Method of producing hemp-blended single spun yarn

A method of producing a hemp-blended single spun yarn, the method comprising:

• a fiber blending step of passing hemp fiber, together with latent crimped yarn fiber, through an opener in order to increase cohesion of the hemp fiber by a three-dimensional chain structure of the latent crimped yarn fiber, thereby producing a blended fiber comprising 10% to 60% latent crimped yarn fiber;
• a sliver production step of carding the blended fiber through a carding machine, and drafting the carded fiber through a drafting machine, thereby producing a sliver;
• and
• a spinning step of supplying the sliver as a roving yarn through a plurality of rollers to a twisting unit, and supplying a combined filament yarn, produced by twisting and having a structure in which a first filament yarn having a first predetermined stretchability surrounds a second filament yarn having a second predetermined stretchability, the first predetermined stretchability being lower than the second predetermined stretchability, as a core yarn to the twisting unit without being passed through the plurality of rollers, wherein the combined filament yarn enters a position on top of the twisting unit, at which twisting of 5% to 20% of a predetermined twisting number for the hemp-blended single spun yarn is performed,
• wherein the combined filament yarn is unwound from a winding unit at a constant speed, descends via a guiding bar, passes vertically in a zigzag pattern (downward, upward and then downward) through three horizontally interconnected rings provided in a tension control ring unit, and enters the position at which twisting of 5% to 20% of the predetermined twisting number for the hemp-blended single spun yarn is performed.