Today’s firefighters are demanding customers and rightly so. They want their personal protective equipment (PPE) to provide them with maximum protection, but they also want their turnout gear to be as comfortable, mobile and light as possible.
There is a common misconception that the lighter the fabric in the garment, the greater its breathability. Our own Hainsworth Titan 1220 has a conditioned weight of 220gsm, while similar garments are 205gsm and even 195gsm. Tests have shown that such differentiation in weight does not affect the thermal performance of the product. It is a balance between open weave and thermal protection in which the lighter fabric has a denser fabric construction offering thermal protection even at lighter weights.
A much more important factor in determining the performance capabilities of a firefighter’s PPE is the fabric construction. Manufacturers such as Hainsworth are able to maximise the comfort, thermal performance and durability of firefighter garments by carefully positioning different fibres such as PBI and Nomex with Kevlar and yarns with different physical and mechanical properties within the fabric structure. These fabric structures enhance breathability, durability and thermal performance.
A huge amount of science lies behind the development of today’s PPE. At Hainsworth, we are able to call upon 230 years of textile innovation, leading to a detailed understanding of how the placement of fibres can be maximised to best effect.
Hainsworth’s UKAS-accredited laboratory carries out a range of standard tests to evaluate specific textile properties, looking at both physical (for example, tensile/tear strength) and chemical(for example, colour fastness).
Tests have consistently shown that a fabric’s effectiveness with regard to breathability can be reduced when packed with too many fibres and yarns. Phase changing aramids like Nomex need room to move during heat energy exchange and their ability to absorb heat energy can be impeded if the yarns are too closely packed, while the passage of vapour and moisture may also be restricted. Ultimately, there is a need for balance between understanding the chemistry – the physical performance of the fabric’s structure and how it performs in different situations and environments – and understanding what you are trying to achieve from the structure within the garment assembly.
Set against these considerations is the reality that firefighter PPE is constantly having to evolve. This is partly due to the changing role of the modern firefighter, but also due to the speed of innovation and technological advances available to the industry. A holistic approach to PPE is therefore critical in today’s constantly evolving world; an approach that places equal emphasis on design, protection and quality, taking fully into account the vast and complex array of duties which our firefighters are expected to perform.
Heat stress is the single biggest issue facing firefighters today. Fabric design technologists have started to take more consideration of this risk with the fabric they design. Advances in PPE have meant that garment outer-shells have increased breathability taking into consideration the flow of air and vapour over the moisture barriers, while inner lining systems such as Hainsworth’s Eco-Dry Active now take account of how they actively pull and push moisture and heat away from the body.
Manufacturers also have to ensure that their garments are also able to give the firefighter the greatest possible defence against the worst case scenario of a “flashover”. This is when the structure of the garment and its complex chemistry
is tested to the absolute limit.
It is not about individual factors such as whether a garment is lighter, more comfortable or offers greater mobility. Equally, it is not about the number of fibres or yarns that go into the creation of a garment or its moisture management or flame retardancy capability.
It is the interplay of abrasion, strength, construction and the flexing compression and extension of a fabric that affect the total performance of the fabric and the garment in real-life situations. The way these factors affect each other dictate the wear life, thermal protection and comfort offered by the garment to the wearer.
For more information, go to www.protectsyou.co.uk