Mechanical durability of plasma-treated wool pile carpets under static and dynamic loading conditions

چکیده مقاله

This study investigates the effects of atmospheric pressure plasma treatment on the mechanical properties and durability of wool pile carpets. Wool yarns were subjected to plasma treatment using mixtures of argon and oxygen gases. The plasma treatment yielded a 31% enhancement in yarn tensile strength, increasing from 8.50 to 11.13 cN/Tex, and a 20% increase in Young’s modulus, rising from 55.03 to 66.08 cN/Tex. Additionally, surface wettability exhibited significant improvement, as evidenced by a reduction in water absorption time and a decrease in contact angle. Despite these enhancements at the fiber and yarn level, plasma treatment demonstrated a minimal impact on the thermal insulation properties of the wool carpets under the conditions tested. Importantly, durability tests on the carpets revealed that plasma-treated samples exhibited greater thickness loss and reduced recovery under both dynamic and static loading conditions when compared to untreated samples. Carpets woven with plasma-treated wool piles demonstrated a thickness reduction of 19.93% after 100 impacts, in contrast to a reduction of 4.03% observed in untreated samples. Furthermore, after 1000 impacts, the plasma-treated carpets exhibited a 27.13% loss in thickness, compared to a 22.74% loss in untreated carpets. Under static loading conditions, plasma-treated carpets exhibited an immediate thickness reduction of 29.66%, in contrast to a reduction of 21.69% observed in untreated carpets. Furthermore, the 24-h recovery rate for plasma-treated carpets was only 42.58%, compared to 63.11% for untreated carpets. The tuft withdrawal force remained statistically unchanged. These findings underscore the dual effect of plasma treatment. While surface modifications enhance yarn strength and surface properties, they simultaneously weaken carpet resilience by damaging fiber cuticle cells due to etching. The process generates micro-abrasions and increases surface roughness, resulting in altered inter-fiber friction and elasticity. Consequently, carpets with plasma-treated wool yarns exhibit greater susceptibility to deformation and thickness loss under static or repeated loading. This situation underscores the necessity for careful optimization of plasma treatment parameters, particularly in the context of carpet applications, where there is currently limited research. Achieving a balance between surface enhancement and the preservation of structural integrity is essential to ensure overall carpet performance.