Nomex Meta-aramid Needle Felt for High Temperature Resistance

DuPont™ Nomex® fibers were developed to combine thermal resistance with the physical properties of nylon and are used today to produce felts for a wide range of high-temperature filtration applications (up to 200°C/392°F). Their particular characteristics mean they can withstand extreme stresses, provide a long service life under arduous conditions and their unique ‘dog bone’ fiber cross-section results in excellent filtration dust retention.
As there is no one filter suitable for all uses, it is necessary to select the optimum filter medium for each application. As a result, DuPont has focused its research and development on providing a wide selection of filtration products to meet the many different needs of plant designers, plant operators, and the manufacturers of filter media.

Nomex and related aramid polymers are related to nylon, but have aromatic backbones, and hence are more rigid and more durable. Nomex is the premier example of a meta variant of the aramids (Kevlar is a para aramid). Unlike Kevlar, Nomex cannot align during filament formation and has poorer strength. It has excellent thermal, chemical, and radiation resistance.

Nomex (styled NOMEX) is a registered trademark for flame resistant meta-aramid material developed in the early 1960s by DuPont and first marketed in 1967.

Nomex is the friendly brand name for a heat- and flame-resistant textile made by the DuPont™ chemical company. Technically, it's called a synthetic aromatic polyamide polymer—which sounds complex but starts to make more sense if you consider it one word at a time:

Synthetic textiles are made in a chemical laboratory (unlike natural textiles such as cotton, which grows on plants, and wool, which comes from animals).
Aromatic means its molecules have a strong, ring-like structure not unlike that of benzene.
Polyamide means the ring-like aromatic molecules connect together to form long chains. These run inside (and parallel to) the fibers of Nomex a bit like the steel bars in reinforced concrete.
Polymer means that Nomex is made from many identical molecules bonded together (each one of which is called a monomer). Plastics are the most familiar polymers in our world. As we've seen, the monomers in Nomex are based on a modified, benzene-like ring syructure.
In short, what we have in Nomex is a man-made textile whose ring-like monomers are bonded together into tough, long chains to make immensely strong fibers. Break Nomex up and sort it into its atoms and you'd have four neat piles of carbon hydrogen, oxygen, and nitrogen.

Aromatic polyamides such as Nomex are often called aramids for short. Kevlar® (another DuPont textile) is also an aramid, but with a slightly different chemical structure. If you're interested, the full chemical name of Nomex is poly (m-phenylenediamine isophthalamide), while Kevlar is poly (p-phenylenediamine terephthalamide); Nomex is a meta-aramid polymer while Kevlar is a para-aramid polymer.

Aramids are made in a two-stage process. First, the basic polymer is made by reacting together organic (carbon-based) substances to form a liquid. In the second stage, the liquid is spun out to make solid fibers, which can then be woven into textiles or converted into sheet form.

In the field of filter bag, usually people regard the bag as the heart of filter bag, what kind of flue gas that the filter bag can deal with, it dependson the chemical fiber itself for the bag. Under the common flue gas condition, it needs that the bag can endure the 150℃ below, in this occasion, polyester, polypropylene, acrylon, chinlon etc could be suitable for this. But in the high temperature occasion, such as chemical, carbon black (white carbon black) tail gas, blast furnace gas in irons melting plant, vertical kiln tail gas in cement plant, kiln furnace tail gas from calcium carbide plant, casting, flue gas of steel smelting, gypsum concrete gas, fire-resisting brick gas, coking gas etc. the powder gas is unfit for electricity dust-collecting, only using the bag or others because of the mass resistively limit, the second reason is if we cool the powder gas below the 150℃ , the investment cost is higher and the space site is limited, the third is because of the sulphur content of the flue gas, and the powder gas contain the acid dewing point, it can filtrate and separate that the flue gas is under the high temperature condition, which needs the high temperature resistant chemical fiber to make the filter medium.Our factory selects METAMAX fiber from Dupont Teijin fiber co., ltd.