1、Generally, the POY tail yarn refers to the few turns of yarn left between the package and the tail groove when the yarn cake is opened on the winder and retained according to the tail-leaving time process. (Some people also call the yarn that remains on the cake surface due to the winder’s inertia after winding ends a tail yarn.) Its core mission is simple: during feed changeover on the texturing machine, it must be located quickly and joined successfully to ensure continuous production.
What chain reaction can a defective tail yarn cause? When this “relay baton” is defective, the texturing line typically experiences the following scenarios:
Failed starts and frequent breaks: when changing packages the operator cannot find or extract the tail yarn, or the tail yarn breaks at the slightest touch, causing start-up failure and machine stoppage.
Sharp drop in efficiency and rising costs: each failed start means several minutes or more of downtime to recover, reducing per-machine output and increasing unit energy and labor costs.
Material waste and quality concerns: repeated start-up attempts waste POY feed and DTY finished yarn. Instability during start-up can also potentially affect the quality of DTY near the join point.
Core customer complaints: downstream weaving mills least want frequent stops on the texturing machine caused by feed problems, because this directly affects their delivery schedules and production costs.
二、Four abnormal conditions of POY tail yarn
Based on on-site complaint feedback, problematic tail yarns mainly appear in the following forms:
1、Tail yarn that is too long or too short
Too long: The tail yarn is tangled and buried deep within the yarn layers, making it difficult to find; or it flutters in the air and becomes entangled with other parts. Too short: The tail yarn is not long enough to be reliably picked up and pulled by the suction nozzle, increasing the difficulty of handling.
2、Poor tail formation
Curled/looped: The tail yarn is not straightened and is coiled like a spring, preventing it from passing smoothly through the guide eye.
Loosely formed: Not securely fixed in the tube groove; it falls out or is lost with the slightest touch.
Incorrect position: Not placed in the specified, clearly marked location, causing time-consuming searching.
3、Oil contamination The tail yarn is soiled with oil, which reduces its strength and causes it to break under the tension during start-up.
4、“Misplaced tail yarn” This is actually foreign/expired yarn (entangled waste yarn) mixed into the tail turns, causing poor joining on the texturing machine.
三、Root cause analysis: who damaged the “relay baton”?
1、Improper POY winder equipment and process settings
Tail-leaving auxiliary device failure or not enabled: e.g., tail catchers or pneumatic clamps not functioning properly.
Tube groove design is inadequate: too smooth or too shallow to hold the tail yarn securely.
The tail-leaving time setting has drifted over time and was not adjusted or coordinated with the equipment team in time.
2、Inadequate maintenance inside the winder Poor internal maintenance of the winder leads to frequent pseudo-tail occurrences (actually entangled/waste yarn).
3、Design defects in the automatic doffing carriage
When the automatic doffing carriage is full of wound packages, it often pulls on the outer-layer tail yarns of the packages inside; these break and spring into the package currently having its tail laid, causing frequent pseudo-tails (in fact entangled/waste yarn).
四、How to produce a “reliable” relay baton (tail yarn)
1、Establish and enforce SOPs (standard operating procedures): specify the number of tail turns to be left for each product type according to customer requirements. Set up a periodic inspection plan for tail yarns and coordinate adjustments with the equipment team. Strengthen external inspection of tail yarns for product types that generate complaints.
2、Equipment and tooling assurance: ensure tail-leaving auxiliary devices (such as tail clamps and threading hooks) are in good working order. Clean the inside of winders regularly. Fit (or improve) the automatic doffing carriage to reduce pulling on tails of full packages.
3、Strengthen training and assessment: make tail-leaving operations a key part of new-operator training and routine skills assessments. Emphasize the concept that “the next process is the customer” and cultivate a quality-chain mindset.
五、Conclusion
The POY tail yarn—the short yarn end generally under twenty centimeters long—is the “last centimeter” connecting spinning and texturing. Its condition directly reflects the fineness of the POY producer’s operating practices and customer-orientation. While pursuing high speed and high output, these details must not be neglected. Only by upstream–downstream collaboration and by treating small items like tail-leaving as critical—standardizing and institutionalizing them—can the production relay run steadier, faster, and smoother.
