Aramid paper pulp

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. ... 

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. 

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. 

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. 

Blending, beating, and fluffing the aramid pulp slurry and the aramid short fiber slurry in a given ratio to afford a paper pulp at a desired concentration,... 

Various nonwoven structures have been developed as well. The least important among sheet structures are films. There are two film products (see Section 13.3) based onp-aramids and none on m-aramids. The significant cost differential is the most likely reason for this situation. On the other hand a very large market has been developed for papers based on both p-aramids and m-aramids. In general, these papers are based on short fibers (floe) and a binder (fibrids), but other components have been explored as well. A very small market exists for particles other than fibrids and pulps. 

Manual transmissions use a clutch facing made from a resin impregnated wound structure composed of staple yarns, p-Aramid in yam form provides more strength and durability than a pulp-based paper sheet in this more demanding application. Although aramid reinforced facings have sufficient thermal stability for this application, compositions based on glass and metal fibers dominate this market. 

Yarns, films, fibrids, papers and pulp are the usual aramids commercial forms. 

For pulp manufacture, the PPTA yarn is chopped into short fibers, which are then suspended in water. The suspension passes through a refiner mill similar to the kind used in paper manufacture from wood pulp. In the mill aramid fibers are chopped even further, whereby the cutting action of the rotors gives rise to a random distribution of fiber length. At the same time, some crystalline domains partially detach themselves from the main... 

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