Increased life for body armour

Mexican researchers have developed a process to strengthen fabrics with ceramic nanoparticles that could dramatically increase the lifetime of body armour, nylon and vehicle tyres.

The process bonds ceramic nanoparticles on to the fibres of the family of fabrics that includes Dupont’s Kevlar and nylon, leaving them stronger but flexible.

Prof Victor Castano of the Universidad Nacional Autonoma de Mexico said that Kevlar used for body armour quickly degrades. ‘The fibre bonds hydrolise and break in high humidity and they are also sensitive to UV light,’ he said. ‘Police need to replace their vests after a couple of years even if it has not been used. Our technology increases the lifespan of a Kevlar vest to well over 10 years.’

The team’s technique modifies the material on the nanoscale, he said. ‘The idea is not to physically deposit the nanoparticles but to chemically attach them and alter the surface,’ said Castano.

The ceramic nanoparticles are a combination of zirconium and titanium oxide. ‘Ceramic material is very tough – it can survive thousands of years,’ he said. ‘You could put a coating of ceramic on the fibres, but it would become stiff. Our technique preserves flexibility.’

The fabric fulfils and may even surpass armour requirements, said Castano. ‘In tests the performance of the ballistic properties is at least the same as existing vests, and we think they’ve improved.’

The team said the process is also applicable to fabrics like nylon, which could for example improve the strength and durability of gloves or toothbrushes. The technique could be applied to produce electronic ‘smart’ clothing, he said, and could also improve the life and performance of vehicle tyres, which can often worsen because of temperature change, humidity or biological effects.

The team is investigating whether the nanoparticles will attach to Zylon fabric for body armour, which is up to three times stronger than Kevlar but just as degradable. They have licensed their technology to Spanish company Parafly, and said that the process adds little extra cost to body armour production.

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