The invention relates to a soft and clean
spinning method which can be used for improving the performances of
yarn, especially the performances of
yarn hairiness and belongs to the technical field of
textile processing. On each drafting mechanism of a ring
spinning frame, a roving sliver subjected to drafting is output from a front jaw, and a heat and
moisture treatment device is used for performing on-line heat and
moisture treatment on the on-line twisted roving slivers which are output from the front jaws and enter into a twisting triangular area. Under the combined action of heat and
moisture, bending modulus and rigidity of
fiber of the on-line twisted roving slivers are greatly reduced immediately, the
softening speed and the degree are greatly improved, soft twisting and
yarn forming can be performed on the thicker slivers when the lower modulus and the lower rigidity performance are achieved, and the ends of the
fiber are easier to transfer and wind under the action of twisting torsional force and finally twisted into yarn bodies or attached on the surfaces of the slivers, thereby effectively eliminating hair
feather in the formed yarn and greatly improving the degree of finish of the surface of the formed yarn. Simultaneously, the residual torque and
residual stress of the ring-spun yarn can be reduced, not only can the entanglement phenomenon in the formed yarn be effectively solved, but also the softness of the formed yarn can be improved.