Method for preparing black fibers

A method for preparing black fiber, using a drawn textured yarn (DTY) texturing process, wherein a polyester pre-oriented yarn (POY) fiber and a polyester fully drawn yarn (FDY) fiber are sequentially passed through a first yarn guide, a yarn guide roller, a tensioner, a first yarn feeding roller, pre-entangling, a second yarn feeding roller, a first deformation hot box, a cooling plate, a false twister, a third yarn feeding roller, a middle entangling device, a setting hot box, a setting yarn feeding roller, oiling, and winding to obtain the black fiber;

• wherein the polyester POY fiber and the polyester FDY fiber both contain carbon black;
• wherein the first yarn guide is a yarn guide wheel, a rim width of the yarn guide wheel is 20-25 mm, an outer diameter of an outer wheel of the yarn guide wheel is 9.4-10.7 mm, and an inner diameter of the groove bottom is 6-7.4 mm;
• wherein a material of the first yarn guide is ceramic, a surface hardness of the groove bottom of the first yarn guide is 1500-2000 HV;
• wherein a tow contacts a groove bottom of the first yarn guide in a process of movement, driving the first yarn guide to rotate;
• wherein the tensioner is a magnetic tensioner;
• wherein the tow contacts a groove bottom of a yarn guide wheel carried by the tensioner in the process of movement;
• wherein a setting tension value of the tensioner is 7-10 cN;
• wherein a linear velocity ratio of the first yarn feeding roller to the second yarn feeding roller is 1.03-1.04.