Control of yarn defects during spinning
Yarn defects classification
1.1 classification according to the probability of yarn defects.
It can be divided into regular yarn defects and accidental yarn defects.
1.1.1 regular yarn defects.
The constant yarn defects include kilometer cotton knot, kilometer thick section and kilometer detail. Onset of yarn defects often short, small, many, not easy to clean thoroughly, the production efficiency of weaving and fabric defect rate does not cause serious influence, but obvious effects on the fabric cloth cover style, so it must control the number of cases of yarn defects.
1.1.2 accidental yarn defects.
Accidental yarn defect is also called sudden yarn defect, which is usually sudden, widespread and harmful. Accidental yarn defects is mostly due to poor production management, operation, equipment, and designed a bad condition of operation, process caused by unreasonable wait for a reason, after the process and the fabric quality will cause serious adverse effects, so must be removed. In the process of production, accidental yarn defects often appeared along with the change of certain factors, quickly spread to the production line of parts of the varieties or make some quality indexes appeared more substantial fluctuations.
1.2 according to the nature of yarn defects and the classification of damage to the fabric.
The yarn defects can be divided into three categories: material yarn defects, stretch yarn defects and operation management.
1.2.1 material defects.
Raw material yarn defects are usually caused by poor performance of raw materials or poor carding, such as poor length uniformity of fiber; The fineness difference is too large; Short down rate; Low maturity; High content of cotton, leaves, cottonseed shells and fiber seeds; The degree of separation, straightness and parallelism of the fibers. The yarn defects of general raw material are short and small, and are often characterized by frequent yarn defects.
1.2.2 defects of drafting yarn.
The defects of the draft yarn are due to the unreasonable design of the process parameters, such as too large or too small roller spacing, unreasonable distribution of draft in the rear area, too large or too small for the rubber ring. The rubber roller is too hard or too soft, the grinding cycle is unreasonable, and the carding part is made, so that the straightening of the fiber bending hook or the fiber in the drafting process can be broken and produced. The defects of draft yarn are accidental yarn defects, most of which are 1 ~ 4cm thick and long details, which are more harmful to the cloth surface, and are often referred to as harmful yarn defects.
1.2.3 operation management yarn defects.
It mainly refers to long and thick sections with length greater than 4cm. It relates to equipment, process, operation management, temperature and humidity, etc. For example, the rough details produced by the bad connection; The whole work, the car workers to the machine to clean the flying flowers, the velvet flowers. In addition, due to the poor maintenance or improper operation of the fender, the slanting spindle, the tilted air ring, the steel collar plate, the hair of the tube head, produce a large area of woollen yarn; The damaged rubber roller rubber ring or cotton yarn channel area hanging flowers produce bamboo, rough details and so on. These two kinds of yarn defects are generally reflected in the fabric, both are harmful yarn defects, and are the yarn defects that need to be controlled.
1.3 classification of process by yarn defects.
Can be divided into semi - finished yarn defects and finished yarn defects.
1.3.1 semi-finished yarn defects.
Semi - finished yarn defects, such as flannelwood, greasy flower, dirty flowers, flying flowers, or tampons, are caused by the unpacking of pimples, thick strips, woolen strips, hanging flowers, and different fibers, etc.
1.3.2 yarn defects.
Finished product defects including regular slub yarn, cotton waste into, fly into, raw head bad, oil gauze, gauze, poor, weak twist yarn bobbin forming, strong, fibrous yarn, yarn twist unevenness of grain, cotton yarn, slub yarn, details, etc.