With the continuous increase of packages and the large-scale use of suspended roving frames, the problem of end-breakage of rovings during unwinding of spun yarns is becoming more and more serious. By analyzing the causes of end breakage during roving unwinding, the following solutions are summarized:
1) In view of the breakage caused by the tension during unwinding of the roving, you only need to set the roving twist coefficient reasonably, adjust the position of the yarn guide rod, keep the hanging spindle flexible, and eliminate the problem of bell mouth accumulation and blockage, so that such breakage can be completely eliminated. .
2) For end breaks caused by untwisted slugs and long details, it is only necessary to control such roving defects.
3) On the suspended roving frame, in order to facilitate doffing and post-spinning, there is a pile loop on the upper part of the roving tube specifically to assist in spinning up. Due to the improper doffing operation of the roving lathe, the roving will be unwound to the last two layers in the upper pile. The phenomenon of decapitation at the circle is relatively common.
This type of end breakage requires correct positioning and doffing operation methods, and is completely avoidable. Correct positioning and doffing operation method: maintain the correct dragon rib height positioning. The starting position of spinning must be higher than the pile loop position. When driving after doffing, the dragon ribs go upwards, and the wound roving first moves from the upper position of the pile loop to The lower part is rolled up and the pile loop is pressed. Even if adhesive breakage still occurs, since the length of roving left on the roving tube is already very short, it will have little impact on production.
4) The other type of breakage is completely different from the above three types of breakage. The breakage pattern is as follows: it is less when the roving and large yarns are unwinding, and gradually increases after the medium and small yarns (especially the small yarns); There are many varieties of chemical fibers and few pure cotton varieties; some rovings are sticky and some are not; it is more likely to occur when the temperature and humidity are low; some rovings even form a small sticky ring behind the medium and small yarns (sometimes is a bundle of fibers), causing broken ends in an uncertain position. The main reason is the breakage caused by the adhesion of the roving caused by various factors.
Solutions to this type of end breakage: control drawing weight unevenness, especially reducing thin slivers; promptly replace the aging false twister, and regularly clean the false twister with gasoline when spinning chemical fibers; ensure the hollow arm of the spindle flyer Smooth, it should be polished and cleaned regularly with gasoline strips; the temperature and humidity of the workshop should be adjusted according to the raw materials, especially the relative humidity in winter should be moderately high to prevent the adhesion and breakage of the roving during unwinding caused by the static electricity of the raw materials; the roving twist coefficient should be reasonably designed (should not be too small) and spinning tension; the roving storage time should not be too long; reduce poor roving formation caused by various reasons.
Through the implementation of the above measures, the breakage caused by roving unwinding has been significantly reduced, which has reduced the labor intensity of the turner, improved production efficiency, reduced production costs, and improved yarn quality.
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