For cotton spinning, use is made of a treatment agent containing silicone with viscosity at 25 DEG C. of 10 centistokes or greater such as dimethylsilicone, end hydroxy modified dimethylsilicone or epoxy modified dimethylsilicone and an emulsifier such as polyoxyethylene alkylether or polyoxyethylene alkylphenylether. The treatment agent may also contain a cationic or non-ionic surface-active agent within a specified range of weight ratio. The treatment agent is applied to raw cotton during its bale opening or beating opener process at the rate of 0.001-2.0 wt %.
