Innovation for Electrical Utility Workers
W. L. Gore & Associates presents lightweight arc rated protective clothing for everyday wear.
People who work either on or close to the live parts of electrical equipment face the risk of an electric arc incident. So far, protective gear that can eliminate this risk has needed at least two textile layers, making such garments anything but comfortable. W. L. Gore & Associates has now achieved a technological breakthrough: it has developed the first functional fabric that allows for the manufacture of protective garments with only one layer. This results in a lightweight and comfortable garment that still provides the highest level of electric arc protection (class 2).
The work of an electrical utility worker presents a special set of challenges. On the one hand, these workers need protective clothing that is functional and as comfortable as possible so that they can wear it all day long without feeling encumbered by it – even at temperatures of 40°C to 50°C, which can sometimes be reached in switch rooms or on very hot summer days. On the other hand, the possibility of sudden exposure to an electric arc can never be entirely dismissed.
That is why their protective clothing has to be sufficiently stable to act as a protective shield against plasma that can reach temperatures upwards of 5000°C and instantly set fire to clothing and burn the body. According to the German statutory occupational accident insurance fund responsible for the energy, textile, electronics and media sectors (BG ETEM), severe electric arc injuries occur in Germany several hundred times a year, causing the death of two or three people.
To satisfy the contradictory requirements of protection and comfort, back in 2011 Gore launched its revolutionary new PYRAD® fabric technology for use in rain. This innovation paved the way for protective garments for the utilities industry that were, in the true sense of the word, smart. On sudden exposure to heat and flames, or the moment at which an electric arc occurs, an effective protection in the form of an insulating barrier covering the full area appears on the lightweight outer fabric made of polyester or polyamide. As a result, in recent years the weight of the fabric has dropped from over 650 g/m2 to just under 350g/m2. At the same time wearer comfort has increased.
This system has since established a strong position in the marketplace. However, so far PYRAD® protective clothing has only been designed for outdoor wear, featuring uncompromising weather protection thanks to the GORE-TEX membrane incorporated into the garment.
“From the many conversations we have had with technical specialists from all over Europe, we know that the previously available protective garments had, figuratively speaking, been a bit of a burden. In response, we were able to offer a much lighter alternative featuring class 2 and wet weather protection. Feedback from the market was very positive. At the same time, people said that they would like to see us develop protective clothing for everyday wear that was lightweight and pleasant to wear, irrespective of the weather. So, that’s what we did.”
One layer – 50 % lighter
With its new arc rated GORE® PYRAD® protective garments, Gore has brought about a textile revolution in the PPE sector. “Because we know how to exploit the technology, we’re able to combine the highest levels of protection and comfort in one single layer,” says PYRAD® development leader at Gore Dr. Peter Wimmer. The desire for an innovation that could achieve exactly this had often been expressed in the marketplace. At 330 g/m2 the new laminate weighs roughly 50% less than the previous system, incorporating three components into one fabric: the outer shell, a special membrane and the protective PYRAD® technology.
This development has set the scene for the production of first-of-a-kind, lightweight workwear garments for everyday use that are as comfortable to wear indoors as they are outdoors on warm, dry days and that minimize the agony of heat stress in the workplace. Plus, with arc protection class 2, in a worst-case scenario they will still offer the highest level of protection against the thermal hazards of an electric arc. The single-layer fabric enhances the breathability and flexibility of the clothing and delivers the added benefit of allowing manufacturers more choice in the specific design of their protective garments. It can be produced in different colours and in high-visibility luminous colours.
Generally speaking, single-layer protective clothing that is currently available on the market only achieves a class 1 rating. This is the case even if the garment is designed with reinforcements that target the parts of the body that need extra protection but also add weight to the garment.
25 milliseconds – real-time protection
The PYRAD® technology is based on a physical process that was discovered more than 100 years ago. However, Gore was the first in the industry to develop the technical expertise to apply this process to a textile substrate. It spent four years working on this development and has since applied for a patent. Countless little dots made of a graphite material are always in position on the outer fabric in preparation for a worst-case scenario. In everyday use the fabric remains lightweight, supple and flexible. If a flash fire or electric arc incident causes the dots to heat up suddenly, they react immediately to form a stable carbonaceous char that effectively blocks the massive convective heat flow during arc exposure.
“The reaction is similar to that of a car airbag,” says Peter Wimmer. An electric arc releases a massive amount of electrical energy within 25 milliseconds. However, the PYRAD® technology on the outer fabric is even quicker to cover the area with its barrier so that the sizzling hot flash of plasma is successfully blocked. All this happens “in real-time”. No burns on the skin, no burning garments, no holes in the fabric, despite exposure to incredibly intense heat – the lightweight single-layer laminate meets the rigorous requirements of protection class 2 by means of the perfectly tuned combination of an PYRAD®-endowed outer fabric and a wafer-thin, non-inflammable ePTFE membrane (expanded polytetraflouroethylene).
New field of activity for Gore
The lightweight fabric system has been certified in accordance with several European standards. First and foremost, it complies with EN 61482-1-2 for protective clothing against the thermal hazards of an electric arc. The other standards that it complies with set performance requirements for clothing to protect against heat and flame, for protective clothing for use in welding and allied processes, for high-visibility clothing, for clothing to protect against liquid chemicals, for protective clothing with electrostatic properties and, last but not least, for the washing durability of protective clothing.
The groundbreaking, lightweight PYRAD® technology opens up a completely new field of activity for Gore: protective clothing that keeps wearers safe and can be worn every day. And if ever work does need to be done outdoors in the rain, the most comfortable solution is simply to put a rain jacket on over the top. Utility company procurement officers now have far greater scope than ever before when it comes tailoring the protective clothing of their workforce to suit the specific needs of the company.
For more information, visit www.gore.com.