Assessing the mechanical properties of low-quality sheep wool yarn

Abstract

In response to growing environmental awareness and the need for sustainable practices, the construction sector is seeking innovative solutions to reduce its environmental impact. This study examines the use of low-quality sheep wool, typically discarded by the textile industry as a potential resource for the construction sector. Unlike natural plant fibers which must be specifically cultivated sheep wool is an agricultural by-product produced in large quantities without a designated end-use, despite its potential applications. The primary objective is to assess the mechanical properties of sheep wool yarn, tested through various experimental methods, to evaluate its potential as a reinforcement in biocomposites. The research investigates yarn performance in both its dry state and after impregnation with a bio-based resin. Two testing configurations were employed for dry yarns: capstan grips (DYR) and straight sample configurations (DYC). For impregnated yarns, two polymerization strategies were assessed: with pre-tensioning (IYT) and without pre-tensioning (IY). Results revealed no significant differences between the two testing configurations for dry yarns (DYR and DYC). The pre-tensioned impregnated yarn (IYT) exhibited the best mechanical performance, with tensile strength increasing from 89.45 MPa (average of DYR and DYC) to 142.92 MPa, and elastic modulus rising from 1.30 GPa to 11.07 GPa. These improvements are attributed to better fiber alignment and structural compaction promoted by the pre-tensioning process. These findings demonstrate the potential of waste wool as a reinforcement material for construction applications. Despite promising results, challenges remain. Wool’s hygroscopic nature affects fiber–matrix adhesion, and further research is needed to evaluate compatibility with various polymer matrices. Addressing these issues could establish waste wool as a sustainable resource, aligning with global demand for circular economy and eco-friendly materials.