Wool researchers spin a good yarn

We've been counting sheep to nod off for generations - now it's their woolly fleece being touted as a sure way to a good night's sleep.

Scientists have found a way to make woollen sheets and pyjamas that won't itch, won't shrink and won't need drycleaning.

The breakthrough fabric is the result of 25 years of research into the "prickle factor", said AgResearch scientist Dr Surinder Tandon.

That woolly itch, often mistaken for allergic reaction, is related to the size of the wool fibres. The smaller the fibre, the softer the wool.

Non-itch woollen fabric is made by selecting particularly fine merino fibres, which are spun into a compact yarn.

The spinning technology, which uses single-ply yarn, rather than standard double-ply, has taken more than eight years to develop.

The yarn is woven into fabric and finished to a smooth surface, without any protruding fibres, or "hairs".

The result is too compact to shrink in the washing machine, even without the chlorine treatment usually applied to prevent shrinkage.

But the new fabric is still ahead of its time. There are no weaving machines that can produce sheets any bigger than a single size.

"Only cotton manufacturers have that, so it's a challenge at the moment to find the right partner," Tandon said.

While it's not known when woolly sheets will be in the shops, pyjamas might be on sale next year.

Timaru company South Canterbury Textiles is using AgResearch technology to make fabrics from wool blended with bamboo and silk. The company will then work with garment companies to make the fabric into washable, non-itch sleepwear.