JPS6136095B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improvement in a doffing tube change method for a false twisting machine, and provides a method that does not cause the yarn to become brittle or break and can efficiently perform the tube change operation. Simultaneous drawing and false twisting has recently come to be carried out in the production process of false twisted yarns of synthetic fibers, since the processing speed can be dramatically increased by applying the friction false twisting method. As the machining speed increases, the dotting operation becomes more complicated.
It becomes difficult. Conventionally, the method of operating a draw-twisting machine when changing the doffing pipe is to stop the machine after one sai and start it again after the next sai, but this method can also be used to change the doffing pipe of a simultaneous drawing and twisting machine. Applied. When changing the doffing tube of a draw-twisting machine, even if the machine is stopped and restarted between each dop, there is no problem of thermal embrittlement of the needle threads that are not subjected to heat treatment. However, in the case of a false twister, heat treatment is inevitably involved, so the yarn that is not running during tube change is heat treated with a high-temperature heater. It is known that if the heat treatment time is longer than a predetermined time, the yarn becomes brittle, and to prevent this, the yarn is automatically moved a certain distance away from the heater. In reality, the threads are heated to high temperatures by radiant heat or the like, and the yarn becomes brittle during the residence time of the doffing pipe change operation. Therefore, when the apparatus is restarted in a state where the embrittlement has progressed in this manner, thread breakage occurs frequently, and a large amount of time is required to dispose of the thread breakage. The present invention has been achieved in order to eliminate the drawbacks of the prior art, and is a method of stopping the machine for simultaneous stretching and false twisting in one sai and starting it every other sai (one sai start-stop method). To provide a new method that prevents yarn breakage that occurs when restarting after doffing tube change when applied, and allows easy rethreading of a weight whose yarn has broken during production after doffing tube change. The purpose is to The structure of the present invention for achieving the above object is characterized in that the following procedure is carried out when changing the doffing tube of a quantitative cheese obtained by simultaneous stretching and simultaneous false twisting. First step: The false twisted yarn running at production speed is taken from the winding cheese into the waist device. Second step: The entire false twisting machine is run at a speed close to the yarn cutting limit speed at which the running yarn does not break. Third step: Doff the wound cheese on the false twister at the yarn running speed and install an empty bobbin. Fourth step: The speed of the false twisting machine is increased to a speed higher than the speed at the time of the tube change but lower than the production speed at which yarn can be threaded, and the thread trimming weight is rethreaded as necessary. Fifth step: The speed of the entire false twisting machine is increased to the production speed, and the yarn taken up by the waist device is returned to the normal yarn path and threaded. The present invention was obtained as a result of studying the drawbacks of the above-mentioned prior art when the yarn is completely stopped, and is based on the following knowledge. (1) When the yarn in contact with the heater completely stops, this yarn deteriorates in a short time. This phenomenon occurs even when the yarn does not come into contact with the heater and is stopped in close proximity to the heater. However, if the yarn is moving at an extremely low speed, there will be little deterioration, and even if there is slight deterioration, yarn breakage will not occur. (2) On the other hand, when the speed drops below a certain level, the frictional force between the traveling system and the rotating body of the false-twisting device increases rapidly, and the number of twists in the false-twisting section increases accordingly, approaching the double twisting limit and untwisting. Ratio of tension T ₂ to false twisting tension T ₁ T ₂ /
T ₁ descends. When this tension ratio T ₂ /T ₁ decreases, the machining condition becomes unstable. However, if threading is completed at a relatively high speed and the speed is continuously lowered, it is possible to transfer the thread without breaking the thread even at a very low speed. Judging from the above phenomenon, once the yarn is threaded, yarn breakage does not occur even if the speed is continuously reduced from the steady processing speed, so the yarn can be transferred at a considerably low speed. . On the other hand, when the yarn is transferred at the low speed, the tension ratio
As T ₂ /T ₁ becomes smaller, the false twisting state becomes unstable, which may cause yarn breakage. Moreover, in this state, threading becomes difficult. However, when the speed is gradually increased from the above-mentioned speed, there is a speed range in which the false twisting state becomes stable and threading becomes easy. The present invention was obtained based on the above-mentioned knowledge, and involves reducing the yarn speed to a low speed that does not break the yarn while taking over the yarn with a waist device during tube change operation, and keeping the false twisting machine at this speed. Complete the pipe change while maintaining the same speed as above, then increase the speed of the false twisting machine to a speed that is higher than the speed at the time of pipe change but lower than the production speed at which yarn can be threaded, and re-thread the thread trimming weight as necessary. After carrying out threading, the production speed is increased and the yarn taken up by the waist device is wound onto a new bobbin. Transfer the yarn from the waist device to the new bobbin,
Yarn breakage may occur during the winding process, but in this state, most of the weights have already been threaded, so the false twisting process is stable, but at the slowest possible speed. In addition, the thread speed can be reduced to a speed at which threading can be performed, and threading of the thread cutting weight can be carried out in this state. Next, embodiments of the present invention will be described with reference to the drawings. The figure is a perspective view showing a drive system diagram of a simultaneous stretching and false-twisting device used in an embodiment of the present invention. The synthetic fiber multifilament yarn Y supplied to the first roller 1 passes through a first heater 2 and a cooling plate 3, is supplied to a friction false twisting device 4, and is stretched and false twisted at the same time before passing through a second roller 5. Processing is performed. In this state, without heat treatment, the roller 7
One is wound onto the bobbin 11 after passing through the second heater 6, and the other is wound onto the bobbin 11 after being heat-treated through the second heater 6.
Two types of false-twisted yarns can be manufactured: 10 is a winding roller, on which a bobbin 11 is placed.
are brought into contact with each other and driven, and the false twisted yarn Y ₁ is wound into the bobbin 11 while being given traverse motion by a traverse roller 9 . A waist roller 8 is provided in connection with this winding device, and the yarn is
It is configured to involve Y ₁ in this. 12 is a gear box, and motor 13 is attached to this.
14 and 15 are supplied with power. This motor 1
3 is a motor that can drive the device at the production speed, that is, the first speed, and motor 14 is a motor that is driven at a second speed that is slower than the first speed, allows threading, and allows stable false twisting. It is. Further, the motor 15 is a motor that is driven at a thread cutting limit speed, which is the limit at which the running thread at a speed lower than the second speed is not cut, or at a speed slightly higher than this, that is, a third speed. Part of the power from the gearbox 12 is transmitted to the gearbox 16, which drives the third roller 7 and also drives the waist roller 8 and the take-up roller 1.
Drive 0. Further, 17 is a take-up traverse motor, which drives the traverse roller 9. The gearboxes 12 and 16 are variable speed gearboxes, and are configured to arbitrarily adjust various conditions such as the drawing ratio of the yarn and the false twisting speed. When the synthetic fiber end drawn yarn Y is supplied to the device,
Stretching at a predetermined stretching ratio and false twisting by a false twisting device 4 are performed between the first roller 1 and the second roller 5, and between the second roller 5 and the third roller 7 as necessary. The yarn is then heat-treated and wound onto a winding bobbin 11 as a heat-treated false-twisted yarn or a non-heat-treated yarn. Next, an operating method for implementing the present invention in the above device will be explained. The drawing false twisting device is operated at the production speed by the motor 13, and when the dotting time comes, the false twisting yarn _Y1 is transferred from the winding bobbin 11 (winding cheese) to the waist roller 8, where it is taken off as a waist yarn, The rotational speed of the motor 13 is continuously reduced, and when the third speed, that is, the thread cutting limit speed or a speed slightly higher than this speed is reached, the drive is switched to the motor 15. At this third speed, the full bobbin 11 (quantity cheese) is removed and doffing is performed. Next, after completing this doffing by loading a new empty bobbin into the weight, the motor 15
to drive the motor 14, re-thread the thread trimming weights as necessary, and after confirming that threading has been completed to all spindles, switch to the motor 13 and gradually increase the speed to start the device. After the entire machine reaches the production speed, the running yarn is returned from the waist roller 8 to the empty bobbin, and the production state is restored. In addition to the waist roller described above, a suction gun, a pneumatic film, etc. can be used as the waist device, but in any case, the thread feeding speed changes during the threading operation, so the thread cannot be pulled at any of these speeds. It is necessary to have the ability to take In order to carry out the present invention, it is important to know the second speed (the speed at which false twisting is possible and threading can be carried out) and the third speed (the thread cutting limit speed or a speed slightly higher than this). be. The table shows the relationship between the processing speed (Vm/min), the thread hooking property, and the state of thread cutting at its acceleration.

[Table] From the above table, it can be seen that when Vm is 0, thread breakage occurs frequently, and when Vm is 0.5, the processing state is unstable, but when it is 1.0 or more, the processing state is stable and no thread breakage occurs. However, at 6.0 or lower, the yarn speed is too slow and the processing condition is unstable, making threading difficult.
Preferably, when it is 25.0 or more, threading is possible and the processing condition is good. The operating conditions for the synthetic fibers and simultaneous stretching and false twisting machine used to obtain the data in the table above are as follows. A Supply yarn type: Polyester 75 denier, 36
Semi-drawn yarn for filament B Drawing ratio: 1.73 C Surface speed of second roller: 400 m/min D Number of false twists: 3400 T/M E False twisting method: Friction false twist F Temperature of first heater: 205℃ Based on the above conditions Judging, as the third speed
V ₃ ≧0.5m/min is suitable, and doffing and pipe changes are carried out at this speed. However, as is clear from the table, at a yarn running speed of 0.5 m/min, the processing condition is unstable and threading is therefore impossible. After running at V ₃ , it is necessary to rethread the weight that was trimmed during production before doffing or during doffing or tube change, so V ₂ ≧15 m/min was selected as the second speed for this operation. be done. From the table above, it is confirmed that threading is possible, although the processing condition is somewhat unstable when Vm is 15.0 m/min, and there is no problem in threading operation. According to the present invention, in V ₃ , doffing and pipe changing operations are performed while preventing the false twisted yarn from becoming brittle, and if necessary, threading of the yarn cutting weight is performed in V ₂ , and then
Normal production can be carried out at _V1 . Note that V ₁ , V ₂ ,
Although V ₃ changes, if you confirm this value experimentally, you can smoothly perform doffing and pipe changing operations without causing yarn breakage due to yarn embrittlement during doffing and pipe changing operations. It can be implemented. In addition, if there is a weight whose thread was cut during production,
Since the threading work can be carried out at a speed higher than _V3 up to the speed of _V2 , the threading work is easy and the generation of wasted thread can be prevented as much as possible.

[Brief explanation of the drawing]

The figure is a perspective view schematically showing an apparatus for carrying out simultaneous stretching and false twisting of synthetic fibers. 1... Feed roller, 2... First heater, 3... Cooling plate, 4... False twisting device, 5... Second
Roller, 6... Second heater, 7... Third roller, 8... Waist roller, 9... Traverse roller, 10... Winding roller, 11... Winding bobbin, 12, 16... Speed change gear box, 1
3, 14, 15...Motor.

Claims (1)

[Claims] 1 Doffing the rolled cheese obtained by drawing and simultaneously false-twisting thermoplastic synthetic fiber yarn from a false-twisting machine,
In a doffing/tube change method in a false twisting machine, the empty bobbin is subsequently installed in the false twisting machine and the tube change is completed, and then the false twisted yarn is wound again onto the empty bobbin.
After the false-twisted processed yarn running at the production speed is taken from the winding yarn cheese to the waist device, the speed of the entire false-twisting machine is set at a speed higher than the thread cutting limit speed at which the running yarn does not break and close to the thread cutting limit speed. reduce the speed to
While keeping the speed of the false twister at this speed, doff the rolled cheese on the false twister and attach an empty bobbin to complete the tube change, then increase the speed of the false twister to the speed at the time of the tube change mentioned above or higher. It is characterized by increasing the speed to a speed lower than the production speed at which threading is possible, re-threading the thread trimming weight as necessary, then returning to the production speed and returning the running thread from the waist device to the empty bobbin. A doffing tube change method in a false twisting machine.