Analysis of common problems of fibers and yarns

(1) Cotton grains

Appearance: The cloth surface presents cotton fibers with a size similar to the joint, and is spun into the yarn. If it is pulled out, the yarn is in a state of breaking or about to break. Rovings spun from low-grade raw cotton often have such defects.

Causes: 1). There are dead cotton fibers in the raw cotton, which are not completely removed during the cleaning process. 2). When carding, the needles of the cylinder or the needle plate are not sharp enough, or the distance between the two is not properly set, so that the carding effect cannot be fully exerted.

(2) Cottonseed skin

Appearance: The surface of pure cotton or cotton fiber blended fabric, with some small black or dark non-fiber fibers. Permanent antibacterial and deodorant yarn

Causes: 1). When the cotton fiber is separated from the cottonseed in the cotton ginning process, the root end of the fiber has cottonseed skin, or the cottonseed is crushed and mixed into the raw cotton. 2). The cottonseed skin was not completely removed during the cleaning process.

(3) Rough knot

Appearance: On the warp or weft of the fabric, there is occasionally a small section of tufted fibers with a length of about 5 to 20mm, which is thicker than the normal diameter of the yarn and less than the normal number of twists in the frying.

Causes: 1). In the roving fed during worst spinning, the density of the fibers is not uniform, and there are small and dense fusiform fiber bundles. 2). The top rollers and aprons of the worst spinning machine cannot uniformly hold the fed roving.

(4) Flying flowers

Appearance: Similar to the thick knot, but it is thicker, not as slender as the thick knot, and the fibers are lumpy. The yarn is slightly untwisted to prevent the yarn from breaking.

Cause: The fiber mass floating in the air between the spun yarns, or the fiber mass accumulated on the nearby table fed by the machine, is entangled on the yarn.

(5) Yarn

Appearance: In a section of yarn about the width and length of the fiber, there are large and thick knots at intervals. The thickness of the yarn changes like a slub, which is generally more common in the weft of roving fabrics, so it is also called slub weft.

Cause: The setting of the drafting roller of the worst spinning machine is too tight, the roller cover is too loose, and there are occasionally abnormal fibers in the fed roving.

(6) Uneven yarn count

Appearance: Observed from the long side of the fabric, the woven yarn has uneven thickness. Generally occurs in the weft. Permanent antibacterial and deodorant yarn

Cause: The yarn spun by the spinning frame is sometimes thicker and finer for a period of time due to the failure of the drafting mechanism or poor performance.

(7) Cloud Weaving

Appearance: The count of the weft yarns is significantly uneven, and the thick or thin yarns are just concentrated and arranged together during weaving, forming a sheet shape.

Cause: The weft yarns are irregular in regularity, and the weft yarns are arranged so thickly or thinly together during weaving.

(8) Fiber point

Appearance: Dyeing fabrics with a small amount of fibers on the surface of the fabric that are not colored, or are lightly colored and appear whitish.

Causes: 1). There are dead cotton fibers in the cotton fibers. 2) During the spinning process, due to negligence or lack of control, a small amount of polyester fiber is mixed, and disperse dyes are not used during dyeing, and the polyester fiber is not dyed at high temperature.