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Nomex® FAQ


Browse our Nomex® FAQs to learn more about the product. Please choose a category below.

 
Selection
Use and care
General product info

 
Selection

What does DuPont™ recommend as a solution against electric arc hazards?
DuPont would always recommend that a thorough risk assessment be made by a qualified party before going through the analysis of what protection is required. The level of thermal protection must match the expected arc hazard level. DuPont can offer advice on suitable protective clothing systems made from Nomex® fabric. In addition, DuPont operates the test facility ARC-MAN®, which allows manufacturer end-users to test and evaluate the performance of different fabric and garment systems. For example, in general, two (or more) lightweight layers offer greater protection than one heavy layer.
What are the available colours of Nomex®?
Nomex® can be dyed in fabric form, or coloured by pigment. These pigments are injected into the polymer before the fibre is made. With the exception of white and other very light pastel shades, a very wide range of colours is thus available. Pigments have much higher light stability than the piece dyed Nomex® fabrics. The colour flexibility of Nomex® is undoubtedly the greatest and widest available in the segment of protective clothing made of aramid fibre.
Does Nomex® exist in high visibility colours?
Nomex® in high visibility colours according to EN471 (orange, yellow) is available in fabric form and can be used for example as outershell material in multilayer systems.
What is the difference between piece-dyed and pigmented fabrics?
For pigmented fabrics, colour (in the form of pigments) is injected into the polymer before the fibre is made. For piece-dyed fabrics, colour (in the form of dyestuffs) is added to an ecru or greige fabric during dyeing. With the exception of white and other very light pastel shades, a very wide range of pigmented fabric is available.
Piece-dyed fabrics can be made in virtually any shade. The main performance difference is light/colour fastness, where pigmented fabrics are generally better than piece-dyed fabrics.
Do racing drivers wear similar garments made of Nomex® fibre to firefighter/industrial?
The garments for racing drivers and firefighters / industrial firefighters are made of the same Nomex® fabric. But the garments are made of fabrics which have been specially developed for the specific use, as the activities of driving a car and fighting a fire are completely different. Fighting a fire requires movement and activity of the body, which generates heat from within the garment. The garment thus needs to be looser fitting and have a very durable outer shell. A racing driver needs a non-bulky garment, which is not waterproof and breathes well, and at the same time looks good. In a flash fire a driver needs to be protected in a sitting position; a one-piece garment does this best.
Does DuPont have a product that meets EN 1149 for antistatic protection?
Yes, DuPont™ Nomex® products on offer have permanent antistatic properties. They contain 2% P140, a carbon-core antistatic fibre. These meet the requirements of EN1149-3:2001.
What does DuPont recommend for the design of garments?
It is important to consider the impact of design on thermal protection – e.g. covering of zippers and buttons, use of Nomex® sewing thread and velcro, not skin tight fitting, elasticised cuffs and ankles. Experience has shown that for a fireman, the normal size should usually be increased by 1 unit. THERMO-MAN® and ARC-MAN® can give comparative guidance on garment design using Nomex® fabric.
What fabric weight do you recommend for petrochemical workers?
There is no simple overall answer to this. Risk assessment is the first step toward finding an appropriate solution. The typical range of Nomex® fabric weights is from 150g/m² up to 265g/m². Nomex® is often selected because of its light weight and comfort, and a good balance needs to be struck between protection and comfort. Only a PPE that is actually worn by the worker can protect in case of an emergency.
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Use and care

What will happen if I home launder Nomex® garments?
If home laundering instructions for Nomex® fabric is followed precisely, nothing negative should happen to any of these garments. However, there have been specific instances when FR-treated cotton/nylon garments were laundered using hydrogen peroxide (a type of oxygen bleach) during the wash cycle and the flame resistant properties of the FR cotton/nylon fabrics were compromised. This was reported by Westex in their “Update to Industrial Laundry Care Advisory” dated October 2, 2003.
If Nomex® fabrics are inherently FR, why do the DuPont™ laundry instructions advise me not to use chlorine bleach?
Repeated use of chlorine bleach in the laundry can affect fabric color and can weaken fabric strength, which may shorten the useful wear life of the garment. Exposure to chlorine bleach will not affect the flame-resistant properties of inherently FR fabrics like Nomex®.
When should I ‘retire’ my FR garments from service?
Any garment with visible holes, rips, and/or tears or contamination from flammable materials should be properly repaired, cleaned, or removed from service. Since the FR properties of a truly inherent FR fabric, like Nomex® do not change with use or laundering, the FR properties for Nomex® fabric will be there no matter the garment age or how it was laundered.
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General product info

What kind of tests can DuPont™ carry out?
Most of the norm testing can be carried out by DuPont. DuPont further specialises in obtaining and interpreting test data beyond the norm requirements. These tests involve unique, sophisticated hi-tech equipment.

They are based on full-sized finished products, such as garments. The two key testing facilities are the DuPont™ THERMO-MAN® and ARC-MAN®. Special attention is given to testing where a specific need cannot be measured by standard testing equipment. DuPont also has access to the latest techniques in comfort testing.
What should I consider when starting a protective clothing programme?
First and foremost a risk assessment must be carried out. As any end-user, you must contribute to this risk assessment which should be carried out by an expert in this field. Once this has been done, DuPont can then assist in advice on thermal protection and basic design.
Why should I go to DuPont for advice on heat and flame protective clothing?
DuPont is acknowledged as the expert in the field of protecting people from heat and flames. DuPont invented aramid fibres more than 40 years ago. Since then, DuPont has invested in developing thermal testing equipment (such as THERMO-MAN® and ARC-MAN®) and gathered vital experience from continuous contact with end-users.
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