Aramid Paper

Aramid paper pulp may consist both of the meta and the para form of aramid. Short fibers, staple fibers, pulp, and polymer particles of aramid swollen with water can be used as starting material for aramid paper. Papermaking is done in a conventional manner. 

Aramid paper pulp can contain both aramid floe and aramid fibers. Floes are addressed as short fibers cut from longer aramid fibers. High porosity papers can be made using high levels of floe instead of fibers.  

Alkaline treatment of the pulp results in papers with enhanced tensile strength. It is helieved that the alkaline treatment effects hydrolysis reaction of the surface of the polymer. Thus the surface contains an increased amount of amino groups. These materials can be used in slipping clutches. 

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Aramid pulp is widely used as a substitute for asbestos. The aramid paper is used as insulating paper. In this case, mica, ground quartz, glass fibers, alumina, or talc, can be incorporated to improve the insulating properties. In contrast, if alumina laminae, carbon black, or stainless steel short fibers are incorporated, electrical conductive papers are obtained. Aramid paper is also used as a reinforcing agent in honeycombs. 

In the case of high loading rates an increase in material stiffness and strength compared to the static behavior may occur. This is addressed as strain rate effect. This effect is important in dynamic hnite element calculations. Actually, in taking account of this effect the material may be designed more lightly. A strain rate effect has been demonstrated for aramid paper honeycombs. ... 

L. J. Hesler and S. C. Park. Aramid papers containing aramid paper pulp. US Patent 5026456, assigned to E. I. Du Pont de Nemours and Company (Wihnington, DE), June 25, 1991. 

H. Werlich, W. ZwUling, and U. Wecker. Process for preparing p-aramide paper, p-aramide pulp, and the use of the paper and the pulp. EP Patent 1277 880, assigned to Teijin Twaron Gmbh (DE), January 22, 2003. 

M. Bubacz, A. Beyle, D. Hui, and C. C. Ibeh. Helium permeability of coated aramid papers. Composites Part B, 39(l) 50-56, January 2008. 

Aramid reinforcement is also available as paper and sold under tradenames of Nomex by DuPont and TP Technora from Teijin America. Aramid paper is used in circuit boards to improve crack resistance and to... 

Aramids papers are found in a much broader range of applications than films (see Applications section). Most papers are comprised of a composite structure of short fibers and a binder. Paper properties can be tailored by changing the composition and the processing conditions. Selected properties are illustrated in Table 13.6. 

Source From E.I. DuPont de Nemours Co., Inc, NOMEX Aramid Paper Type 410—Typical Properties, H-22368, 8/98 Magellan International Hendren, G.L., Kirayoglu, B., Powell, D.J., and Weinhold, M., Adv. Mater., 10(15),... 

As we have mentioned earlier, m-aramid papers are produced exclusively by DuPont and thus most of the application data are based on Nomex papers. 

Tags and labels of m-aramid paper for in-process bar coding are used where high temperature stability and chemical resistance are required. In loudspeakers, m-aramid sheets are used for voice coil insulation and for the speaker cone itself. Bus bars in lithium ion batteries for portable telephones and computers are insulated with m-aramid paper. Photocopiers and laser printers that operate at high temperatures use cleaning rollers and webs made from m-aramid paper. 

PinzeUi, R. and Loken, H., Honeycomb cores from NOMEX to KEVLAR aramid papers, JEC Composites, 2004, 8, 133. 

E.I. DuPont de Nemours Co., Inc., NOMEX Aramid Paper Type 410— Typical Properties, H-22368, 8/98. 

Further, aramid paper is less hygroscopic than cellulose paper [40]. However, a poly(ether imide) paper absorbs less water than a conventional aramid paper [41]. Therefore, especially under humid conditions, a poly(ether imide) paper is superior to an aramid paper. 

Aramid paper laminates can be formed by calendering the opposing surfaces of the aramid paper at different temperatures prior to laminate formation [45]. Laminates made from aramid paper laminates are useful in electrical transformers, wherein the laminate serves as a dielectric insulation material. 

An electroconductive aramid paper can be made by the addition of a conductive filler, such as carbon fiber [46]. The paper should also have a certain level of surface resistivity to avoid the buildup of charge and provide an optimum electrical shielding. 

Kawka DW, Anderson DW, Brown MJ. Formation of aramid paper laminate. US Patent 7 335 276, assigned to E.I. du Pont de Nemours and Company, Wilmington, DE 2008. 

Zhong Z. Method for preparing aramid paper and the aramid paper obtained therefrom. US Patent 8444813 2013. 

Nomex Aramid paper strip dipped in Good strength weight ratio, More difficult to shape-... 

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