JP2013067885A - Air spinning device, spinning unit, spinning machine and air spinning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air spinning device, a spinning unit, a spinning machine, and an air spinning method, which can control the length of a fiber bundle portion of a yarn end of a divided spun yarn.SOLUTION: An air spinning device 100, which generates a spun yarn 10 by spinning a fiber bundle 8 by using a whirling air current, comprises: a nozzle block 134 provided with a whirling air current generating nozzle 127 for injecting spinning compressed air into a spinning chamber 126 so as to generate the whirling air current inside the spinning chamber 126; a circulation pipe 200 in which the spinning compressed air to be supplied to the whirling air current generating nozzle 127 is circulated; and a spinning switch valve 203 provided in the circulation pipe 200, for switching between the circulation of the spinning compressed air circulating inside the circulation pipe 200 and cutoff of the circulation. The volume inside a first circulation pipe 201 is set so that the length of a fiber bundle 10e at a yarn end of the spun yarn 10 cut by the cutoff of the circulation of the spinning compressed air is a first length.

Description

  The present invention relates to an air spinning device, a spinning unit, a spinning machine, and an air spinning method.

  Conventionally, as a technique in such a field, a spinning unit described in Patent Document 1 below is known. The spinning device provided in the spinning unit generates a swirling airflow by injecting compressed air into the spinning chamber, and twists the fiber bundle introduced into the spinning chamber by using the swirling airflow to produce a spun yarn. Is generated. The spun yarn spun by the spinning device is wound around the package by a winding device disposed on the downstream side. Further, a yarn clearer for detecting a yarn defect of the spun yarn is disposed between the spinning device and the winding device.

  When a yarn defect is detected by the yarn clearer, the spinning device stops jetting the compressed air into the spinning chamber and stops twisting of the fiber bundle. The winding device winds the spun yarn in a state where the twisting of the fiber bundle is stopped, so that the continuous state of the fiber bundle and the spun yarn is divided in the spinning chamber portion.

JP 2006-144136 A

  By the way, the fiber bundle part which is not twisted adheres to the yarn end of the spun yarn which is divided by this spinning device and wound by the winding device. However, control of the length of the fiber bundle part adhering to the spun yarn has not been performed. For this reason, depending on the length of the fiber bundle portion at the yarn end of the spun yarn, the yarn end may not be easily pulled out from the package wound by the winding device. In view of this situation, an object of the present invention is to provide an air spinning device, a spinning unit, a spinning machine, and an air spinning method capable of controlling the length of the fiber bundle portion at the yarn end of the divided spun yarn.

  The pneumatic spinning device according to the present invention is an pneumatic spinning device that produces a spun yarn by spinning a fiber bundle with a swirling airflow, and is a swirling that jets compressed air for spinning into the spinning chamber so that a swirling airflow is generated in the spinning chamber. Nozzle block in which an airflow generating nozzle is formed, a spinning distribution pipe through which compressed spinning air supplied to the swirling airflow generating nozzle circulates, and a spinning compressed air that is provided in the spinning distribution pipe and circulates in the distribution pipe A spinning switching valve for switching between the distribution and the block of the flow, and for spinning so that the length of the fiber bundle portion at the yarn end of the spun yarn cut by the block of the flow becomes the first length A volume in the spinning distribution pipe between the switching valve and the swirling airflow generation nozzle is set.

  In this pneumatic spinning device, it is possible to control the length of the fiber bundle portion at the yarn end of the spun yarn by the volume in the flow pipe between the spinning switching valve and the swirling airflow generating nozzle, and the fiber A spun yarn in which the bundle portion has the first length can be obtained.

The volume in the spinning distribution pipe between the spinning switching valve and the swirling airflow generating nozzle is preferably 1500 mm ³ or less. Here, in the conventional pneumatic spinning apparatus, even when the spinning switching valve is shut off, the compressed air remaining in the flow pipe between the spinning switching valve and the swirling airflow generating nozzle is transferred from the swirling airflow generating nozzle into the spinning chamber. Slowly flowing out, a swirling airflow is generated in the spinning chamber. This swirling airflow has a weak turning force, and the turning force gradually weakens. This swirling airflow causes the fiber bundle to be drawn into the spinning chamber even after the spinning switching valve is shut off, and spinning is not performed properly due to the weak swirling force of the swirling airflow. It will be in the state where the untwisted fiber bundle part adhered. Therefore, the volume in the spinning distribution pipe between the spinning switching valve and the swirling airflow generating nozzle was set to 1500 mm ³ or less. Thereby, the injection of the compressed air from the swirling airflow generating nozzle can be stopped at the same time or almost simultaneously with the shutoff of the spinning compressed air flow by the spinning switching valve, and the generation of the swirling airflow can be stopped. Accordingly, since the drawing of the fiber bundle into the spinning chamber is stopped at the same time or almost simultaneously with the interruption of the flow of the compressed air for spinning by the switching valve for spinning, the length of the fiber bundle portion at the yarn end of the divided spun yarn Can be shortened or the fiber bundle portion can be eliminated.

  The spinning distribution pipe between the spinning switching valve and the swirling airflow generation nozzle preferably has a pipe inner diameter of 2 mm or more and 4 mm or less and a pipe length of 500 mm or less. According to this configuration, it is possible to obtain an optimum spinning distribution pipe that takes into account pressure loss and the like when air flows through the distribution pipe.

  The pneumatic spinning device injects blown compressed air between the introduction path for introducing the fiber bundle into the spinning chamber, the outlet path for leading the spun yarn spun by the swirling airflow to the outside of the spinning chamber, and the introduction path and the outlet path. It is preferable to further include a blow nozzle block in which a blow nozzle is formed. According to this structure, the fiber bundle adhering to the yarn end of the spun yarn can be separated from the spun yarn by injecting the blown compressed air from the blow nozzle between the lead-out path and the introduction path. In this way, the length of the fiber bundle portion at the yarn end of the spun yarn can also be controlled by the blown compressed air injected from the blow nozzle.

  It is preferable to further include a control unit that controls injection of the compressed air for blowing from the blow nozzle so that the length of the fiber bundle portion becomes a second length shorter than the first length. According to this configuration, the length of the fiber bundle portion at the yarn end of the divided spun yarn is set to the second length shorter than the first length by jetting the compressed air for blow from the blow nozzle. Can do.

  A spinning unit according to the present invention includes the above-described pneumatic spinning device and a winding device that forms a package by winding the spun yarn spun by the pneumatic spinning device. According to this configuration, the length of the fiber bundle portion of the yarn end of the spun yarn of the package formed by the winding device can be controlled to a suitable length. For example, the yarn end of the spun yarn from the package can be controlled. The drawer operation and the like are facilitated.

  The spinning unit according to the present invention further includes the above-described air spinning device and a winding device that forms a package by winding the spun yarn spun by the air spinning device, and the control unit is formed by the winding device. The injection of the compressed air for blow from the blow nozzle is controlled so that the second length is adjusted according to the diameter of the package. According to this configuration, the length of the fiber bundle portion of the yarn end of the spun yarn of the package formed by the winding device can be controlled to a suitable length, for example, a yarn end drawing operation from the package, etc. Becomes easy. In addition, when the diameter of the package is small and the fiber bundle part at the end of the wound spun yarn is unnecessarily long, for example, the fiber bundle part goes around the package and the fiber bundle parts are entangled with each other, There is a risk that it will be difficult to pull out the yarn end from the package. Therefore, by reducing the second length as the package diameter is smaller, for example, it is possible to suppress a problem such that the fiber bundle part goes around the package and the fiber bundle parts get entangled.

  It is preferable that the control unit controls the injection of the compressed air for blowing from the blow nozzle so that the second length becomes a predetermined length when the package becomes full. This prevents an unnecessarily long fiber bundle at the yarn end of the full package.

  The spinning unit captures the yarn end of the spun yarn wound by the winding device, spun the yarn captured by the trapping device, and spun the spun yarn derived from the air spinning device. And a yarn splicing device. According to this configuration, since the yarn catching device catches the yarn end of the spun yarn in which the length of the fiber bundle portion is controlled, the success rate of catching the spun yarn by the yarn catching device is improved. As a result, the yarn joining by the yarn joining device can be performed efficiently, and the operation efficiency of the spinning unit can be improved.

  A spinning machine according to the present invention includes a plurality of the spinning units described above. According to this configuration, the length of the fiber bundle portion at the yarn end of the spun yarn of the package formed by the winding device can be controlled, and the spun yarn production efficiency can be improved as the whole spinning machine. .

  The pneumatic spinning method according to the present invention is an pneumatic spinning method for producing a spun yarn by spinning a fiber bundle by injecting a swirling airflow into the fiber bundle, and timing for stopping the injection of the swirling airflow acting on the fiber bundle And a control step for controlling the length of the fiber bundle portion attached to the spun yarn.

  According to this pneumatic spinning method, it is possible to control the length of the fiber bundle portion at the yarn end of the divided spun yarn by controlling the timing of stopping the jet of the swirling airflow acting on the fiber bundle. .

  The pneumatic spinning method may further include a setting step for setting the length of the fiber bundle portion formed at the yarn end of the spun yarn. According to this, the spun yarn which has the fiber bundle part of the length set by the setting step at the yarn end can be obtained.

  According to the present invention, it is possible to control the length of the fiber bundle portion at the yarn end of the divided spun yarn.

1 is a front view of a spinning machine according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the spinning machine of FIG. FIG. 2 is a hardware block diagram showing the periphery of a distribution pipe of the spinning unit in FIG. 1. It is sectional drawing of the pneumatic spinning apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the pneumatic spinning apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the pneumatic spinning apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the pneumatic spinning apparatus which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the present specification, “upstream” and “downstream” mean upstream and downstream in the traveling direction of the yarn during spinning. FIG. 1 is a front view showing the overall configuration of the spinning machine, and FIG. 2 is a longitudinal sectional view of the spinning machine. FIG. 3 is a hardware block diagram showing the periphery of the circulation pipe of the spinning unit. In FIG. 3, an arrow indicated by a broken line represents a signal line.

  A spinning machine 1 shown in FIG. 1 includes a large number of spinning units 2 arranged side by side. The spinning machine 1 includes a yarn splicing carriage 3, a blower box 80, and a prime mover box 5. In the following description, the yarn path side of the spun yarn 10 with respect to the yarn joining cart 3 may be referred to as the front side of the spinning machine 1, and the opposite side may be referred to as the back side. An operator passage extending in the arrangement direction of the spinning units 2 is provided on the front side of the spinning machine 1. The worker can operate and monitor each spinning unit 2 from the worker passage side.

  As shown in FIG. 1, each spinning unit 2 includes a draft device 7, an air spinning device 100, a yarn storage device 12, a waxing device 9, and a winding device 13 in order from upstream to downstream. I have. The draft device 7 is provided in the vicinity of the upper end of the casing 6 of the spinning machine 1. The fiber bundle 8 sent from the draft device 7 is spun by the air spinning device 100. The spun yarn 10 delivered from the pneumatic spinning device 100 passes through the yarn clearer 52, and is further sent downward by the yarn accumulating device 12 to be waxed by the waxing device 9. Thereafter, the spun yarn 10 is wound up by the winding device 13, whereby a package 45 is formed.

  The draft device 7 is for drawing the sliver 15 into the fiber bundle 8. As shown in FIG. 2, the draft device 7 includes four roller pairs: a back roller pair 16, a third roller pair 17, a middle roller pair 19 on which an apron belt 18 is mounted, and a front roller pair 20. The bottom rollers of each of the roller pairs 16, 17, 19, and 20 are driven by power from the motor box 5 or a drive source (not shown) provided individually. Each of the roller pairs 16, 17, 19, and 20 is driven at different rotational speeds. As a result, the sliver 15 supplied from the upstream side is drawn into the fiber bundle 8 and sent to the downstream air spinning device 100. be able to. The air spinning device 100 twists the fiber bundle 8 using a swirling airflow to generate a spun yarn 10.

  A yarn accumulating device 12 is provided downstream of the pneumatic spinning device 100. This yarn accumulating device 12 retains the spun yarn 10 sent from the air spinning device 100 when a yarn is spliced by the yarn splicing carriage 3 and the function of applying a predetermined tension to the spun yarn 10 and pulling it out from the pneumatic spinning device 100. The function of preventing the slack of the spun yarn 10 and the function of adjusting the tension so that the fluctuation of the tension on the winding device 13 side is not transmitted to the pneumatic spinning device 100 side. As shown in FIG. 2, the yarn storage device 12 includes a yarn storage roller 21, a yarn hooking member 22, an upstream guide 23, an electric motor 25, a downstream guide 26, and a yarn storage amount sensor 27. I have.

  The yarn hooking member 22 is configured to be able to engage (hang) with the spun yarn 10, and rotates integrally with the yarn accumulating roller 21 while being engaged with the spun yarn 10, thereby the yarn accumulating roller 21. It is comprised so that the spun yarn 10 can be wound around the outer peripheral surface.

  The yarn accumulating roller 21 is configured to be able to wind and store a certain amount of the spun yarn 10 around its outer peripheral surface. The yarn accumulating roller 21 is rotationally driven by the electric motor 25. With this configuration, the spun yarn 10 wound around the outer periphery of the yarn accumulating roller 21 is wound so as to tighten the yarn accumulating roller 21 as the yarn accumulating roller 21 rotates, and is upstream of the yarn accumulating device 12. Pull the spun yarn 10. That is, by rotating the yarn storage roller 21 with the spun yarn 10 wound around the outer periphery at a predetermined rotation speed, a predetermined tension is applied to the spun yarn 10 and the spun yarn 10 is pulled out from the air spinning device 100 at a predetermined speed. It can be conveyed downstream at a speed.

  A predetermined contact area can be ensured between the yarn storage roller 21 and the spun yarn 10 by winding a predetermined amount of the spun yarn 10 around the outer periphery of the yarn storage roller 21. As a result, the yarn storage roller 21 can hold and pull the spun yarn 10 with a sufficient force, and the yarn storage device 12 can rotate the spun yarn 10 at a stable speed from the pneumatic spinning device 100 without causing a slip or the like. Can be pulled out.

  The yarn storage amount sensor 27 is configured to detect the storage amount of the spun yarn 10 stored on the yarn storage roller 21 in a non-contact manner and to transmit it to the unit controller 32.

  The upstream guide 23 is disposed slightly upstream of the yarn accumulating roller 21. The upstream guide 23 is a guide member that appropriately guides the spun yarn 10 with respect to the outer peripheral surface of the yarn accumulating roller 21, and the twist of the spun yarn 10 propagated from the pneumatic spinning device 100 is the upstream guide 23. It also serves as a twist-preventing member that prevents it from being transmitted downstream.

  A yarn clearer 52 is provided on the front side of the casing 6 of the spinning machine 1 and at a position between the pneumatic spinning device 100 and the yarn storage device 12. The spun yarn 10 spun by the pneumatic spinning device 100 passes through the yarn clearer 52 before being wound by the yarn accumulating device 12. The yarn clearer 52 is configured to monitor the thickness of the traveling spun yarn 10 and transmit a yarn defect detection signal to the unit controller 32 when a yarn defect of the spun yarn 10 is detected. Further, the yarn clearer 52 transmits a signal for detecting the length of the spun yarn passing through the yarn clearer 52 to the unit controller 32. As this signal, for example, a signal related to the time when the spun yarn 10 has passed through the yarn clearer 52 can be used.

  Upon receipt of the yarn defect detection signal, the unit controller 32 immediately stops the ejection of compressed air from the swirling airflow generation nozzle 127 (see FIG. 4) of the pneumatic spinning device 100. As a result, the swirling airflow is stopped, the twisting of the fiber bundle 8 is stopped, and the introduction of the fiber bundle 8 into the pneumatic spinning device 100 is also stopped. Then, the continuous state of the fibers is divided in the pneumatic spinning device 100, and the spun yarn 10 is cut. Thereafter, the unit controller 32 further stops the draft device 7 and the like. In addition, the unit controller 32 sends a control signal to the yarn splicing carriage 3 to travel to the front of the spinning unit 2. Thereafter, the pneumatic spinning device 100 and the like are driven again, and the yarn joining cart 3 is spliced to resume winding. At this time, the yarn accumulating device 12 sends the spun yarn 10 continuously sent from the air spinning device 100 to the yarn accumulating roller 21 until the winding is resumed after the air spinning device 100 resumes spinning. The slack of the spun yarn 10 is removed by allowing it to stay.

  As shown in FIGS. 1 and 2, the yarn joining cart 3 includes a splicer (yarn joining device) 43, a suction pipe 44, and a suction mouth (yarn catching device) 46. When yarn breakage or yarn breakage occurs in a spinning unit 2, the yarn joining cart 3 travels on the rail 41 to the spinning unit 2 and stops. The suction pipe 44 sucks and captures the yarn end sent from the pneumatic spinning device 100 and guides it to the splicer 43 while rotating in the vertical direction about the axis. The suction mouse 46 sucks the yarn end from the package 45 supported by the winding device 13 and guides it to the splicer 43 while rotating in the vertical direction about the axis. The splicer 43 performs splicing between the guided yarn ends. Thus, the spinning unit 2 shares the splicer 43, the suction mouse 46, and the suction pipe 44.

  A waxing device 9 is provided downstream of the yarn storage device 12. The waxing device 9 is a device that applies wax to the spun yarn 10 that travels from the yarn storage device 12 toward the winding device 13.

  The winding device 13 includes a cradle arm 71 supported so as to be rotatable around a support shaft 70. The cradle arm 71 can rotatably support a bobbin 48 for winding the spun yarn 10.

  The winding device 13 includes a winding drum 72 and a traverse device 75. The winding drum 72 is configured to be able to be driven in contact with the outer peripheral surface of the package 45 formed by winding the bobbin 48 and the spun yarn 10 thereon. The traverse device 75 includes a traverse guide 76 that can be engaged with the spun yarn 10. With this configuration, the winding device 13 is a package that contacts the winding drum 72 by driving the winding drum 72 by an electric motor (not shown) while reciprocating the traverse guide 76 by a driving means (not shown). 45 is rotated, and the package 45 is wound up while traversing the spun yarn 10. The traverse guide 76 of the traverse device 75 is driven in common by the spinning units 2 by a shaft shared by the plurality of spinning units 2.

  The blower box 80 stores an air supply source (for example, a compressed air supply source 400) that generates air to be supplied to each part of the spinning unit 2, the yarn splicing cart 3, and the like.

  Next, the above-described pneumatic spinning device 100 will be described in more detail with reference to FIGS. 4 and 5 are cross-sectional views of the pneumatic spinning device according to one embodiment of the present invention. As shown in FIG. 4, the air spinning device 100 includes an air spinning nozzle 119 that gives a swirling airflow to the fiber bundle 8 while inserting the fiber bundle 8 sent from the front roller pair 20, and a tip of the air spinning nozzle 119. And a hollow guide shaft body 120 into which a portion is coaxially inserted.

  The air spinning nozzle 119 includes a needle holder 123, a nozzle block 134, a nozzle casing (blow nozzle block) 153 that supports the nozzle block 134, an upper cover 111 that covers an upstream surface of the nozzle casing 153, A shaft body holding member 159 that covers the downstream surface of the nozzle casing 153. The needle holder 123 has a guide hole (introduction path) 121 for introducing the fiber bundle 8 drafted by the upstream draft device 7, and the needle 122 is placed on the flow path of the fiber bundle 8 discharged from the guide hole 121. Holding. The upstream end of the needle holder 123 penetrates the upper cover 111 and is exposed to the outside.

  A tapered hole 154 is provided in the nozzle block 134 at a position downstream of the needle holder 123, and the distal end portion 124 of the hollow guide shaft body 120 having a taper angle substantially equal to the tapered hole 154 is coaxial with the tapered hole 154. And a predetermined gap. A spinning chamber 126 as a twisting region is formed between the distal end surface of the hollow guide shaft body 120 and the needle holder 123. In the spinning chamber 126, the tip of the needle 122 protrudes, and the tip of the needle 122 faces the tip surface of the hollow guide shaft body 120.

  A swirl airflow generation chamber 125 is formed between the tapered hole 154 and the tip end portion 124. The nozzle casing 153 has an air discharge space 155, and a negative pressure source (not shown) is connected to the side of the air discharge space 155 through a pipe 160. A blow nozzle 310 that communicates with the air discharge space 155 and the outside of the nozzle portion casing 153 is provided at the other side of the air discharge space 155. The nozzle casing 153 is connected to a blow pipe 300 through which compressed air supplied from a compressed air supply source 400 (see FIG. 4) flows so as to communicate with the blow nozzle 310. 4 shows a state in which the pipe 160 and the blow pipe 300 are opposed to each other with the hollow guide shaft body 120 interposed therebetween, the positional relationship between the pipe 160 and the blow nozzle 310 is limited to this. It is not a thing.

  Compressed air (blow compressed air) supplied from the compressed air supply source 400 is injected from the blow nozzle 310 into the air discharge space 155. The blow pipe 300 is provided with a blow switching valve 301 (see FIG. 3) for switching supply / stop of compressed air from the compressed air supply source 400 to the blow nozzle 310. The blow switching valve 301 is controlled by a control signal generated by the unit controller 32.

  The nozzle block 134 is provided with a plurality of swirling airflow generating nozzles 127 whose outlet ends are opened to the spinning chamber 126. These swirling airflow generating nozzles 127 are holes formed in the nozzle block 134 and are inclined in the tangential direction of the spinning chamber 126 and downstream in the yarn feeding direction. Between the nozzle block 134 and the upper cover 111, compressed air is introduced around the inlet end of the swirling airflow generating nozzle 127 (the end opposite to the end of the swirling airflow generating nozzle 127 on the spinning chamber 126 side). A chamber 128 is formed. A distribution pipe (spinning distribution pipe) 200 through which compressed air for spinning (compressed air for spinning) supplied from a compressed air supply source 400 (see FIG. 3) flows is connected to the side of the compressed air introduction chamber 128. ing. 4 to 7, the distribution pipe 200 and the blow pipe 300 sandwich the path of the fiber bundle 8 and the spun yarn 10 in the pneumatic spinning device 100 (the guide hole 121, the spinning chamber 126, and the yarn passage 129). However, the positional relationship between the distribution pipe 200 and the blow pipe 300 is not limited to this.

  The compressed air supplied from the compressed air supply source 400 is injected into the spinning chamber 126 through the distribution pipe 200 through the compressed air introduction chamber 128 and the swirling airflow generation nozzle 127. Further, the circulation pipe 200 is provided with a spinning switching valve 203 (see FIG. 3) for switching supply / stop of compressed air from the compressed air supply source 400 into the spinning chamber 126. The spinning switching valve 203 is controlled by a control signal generated by the unit controller 32.

  It should be noted that, on the back side of the spinning unit 2 (the side far from the operator passage), piping for supplying compressed air and the like, a frame for supporting the spinning unit 2, and the like are arranged, so the installation position of the switching valve 203 for spinning is set. There are restrictions. Therefore, in the present embodiment, it is possible to provide the spinning switching valve 203 at a position on the near side (close to the worker passage) in the spinning unit 2 and in the vicinity of the pneumatic spinning device 100. This is preferable because of constraints. However, the installation position of the spinning switching valve 203 is not limited to the above-described position, and can be provided at an appropriate position depending on the presence or absence of installation space.

As shown in FIG. 3, the distribution pipe 200 includes a first distribution pipe 201 that connects between the compressed air introduction chamber 128 and the spinning switching valve 203, and between the spinning switching valve 203 and the compressed air supply source 400. And a second distribution pipe 202 for connecting the two. The volume in the first distribution pipe 201 is set so that the length of the fiber bundle (fiber bundle portion) 8 attached to the yarn end when the spun yarn 10 is cut becomes the first length. Moreover, it is preferable to use the 1st distribution | circulation piping 201 whose volume in the said 1st distribution | circulation piping 201 is 1500 mm < ³ > or less. Moreover, as the 1st distribution | circulation piping 201, it is preferable that piping internal diameter is 2 mm or more and 4 mm or less, and piping length is 500 mm or less. It is more preferable to set the volume in the first flow pipe 201 in consideration of the volume of the compressed air introduction chamber 128 that exists between the first flow pipe 201 and the swirling air flow generation nozzle 127. Specifically, for example, it is preferable to use the first distribution pipe 201 in which the sum of the volume in the first distribution pipe 201 and the volume of the spinning chamber 126 satisfies 1500 mm ³ or less.

  The swirling airflow generation nozzle 127 injects the compressed air introduced through the first distribution pipe 201 into the spinning chamber 126, and generates, for example, a swirling airflow (see FIG. 5) counterclockwise in plan view in the spinning chamber 126. The swirling airflow spirally flows downstream along the swirling airflow generating chamber 125 around the distal end portion 124 of the hollow guide shaft body 120 and is discharged from the air discharge space 155 formed in the nozzle casing 153.

  The hollow guide shaft body 120 includes a cylindrical body 156 having a distal end portion 124. The hollow guide shaft 120 is formed with a yarn passage (lead-out passage) 129 along the axis thereof. After the spun yarn 10 passes through the yarn passage 129, the spun yarn 10 is passed through the downstream outlet hole. Is discharged. The cylindrical body 156 is formed with a large-diameter portion 158 having an enlarged diameter downstream from the distal end portion 124, and the large-diameter portion 158 is exposed to the air discharge space 155. The large diameter portion 158 is inserted and fixed to the shaft body holding member 159.

  Next, the operation of the pneumatic spinning device 100 will be described. As shown in FIG. 5, at the time of spinning, the fiber bundle 8 or the spun yarn 10 is in a continuous state from the front roller pair 20 to the downstream yarn storage device 12 through the guide hole 121, the spinning chamber 126, and the yarn passage 129. By applying a feeding force to the downstream side by the yarn storage device 12 shown in FIG. 2, tension is applied to the spun yarn 10.

  In FIG. 5, the swirling airflow (thick black arrow) generated by the compressed air injected from the swirling airflow generating nozzle 127 causes the spinning chamber 126 to have a negative pressure. As a result, the upstream fiber bundle 8 passes through the guide hole 121. A suction airflow drawn into the spinning chamber 126 is generated via the white arrow (the white arrow in FIG. 5). Accordingly, the fiber bundle 8 discharged from the front roller pair 20 of the draft device 7 is drawn into the spinning chamber 126 by the suction airflow, and is subjected to the action of the swirling airflow by the swirling airflow generation nozzle 127. As a result, the rear ends of the surrounding fibers are separated from the fibers that become the core fibers of the fiber bundle 8 and opened, and the fibers are swung and twisted in the swirling air flow generation chamber 125 to be wound around the core fibers. Go.

  Although this twist tries to propagate to the front roller pair 20 side, the propagation is blocked by the needle 122, so that the fiber bundle 8 sent out from the front roller pair 20 is not twisted by the twist. That is, the needle 122 serves as a twist propagation preventing means. The fibers twisted as described above are sequentially generated in the actual twisted spun yarn 10, pass through the yarn passage 129, and are discharged from the pneumatic spinning device 100. The spun yarn 10 is wound up by the winding device 13 through the yarn clearer 52 and the yarn accumulating device 12 shown in FIG.

  Next, control of the spinning switching valve 203 and the blow switching valve 301 of the pneumatic spinning device 100 will be described. As shown in FIG. 3, the unit controller 32 includes a spinning control unit (control unit) 33 that controls the spinning switching valve 203 and a blow control unit (control unit) 34 that controls the blowing switching valve 301. And have. The spinning control unit 33 controls the spinning switching valve 203 to inject compressed air from the swirling airflow generating nozzle 127 to generate a swirling airflow in the spinning chamber 126. For example, when a yarn defect signal is input from the yarn clearer 52, the spinning control unit 33 sets the spinning switching valve 203 so that the injection of compressed air from the swirling airflow generation nozzle 127 into the spinning chamber 126 is stopped. Control.

  The blow control unit 34 determines that the spinning switching valve 203 is controlled by the spinning control unit 33 so that the supply of compressed air into the spinning chamber 126 is stopped, and that the package 45 is fully wound. In this case, the blow switching valve 301 is controlled so that the compressed air is jetted from the blow nozzle 310. The unit controller 32 calculates the length of the spun yarn 10 wound by the winding device 13 based on a signal for detecting the length of the spun yarn 10 input from the yarn clearer 52. . The blow control unit 34 determines whether or not the package 45 is fully wound based on the calculation result by the unit controller 32. Further, the blow control unit 34 controls the spinning switching valve 203 so that the supply of compressed air into the spinning chamber 126 is stopped by the spinning control unit 33, and the wound yarn 10 is wound. When the length is equal to or shorter than the predetermined winding length, the blow switching valve 301 is controlled so that the compressed air is injected from the blow nozzle 310. The predetermined winding length is a length in which the diameter of the package 45 formed by winding the spun yarn 10 having a predetermined length is equal to or smaller than the predetermined diameter.

  The unit controller 32 further includes a roller control unit 35. When the yarn defect signal is input from the yarn clearer 52, the roller controller 35 stops the motors that drive the roller pairs 16, 17, 19, and 20. When the roller controller 35 determines that the package 45 is fully wound based on the length of the spun yarn 10 wound by the winding device 13 calculated by the unit controller 32, the unit 45 The controller 32 stops the motors that drive the roller pairs 16, 17, 19, and 20.

  Next, the operation of each part at the time of yarn defect detection by the yarn clearer 52 will be described. First, the operation of each part when the yarn defect is detected and the diameter of the package 45 is larger than a predetermined diameter and before full winding will be described. When the yarn clearer 52 that monitors the spun yarn 10 detects a yarn defect during spinning, the yarn clearer 52 sends a yarn defect detection signal to the unit controller 32. Receiving this signal, the roller controller 35 of the unit controller 32 stops the motors that drive the back roller pair 16 and the third roller pair 17. As a result, the supply of the fiber bundle 8 from the draft device 7 is stopped.

  Even after the back roller pair 16 and the third roller pair 17 are stopped, the driving of the middle roller pair 19 and the front roller pair 20 is continued for at least a predetermined time. As a result, the sliver 15 or the fiber bundle 8 is divided between the middle roller pair 19 being driven and the third roller pair 17 being stopped.

  Immediately after or almost simultaneously with the stop control of the back roller pair 16 and the third roller pair 17, the spinning control unit 33 stops the injection of compressed air from the swirling airflow generation nozzle 127 into the spinning chamber 126. The switching valve 203 for spinning is controlled. As a result, the swirling airflow disappears, so that twisting is stopped, and the suction airflow that introduces the fiber bundle 8 into the spinning chamber 126 from the guide hole 121 disappears, and the fiber bundle 8 has the hollow guide shaft 120. Is no longer drawn into the interior of

  On the other hand, the spun yarn 10 that has already been fed into the yarn passage 129 in the hollow guide shaft 120 is left by the yarn storage device 12 with the untwisted fiber bundle 8 attached to the tip of the spun yarn 10. Pulled downstream. As a result, in the fiber bundle 8 or the spun yarn 10, the continuous state of the fibers is divided at the vicinity of the tip end portion of the hollow guide shaft body 120. The yarn end of the spun yarn 10 on the downstream side is in a state where an untwisted fiber bundle (fiber bundle portion) 10e is attached as shown in FIG. After the spun yarn 10 is divided, the upstream fiber bundle 8d stays in the guide hole 121 and the vicinity thereof by feeding the front roller pair 20, and the stayed fiber bundle 8d is sucked by a suction means (not shown). Removed.

Here, as for the 1st distribution piping 201 arrange | positioned between the whirling airflow generation nozzle 127 and the switching valve 203 for spinning, the volume in the 1st distribution piping 201 is 1500 mm < ³ > or less as mentioned above. In this way, by reducing the volume in the first distribution pipe 201, the spinning switching valve 203 is controlled so as to stop the supply of compressed air to the swirl airflow generation nozzle 127, and immediately after the swirl airflow is generated. The supply of compressed air to the nozzle 127 is stopped. As a result, the swirling air flow can be quickly extinguished without generating a weak swirling air flow in the spinning chamber 126 for a long time by slowly flowing out the compressed air remaining in the first circulation pipe 201 as in the conventional apparatus. Can do. Accordingly, the length of the fiber bundle 8 drawn into the hollow guide shaft body 120 is shortened, and the fiber bundle 8 adheres to the yarn end of the spun yarn 10 when the continuous state of the fiber is divided in the vicinity of the tip of the hollow guide shaft body 120. The length of the fiber bundle 10e to be shortened can be shortened.

Incidentally, if the volume within the first circulation pipe 201 is greater than 1500 mm ^3, it is not possible to quickly stop the supply of compressed air to the whirling air current generating nozzle 127, the fiber bundle 10e adhered to the yarn end of the spun yarn 10 Length becomes long. Moreover, it is preferable that the length (1st length) of the fiber bundle 10e adhering to the yarn end of the spun yarn 10 shall be 5 cm-20 cm, for example. By setting the length of the fiber bundle 10 e to, for example, 5 cm to 20 cm, the fiber bundle 10 e that adheres around the package 45 to the yarn end of the spun yarn 10 when the yarn end of the spun yarn 10 is wound around the package 45. The fiber bundles 10e are not entangled with each other, and the suction end of the spun yarn 10 (fiber bundle 10e portion) can be easily sucked by the suction mouth 46.

  Next, the operation of each part when the diameter of the package 45 is equal to or smaller than a predetermined diameter when a yarn defect is detected will be described. When the yarn clearer 52 that monitors the spun yarn 10 detects a yarn defect during spinning, the yarn clearer 52 sends a yarn defect detection signal to the unit controller 32. Receiving this signal, the roller controller 35 of the unit controller 32 stops the motors that drive the back roller pair 16 and the third roller pair 17. As a result, the supply of the fiber bundle 8 from the draft device 7 is stopped.

  Even after the back roller pair 16 and the third roller pair 17 are stopped, the driving of the middle roller pair 19 and the front roller pair 20 is continued for at least a predetermined time. As a result, the sliver 15 or the fiber bundle 8 is divided between the driven middle roller pair 19 and the stopped third roller pair 17.

  Immediately after or almost simultaneously with the stop control of the back roller pair 16 and the third roller pair 17, the spinning control unit 33 stops the injection of compressed air from the swirling airflow generation nozzle 127 into the spinning chamber 126. The switching valve 203 for spinning is controlled. As a result, the swirling airflow disappears, so that twisting is stopped, and the suction airflow that introduces the fiber bundle 8 into the spinning chamber 126 from the guide hole 121 disappears, and the fiber bundle 8 has the hollow guide shaft 120. Is no longer drawn into the interior of

  On the other hand, the spun yarn 10 that has already been fed into the yarn passage 129 in the hollow guide shaft body 120 is left by the yarn accumulating device 12 with the untwisted fiber bundle 10e attached to the tip of the spun yarn 10. Pulled downstream.

  Further, after controlling the spinning switching valve 203 by the spinning control unit 33, the blowing control unit 34 controls the blowing switching valve 301 so that compressed air for blowing is jetted from the blow nozzle 310. Here, when the spinning is interrupted, as shown in FIG. 7, the nozzle casing 153 and the shaft body holding member 159 that holds the hollow guide shaft body 120 are separated from each other. That is, the spun yarn 10 is exposed to the outside air. From the blow nozzle 310, compression is performed between the guide hole 121 and the yarn passage 129, that is, toward the distal end portion 124 of the hollow guide shaft body 120 that moves by separating the nozzle casing 153 and the shaft body holding member 159 from each other. Air is injected. Thereby, the continuous state of the untwisted fiber bundle 10e adhering to the tip of the spun yarn 10 is divided by the pressure of air. Accordingly, the yarn end of the spun yarn 10 is in a state where a non-twisted fiber bundle (fiber bundle portion) 10f having a predetermined length is attached as shown in FIG.

  The blow control unit 34 controls the blow switching valve 301 so that the length of the fiber bundle 10f adhering to the yarn end of the spun yarn 10 becomes the second length, and the blow nozzle 310 controls the blow. Compressed air is injected. The length of the fiber bundle 10f adhering to the yarn end of the spun yarn 10 is determined, for example, by the blow nozzle by the blow control unit 34 after the injection of the compressed air into the spinning chamber 126 is stopped by the control of the spinning control unit 33. It can be controlled by the time until the injection of the compressed air for blowing from 310 is performed. Further, the predetermined length of the fiber bundle 10f adhering to the yarn end of the spun yarn 10 is, for example, a length that the fiber bundle 10f does not make a round around the package 45. The length of the fiber bundle 10f adhering to the yarn end of the spun yarn 10 may be zero, but in order to allow the yarn end of the spun yarn 10 to be easily sucked by the suction mouth 46, a predetermined length is used. It is preferable that the fiber bundle 10f having a length is attached to the yarn end of the spun yarn 10. Further, the blow control unit 34 may control the blow switching valve 301 so that the length of the fiber bundle 10f attached to the yarn end of the spun yarn 10 becomes shorter as the diameter of the package 45 is smaller.

  As described above, when the diameter of the package 45 is equal to or smaller than the predetermined diameter, the length of the fiber bundle 10f attached to the yarn end of the spun yarn 10 by jetting the compressed air for blowing from the blow nozzle 310 is set to the predetermined length. Thus, for example, it is possible to prevent a problem that the fiber bundle attached to the yarn end of the spun yarn 10 makes a round around the package 45 and the fiber bundles are entangled. Further, the blown compressed air is jetted from the blow nozzle 310 under the control of the blow control unit 34, and the fiber bundle 10e adhering to the yarn end of the spun yarn 10 is actively cut, so that the blown compressed air is reduced. Compared with the case where the spun yarn 10 is cut without using it, the length of the fiber bundle 10f attached to the yarn end of the spun yarn 10 can be further shortened.

  Next, the operation of each part when the package 45 is fully wound will be described. At the time of spinning, when the roller control unit 35 detects the full winding state of the package 45 based on the signal input from the yarn clearer 52, the motors that drive the back roller pair 16 and the third roller pair 17 are stopped. As a result, the supply of the fiber bundle 8 from the draft device 7 is stopped. At this time, similarly to the roller control unit 35, the spinning control unit 33 and the blow control unit 34 also detect the full winding state of the package 45 based on the signal from the yarn clearer 52. The subsequent operation is similar to the operation of each part in the above-described “when the diameter of the package 45 is equal to or smaller than the predetermined diameter when a yarn defect is detected”, and controls the spinning switching valve 203 to control the spinning chamber 126. The supply of compressed air to the inside is stopped, and the blow switching valve 301 is controlled to inject the blown compressed air from the blow nozzle 310.

  Thereby, when the package 45 is fully wound, the length of the fiber bundle 10f attached to the yarn end of the spun yarn 10 is zero, or the yarn end of the spun yarn 10 is easily sucked by the suction mouth 46. Can be as long as possible. Also in this case, the length of the fiber bundle 10f adhering to the yarn end of the spun yarn 10 can be further reduced as compared with the case where the spun yarn 10 is cut without using the compressed air for blowing. it can.

  As described above, in the pneumatic spinning device 100 according to this embodiment, the spinning switch valve 203 and the swirling airflow generating nozzle 127 are arranged so that the fiber bundle 8 attached to the yarn end of the spun yarn 10 has the first length. The volume in the 1st distribution piping 201 arrange | positioned to is set. Thereby, it becomes possible to control the length of the fiber bundle 10e adhering to the yarn ends of the divided spun yarn 10 by the volume in the first distribution pipe 201, and the fiber bundle 10e having the first length adheres. The spun yarn 10 thus obtained can be obtained.

The volume in the 1st distribution piping 201 arrange | positioned between the switching valve 203 for spinning and the whirling airflow generation nozzle 127 was 1500 mm < ³ > or less. As a result, the injection of the compressed air from the swirling airflow generating nozzle 127 can be stopped at the same time or almost simultaneously with the blockage of the spinning compressed air flow by the spinning switching valve 203, and the generation of the swirling airflow can be stopped. Accordingly, the drawing of the fiber bundle 8 into the spinning chamber 126 is stopped at the same time or almost simultaneously with the interruption of the flow of the compressed air for spinning by the spinning switching valve 203. The length of the attached fiber bundle 10e can be shortened or the attachment of the fiber bundle 10e can be eliminated.

  The first flow pipe 201 preferably has a pipe inner diameter of 2 mm or more and 4 mm or less and a pipe length of 500 mm or less. In this case, the optimum first distribution pipe 201 can be obtained in consideration of pressure loss when the spinning compressed air flows in the first distribution pipe 201.

  By injecting blown compressed air from the blow nozzle 310, the fiber bundle 10e adhering to the yarn end of the spun yarn 10 can be separated from the spun yarn 10. In this case, the fiber bundle 10e adhering to the yarn end of the spun yarn 10 can be actively cut, and the spun yarn is compared with the case where the spun yarn 10 is cut without using compressed air for blowing. The length of the fiber bundle 10f attached to the ten yarn ends can be further shortened.

  In the spinning unit 2 including the pneumatic spinning device 100 as described above, the pneumatic spinning device 100 controls the length of the fiber bundles 10e and 10f adhering to the yarn end of the spun yarn 10 to a length that can be easily sucked by the suction mouth 46. Therefore, during the yarn splicing operation by the splicer 43, the yarn end of the spun yarn 10 wound by the winding device 13 can be reliably captured by the suction mouth 46.

  The spinning unit 2 including the air spinning device 100 as described above adheres to the yarn end of the spun yarn 10 when the spun yarn 10 is cut when the package 45 wound by the wind device 13 is fully wound. The blow switching valve 301 is controlled so that the fiber bundle 10e has the second length. Thereby, for example, it is possible to prevent the fiber bundle having an unnecessary length from adhering to the yarn end of the spun yarn 10 that has been wound up.

  In the spinning unit 2 including the pneumatic spinning device 100 as described above, when the diameter of the package 45 wound up by the winding device 13 is small, it adheres to the yarn end of the spun yarn 10 wound up by the winding device 13. The blow switching valve 301 is controlled so that the fiber bundle 8 has the second length. Thereby, for example, it is possible to suppress such a problem that the fiber bundle 10f adhering to the spun yarn 10 goes around the package 45 and the fiber bundles are entangled.

  In the spinning machine 1 provided with a plurality of spinning units 2 as described above, the yarn end of the spun yarn 10 taken up by the take-up device 13 can be reliably captured by the suction mouth 46, so that the spinning machine 1 as a whole is spun. The production efficiency of the yarn 10 can be improved.

  Note that, in the embodiment, controlling the stop timing of the swirling airflow injection by the volume in the first distribution pipe 201 corresponds to the control step of the pneumatic spinning method according to the present invention. Setting the volume in the first flow pipe 201 so that the fiber bundle 10e having a desired length adheres to the yarn end of the spun yarn 10 corresponds to the setting step of the pneumatic spinning method according to the present invention.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and may be modified without changing the gist described in each claim.

  For example, in the spinning machine 1 and the spinning unit 2 of the embodiment, the spun yarn 10 is pulled out from the pneumatic spinning device 100 by the yarn accumulating roller 21 that winds and stores the spun yarn 10 by a certain amount. Therefore, the present invention may be applied to a spinning machine and a spinning unit that draws a spun yarn from an air spinning device.

  In the spinning machine 1 and the spinning unit 2 of the embodiment, the yarn path is set so that the spun yarn 10 travels downward from the upper draft device 7 toward the lower winding device 13. The present invention may be applied to a spinning machine or a spinning unit in which a yarn path is set so that the spun yarn travels from the bottom to the top in the machine base height direction.

  In the pneumatic spinning device 100 of the embodiment, compressed air is supplied from the spinning switching valve 203 into the spinning chamber 126 via the first distribution pipe 201. However, the spinning switching valve 203 is connected to the upper cover 111 and the like. By directly attaching, the compressed air may be supplied from the spinning switching valve 203 into the spinning chamber 126 without going through the first distribution pipe 201. In this case, the volume of the space between the spinning switching valve 203 and the swirling airflow generation nozzle 127 formed in the upper cover 111, that is, the volume of the compressed air introduction chamber 128 (in the spinning distribution pipe in claim 1). A fiber bundle having a length corresponding to (volume) adheres to the yarn end of the spun yarn 10.

  In the spinning machine 1 and the spinning unit 2 of the embodiment, the pneumatic spinning device 10 includes the needle 122 that prevents the twist propagation of the fiber bundle 8, but instead of the needle 122, the downstream end of the guide hole 121. Thus, the twist propagation of the fiber bundle 8 may be prevented. The air spinning device 100 may include a pair of air jet nozzles that twist in opposite directions.

  In the spinning machine 1 and the spinning unit 2 of the embodiment, at least some of the plurality of bottom rollers of the draft device 7 and the traverse guide 76 of the traverse device 75 are driven in common to each spinning unit 2. The invention may be applied to a spinning machine and a spinning unit in which each part of the spinning unit (for example, a drafting device, a pneumatic spinning device, a yarn winding device, etc.) is independently driven by each spinning unit 2.

  In the spinning unit 2 of the embodiment, the splicer 43, the suction mouth 46, and the suction pipe 44 are shared, but the splicer 43, the suction mouth 46, and the suction pipe 44 are provided in each spinning unit 2. It may be.

  The yarn clearer 52 according to the embodiment detects the yarn defect of the spun yarn 10 by monitoring the thickness of the spun yarn 10. However, the yarn clearer 52 monitors the presence or absence of the foreign material contained in the spun yarn 10 and contains the foreign material. It can also be detected as a yarn defect.

  DESCRIPTION OF SYMBOLS 1 ... Spinning machine, 2 ... Spinning unit, 10 ... Spinning yarn, 10e, 10f ... Fiber bundle (fiber bundle part), 13 ... Winding device, 33 ... Spinning control part (control part), 34 ... Blow control part (Control part), 43 ... splicer (yarn splicing device), 45 ... package, 46 ... suction mouse (yarn catching device), 100 ... pneumatic spinning device, 121 ... guide hole (introduction path), 125 ... swirl airflow generation chamber, DESCRIPTION OF SYMBOLS 127 ... Whirling airflow generation nozzle, 129 ... Yarn path (leading path), 153 ... Nozzle section casing (blow nozzle block), 201 ... First distribution pipe (spinning distribution pipe), 203 ... Spinning switching valve, 301 ... Blow Switching valve, 310 ... blow nozzle.

Claims (12)

An air spinning device that produces a spun yarn by spinning a fiber bundle with a swirling airflow,
A nozzle block formed with a swirling airflow generation nozzle that injects spinning compressed air into the spinning chamber so that the swirling airflow is generated in the spinning chamber;
A distribution pipe for spinning through which the compressed air for spinning supplied to the swirling airflow generating nozzle flows;
A spinning switching valve provided on the spinning distribution pipe and configured to switch between the circulation of the spinning compressed air flowing in the circulation pipe and the blocking of the circulation;
The spinning flow between the spinning switching valve and the swirling air flow generation nozzle so that the length of the fiber bundle portion at the yarn end of the spun yarn cut by the flow interruption becomes the first length. An air spinning device characterized in that a volume in a pipe is set. 2. The pneumatic spinning device according to claim 1, wherein a volume in the spinning distribution pipe between the spinning switching valve and the swirling airflow generation nozzle is 1500 mm ³ or less.   2. The spinning distribution pipe between the spinning switching valve and the swirling airflow generating nozzle has a pipe inner diameter of 2 mm or more and 4 mm or less, and a pipe length of 500 mm or less. Or the pneumatic spinning device according to 2; An introduction path for introducing the fiber bundle into the spinning chamber;
A lead-out path for leading the spun yarn spun by the swirling airflow out of the spinning chamber;
A blow nozzle block formed with a blow nozzle for injecting blown compressed air between the introduction path and the outlet path;
The pneumatic spinning device according to claim 1, further comprising:   The apparatus further includes a control unit that controls injection of the compressed air for blow from the blow nozzle so that the length of the fiber bundle portion is a second length shorter than the first length. The pneumatic spinning device according to claim 4. The pneumatic spinning device according to any one of claims 1 to 5,
A winding device that forms a package by winding the spun yarn spun by the pneumatic spinning device;
A spinning unit comprising: An air spinning device according to claim 5;
A winding device that forms a package by winding the spun yarn spun by the pneumatic spinning device;
The control unit controls injection of the compressed air for blowing from the blow nozzle so that the second length is adjusted according to a diameter of the package formed by the winding device. Spinning unit.   The said control part controls injection of the said compressed air for a blow from the said blow nozzle so that the said 2nd length may become predetermined length when the said package becomes a full volume. The spinning unit according to 7. A yarn catching device for catching a yarn end of the spun yarn wound by the winding device;
A splicing device that performs splicing of the spun yarn that has been captured by the capturing device, and the spun yarn that has been led out from the pneumatic spinning device;
The spinning unit according to any one of claims 6 to 8, further comprising:   A spinning machine comprising a plurality of the spinning units according to any one of claims 6 to 9. A spinning method in which a fiber bundle is spun by injecting a swirling airflow into the fiber bundle to produce a spun yarn,
An air spinning method comprising: a control step of controlling a timing of stopping the jet of the swirling airflow acting on the fiber bundle and controlling a length of the fiber bundle portion attached to the spun yarn.   The pneumatic spinning method according to claim 11, further comprising a setting step of setting a length of the fiber bundle portion formed at a yarn end of the spun yarn.

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