Bleaching of Hemp (Cannabis Sativa L.) Fibers with Peracetic Acid for Textiles Industry Purposes

Hemp plant exhibits various eco-friendly properties and hemp fiber processing does not cause environmental damage, however, it is known that most chemical operations have a risk to interrupt a sustainable production. As stated in several studies, peracetic acid is an important environmental friendly bleaching agent when compared to its conventional competitors. In this study, hemp fabric was bleached with peracetic acid with exhaustion and padding methods. The effects of temperature, pH, process time, concentration on whiteness values were determined. The influences of bleaching processes were investigated via instrumental and imaging methods. Physical properties of the treated fibers were also tested. Besides peracetic acid, hydrogen peroxide bleaching was carried out for comparison. COD values of bleaching effluents were analyzed for selected samples. Higher whiteness values were obtained with exhaustion bleachings than pad-batch bleachings. Quite high whiteness values (up to 68.13 Stensby whiteness index) attained in peracetic acid without significant fiber damage.