Abstract: A device for separating a moving fiber from processing fluid is disclosed and claimed. A chamber defining hydrophilic and hydrophobic flow paths respectively is exemplified. The device is placed so that substantially all water associated with processing exits via the hydrophilic path while the fiber exits via the hydrophobic path.

Abstract: Heretofore polybenzimidazole fibrous materials have proven to be extremely difficult to dye successfully. The present invention provides an effective route for the achievement of a satisfactorily dyed polybenzimidazole fibrous material. The fibrous material initially is contacted at an elevated temperature with a liquid (e.g., an aqueous emulsion) comprising an organic swelling agent and salicylic acid to form polybenzimidazonium salicylate, and subsequently is dyed with an anionic dyestuff. Complete and uniform dye penetration is made possible through the use of the present process, and the resulting dyed article is capable of resisting dye sublimation when utilized in an environment where elevated temperatures are encountered.