Vests more bullet-proof with wool

By AAP with AG Staff 5 April 2011
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Adding wool to kevlar makes a lighter, stronger and cheaper bullet-proof vest, new research shows.

WOOL HAS MANY PROPERTIES ideal for fashion; this natural fibre is warm, elastic fire- and static-resistant, and easy to clean. But new research has uncovered a new use: making body armour even more bullet resistant.

Scientists at the Royal Melbourne Institute of Technology school of fashion and textiles discovered that a blend of wool and kevlar, the synthetic fibre widely used in body armour, was lighter and cheaper and worked better in some conditions than kevlar alone.

The RMIT textile technologist Dr Rajiv Padhye says the standard bullet-proof vest was generally made of kevlar, a dense, strong and expensive fibre. For military use, a heavy ceramic plate provides greater protection over vital areas.

A kevlar vests typically comprises some 36 layers of kevlar fabric. But it loses about 20 per cent of its effectiveness when wet, requiring an expensive waterproofing process.

“What we did was kept the kevlar but added a wool yarn into this,” he says.

Adding wool makes for a lighter, cheaper and stronger bullet-proof vest

The increased friction of the wool in a tight weave means that a vest with 28-30 layers of fabric, provides the same level of bullet resistance as 36 layers of kevlar.

“And because wool fibres expand naturally in water by up to 16 per cent, the wool-Kevlar blend actually becomes more effective in wet conditions,” he says. “The result is a cheaper bullet-resistant vest that works even better when it’s wet.”

That’s a significant matter, considering kevlar costs about $70 a kilogram, compared with about $12 a kilogram for wool.

Rajiv says RMIT had worked with Australian Defence Apparel (ADA) as an industry partner and had taken out a patent. ADA currently provides body armour and uniforms to the Australian Defence Force.

“The next step is to see see if we can move ahead with ADA or any company and see if we are able to commercialise this,” he says.