PROCESS TO DRY AND HEAT-TREAT POLYBENZAZOLE FILMS

摘要

A simplified and more efficient process is described for drying (and heat-treating) a lyotropic polybenzazole film in which the film is constrained in only the machine direction during drying (and heat-treating). The amount of stretching in the transverse direction the film undergoes prior to it being coagulated can be increased to compensate for the relaxation of the film during the drying process and the lack of stretching during the heat-treating process. Films made in this manner have acceptable finished properties.