Electrostatic properties

Architects and Interior Designers specifying carpet for high rise buildings are usually aware that woollen carpets do not experience problems from static charge under normal conditions.

No discomfort from static discharge should be expected under normal atmospheric conditions of approximately 45% Relative Humidity and 20 Celcius.

Carpet after backing is rolled up in a “dry state” and therefore is often quite dry when first installed. Under normal conditions wool absorbs up to 17% moisture from the atmosphere.

Some buildings have air conditioning that does not achieve normal humidity levels and causes the air to remain particularly dry.

In such a case a wool carpet may be dry enough to create static charge when rubbed by the soles of shoes and depending upon the type of sole.

The remedies for dry air conditioning affecting static charge include spraying the carpet with “water mist” to increase moisture regain, opening windows for a few days whilst air conditioning is turned off, or spraying the carpet with an anti - stat spray.

The important thing is to understand that if there is a problem with static charge from a wool carpet in a building then it is actually a problem with the air conditioning system causing unduly dry air.

Wool is usually preferred as a result of its very low flammability and smoke developed qualities compared to synthetic fibres.