Valorization of the agricultural industrial hemp by-products for textile applications: assessment of their spinning potential through mechanical-chemical cottonization

Abstract

This research focused on establishing the spinning potential of non-textile hemp by using mechanical-chemical cottonization. The raw material used was an agricultural residue that is mainly employed for paper manufacturing. These fibers were subjected to an alkaline chemical treatment followed by an oxidizing treatment (H2O2) to reduce non-cellulosic components. Subsequently, a mechanical process was carried out to increase fiber elementarization and obtain suitable slivers for spinning. The potential of open-end rotor spinning was evaluated for both the 100% treated hemp and blends of 25% hemp/75% cotton. The selection criteria included a low reduction of the degree of cellulose polymerization, a low mass loss during the process, an appropriate tensile strength of the resulting yarns, an absence of breakage during spinning, and a low twist. The hemp treated with a high level of H2O2 stabilizer, according to the established experimental design for the oxidizing process, exhibited superior performance when blended with cotton and spun with a count of 40 tex and a twist coefficient (αm) of 170. These outcomes are of industrial interest for the production of fine yarns because they can be easily implemented using existing machinery devoted to processing cotton. Furthermore, it contributes to the circular economy within the textile industry by adding value to a waste material that can serve as an alternative source of more environmentally friendly cellulosic fibers.