Prospects of Aramid as a Substitute for Asbestos

Apart from the high tenacity and modulus of elasticity, aramid based on paraphenylene terephthalamide also has very favorable temperature properties. These include high temperature resistance, nonflammability, and absence of heat shrinkage. Another advantage lies in its high chemical resistance. Compared with asbestos and particularly with inorganic manmade fibers, aramid is highly superior in textile processing. Together, these properties make aramid fiber one of the most promising candidates for asbestos replacement, which is supported by the results of experiments carried out in practice with friction materials. Aramid can be used in brake linings as well as in clutch facings. It is difficult to produce homogeneous compounds using aramid; therefore mixing techniques used for asbestos have to be adjusted. Gaskets and packings are other end-uses where aramid gives spectacular results. For heavy thermal protective clothing aramid fibers have much to offer with respect to wearing comfort. At very high temperatures, however, certain limitations must be considered.