DYSON is expanding from vacuum cleaners to beauty with the launch of a hair dryer featuring its trademark bladeless fan.

The Malmesbury-based company said it had invested almost £50m in the £300 Supersonic hair dryer, which it claims intelligently protects the hair and scalp from heat damage with a glass bead thermistor that measures the air temperature 20 times a second.

The bladeless fan eliminates the risk of hair being sucked into the motor, which is tucked into the handle rather than the head of the machine to provide better balance.

The V9 digital motor uses Dyson's patented Air Multiplier technology, and the company claims that although it is its smallest and lightest yet, it is up to eight times faster than other hair dryer motors and half the weight.

It has four heat settings, three airflow settings and a cold shot, while three magnetic attachments with 16 patents pending cater for all hair types and styles.

Dyson said 103 of its engineers worked on the machine over four years, testing it on more than 1,010 miles (1,600 km) of human hair.

Sir James Dyson said: "Hair dryers can be heavy, inefficient and make a racket. By looking at them further we realised that they can also cause extreme heat damage to hair.

"I challenged Dyson engineers to really understand the science of hair and develop technology which helps overcome the problems of hot, bulky and unintelligent hair dryers."

Dyson, which employs more than 3,600 staff worldwide, was founded in 1992 and now sells machines, including hand dryers, in more than 50 markets.

The Supersonic will go on sale in the UK at the start of June.