JPH059351B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a winding method using an automatic thread switching winding machine that automatically switches thread from a full bobbin during winding to an empty bobbin on a spare spindle running up to 4000 m/min. The present invention relates to a method for improving the yarn switching success rate during high-speed winding without causing a decrease in yarn quality in the innermost layer of a package. [Prior art] In a spinning method such as a direct spinning drawing method and a high-speed spinning method, in which yarn is continuously spun from a spinning device without interruption and then wound, the empty bobbin is During the thread switching operation to the bobbin, a method has generally been adopted in which the spun yarn is sucked into a suction gun or wound around a waist roller. However, in this conventional method, there is a loss that all the threads during the thread switching operation become waste threads, so a spare spindle is provided, and after the empty bobbin is attached to the spare spindle and run-up, the yarn is removed from the fully wound bobbin. Automatic thread switching winding machines that automatically switch thread to an empty bobbin have recently come into use. In this automatic yarn switching winding machine, the yarn switching operation is performed by removing the traveling yarn from the traverse device in order to capture the yarn in the blade cut of the empty bobbin. If the rotational speed of the spindle at the time of yarn switching is the same as during steady winding, the actual yarn winding speed will decrease due to the lack of winding angle due to traverse at the time of yarn switching, and the winding speed at the upstream side of the winding device will decrease. A problem arises in that the speed balance between the yarn device and the winding device is lost. Furthermore, since the thread switching operation is performed using a thread guiding guide, the winding tension may be lowered due to the running thread coming into contact with the guiding guide, or when the thread is switched onto an empty bobbin. Even due to the instantaneous slack that occurs, the winding tension is considerably reduced at the time of yarn change. In this way, as a result of the speed balance being disrupted and the winding tension being reduced, the yarn is more likely to wrap around the yarn feeding device, etc., resulting in a major drawback in that yarn switching failures occur frequently. In particular, when winding is performed at high speed, the winding tension is kept to the lowest possible tension in order to make the yarn quality uniform and improve the package form, so when the thread is switched, the speed balance is lost and the winding tension is reduced. When this decreases, large slack is likely to occur in the running yarn, and the probability that yarn switching will fail becomes higher. Therefore, in order to suppress the yarn wrapping around the yarn feeding device, etc. that occurs when switching the yarn, and improve the success rate of yarn switching, the speed of the bobbin during winding V ₁ and the speed of the spare bobbin at the time of switching are adjusted. A method has been proposed for preventing the above-mentioned yarn speed imbalance by making V ₂ faster than the bobbin speed V ₀ during steady winding (Japanese Patent Publication No. 11824/1982). In this method, the bobbin speed V ₁ during winding is increased to an extent that compensates for the decrease in the actual yarn winding speed due to the yarn not traversing, and the winding tension before yarn switching is adjusted to the normal winding state. By setting the speed to be the same as that of the winding bobbin, it is possible to prevent the yarn from winding around the yarn feeding device, etc., and by setting the speed of the spare bobbin V ₂ to be higher than the speed V ₁ of the bobbin during winding. The idea is to increase the success rate of thread switching. However, in this method, the speed of the spare bobbin at the time of the thread change is set to V ₂ during winding in order to prevent the yarn quality from deteriorating when the thread is wound immediately before the thread change (this becomes the outermost layer of the package). Since the bobbin speed is higher than the bobbin speed V ₁ , the thread switching is wound immediately after the thread switching (this becomes the innermost layer of the package cage).
The disadvantage is that the quality of the threads deteriorates. The threads in the innermost layer of the package cannot be removed after the package is formed and become part of the product, so the decrease in yarn quality in the innermost layer of the package is actually lower than the decrease in the quality of the yarn in the outermost layer of the package. The above is a more severe problem. Furthermore, with this method of increasing the thread switching success rate by increasing the speed V ₂ of the spare bobbin during thread switching, when the winding speed is increased to 4000 m/min or higher, a sufficiently high thread switching success rate can be achieved. It is difficult to obtain. Also, a method has been proposed in which the speed V ₁ of the bobbin during winding is increased when switching the thread, and the winding tension before the switching is set to a level that is approximately 10 to 50% higher than the steady winding tension. (Japanese Unexamined Patent Publication No. 120368/1983). However, even with this method, when the winding speed is increased to 4000 m/min or higher, it is difficult to obtain a sufficiently high yarn switching success rate. [Problems to be solved by the invention] Therefore, the present invention is capable of improving the thread switching success rate without causing deterioration of the thread quality of the innermost layer of the package cage, and is capable of improving the thread switching success rate at a high winding speed of 4000 m/min or more. The main purpose of this invention is to provide a method that can obtain a sufficiently high thread switching success rate. [Means for Solving the Problems] To achieve the above object, the present invention provides a method for winding yarn at a speed of 4000 m/min or more using an automatic yarn switching winding machine having a spare spindle. When switching, the rotational speed of the bobbin during winding is increased, and when the winding tension T ₁ reaches T ₁ /T ₀ = 2 to 4 (T ₀ : winding tension during steady winding), the thread is switched. The yarn is placed on a spare bobbin that rotates at a speed set so that the subsequent winding tension T ₂ becomes T ₂ /T ₀ = 1.1 to 1.8, and then the rotation speed of the spare bobbin is set to the same speed as that during steady winding. To provide a winding method in an automatic yarn switching winding machine that reduces the winding speed to the winding speed and removes the outermost yarn layer portion of the package obtained by winding to obtain a product package. In the present invention, the winding of the yarn around the yarn feeding device, etc. that occurs when switching the yarn, and the decrease in yarn quality when the winding machine speed is increased too much depend on the value of the winding tension. The degree of increase in bobbin rotation speed at the time of thread switching is expressed in terms of the level of winding tension.
The winding tension is a value measured by the tension of the yarn running near the traverse swing fulcrum. [Function] In order to prevent the yarn from wrapping around the yarn feeding device etc. that occurs during the yarn switching operation, the winding tension before the yarn switching must be adjusted.
It is necessary to set T ₁ and the winding tension T ₂ after yarn switching to a certain level higher than the winding tension T ₀ during steady state. That is, the winding tension T ₂ after yarn switching needs to be at least 1.1 times the steady winding tension T ₀ in order to improve yarn switching performance, and to prevent deterioration of yarn quality in the innermost layer of the package. Therefore, it is necessary that T ₂ /T ₀ be 1.8 or less. In addition, the winding tension T ₁ immediately before the thread switching should be set at a level of T ₁ /T ₀ = 2 to 4, based on the winding tension T ₀ during steady state. necessary in order to obtain a sufficient thread switching success rate in some cases. In the method of the present invention, the rotational speed of the fully wound bobbin is increased before starting the thread switching operation from the bobbin being wound (referred to as a fully wound bobbin) to a spare bobbin (referred to as an empty bobbin). The larger the degree of speed increase, the higher the yarn winding tension and the higher the yarn switching success rate. However, when the speed increase reaches a certain level, the effect of improving the switching success rate reaches saturation, and rather ,
The amount of waste yarn increases as the time required to increase the speed increases. Therefore, the tension immediately before thread switching T ₁ is the steady state tension T ₀
It is necessary that the level is 2 to 4 times that of the above. In addition, even after the thread is switched from a full bobbin to an empty bobbin, the full bobbin continues to rotate for a while. In order to prevent the thread end from being disturbed on the rotating fully wound bobbin,
It is effective to increase the tension just before switching the yarn to the above-mentioned level and to wind the end portion of the yarn (thread yarn) to be wound last with high hardness. It is preferable to increase the rotational speed of the fully wound bobbin before switching the thread, preferably within 30 seconds before the thread switching operation, especially within 10 seconds before the thread switching operation starts. It may be determined experimentally, taking into consideration the resistance of mechanical parts such as bearings. On the other hand, for the empty bobbin, it is necessary to start the run-up rotation and increase the rotation speed to a level such that the tension T ₂ after thread switching becomes T ₂ /T ₀ = 1.1 to 1.8. . The higher the tension T ₂ after thread switching, the higher the success rate of thread switching, but in order to prevent the thread quality from deteriorating in the innermost layer of the package cage, it is better to keep the tension T ₂ as close to the steady state as possible. In view of the balance between the two, the above level is optimal. The level of the tension _T2 after yarn switching to be actually adopted may be determined depending on whether or not the roller immediately before winding is heated, or the yarn spinning process conditions such as the roughness of the roller display. Note that the steady state tension T ₀ is generally 0.1 to 0.3 for nylon fiber when winding at a high speed of 4000 m/min or higher.
It is sufficient if it is about g/d. After the thread is switched to the empty bobbin, the rotational speed of the empty bobbin (which becomes the bobbin being wound after the thread switching) is reduced to the winding speed at the time of steady winding, and a transition is made to steady winding. On the other hand, the fully wound bobbin is stopped from rotating and removed from the spindle, and then the outermost yarn layer is removed and the yarn ends are locked by conventional means to form a product package. At this time, the rotational speed of the fully wound bobbin is increased before the start of the yarn switching operation, and the winding tension of the outermost yarn layer portion to be removed from the winding package is equal to T ₂ (the winding tension after yarn switching). This refers to the yarn layer portion where yarn quality has deteriorated, such as the yarn layer portion that is wound at a higher value than the winding tension value set as . The yarn layer portion to be removed can be roughly estimated as the length of the wound yarn, etc. from the time from increasing the rotational speed of the fully wound bobbin to the time when the yarn is switched and the rotational speed. Note that the change in the winding tension carried out in the method of the present invention is carried out by increasing or decreasing the rotational speed of the bobbin. This can be done by means of temporally controlling the frequency using a computer program or the like. The method of the present invention can be widely applied to winding synthetic fibers at high speeds of 4000 m/min or higher using a yarn switching winder equipped with a spare spindle. Effective for winding. Further, it can be applied to a spinning method in which the yarn is wound without substantially stretching after spinning, or a spinning method in which the yarn is stretched and then wound after spinning, but it is particularly effective in a spinning method in which the yarn is stretched and then wound after spinning. [Example] - Example and Comparative Example 1 In order to obtain 6 nylon yarn of 70 denier and 24 filaments, after melt spinning, a peripheral speed of 4300
Take-up by the first roller at m/min, followed by circumferential speed of 5150
After passing through the second roller heated to 180℃ at m/min,
The yarn was wound using a turret-type automatic yarn switching winder that performs cheese-like winding (winding speed of about 5000 m/min) at a steady winding tension T _{0 of} 14 g (=0.2 g/d). When the spinning yarn being wound becomes full, 60 seconds before the yarn switching operation starts, the spindle on the empty bobbin side starts running, and the spindle on the bobbin side is kept on standby at a circumferential speed of 5050 m/min. The spindle increases the rotational speed from 6 seconds before the start of thread switching to increase the winding tension.
Thread switching was performed immediately after T ₁ reached 35 g (T ₁ /T ₀ =2.5). The winding tension T ₂ after the yarn winding is switched to the empty bobbin side is 18 g (T ₂ /T ₀ = 1.3), and the rotational speed of the empty bobbin is changed to the normal winding speed within 10 seconds after this yarn switching. The winding speed was reduced to maintain a steady winding tension. A thread switching success rate of 99% was obtained by switching the thread under these conditions. No deterioration in thread quality was observed in the innermost layer of the resulting package. Of the outermost layer of the obtained package, the yarn layer portion wound after the rotational speed of the spindle on the fully wound bobbin side began to increase was removed to obtain a product package. The winding tension before and after the above thread switching point is the first
Changes were shown as shown in the figure. The horizontal axis in FIG. 1 represents the passage of time, with code A indicating the point in time when the rotational speed of the spindle on the fully wound bobbin side started to increase, code B indicating the point in time when the thread switching operation started, and code C indicating the time point when the rotational speed of the spindle on the fully wound bobbin side started to increase. The points at which the running yarn is captured on the empty bobbin side are shown. In addition, the same method as above was repeated except that only the tension T ₁ immediately before the thread switching was varied, or only the tension T ₂ after the thread switching was varied. The innermost layer of the resulting package was subjected to a staining test to evaluate the degree of staining, and the results are shown in Table 1.

[Table] As can be seen from Table 1, in order to improve the thread switching success rate during high-speed winding of 4000 m/min or higher, T ₁ /T ₀ ≧2 and T ₂ /T ₀ ≧1.1 are required. In addition, the tension _T2 after thread switching is
In order to sufficiently improve the success rate of yarn switching by preventing the yarn from wrapping around the yarn feeding device, etc. during yarn switching, and to prevent a decrease in yarn quality in the innermost layer portion, T ₂ /T ₀ = 1.1. ~
It is necessary to keep it within the range of 1.8 (No. 1, 12 to 15). - Comparative Example 2 The winding speed immediately before thread switching was 5050 m/min (the winding tension T ₁ at that time was 0.26 g/d, that is, T ₁ /T ₀ = 1.3)
And the winding speed after thread switching is 5150 m/min (the winding tension T ₂ at that time is 0.40 g/d, that is, T ₁ /
When the same method as in Example 1 was repeated except that T ₂ = 2.0), the thread switching success rate was as low as 10%, and the innermost layer of the resulting package cage showed no staining spots as a result of the dyeing test. It became. From this, even if the post-switching tension T ₂ is quite high, if the pre-switching tension T ₁ is low and T ₁ /T ₀ is less than 2.0, there will be sufficient yarn for high-speed winding of 4000 m/min or more. It can be seen that it is difficult to obtain a switching success rate. [Effect of the invention] When the yarn is switched and winding is performed using an automatic yarn switching winding machine according to the method of the present invention, the winding speed is 4000 m/min.
Even at high speeds of more than 1 minute, the winding tension T ₁ immediately before thread switching and the winding tension T ₂ after thread switching are set to a specific level of T ₁ /T ₀ = 2 to 4 and T ₂ /T ₀ = 1.1 to 1.8. By doing so, a sufficiently high thread switching success rate can be obtained. Furthermore, it is possible to obtain a high-quality product package in which neither the innermost layer nor the outermost layer of the package has a portion with reduced thread quality. Furthermore, according to the method of the present invention, it is possible to suppress the disturbance of the yarn end of a fully wound bobbin that continues to rotate even after the yarn is switched.

[Brief explanation of the drawing]

FIG. 1 is a graph showing changes in winding tension before and after yarn switching in Example 1. A: The time when the speed of the spindle on the full bobbin side starts increasing, B: The time when the thread switching operation starts, C: The time when the yarn is captured on the empty bobbin side.

Claims (1)

[Claims] 1. Automatic yarn switching winding machine with spare spindle
In a method for winding yarn at a speed of 4000 m/min or more, when switching the winding bobbin, the rotational speed of the bobbin during winding is increased so that the winding tension T ₁ becomes T ₁ /T ₀ = 2~
4 (T ₀ : winding tension during steady winding), the spare bobbin rotates at a speed set so that the winding tension T ₂ after thread switching becomes T ₂ /T ₀ = 1.1 to 1.8. Then, the rotational speed of the spare bobbin is reduced to the winding speed during steady winding, and the outermost yarn layer portion of the package obtained by winding is removed to form a product package. A winding method in an automatic thread switching winding machine characterized by: