A unique stab and flame-resistant material combines wool with high-strength synthetic to add comfort to protective clothing. Find out about the research and development behind this new material.

How the research started

When AgResearch in Christchurch purchased a new type of machine – a Fibreknit machine – scientists began exploring different types of fabrics they could make on it. An idea to trial a high-strength cut-resistant yarn with short wool fibres initiated the research and development of a new lightweight, comfortable stab and flame-resistant fabric.

The Fibreknit machine is able to blend two materials together in a unique way. It can incorporate short fibres into a knitted backing structure using a sliver of fibres, eliminating the need to spin the fibres into yarn.

Initial research aim for high-level protection and comfort

Initially, researchers aimed to make a protective fabric for police or military environments that was more comfortable to wear. Using high-strength Vectran™ yarn for cut resistance and wool fibre for comfort, they produced the first concept samples.

Find out more about this new stab and flame-resistant fabric.

Early testing verifies fabric performance

Once researchers had produced the first samples, they needed to verify the fabric performance. They built equipment that allowed them to apply a standard test method for stab-resistant garments to the fabric to measure its level of protection.

The fabric didn’t meet this standard, which was established for conventional stab-resistant materials. However, when they changed the type of weapon used from a very fine-pointed, extremely sharp knife to something like a screwdriver, they found the fabric gave a good level of protection. This showed them that, in an environment where the weapon might be improvised, the fabric could provide an appropriate level of protection.

Test results identify new market opportunities

The test results led researchers to consider other market opportunities where a garment with greater comfort and a lower level of protection may be needed. Being comfortable, you can wear it all day, so it’s ideal for situations where there’s occasional risk and you’d otherwise have no protection, such as security guards or ambulance officers.

With increasing levels of violence in society, New Zealand Police now routinely wear stab-resistant body armour. Demand for more protection for people in environments where there is a moderate level of risk is driving a growing interest in protective fabrics.

Optimising fabric performance

Once researchers had initial evidence of the fabric performance, the next stage was to optimise this performance. This involved experimenting with different structural parameters, such as the way the loops were knitted, the amount of wool included and the tightness of the structure. Then they put it through more rigorous testing where they looked not only at the penetration resistance in the stabbing scenario but also at the rupture force – how much energy it took to rupture the fabric. They also carried out standard flame-resistance tests on the fabric.

Testing consumer acceptability

Consumers today expect clothing to look good, be comfortable to wear and be easy to look after, so after optimising the protective qualities of the fabric, researchers carried out consumer acceptability tests. These included pilling, abrasion resistance and washability.

Wool has a natural tendency to shrink and mat when washed, so the fabric has to be hand washed or dry cleaned. Researchers are looking at developing a machine-washable and shrink-resistant treatment they can add after manufacture to make it easier to care for. This is likely to increase consumer acceptability.

Market demand follows promotion

AgResearch made the finished fabric into a vest to promote it in the marketplace. The vest was modelled in the 2008 New Zealand Fashion Week show and its flame resistance demonstrated using a blowtorch. It has also been widely promoted in the media.

The publicity has sparked interest from fabric and garment manufacturers and the general public, and many ideas have been suggested for possible uses including work, leisure and sporting applications.

Ready for commercialisation

Researchers are now starting to interact more with end-users and potential commercial partners. Feedback from these sectors will influence how development proceeds in the future.

Once a commercial partner is established and a target market decided, researchers will optimise the fabric for the specified application, then transfer the technology. Technology transfer involves taking the fabric from pilot scale at AgResearch and putting it into a commercial factory. AgResearch then help the company work through the processes of making, finishing and quality control of the fabric.

Using this unit plan, New opportunities for protective wear your students will consider the performance properties of new stab and flame-resistant fabric and design protective wear for new market opportunities.

    Published 27 May 2010