Optimization of durability of Persian hand-knotted wool carpets by using desirability functions

Lower abrasion loss and compression, as well as higher compression recovery, are desirable for obtaining maximum carpet durability. Hand-made carpet manufacturers need to satisfy consumers on these diverse durability requirements. Therefore, it is necessary to optimize the carpet durability by considering several objectives simultaneously. In this investigation, carpet durability has been optimized by considering abrasion loss, compression and compression recovery simultaneously. The desirability function approach has been used to combine multiple objectives into a single objective. Knot density, pile height, number of plies in the pile yarn and pile yarn twist have been considered as the four independent variables. The optimum desirability of carpet durability was found to be 0.8. The validation sample also showed good agreement (error < 5%) with the optimized values of carpet durability attributes.