Effect of Denier-per-Filament of Polyester on Yarn Strength in Open-End Rotor Spinning

There is considerable interest in replacing fine ring spun yarns with fine rotor spun yarns for uniforms and career apparel because the cost of yarn manufacture is much lower with rotor spinning than with conventional ring spinning. However, rotor spun yarns are inherently weaker than ring spun yarns. The effect of the denier-per-filament (DPF) of polyester on the yarn strength of rotor spun yarns is investigated and com pared to the ring spun counterparts. The strengths of both rotor and ring spun yams increased linearly with a decrease in the DPF of the polyester, and the magnitude of the change was the same for both spinning systems. The strengths and elongations of the ring spun yarns were 44% and 37% higher than those of the rotor spun yarns when the same polyester was used. The strength of the rotor spun yarn increased 23% over the DPF range that is commercially available.