Roving “cotton rat”, which is what we often call “rat yarn”. It is a small cotton bundle defect randomly mixed in the roving spun by the roving machine. If the carding air suction is poor, the carding airflow will be disordered, and there will be too much disordered fibers and short lint in the raw sliver. In addition, the draw spacing will be improper, and the fiber straightness and parallelism in the cooked sliver will be poor after drafting, and the evenness will be poor. If the roving cannot be pulled apart, it will cause short slugs.
Roving produces “cotton rats”, you must distinguish the following two situations:
1. Only thick parts, no details or the details are not obvious. The reason for this situation is usually drawing, and sometimes roving flowers will also form. But one thing is for sure: this situation has nothing to do with the roving drafting area.
2. Thick sections should be followed by details. In this case, it is certain that the problem must occur in the roving drafting area, usually caused by the failure of the upper and lower aprons to rotate properly.
Other influencing factors: hanging flowers and collecting flowers in the Xilindorf Triangle; tin The outlet distance of the lower cover plate in front of the forest is too large, and the damage to the doffer card clothing is not transferred well; the air suction of the draw frame is small, and the short velvet of the pile cover is not sucked away by the suction air but is brought back into the cotton sliver by the pile cover; the coiled inclined tube , Chassis hanging; poor cradle pressure; roving spacing is too small, improper draft distribution, spindle wing hanging flowers, pile board flowers are brought in; temperature and humidity changes greatly, etc.
There are many causes of “cotton rats” in roving. In order to strengthen equipment maintenance and strictly control operation, While operating and managing, the choice of process cannot be ignored. Reasonable selection of process parameters is the guarantee of stable product quality, so that products that satisfy customers can be produced.