| Abstract:Due to its poor surface hydrophilicity, meta-aramid staple fibers are easily entangled to form flocs, which seriously affects the uniformity of meta-aramid paper and limits the application of meta-aramid paper based materials in relevant high-end fields such as defense, power and transportation. To investigate the flocculation mechanism of meta-aramid fiber suspensions, the critical flocculant concentration, shear and compressive yield stress of the mixture suspensions of meta-aramid staple fibers and fibrids were examined, and relations between the formation index and rheological properties could be found, based on the rheological theory. The results showed that the gel concentration ranged from 0.37 to 0.64 g/L, and the compressive yield stress and shear yield stress of the suspension were found to depend on the mass concentration via a linear and a power-law relationship, respectively. In addition, both the compressive yield stress and the shear yield stress decreased as the proportion of fibrid increased at a certain concentration, with the exception of pure staple fiber suspensions. Moreover, as the concentration increased, the Froude number were found to decrease accordingly, and the formation index of aramid paper with a fixed staple fiber to fibrid ratio increased with increasing the Froude number. |