The reasons for the occurrence of long details are relatively complex. In actual production, many factors will cause different types of long details. The following will discuss from the three aspects of equipment, operation and process.
Equipment factors
1. Not merged
The guide roller rotates inflexibly and is easy to get stuck; the surface of the guide roller has rust spots or there are burrs on the collector, bell mouth, coiler and other parts, which is easy to hang; the roller glue The roller is eccentric, the surface of the rubber roller is stained with cotton wax, and it is easy to get tangled; the transmission key pin is loose, the gear is worn, and it stutters during operation; the automatic stop fails.
2. Roving
Guide roller burrs and hanging flowers; yarn channels such as spindle caps, hollow arms, and rear horns Burrs at the mouth and other places, and cotton wax stuck on it cause unexpected tension increase; the upper pin is skewed and deformed, the pressing palm is deformed, etc., causing the cotton sliver to be accidentally stretched.
3. Spinning yarn
Rust spots and burrs on the guide bars cause burrs; burrs on the bell mouth cause burrs; the hanging spindle does not rotate Flexible; the upper pin is skewed and deformed; the rubber roller and rubber ring are damaged.
Operational factors
1. Ending
Manually lift the guide roller; missing strands The feeding and automatic stop failed, and the lathe cut the sliver cleanly; improper operation caused damage to the sliver during transportation and handling; the joints were unqualified and too thin; after wrapping the rubber roller, the defective sliver could not be found.
2. Roving
The cotton sliver is twisted and split behind the machine; the joints in front and behind the machine are illegal and too thin; The cotton sliver does not pass through the normal channel and is wrapped around the guide fork.
3. Spun yarn
The roving does not go through the normal passage during the unwinding process, and appears to wind around the cradle axis and the guide yarn. Rods, winding rubber rollers, etc. can easily cause accidental drafting; poor cleaning of the drafting area, pinched rubber rings, and lifted upper pins can cause accidental drafting; unqualified joints (strong twisting).
Process factors
The process is mainly the influence of tension on the yarn.
End doubling: the draw frame guide bar tension is too high; the coil bar tension is too high.
Roving: The tension of the guide bar of the roving machine is too large; the winding tension is too large; the tension difference between large, medium and small yarns is too large.
In short, excessive tension in each process will provide more opportunities for accidental drafting. On the premise of ensuring normal production, it should be controlled to a small value.
Long detailed preventive measures
1. Strengthen workshop temperature and humidity management, reduce winding and blocking in each process, and make timely adjustments when fluctuations are found.
2. Strengthen equipment maintenance, keep the spinning channel smooth and clean, free of cotton wax, impurities, burrs, etc., and calibrate key parts such as the upper pin and pressure palm periodically to ensure gear engagement. Good, the aging gear needs to be eliminated.
3. Improve the level of operation management so that new employees have quality awareness and understand the basic quality requirements of yarn. There should be no joints before and after the machine, and there should be awareness to check for defects caused by thin strips and missing strands in the previous process.
4. Tighten the threshold value of long details in electronic clearing so that long details yarn defects can be caught in time before leaving the factory.
5. Actively test the spinning process and select the best tension configuration.
6. Develop a complete inspection and assessment system and responsibility system for various factors that are likely to cause growth details.
</p
