In the long-detailed prevention and control process, only by accurately grasping the characteristics of defects and correctly analyzing the process and causes can we get to the point and prescribe the right medicine to solve the problem.
Cause analysis
The reasons for the generation of long details are relatively complex. In actual production, many factors can cause different types of long details. The following is a summary from three aspects: equipment, operation and technology.
1 device
Unmerged:
The guide roller rotates inflexibly and is easy to get stuck; the surface of the guide roller has rust spots, and there are burrs on the collector, bell mouth, coiler and other parts, which is easy to hang; the roller rubber roller is eccentric; the rubber roller roller The surface is sticky with cotton wax, which is easy to get tangled; the transmission key pin is loose, the gear is worn out, and it stutters during operation; the automatic stop fails.
Roving:
Guide roller burr hanging pattern; yarn Burrs and miscellaneous cotton wax in the channels such as the spindle cap, hollow arm, rear bell mouth, etc. cause unexpected tension increases; the upper pin is skewed and deformed, and the pressing palm is deformed, causing the cotton sliver to be stretched unexpectedly; the roving anti-detail device fails.
Spinning yarn:
The guide rod has rust spots, burrs and hanging flowers; horn The mouth burrs are stuck; the hanging spindle is not flexible in rotation; the upper pin is skewed and deformed; the rubber roller and rubber ring are damaged.
2 Operation
Finishing: manually lift the guide roller Start; feeding due to lack of strands, self-stop failure, and unclean cutting of the sliver by the lathe; improper operation of the sliver during transportation and handling caused damage to the sliver; the joint was unqualified and too thin; after wrapping the rubber roller, the sliver could not be found. Defects.
Roving: the sliver is twisted and split behind the machine; the sliver is illegally spliced before and after the machine and is too thin; the sliver is too thin Without going through the normal passage, wrap the guide bar around the fork.
Spinning yarn: During the unwinding process, the roving does not go through the normal channel and winds around the cradle axis and the yarn guide rod. , winding rubber rollers, etc., which can easily cause accidental drafting. The drafting area is poorly cleaned, the apron is pinched, the upper pin is lifted, and accidental drafting occurs; the joint is unqualified (strong twisting).
3 Process
The process is mainly about tensioning the yarn everywhere Line influence.
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, while ensuring normal production. Under the premise, it should be controlled on the small side.
Preventive measures
1) Strengthen workshop temperature and humidity management to reduce Identify winding and blocking problems in each process, detect fluctuations, and make timely adjustments.
2) Strengthen equipment maintenance. The spinning channel should be smooth and clean, free of cotton wax, impurities, and burrs. Key parts such as the upper pin and palm should be calibrated periodically, and the gears should be in good mesh. Retire aging gear.
3) Improve the level of operation management so that new employees have quality awareness and understand the basic quality requirements of yarn. There are no joints in front of and behind the machine. We must be aware of 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 choose the best tension configuration.
6) Develop a complete inspection and assessment system for various factors that are prone to growth details. Responsibilities will be assigned to everyone, and violators will be punished. </p
