Many netizens who follow us have raised questions about spun yarn breakage. We will now summarize and describe the classification and breakage rules of spun yarn as a unified reply to netizens who ask such questions.
Spinning yarn breakage can be divided into two types: breakage before yarn is formed and breakage after yarn is formed.
End breakage before yarn formation refers to the breakage of the yarn before the output roller, that is, it occurs in the feeding part and the drafting part, such as roving end breakage, empty roving, It is caused by the blockage of the collector, the drafting strips running out of the collector, the accumulation of flowers in the apron, the fiber winding around the top roller, the fiber winding around the roller, etc. End breakage after the yarn is formed refers to the breakage of the yarn between the front roller and the bobbin during the twisting and winding process. The causes include abnormal twisting and winding machine parts (such as spindle vibration), Jumping bobbin, wedged traveler, flying traveler, abnormal balloon shape (too large, too small or crooked balloon), poor operation, blocked cotton suction flute tube or low vacuum, poor temperature and humidity control, etc. . In addition, large fluctuations in raw material properties, improper process design, and poor semi-finished product structure cause yarn strength to decrease and strength unevenness to increase, which can lead to end breakage.
Under normal conditions, there are few end-breaks before yarn is formed, and the main ones are end-breaks after yarn is formed. The rules for broken ends after yarn is formed are as follows:
(1) The distribution of broken ends in a doffer is generally the largest number of small yarns, followed by large yarns, and the smallest number of medium yarns. The parts with more broken ends are the place where the empty tube starts spinning, the place where the bottom of the tube is about to be wound with a large diameter, and the place where the large yarn is wound with a small diameter.
(2) After the yarn is formed, the most broken parts are in the spinning section (called upper broken ends), and the parts with broken ends from the traveler to the bobbin (called lower broken ends) ) occurs less often, but when the steel ring and the traveler are not matched properly, it will cause vibration, wedging, wear, burning, flying circles, etc. of the traveler, which will increase the number of broken ends in the lower part. The chance of end breakage occurring in the balloon part is very small. Only when the steel ring is declining and the traveler is too light, the excessively convex shape of the balloon hits the gauze plate, causing the yarn to become hairy or break.
(3) Under normal production conditions, the vast majority of spindles do not have ends broken during the first doffing, and only repeated ends breakage occurs on individual spindles. This is due to the mechanical state It is caused by sudden changes in spinning tension due to poor quality.
(4) As the spindle speed increases or the package increases, the tension also increases, and the breakage generally increases. </p
