S twist and Z twist
The so-called yarn is a continuous fiber bundle composed of fibers. Use a magnifying glass to see that the surface shape of the yarn is like a twist, with a spiral appearance. During the spinning process, when the spindle belt pulls the spindle plate to rotate rapidly, the uniform, fine and clean fiber bundles drawn by the rollers continue to receive the force couple generated by the rotation of the spindle, and are twisted into a twist shape, that is, Just like twisting a straw rope, put one end of a few straws in your palms and rub them, or rub them on your trouser legs to add twist.
The direction of twisting during twisting is different, and the tilt direction of the fibers in the yarn - the direction of twisting is also different. The twisting direction is divided into S twist and Z twist.
For example, after twisting, when viewed vertically, the fibers in the yarn tilt from the bottom right to the upper left, which is S twist, or hand twist, and right twist; the fibers in the yarn tilt from the bottom left to the upper right, which is Z twist, or backhand twist, or left twist. As shown in FIG.
