, abrasion and crush resistance.
• Wicking, tendency of insulation material to absorb liquid due to capillary action.
• Water vapor permeability.

Types of Insulation Materials

Foam Laminated with Metalised Polyester Film
A metalised polyester film is laminated to a thin layer of foam, with a clear polyester film back. This laminate is sturdy and reflective and has excellent insulating properties. It is an ideal insulation material for building industry. It is usually used as a roof thermal insulation and insulation under floor heating. The material has many advantages over other other insulation material. It is easy to handle and harmless to health. The material is dimensionally stable and has good resistance against chemicals.

Cellular Glass
Cellular glass has excellent compressive strength but it is rigid. It is fabricated to be used on piping and vessels. When installed on applications that are subject to excessive vibration, the inner surface of the material needs to be coated. When installed on refrigerator systems, provisions for expansion and contraction of the insulation are usually only recommended for application that cycle from below ambient to high temperatures.

Flexible Elastomerics
Flexible elastomerics are soft and flexible. It is suitable for use on non-rigid tubing. It is light weight and has low vapor permeability. It is normally limited to services between –70 degree F up to +180 degree F.

Closed Cell Phenolic
Closed-cell phenolic foam insulation has a very low thermal conductivity. It is able to provide the same thermal performance as other insulations at reduced thickness.

PVC Insulation
PVC compounds are moderately good dielectric materials. Depending on the formulation, the dielectric constant can vary from 3 to 6. Formulations typically include the PVC resin, plasticizer, stabilizer, flame retardants, fillers, and additives.

Polyethylene Insulation
Electrical performance of polyethylene is excellent. Dielectric quality is known by a high dielectric strength, low dielectric constant, low dissipation factor and high insulation resistance. These properties are stable over a broad range of frequencies and temperatures.

Non Halogen Insulation
Non halogen insulation is flame retardant compounds, which offer great protection against fatalities, injuries and property damage from fire. They have good crush and deformation resistance, good flexibility, excellent long-term aging properties plus physical integrity at low temperatures.