Spinning equipment

Abstract

To provide a spinning equipment enabling suppression of reduction in temperature or ambient temperature of a spinneret.SOLUTION: A spinning equipment comprises: a spinning beam 21 into which a spinning pack 23 to spin a molten polymer downward from a spinneret 24 is inserted; a cooling device 3, which is disposed below the spinning beam 21 and has a spinning chimney 31 extending in vertical direction so as to surround the molten polymer spun from the spinneret 24 and cools the molten polymer by a cooling air CF fed from circumferential direction of the spinning chimney 31; an air cylinder 5 that can move the cooling device 3 downward with respect to the spinning beam 21 so that a work space is formed between the air cylinder and the spinning beam 21; and a control device that stops supply of the cooling air CF to the spinning chimney 31 or controls supply amount of the cooling air CF to the spinning chimney 31 in a state where the cooling device 3 is moved downward at least with respect to the spinning beam 21.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a spinning equipment. [Background Art]

[0002] Conventionally, spinning equipment has a cooling device provided below a spinning beam into which a spinning pack for spinning high-temperature molten polymer from a spinneret is inserted. This cooling device includes a spinning chimney that surrounds the high-temperature molten polymer spun from the spinneret, and supplies cooling air to the spinning chimney to blow the cooling air onto the high-temperature molten polymer, thereby cooling and solidifying the polymer to form a yarn.

[0003] In this type of spinning equipment, maintenance is regularly performed to replace the spinning pack and clean the spinneret surface (hereinafter referred to as "surface cleaning") in order to maintain productivity and yarn quality. For example, Patent Document 1 (see particularly paragraph

[0026] ) discloses that the cooling device is lowered to secure a working space between the cooling device and the spinning beam, thereby performing maintenance on the spinning equipment. In addition, Patent Document 2 (see particularly paragraph

[0023] ) discloses a yarn cooling device that can be lifted and lowered, so that replacement of the spinning pack and surface cleaning can be performed when the yarn cooling device is lowered. [Prior Art Literature] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2014-145132 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2005-42227 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, according to the technologies described in Patent Documents 1 and 2, when the cooling device is lowered or raised, there is a risk that the airflow from the spinning cylinder upwards will significantly lower the temperature of the spinneret and its surroundings. If the temperature of the spinneret and its surroundings drops significantly, it will take time for the temperature of the spinneret and its surroundings to return to its original temperature after production has started following maintenance. Yarn produced with a low temperature of the spinneret and its surroundings will have reduced physical properties, leading to problems such as an increase in discarded yarn.

[0006] This invention has been made in view of the above problems, and aims to provide a spinning apparatus that can suppress the decrease in the temperature of the die and the temperature around the die. [Means for solving the problem]

[0007] (1) The spinning equipment of the present invention is A spinning beam into which a spinning pack is inserted to spin molten polymer downwards from the die, A cooling device is provided, which is positioned below the spinning beam and has a spinning cylinder that extends vertically to surround the molten polymer spun from the die, and cools the molten polymer with cooling air supplied from the circumferential direction of the spinning cylinder. A moving mechanism capable of moving the cooling device downward relative to the spinning beam so that a gap is formed between it and the spinning beam, A temperature drop suppression means for suppressing a temperature drop in the die, at least when the cooling device is moved downward relative to the spinning beam, It is characterized by having the following features.

[0008] According to the spinning equipment described in (1) above, when maintenance is performed by lowering the cooling device, the decrease in the temperature of the spinneret and the area surrounding the spinneret can be suppressed. As a result, the time it takes for the temperature of the spinneret and the area surrounding the spinneret to return to the original temperature, and consequently the time it takes for the yarn properties to stabilize, can be shortened, making it possible to reduce the amount of yarn that is wasted.

[0009] (2) In the spinning equipment described in (1) above, The aforementioned temperature drop suppression means is The control device includes at least control over the supply of cooling air to the spinning cylinder, The control device is At least when the cooling device is moved downward relative to the spinning beam, it is possible to perform control to stop the supply of cooling air to the spinning cylinder, or control to suppress the amount of cooling air supplied to the spinning cylinder compared to the state before the spinning of the molten polymer was stopped. It is characterized by the following:

[0010] According to the spinning equipment described in (2) above, control is performed to stop or reduce the amount of cooling air supplied to the spinning cylinder, at least when the cooling device is moved downward relative to the spinning beam. As a result, the upward airflow from the spinning cylinder can be stopped or its amount can be reduced, and the decrease in the temperature of the die and its surroundings due to the upward airflow from the spinning cylinder can be suppressed.

[0011] (3) In the spinning equipment described in (2) above, The aforementioned temperature drop suppression means is The system includes a blower that blows air between the spinning beam and the cooling device, and in a direction intersecting the thread path of the molten polymer spun from the die, It is characterized by the following:

[0012] The spinning equipment described in (3) above makes it possible to easily thread the yarn into the spinning cylinder after maintenance is completed while suppressing a drop in the temperature of the die and its surroundings. More specifically, when performing maintenance on the spinning equipment, if the supply of cooling air to the spinning cylinder is stopped or the amount of cooling air supplied to the spinning cylinder is reduced, the molten polymer spun from the die will not cool and solidify, which may make it difficult to thread the yarn into the spinning cylinder after maintenance is completed. Therefore, by blowing air between the spinning beam and the cooling device, and in a direction intersecting the yarn path of the molten polymer spun from the die, it is possible to cool and solidify the molten polymer spun from the die even if the supply of cooling air to the spinning cylinder is stopped or the amount of cooling air supplied to the spinning cylinder is reduced. As a result, it is possible to easily thread the yarn into the spinning cylinder after maintenance is completed while suppressing a drop in the temperature of the die and its surroundings. Furthermore, in addition to being able to cool and solidify the molten polymer spun from the nozzle, it can also block air even if there is air heading towards the nozzle, and consequently, it can block air heading towards the nozzle or suppress the amount of air heading towards the nozzle.

[0013] (4) In the spinning equipment described in (3) above, The aforementioned blower device is The operation stops when the spinning beam and the cooling device come into contact. It is characterized by the following:

[0014] According to the spinning equipment described in (4) above, when the spinning beam and the cooling device come into contact, the upper opening of the spinning cylinder is closed. When the upper opening of the spinning cylinder is closed, most of the cooling air supplied from the cooling device flows downward, which suppresses the decrease in the temperature of the die and the area surrounding the die. As a result, it is possible to shorten the time it takes for the temperature of the die and the area surrounding the die to return to the original temperature, and consequently, the time it takes for the yarn properties to stabilize.

[0015] (5) The spinning equipment of the present invention is A spinning beam into which a spinning pack is inserted to spin molten polymer downwards from the die, a cooling device disposed below the spinning beam, comprising a spinning cylinder extending vertically to surround the molten polymer spun out from the spinneret, the cooling device cooling the molten polymer by cooling air supplied to the spinning cylinder; a spinning equipment comprising: a preparation step of moving the cooling device downward relative to the spinning beam such that a gap is formed between the cooling device and the spinning beam; a temperature drop suppressing step of suppressing a temperature drop of the spinneret at least in a state where the cooling device is moved downward relative to the spinning beam; a restoration step of, after performing maintenance by moving the cooling device downward relative to the spinning beam, moving the cooling device upward relative to the spinning beam while suppressing the temperature drop of the spinneret; wherein the steps described above are performed.

[0016] According to the spinning equipment described in (5) above, when maintenance is performed by lowering the cooling device, a temperature drop of the spinneret and the area around the spinneret can be suppressed. Therefore, the time required for the temperature of the spinneret and the area around the spinneret to return to the original temperature, and thus the time required for the physical properties of the yarn to stabilize, can be shortened, and the amount of discarded yarn can be reduced.

[0017] (6) In the spinning equipment according to (5) above, the temperature drop suppressing step: comprises a step of stopping the supply of cooling air to the spinning cylinder, or a step of suppressing the supply amount of cooling air to the spinning cylinder compared to the state before the preparation step is performed, which is characterized by the above.

[0018] According to the spinning equipment described in (6) above, air is blown onto the molten polymer passing through the gap formed between the spinning beam and the cooling device in a direction intersecting the thread path of the molten polymer. This allows the molten polymer spun from the die to be cooled and solidified while suppressing a decrease in the temperature of the die and its surroundings. As a result, threading the yarn into the spinning cylinder can be easily performed. Note that stopping or reducing the amount of cooling air supplied to the spinning cylinder only needs to be done when the cooling device is moved downward relative to the spinning beam.

[0019] (7) In the spinning apparatus of the present invention, The aforementioned temperature drop suppression step is The process includes a blowing step of blowing air between the spinning beam and the cooling device, and in a direction intersecting the thread path of the molten polymer spun from the die, It is characterized by the following:

[0020] The spinning equipment described in (7) above makes it possible to easily thread the yarn into the spinning cylinder after maintenance is completed while suppressing a drop in the temperature of the die and its surroundings. More specifically, when performing maintenance on the spinning equipment, if the supply of cooling air to the spinning cylinder is stopped or the amount of cooling air supplied to the spinning cylinder is reduced, the molten polymer spun from the die will not cool and solidify, which may make it difficult to thread the yarn into the spinning cylinder after maintenance is completed. Therefore, by blowing air between the spinning beam and the cooling device, and in a direction intersecting the yarn path of the molten polymer spun from the die, it is possible to cool and solidify the molten polymer spun from the die even if the supply of cooling air to the spinning cylinder is stopped or the amount of cooling air supplied to the spinning cylinder is reduced. As a result, it is possible to easily thread the yarn into the spinning cylinder after maintenance is completed while suppressing a drop in the temperature of the die and its surroundings. Furthermore, in addition to being able to cool and solidify the molten polymer spun from the nozzle, it can also block air even if there is air heading towards the nozzle, and consequently, it can block air heading towards the nozzle or suppress the amount of air heading towards the nozzle.

[0021] (8) In the spinning equipment described in (7) above, The aforementioned blowing process is, After the maintenance is performed, the airflow is terminated during or after the recovery process is completed. It is characterized by the following:

[0022] According to the spinning equipment described in (8) above, the upper opening of the spinning cylinder closes when the recovery process is completed. When the upper opening of the spinning cylinder closes, most of the cooling air supplied from the cooling device flows downward, which suppresses the decrease in the temperature of the die and the area surrounding the die. As a result, it is possible to shorten the time it takes for the temperature of the die and the area surrounding the die to return to the original temperature, and consequently, the time it takes for the yarn properties to stabilize.

[0023] Furthermore, it is not essential that the spinning equipment according to the present invention includes all of the configurations described in (1) to (4) above. For example, in the invention relating to the spinning equipment described in (1) above, the configurations described in (2) to (4) above are not essential. Also, within the scope where compatibility can be maintained, the configuration described in (1) above and some or all of the configurations described in (2) above may be arbitrarily combined, or the configuration described in (1) above and some or all of the configurations described in (2) above may be arbitrarily combined, or the configuration described in (1) above and some or all of the configurations described in (2) above may be arbitrarily combined, or the configuration described in (1) above and some or all of the configurations described in (2) above may be arbitrarily combined, or some or all of the configurations described in (3) above may be arbitrarily combined. Similarly, it is not essential that the spinning equipment according to the present invention includes all of the configurations described in (5) to (8) above. For example, in the invention relating to the spinning equipment described in (5) above, the configurations described in (6) to (8) above are not essential. Furthermore, within the scope that consistency can be maintained, the configuration described in (5) above and some or all of the configurations described in (6) above may be arbitrarily combined, or the configuration described in (5) above and some or all of the configurations described in (6) above and some or all of the configurations described in (7) above may be arbitrarily combined, or the configuration described in (5) above and some or all of the configurations described in (6) above and some or all of the configurations described in (7) above may be arbitrarily combined. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a spinning apparatus that can suppress the decrease in the temperature of the spinneret and the temperature around the spinneret. [Brief explanation of the drawing]

[0025] [Figure 1]This is an example of a schematic diagram showing a part of the spinning equipment according to this embodiment, viewed from the right side. [Figure 2] Figure 1 is an example of a schematic diagram showing a part of the spinning equipment as viewed from the front. [Figure 3] This is an example of a schematic diagram showing the state of the spinning equipment when the cooling device is lowered, as shown in Figure 1. [Figure 4] This is an example of a block diagram showing the general electrical configuration of a spinning machine. [Figure 5] This diagram illustrates the maintenance process for conventional spinning equipment and is an example of a schematic diagram showing a part of the spinning equipment in operation. [Figure 6] This diagram illustrates the maintenance process for conventional spinning equipment and is an example of a schematic diagram showing a part of the spinning equipment when the spinning of molten polymer has stopped. [Figure 7] This diagram illustrates the maintenance process for conventional spinning equipment and is an example of a schematic diagram showing a portion of the spinning equipment when the cooling device is lowered to its lowest point relative to the spinning beam. [Figure 8] This is a diagram illustrating the maintenance process for conventional spinning equipment, and is an example of a schematic diagram showing a part of the spinning equipment when replacing the spinning pack. [Figure 9] This diagram illustrates the maintenance process for conventional spinning equipment and is an example of a schematic diagram showing a portion of the spinning equipment when molten polymer spinning is resumed. [Figure 10] This is a diagram illustrating the maintenance process for conventional spinning equipment, and is an example of a schematic diagram showing a part of the spinning equipment with the cover over the upper opening of the spinning cylinder removed. [Figure 11] This diagram illustrates the maintenance process for conventional spinning equipment and is an example of a schematic diagram showing a part of the spinning equipment when the threading operation, in which yarn is passed through the spinning cylinder 31, is performed. [Figure 12] This schematic diagram shows the results of circular knitting dyeing evaluation as they change over time after maintenance has been performed using conventional maintenance procedures and the machine has been restored to operational condition. [Figure 13] This graph shows the results of the changes in the thermal stress and untwist tension of the yarn over time after maintenance has been performed using conventional maintenance procedures and the machine has been restored to operational condition. [Figure 14] This graph shows the change in the surface temperature of the nozzle over time, starting from the commencement of maintenance using the conventional maintenance process. [Figure 15] This diagram illustrates a maintenance process according to the present invention and is an example of a schematic diagram showing a part of the spinning equipment when the supply of cooling air to the spinning cylinder is stopped. [Figure 16] This diagram illustrates the maintenance process according to the present invention and is an example of a schematic diagram showing a part of the spinning equipment during surface cleaning. [Figure 17] This diagram illustrates the maintenance process according to the present invention and is an example of a schematic diagram showing a part of the spinning equipment when the spinning of molten polymer from the die is resumed. [Figure 18] This diagram illustrates the maintenance process according to the present invention and is an example of a schematic diagram showing a part of a spinning machine with the cover covering the upper opening of the spinning cylinder removed. [Figure 19] This diagram illustrates a maintenance process according to the present invention and is an example of a schematic diagram showing a part of the spinning equipment when threading yarn through a spinning cylinder is performed. [Figure 20] This diagram illustrates the maintenance process according to the present invention and is an example of a schematic diagram showing a part of the spinning equipment in operation. [Figure 21] This diagram illustrates the maintenance process for a modified example and is an example of a schematic diagram showing a part of the spinning equipment when the spinning of molten polymer is stopped. [Figure 22] This diagram illustrates the maintenance process for a modified example, and is an example of a schematic diagram showing a part of the spinning equipment when the cooling device is lowered to the bottom end relative to the spinning beam. [Figure 23] This diagram illustrates the maintenance process for a modified version and is an example of a schematic diagram showing a part of the spinning equipment after the spinning of molten polymer has resumed. [Figure 24] This diagram illustrates the maintenance process for a modified version and is an example of a schematic diagram showing a part of the spinning equipment when the blower is started. [Figure 25] This diagram illustrates the maintenance process for a modified version and is an example of a schematic diagram showing a part of the spinning equipment when the threading operation, in which yarn is passed through the spinning cylinder, is performed. [Figure 26] This diagram illustrates the maintenance process for a modified example, and is an example of a schematic diagram showing a part of the spinning equipment when the cooling device is raised to the upper end relative to the spinning beam. [Figure 27] This diagram illustrates the maintenance process for a modified version and is an example of a schematic diagram showing a part of the spinning equipment when it has been restored to an operational state. [Figure 28] This schematic diagram shows the results of circular knit dyeing evaluation, which change over time after maintenance is performed according to the maintenance process of the present invention and the machine is restored to an operational state. [Figure 29] This graph shows an example of the results of changes in the thermal stress and untwist tension of the yarn over time after returning to operational condition, when maintenance is performed using a conventional maintenance process and when maintenance is performed using a modified maintenance process. [Figure 30] This graph shows an example of the change in the surface temperature of the nozzle over time, starting from the start of maintenance, in a conventional maintenance process, the maintenance process of the present invention, and a modified maintenance process. [Modes for carrying out the invention]

[0026] The embodiments of the present invention will be described below with reference to the drawings. For the sake of explanation, the vertical, horizontal, and front-to-back directions are as shown in the figures described later.

[0027] [1. Overview of Spinning Facilities] First, an overview of the spinning equipment 1 according to an embodiment of the present invention will be described. Figure 1 is an example of a schematic diagram showing a part of the spinning equipment 1 according to this embodiment viewed from the right side. Figure 2 is an example of a schematic diagram showing a part of the spinning equipment 1 shown in Figure 1 viewed from the front. Figure 3 is an example of a schematic diagram showing the state of the spinning equipment 1 shown in Figure 1 when the cooling device 3 is lowered. However, in Figures 1 and 3, the polymer tank 25 and polymer piping 26 shown in Figure 2 are omitted from the illustration. Also, for convenience, the molten polymer P and yarn Y are omitted from the illustration in Figure 3, but when the cooling device 3 is lowered, the molten polymer P may be spun from the die 24, and the molten polymer P may be cooled and solidified by the cooling device 3 or other conditions to form yarn Y.

[0028] The spinning equipment 1 according to an embodiment of the present invention is equipment for producing yarn Y made of synthetic fibers. For example, as shown in Figure 1, the spinning equipment 1 comprises at least a spinning device 2, a cooling device 3, a moving mechanism 5, a blower 6, and a control device 7 (see Figure 4, described later). In addition to these, the spinning equipment 1 also comprises an oil application device 8, a take-up device (not shown), and a winding device (not shown), but their descriptions are omitted here.

[0029] (Spinning machine) As shown in Figure 1 or Figure 2, the spinning apparatus 2 is a melt spinning apparatus configured to spin a molten polymer P, which is the material for yarn Y. The spinning apparatus 2 includes a spinning beam 21 that is generally rectangular in shape, a plurality of pack housings 22 formed on the spinning beam 21, a plurality of spinning packs 23 (for example, the same number as the plurality of pack housings 22) attached to each of the plurality of pack housings 22, a polymer tank 25 containing polymer, and a plurality of polymer pipes 26 connecting each spinning pack 23 and the polymer tank 25.

[0030] In Figure 2, for convenience, the number of pack housings 22 and spinning packs 23 is shown as 3, but this is not limited to this number, and the number of pack housings 22 and spinning packs 23 may be greater than this (for example, 12).

[0031] The polymer in the polymer tank 25 is sent to multiple spinning packs 23 via multiple polymer pipes 26. When the polymer is sent from the polymer tank 25 to the spinning packs 23, the polymer inside the polymer tank 25 and polymer pipes 26 is heated to a predetermined temperature (e.g., 300°C) by the spinning beam 21 and becomes molten polymer.

[0032] Each spinning pack 23 is supplied with molten polymer heated to a high temperature from the polymer piping 26. A die 24 is positioned at the lower end of each spinning pack 23. That is, the number of die 24s is the same as the number of spinning packs 23. Each die 24 has, for example, multiple nozzles (not shown). The spinning pack 23 extrudes the molten polymer from each of the multiple nozzles of the die 24 (in other words, spins yarn Y). The molten polymer P extruded from the multiple nozzles is cooled by the cooling device 3 to become yarn Y consisting of multiple filaments. That is, one yarn Y is spun from one die 24. Note that it is not necessary for each die 24 to have multiple nozzles; it may have only one nozzle. In this case, yarn Y is produced as a monofilament yarn.

[0033] (cooling device) As shown in Figure 1, the cooling device 3 includes a spinning cylinder 31 positioned below the spinning apparatus 2, a duct 32 connected to the spinning cylinder 31, and a first compressed air source 37 (see Figure 4, described later) that supplies cooling air CF to the spinning cylinder 31 via the duct 32. In this embodiment, for example, an annular yarn cooling device is used as the cooling device 3. The spinning cylinder 31 is, for example, a hollow box that extends vertically so as to surround the molten polymer spun from the die 24 (so that the molten polymer P is located in the hollow part CE). The spinning cylinder 31 has a rectifier plate 33 inside, and the cooling air supplied from the first compressed air source 37 (hereinafter referred to as "cooling air CF") is supplied through the duct 32 into the lower space of the spinning cylinder 31 (the space below the rectifier plate 33). Cooling air CF that flows into the lower space of the spinning cylinder 31 is rectified upward after passing through the rectifier plate 33 and flows into the upper space of the spinning cylinder 31 (the space above the rectifier plate 33). Multiple partition cylinders 35 are positioned directly below the filter member 36. The partition cylinders 35 are configured to prevent cooling air CF from passing through them radially, so that cooling air CF does not flow directly from the lower space of the spinning cylinder 31 into the hollow section CE. Cooling air CF that flows into the upper space of the spinning cylinder 31 is rectified as it passes through the filter member 36, which is composed of, for example, a punching filter and a cooling filter, and flows into the hollow section CE. As a result, cooling air CF is blown onto the yarn material from the circumferential direction of the filter member 36, or more specifically, from the entire outer circumferential direction of the filter 36, cooling the yarn material and turning it into yarn Y. A sealing member 40 is provided at the point where the spinning beam 21 and the spinning cylinder 31 come into contact. This sealing member 40 prevents leakage from the contact surface between the spinning beam 21 and the spinning cylinder 31.

[0034] (moving mechanism) The moving mechanism 5 is composed of, for example, an air cylinder (hereinafter referred to as the air cylinder 5), and is configured to allow the cooling device 3 to move up and down. More specifically, the air cylinder 5 is erected, for example, on the floor of the factory. The air cylinder 5 has a piston rod 52 that is long in the vertical direction and is arranged to expand and contract in the vertical direction. A wall member 10 extending downward is fixed to the lower end of the spinning cylinder 31. The tip of the piston rod 52 is fixed to the side of the wall member 10. In this configuration, the entire cooling device 3 is movable between a first position (see Figure 1) when the spinning equipment 1 is in operation and a second position (see Figure 3) lower than the first position, by the operation of the air cylinder 5. The cooling device 3 rises when the piston rod 52 of the air cylinder 5 operates in the expansion direction (upward in Figure 1), and lowers when the piston rod 52 operates in the contraction direction (downward in Figure 1). When the cooling device 3 is in the first position, yarn Y can be generated. When the cooling device 3 is in the first position, the cooling device 3 is subjected to an upward force (towards the spinning beam 21) by the air cylinder 5. When the cooling device 3 is in the second position, a gap, which serves as a working space Sw, is formed between the spinning apparatus 2 (more specifically, the spinning beam 21) and the cooling device 3 in the vertical direction. Hereinafter, for convenience, the above "first position" will be referred to as the "upper end," and the above "second position" will be referred to as the "lower end." However, the above "first position" is not limited to the upper end, and the above "second position" is not limited to the lower end.

[0035] (Air blower) As shown in Figure 3, the blower 6 is a device that blows air into the workspace Sw so that a crosswind SF flows in a substantially horizontal direction when the cooling device 3 is located at its lower end. In this specification, "blowing air" may also be referred to as "discharge."

[0036] The blower 6 consists of, for example, a second compressed air source 66 (see Figure 4, described later), a plurality of air nozzles 62 capable of releasing air (e.g., compressed air) supplied from the second compressed air source 66 as a crosswind SF, and air piping 64 connecting the second compressed air source 66 and each air nozzle 62. Each of the plurality of air nozzles 62 corresponds to a plurality of spinning packs 23 and is arranged in a line along the left-right direction. In this embodiment, the plurality of air nozzles 62 are arranged so that the crosswind SF released from the air nozzles 62 is released in one direction from rear to front through the working space Sw formed between the spinning apparatus 2 and the cooling apparatus 3 in the vertical direction. The reason why the crosswind SF released from the plurality of air nozzles 62 flows in one direction is to avoid interference between the cooling air CF which is facing in different directions.

[0037] It is not essential to arrange the multiple air nozzles 62 so that the cooling air CF flows from rear to front; for example, they may be arranged so that the crosswind SF flows from front to rear. Alternatively, the multiple air nozzles 62 may be arranged so that the crosswind SF flows from left to right or right to left. However, considering that the flow rate of the crosswind SF decreases as the distance from the air nozzles 62 increases, it is preferable to arrange the air nozzles 62 so that the crosswind SF flows from rear to front or from front to rear.

[0038] Furthermore, it is not essential to arrange multiple spinning packs 23 and corresponding multiple air nozzles 62. For example, instead of multiple air nozzles 62, one flat nozzle wider than the left-to-right length from the leftmost spinning pack 23 to the rightmost spinning pack 23 may be arranged.

[0039] Furthermore, the reason why the crosswind SF released from the air nozzle 62 flows in a substantially horizontal direction through the working space Sw is to prevent the crosswind SF released from the air nozzle 62 from being directed towards the nozzle 24 and its surroundings. Therefore, if the compressed air released from the air nozzle 62 is not directed towards the nozzle 24 and its surroundings, it is not essential to position the air nozzle 62 so that the compressed air released from the air nozzle 62 flows in a substantially horizontal direction as a crosswind SF. For example, the air nozzle 62 may be positioned so that the compressed air released from the air nozzle 62 flows diagonally downward, or the air nozzle 62 may be positioned so that the compressed air released from the air nozzle 62 flows diagonally upward.

[0040] Furthermore, in this embodiment, a second compressed air source 66 for supplying compressed air to the air nozzle 62 and a first compressed air source 37 for supplying cooling air CF to the spinning cylinder 31 are provided separately. However, the system is not limited to this, and a common compressed air source for supplying compressed air to both the air nozzle 62 and the spinning cylinder 31 may be provided. Moreover, it is not essential to connect the second compressed air source 66 and each air nozzle 62 with air piping 64; they may be connected, for example, with air hoses.

[0041] (Control device) Figure 4 is an example of a block diagram showing the schematic electrical configuration of the spinning equipment 1. The control device 7 performs processes related to the operation of the spinning equipment 1, such as spinning and stopping the molten polymer P from the die 24, operating or stopping the air cylinder 5, controlling the flow rate of the cooling air CF supplied to the spinning cylinder 31, i.e., the hollow section CE, and controlling the flow rate of compressed air discharged from the air nozzle 62 that constitutes the blower 6. The "temperature drop suppression means" of the present invention includes the control device 7.

[0042] The control device 7 includes a CPU, ROM, RAM, etc. The control device 7 is connected to an operation unit 72 consisting of buttons that can be operated by an operator, an upper end detection sensor 76 that detects when the cooling device 3 is at its upper end, and a lower end detection sensor 78 that detects when the cooling device 3 is at its lower end. The control device 7 can receive signals from the operation unit 72, the upper end detection sensor 76, the lower end detection sensor 78, etc.

[0043] Furthermore, the control device 7 is connected to a gear pump 28 capable of spinning molten polymer P from the die 24, a first compressed air source 37, a second compressed air source 66, and a solenoid valve 74 capable of operating the air cylinder. Based on receiving various signals from the operating unit 72, the upper end detection sensor 76, and the lower end detection sensor 78, the control device 7 controls the gear pump 28, the first compressed air source 37, the second compressed air source 66, and the solenoid valve 74. The control device 7 controls the operation of the air cylinder 5 by controlling the solenoid valve 74.

[0044] When the first compressed air source 37 is controlled, the flow rate (hereinafter referred to as "airflow") of the cooling air CF supplied to the spinning cylinder 31 is controlled. When the second compressed air source 66 is controlled, the flow rate (hereinafter referred to as "airflow") of the crosswind SF discharged from the air nozzle 62 is controlled.

[0045] Furthermore, the cooling air CF supplied to the spinning cylinder 31 may be controlled not by controlling the operation and stopping of the first compressed air source 37, but by installing an automatic valve upstream of the duct 32 and controlling this automatic valve. Also, the airflow rate of the crosswind SF discharged from the air nozzle 62 may be controlled by installing an automatic valve upstream of the air nozzle 62 and controlling this automatic valve.

[0046] [2. Maintenance Process] Next, the maintenance process in the spinning equipment will be described. Before describing the maintenance process according to the present invention in spinning equipment 1, the conventional maintenance process will first be described with reference to Figures 5 to 11. When describing the conventional maintenance process, the reference numerals assigned to the various components constituting the spinning equipment 1 according to the embodiment of the present invention will be used as is for the various components constituting the conventional spinning equipment 100 (spinning device, cooling device, etc.). However, the conventional spinning equipment 100 does not have the blower device 6 described above.

[0047] [2-1. Maintenance process in conventional spinning equipment] Figure 5 is an example of a schematic diagram showing a part of the spinning equipment 100 during production, i.e., in operation. During operation of the spinning equipment 100, the spinning beam 21 and the cooling device 3 are in contact. During operation of the spinning equipment 100, molten polymer P is spun from the die 24, and cooling air CF is supplied from the first compressed air source 37 to the spinning cylinder 31 via the duct 32. The cooling air CF supplied to the spinning cylinder 31 flows into the hollow section CE in a substantially horizontal direction, cooling the molten polymer P spun from the die 24.

[0048] [2-1-1. Preparation process] Figure 6 is an example of a schematic diagram showing a part of the spinning equipment 100 when the spinning of molten polymer P is stopped. When performing maintenance on the spinning equipment 100, first, as shown in Figure 6, the spinning of molten polymer P from the die 24 is stopped. The stopping of the spinning of molten polymer P is performed by the control device 7, for example, in response to the operator's actions. During maintenance, the supply of cooling air CF by the cooling device 3 continues. In this specification, maintenance includes, for example, cleaning the surface of the die 24 and replacing the spinning pack 23.

[0049] Figure 7 is an example of a schematic diagram showing a part of the spinning equipment 100 when the cooling device 3 is lowered to its lowest point relative to the spinning beam 21. After stopping the spinning of the molten polymer P, the control device 7 operates the air cylinder 5 in the contraction direction to lower the cooling device 3 relative to the spinning beam 21, as shown in Figure 7. When the cooling device 3 is lowered relative to the spinning beam 21, a working space Sw is formed between the spinning apparatus 2 and the cooling device 3 in the vertical direction. As soon as the cooling device 3 is lowered relative to the spinning beam 21, the operator immediately covers the upper opening of the spinning cylinder 31 with the cover 42. By covering the upper opening of the spinning cylinder 31 with the cover 42, the upward airflow (i.e., cooling air CF) from the upper opening of the spinning cylinder 31 can be stopped.

[0050] [2-1-2. Main Maintenance Process] After covering the upper opening of the spinning cylinder 31 with the cover 42, the operator performs maintenance. Maintenance includes cleaning the surface of the die 24 and replacing the spinning pack 23. The time required for maintenance varies depending on the content, but is generally about 10 minutes. The operator cleans the surface of the die 24 or replaces the spinning pack 23 depending on the purpose. Figure 8 is an example of a schematic diagram showing part of the spinning equipment 100 when replacing the spinning pack 23.

[0051] [2-1-3. Restarting the molten polymer spinning process] Figure 9 is an example of a schematic diagram showing part of the spinning equipment 100 when the spinning of molten polymer P is resumed. After maintenance is performed, the control device 7 starts (resumes) the spinning of molten polymer P from the die 24, as shown in Figure 9, for example, in response to operator input.

[0052] [2-1-4. Cover Removal Process] Figure 10 is an example of a schematic diagram showing part of the spinning equipment 100 with the cover 42 covering the upper opening of the spinning cylinder 31 removed. When spinning of the molten polymer P is to be resumed, the operator removes the cover 42 covering the upper opening of the spinning cylinder 31, as shown in Figure 10.

[0053] [2-1-5. Threading process] Figure 11 is an example of a schematic diagram showing part of the spinning equipment 100 when the threading operation is performed to pass the yarn through the spinning cylinder 31. After the cover 42 covering the upper opening of the spinning cylinder 31 is removed, the operator performs the threading operation, passing the molten polymer P (or cooled and solidified yarn Y) spun from the die 24 through the spinning cylinder 31, as shown in Figure 11.

[0054] [2-1-6. Recovery Process] After the threading operation is completed, the control device 7 operates the air cylinder 5 in the expansion direction, for example, in response to the operator's input, to raise the cooling device 3 so that it approaches the spinning beam 21. When the upper end detection sensor 76 (see Figure 4) detects that the cooling device 3 is at its upper end, the control device 7 stops the operation of the air cylinder 5 and stops the rising of the cooling device 3. When the cooling device 3 stops at its upper end, the spinning beam 21 and the cooling device 3 come into contact via the sealing member 40. Other preparations for the start of production are also carried out in the return process, but the illustrations of these other preparations are omitted.

[0055] Once the recovery process is complete, the spinning machine 100 will operate normally and begin production. Traditionally, maintenance of the spinning machine 100 was performed using the process described above.

[0056] [2-1-7. Challenges in conventional maintenance processes] When maintenance is performed using such conventional maintenance processes and the machine is returned to operation, the properties of the yarn deteriorate, and as shown in Figures 12 and 13, for example, it takes a considerable amount of time for the yarn properties to return to normal (i.e., until it is judged to be a normal yarn). Figure 12 is a schematic diagram showing the results of circular knitting dye evaluation that change over time after maintenance is performed using conventional maintenance processes and the machine is returned to operation. Figure 13 is a graph showing the results of thermal stress and untwist tension of the yarn that change over time after maintenance is performed using conventional maintenance processes and the machine is returned to operation.

[0057] As shown in Figure 12, the circular knitting dye evaluation results show that even after approximately 60 minutes have passed since the machine was restored to operation, the color is still lighter than the standard benchmark (hereinafter referred to as "BM"), and therefore the yarn is not judged to be normal. Then, after approximately 70 minutes have passed since the machine was restored to operation, the color becomes close to BM, and the yarn is judged to be normal.

[0058] As shown in Figure 13, both the untwist tension and thermal stress reach values ​​close to the reference values ​​approximately 80 to 90 minutes after returning to the operational state. As shown in Figure 13, the reference value BM for untwist tension is, for example, 30.8 [cN], and the reference value BM for thermal stress is, for example, 83.1 [cN], but BM varies depending on the type of yarn, etc.

[0059] Thus, after performing maintenance using the conventional maintenance process and returning to operational status, it takes a considerable amount of time for the yarn properties to return to normal. Therefore, even if production continues, it will only result in an increase in discarded yarn. The reason why it takes a considerable amount of time for the yarn properties to return to normal after performing maintenance using the conventional maintenance process is thought to be that the temperature of the nozzle 24 and its surroundings drops significantly during the maintenance process, and it takes time for the temperature of the nozzle 24 and its surroundings to return to its original temperature.

[0060] Figure 14 is a graph showing the change in the surface temperature of the spindle nozzle 24 over time, starting from the commencement of maintenance using a conventional maintenance process. As shown in Figure 14, when the cooling device 3 is lowered relative to the spinning beam 21, the surface temperature of the spindle nozzle 24 continues to decrease, and by the time maintenance is completed, the surface temperature of the spindle nozzle 24 has decreased significantly. When maintenance is completed and the cooling device 3 is raised to approach the spinning beam 21, the surface temperature of the spindle nozzle 24 gradually recovers. As shown in Figure 14, it takes approximately 2000 seconds or more from the start of the upward movement of the cooling device 3 for the surface temperature of the spindle nozzle 24 to return to its original temperature (for example, the temperature before maintenance).

[0061] Incidentally, it is thought that the surface temperature of the die 24 drops significantly in the conventional maintenance process because the cooling air CF supplied to the spinning cylinder 31 is directed upward from the upper opening of the spinning cylinder 31. When threading the molten polymer P (or cooled and solidified yarn Y) spun from the die 24 through the spinning cylinder 31, it is cooled and solidified by the cooling air CF (see, for example, Figure 11) flowing upward from the upper opening of the spinning cylinder 31. In this case, the operator can perform the threading work without using tools, but the die 24 and its surrounding temperature are cooled by the cooling air CF directed upward from the upper opening of the spinning cylinder 31. As a result, the temperature of the die 24 and its surrounding temperature drops significantly, and it is thought that it takes time for the temperature of the die 24 and its surrounding temperature to return to its original temperature after the machine returns to operation.

[0062] Therefore, in order to solve the problems that were apparent in such conventional maintenance processes, the spinning equipment 1 according to the embodiment of the present invention is maintained by the following maintenance process. The maintenance process of the spinning equipment 1 according to the embodiment of the present invention will be described below.

[0063] [2-2. Maintenance process according to the present invention] The maintenance process according to the present invention will be described with reference to Figures 5, 6, and 15-20. The main difference between the spinning equipment 1 according to the embodiment of the present invention and the conventional spinning equipment 100 is that cooling air CF is not supplied to the spinning cylinder 31 during the maintenance process. In addition, since the blower 6 is not operated during the maintenance process of the spinning equipment 1 according to the embodiment of the present invention, it is not essential to provide the blower 6. The blower 6 is not shown in Figures 15-20.

[0064] While the spinning equipment 1 is in operation, the lower end of the spinning beam 21 and the upper end of the cooling device 3 are in contact, as shown in Figure 5. While the spinning equipment 1 is in operation, molten polymer P is spun from the die 24, and cooling air CF is supplied to the spinning cylinder 31 from the first compressed air source 37 (see Figure 4; the same applies hereafter) via the duct 32. The cooling air CF supplied to the spinning cylinder 31 flows into the hollow section CE in a substantially horizontal direction, cooling the molten polymer P spun from the die 24.

[0065] [2-2-1. Preparation process] When performing maintenance on the spinning equipment 1, first, the spinning of molten polymer P from the spindle 24 is stopped, as shown in Figure 6. The stopping of the spinning of molten polymer P is performed by the control device 7, for example, in response to the operator's actions.

[0066] Figure 15 is an example of a schematic diagram showing a part of the spinning equipment 1 when the supply of cooling air CF to the spinning cylinder 31 is stopped. After stopping the spinning of molten polymer P from the die 24, the control device 7 stops the operation of the first compressed air source 37, for example, and stops the supply of cooling air CF to the spinning cylinder 31, as shown in Figure 15.

[0067] Figure 16 is an example of a schematic diagram showing a part of the spinning equipment 1 when the cooling device 3 is lowered to its lowest point relative to the spinning beam 21. When the control device 7 stops supplying cooling air CF to the spinning cylinder 31, it operates the air cylinder 5 in the contraction direction, as shown in Figure 16, to lower the cooling device 3 relative to the spinning beam 21. When the cooling device 3 is lowered relative to the spinning beam 21, a working space Sw is formed between the spinning apparatus 2 and the cooling device 3 in the vertical direction. When the cooling device 3 is lowered relative to the spinning beam 21, the operator covers the upper opening of the spinning cylinder 31 with the cover 42. However, since the supply of cooling air CF to the spinning cylinder 31 has stopped, covering the upper opening of the spinning cylinder 31 with the cover 42 is not mandatory.

[0068] The timing for stopping the spinning of the molten polymer P from the die 24 is preferably before the cooling device 3 begins to descend relative to the spinning beam 21, but is not limited to this. It may also be during the descent of the cooling device 3 relative to the spinning beam 21, or after the cooling device 3 has been lowered to its lowest point relative to the spinning beam 21.

[0069] Furthermore, the timing for stopping the supply of cooling air CF to the spinning cylinder 31 is not limited to after stopping the spinning of molten polymer P from the die 24, but may be immediately before stopping the spinning of molten polymer P from the die 24, or it may be approximately simultaneously with stopping the spinning of molten polymer P from the die 24.

[0070] [2-2-2. Main Maintenance Process] The cooling device 3 descends over the spinning beam 21, and although not mandatory, the upper opening of the spinning cylinder 31 is covered with the cover 42. After this, the operator performs maintenance as needed, such as cleaning the surface of the die 24 or replacing the spinning pack 23. The time required for maintenance varies depending on the content of the maintenance, but is generally about 10 minutes.

[0071] [2-2-3. Restarting the molten polymer spinning process] Figure 17 is an example of a schematic diagram showing a part of the spinning equipment 1 when the spinning of molten polymer P from the die 24 is resumed. After maintenance is performed, the control device 7 starts (resumes) the spinning of molten polymer P from the die 24, as shown in Figure 17, for example, in response to operator input.

[0072] [2-2-4. Cover Removal Process] Figure 18 is an example of a schematic diagram showing a part of the spinning equipment 1 with the cover 42 covering the upper opening of the spinning cylinder 31 removed. When the upper opening of the spinning cylinder 31 is covered with the cover 42, after the spinning of molten polymer P from the die 24 is started (restarted), the operator removes the cover 42 covering the upper opening of the spinning cylinder 31. At this time, the supply of cooling air CF to the spinning cylinder 31 is stopped, so no cooling air CF is directed upward from the upper opening of the spinning cylinder 31.

[0073] [2-2-5. Temperature drop suppression process] The timing for stopping the supply of cooling air CF to the spinning cylinder 31 is as described above, but if the upper opening of the spinning cylinder 31 is covered by the cover 42, it is sufficient to stop the cooling air CF to the spinning cylinder 31 at least until the cover 42 is removed. This is because, while the upper opening of the spinning cylinder 31 is covered by the cover 42, it is possible to prevent the cooling air CF from flowing from the upper opening of the spinning cylinder 31 to the spinneret 24. The step of stopping the supply of cooling air CF to the spinning cylinder 31 corresponds to the temperature drop suppression step.

[0074] [2-2-6. Threading process] Figure 19 is an example of a schematic diagram showing a part of the spinning equipment 1 when the threading operation is performed to pass the yarn through the spinning cylinder 31. After the cover 42 covering the upper opening of the spinning cylinder 31 is removed, as shown in Figure 19, the operator performs the threading operation to pass the molten polymer P (or cooled and solidified yarn Y) spun from the die 24 through the spinning cylinder 31. At this time, since cooling air CF is not supplied to the spinning cylinder 31, there is a high possibility that the molten polymer P spun from the die 24 is in a molten state without being cooled and solidified. Therefore, it is preferable for the operator to perform the threading operation using a tool such as scissors.

[0075] [2-2-7. Recovery Process] Figure 20 is an example of a schematic diagram showing a part of the spinning equipment 1 when the cooling device 3 is raised to its upper end relative to the spinning beam 21. After the threading operation is performed, the control device 7 operates the air cylinder 5 in the expansion direction, for example in response to the operator's operation, to raise the cooling device 3 so that it approaches the spinning beam 21, as shown in Figure 20. When the lower end of the spinning beam 21 and the upper end of the cooling device 3 come into contact, the control device 7 stops the operation of the air cylinder 5 and stops the raising of the cooling device 3.

[0076] When the lower end of the spinning beam 21 and the upper end of the cooling device 3 come into contact and the upward movement of the cooling device 3 stops, the operator threads the yarn onto the oil dispenser 8. After threading the yarn onto the oil dispenser 8, the control device 7 restarts the operation of the first compressed air source 37, for example in response to the operator's actions, and starts supplying cooling air CF to the spinning cylinder 31, as shown in Figure 20. Note that the timing of threading the yarn onto the oil dispenser 8 is not limited to after the cooling device 3 has risen relative to the spinning beam 21, but may also be before the cooling device 3 begins to rise relative to the spinning beam 21, or while the cooling device 3 is rising relative to the spinning beam 21.

[0077] During the recovery process, other preparations for the start of production are also carried out, but diagrams regarding these other preparations are omitted. Once the recovery process is complete, spinning equipment 1 will operate normally and begin production.

[0078] [2-2-8. Effects and Effects] In the maintenance process according to the present invention, as described above, the supply of cooling air CF to the spinning cylinder 31 is stopped when the cooling device 3 is moved downward relative to the spinning beam 21. Therefore, the cooling air CF moving upward from the spinning cylinder 31 can be stopped. As a result, the decrease in the temperature of the die 24 and its surrounding area can be suppressed.

[0079] In the maintenance process according to the present invention described above, the supply of cooling air CF to the spinning cylinder 31 was described on the premise that it would be stopped. However, instead of stopping the supply of cooling air CF to the spinning cylinder 31, the amount of cooling air CF supplied to the spinning cylinder 31 may be reduced. By reducing the amount of cooling air CF supplied to the spinning cylinder 31, the amount of cooling air CF directed from the upper opening of the spinning cylinder 31 toward the die 24 is reduced, thereby suppressing the decrease in the temperature of the die 24 and its surroundings. Therefore, it becomes possible to shorten the time it takes for the temperature of the die 24 and its surroundings to return to the original temperature after returning to the operating state, and the amount of yarn that is discarded can be reduced.

[0080] While the maintenance process according to the present invention is as described above, the maintenance process for solving problems that were apparent in conventional maintenance processes is not limited to this. A modified maintenance process will be described below.

[0081] [2-3. Maintenance process related to modified examples] The maintenance process for the modified version will be explained with reference to Figures 21 to 27. Since the state of spinning equipment 1 during production, i.e., in operation, is the same as in Figure 1, the diagram showing the state of spinning equipment 1 in operation will be omitted.

[0082] The main difference between the modified maintenance process and the maintenance process according to the present invention is that, at least while the cooling device 3 is being lowered relative to the spinning beam 21, a crosswind SF is blown into the working space Sw between the spinning apparatus 2 and the cooling device 3 in the vertical direction. However, the fact that cooling air CF is not supplied to the spinning cylinder 31 in this maintenance process is the same as in the maintenance process according to the present invention.

[0083] As shown in Figure 1, during operation of the spinning machine 1, the lower end of the spinning beam 21 and the upper end of the cooling device 3 are in contact. During operation of the spinning machine 1, molten polymer P is spun from the die 24, and cooling air CF is supplied to the spinning cylinder 31 from the first compressed air source 37 via the duct 32 (see Figure 4). The cooling air CF supplied to the spinning cylinder 31 flows into the hollow section CE in a substantially horizontal direction, cooling the molten polymer P spun from the die 24. Note that no crosswind SF is released from the air nozzle 62 during operation of the spinning machine 1.

[0084] [2-3-1. Preparation process] Figure 21 is an example of a schematic diagram showing a part of the spinning equipment 1 when the spinning of molten polymer P is stopped. When performing maintenance on the spinning equipment 1, first, the spinning of molten polymer P from the die 24 is stopped, as shown in Figure 21. The stopping of the spinning of molten polymer P is performed by the control device 7, for example, in response to the operator's actions. The blower 6 is stopped, and since there is no supply of air from the second compressed air source 66 to the air nozzle 62, no crosswind SF is released from the air nozzle 62.

[0085] After stopping the spinning of the molten polymer P, the control device 7 stops the operation of the first compressed air source 37 and stops the supply of cooling air CF to the spinning cylinder 31. By stopping the supply of cooling air CF to the spinning cylinder 31, it is possible to prevent the cooling air CF from flowing from the upper opening of the spinning cylinder 31 towards the die 24, thereby suppressing a significant drop in the temperature of the die 24 and its surroundings.

[0086] Figure 22 is an example of a schematic diagram showing a part of the spinning equipment 1 when the cooling device 3 is lowered to its lowest point relative to the spinning beam 21. When the control device 7 stops supplying cooling air CF to the spinning cylinder 31, it operates the air cylinder 5 in the contraction direction to lower the cooling device 3 relative to the spinning beam 21, as shown in Figure 22. When the cooling device 3 is lowered relative to the spinning beam 21, a working space Sw is formed between the spinning apparatus 2 and the cooling device 3 in the vertical direction. When the cooling device 3 is lowered relative to the spinning beam 21, the operator covers the upper opening of the spinning cylinder 31 with the cover 42. However, since the supply of cooling air CF to the spinning cylinder 31 has stopped, covering the upper opening of the spinning cylinder 31 with the cover 42 is not mandatory. The blower 6 is stopped, and since there is no supply of compressed air from the second compressed air source 66 to the air nozzle 62, no crosswind SF is released from the air nozzle 62.

[0087] The timing for stopping the spinning of the molten polymer P is preferably before the cooling device 3 begins to descend relative to the spinning beam 21, but is not limited to this. It may also be during the descent of the cooling device 3 relative to the spinning beam 21, or after the cooling device 3 has been lowered to its lowest point relative to the yarn beam 21.

[0088] Furthermore, the timing for stopping the supply of cooling air CF to the spinning cylinder 31 is not limited to after stopping the spinning of the molten polymer P, but may also be before stopping the spinning of the molten polymer P, or may be approximately simultaneously with stopping the spinning of the molten polymer P.

[0089] [2-3-2. Main Maintenance Process] The cooling device 3 descends over the spinning beam 21, and although not mandatory, the upper opening of the spinning cylinder 31 is covered with the cover 42. After this, the operator performs maintenance as needed, such as cleaning the surface of the die 24 or replacing the spinning pack 23. The time required for maintenance varies depending on the content of the maintenance, but is generally about 10 minutes.

[0090] [2-3-3. Restarting the molten polymer spinning process] Figure 23 is an example of a schematic diagram showing a part of the spinning equipment 1 after the spinning of molten polymer P has been resumed. After maintenance is performed, the control device 7 starts (resumes) the spinning of molten polymer P from the spinneret 24, as shown in Figure 23, for example, in response to the operator's actions. Also, if the upper opening of the spinning cylinder 31 is covered by a cover 42, the operator removes the cover 42 that covers the upper opening of the spinning cylinder 31.

[0091] [2-3-4. Temperature drop suppression process] The step of stopping the supply of cooling air CF to the spinning cylinder 31, as described above, is included in the temperature drop suppression step. The timing for stopping the supply of cooling air CF to the spinning cylinder 31 is as described above, but if the upper opening of the spinning cylinder 31 is covered by the cover 42, it is sufficient to stop the cooling air CF to the spinning cylinder 31 at least until the cover 42 is removed. This is because, while the upper opening of the spinning cylinder 31 is covered by the cover 42, the cover 42 prevents the cooling air CF from flowing from the upper opening of the spinning cylinder 31 to the spinneret 24.

[0092] Figure 24 is an example of a schematic diagram showing a part of the spinning equipment 1 when the cooling device 3 is started. After the control device 7 resumes spinning of the molten polymer P, it starts operating the blower 6. When the blower 6 starts operating, a crosswind SF is released from the air nozzle 62 in a substantially horizontal direction toward the molten polymer P spun from the die 24 in the working space Sw between the spinning device 2 and the cooling device 3 in the vertical direction. The blowing process of releasing a crosswind SF from the air nozzle 62 in a substantially horizontal direction toward the molten polymer P spun from the die 24 in the working space Sw is also included in the temperature drop suppression process.

[0093] The operation of the blower 6 may be started after the cover 42 covering the upper opening of the spinning cylinder 31 is removed, or it may be started before the cover 42 covering the upper opening of the spinning cylinder 31 is removed. In this case, since cooling air CF is not supplied to the spinning cylinder 31, it is possible to suppress a large drop in the temperature of the spinneret 24 and its surroundings due to the cooling air CF blowing upward from the upper opening of the spinning cylinder 31.

[0094] Furthermore, the timing for starting the operation of the blower 6 is not limited to after the resumption of spinning the molten polymer P, but may also be before the resumption of spinning the molten polymer P from the die 24.

[0095] As mentioned above, since the supply of cooling air CF to the spinning cylinder 31 is stopped, the decrease in the temperature of the die 24 and its surroundings can be suppressed. On the other hand, if the supply of cooling air CF to the spinning cylinder 31 is stopped, the molten polymer P spun from the die 24 cannot be cooled and solidified by the cooling air CF supplied to the spinning cylinder 31. If the molten polymer P spun from the die 24 is not cooled and solidified, it may become difficult to thread the yarn into the spinning cylinder 31 after maintenance is completed. However, in the working space Sw, by releasing crosswind SF from the air nozzle 62 towards the molten polymer P spun from the die 24, the molten polymer P released from the die 24 can be cooled and solidified. As a result, it becomes possible to easily thread the yarn into the spinning cylinder 31 after maintenance is completed while suppressing the decrease in the temperature of the die 24 and its surroundings.

[0096] [2-3-5. Threading process] Figure 25 is an example of a schematic diagram showing a part of the spinning equipment 1 when the threading operation is performed to pass the yarn through the spinning cylinder 31. When the discharge of crosswind SF from the air nozzle 62 begins, as shown in Figure 25, the operator performs the threading operation to pass the molten polymer P (or cooled and solidified yarn Y) spun from the die 24 through the spinning cylinder 31. At this time, the molten polymer P spun from the die 24 is cooled and solidified by the crosswind SF discharged from the air nozzle 62. Therefore, the operator can perform the threading operation without using any tools.

[0097] [2-3-6. Recovery Process] Figure 26 is an example of a schematic diagram showing a part of the spinning equipment 1 when the cooling device 3 is raised to its upper end relative to the spinning beam 21. After the threading operation into the spinning cylinder 31 is performed, the control device 7 operates the air cylinder 5 in the expansion direction, for example in response to the operator's operation, as shown in Figure 26, to raise the cooling device 3 so that it approaches the spinning beam 21. When the spinning beam 21 and the cooling device 3 come into contact, the control device 7 stops the operation of the air cylinder 5 and stops the raising of the cooling device 3. Furthermore, when the spinning beam 21 and the cooling device 3 come into contact and the raising of the cooling device 3 stops, the control device 7 stops the operation of the blower 6 and stops the discharge of crosswind SF from the air nozzle 62, ending the blowing process. The timing for stopping the discharge of crosswind SF from the air nozzle 62 is preferably when the spinning beam 21 and the cooling device 3 come into contact and the raising of the cooling device 3 stops, because this allows the molten polymer P spun from the die 24 to be cooled and solidified. However, the discharge of the crosswind SF from the air nozzle 62 may be stopped before raising the cooling device 3 relative to the spinning beam 21, or while raising the cooling device 3 to approach the spinning beam 21. When the spinning beam 21 and the cooling device 3 come into contact, the upper opening of the spinning cylinder 31 is closed, and all or most of the cooling air CF flowing into the hollow section CE flows downward, so even if the blowing process is completed, the decrease in the die 24 and the ambient temperature of the die 24 can be suppressed. As a result, it is possible to shorten the time it takes for the die 24 and the ambient temperature of the die 24 to return to their original temperature, and consequently the time it takes for the yarn properties to stabilize.

[0098] Furthermore, after the cooling device 3 stops rising relative to the spinning beam 21, the operator threads the yarn onto the oil dispenser 8. The timing of threading the yarn onto the oil dispenser 8 is not limited to after the cooling device 3 rises relative to the spinning beam 21, but may be before the cooling device 3 starts rising relative to the spinning beam 21, or even while the cooling device 3 is rising relative to the spinning beam 21, however, it is preferable to do so after the discharge of crosswind SF from the air nozzle 62 stops.

[0099] Figure 27 is an example of a schematic diagram showing a part of the spinning equipment 1 during production, i.e., when it has returned to an operational state. When the spinning beam 21 and the cooling device 3 come into contact and the rise of the cooling device 3 stops, the control device 7 restarts the operation of the first compressed air source 37 and starts supplying cooling air CF to the spinning cylinder 31.

[0100] During the recovery process, other preparations for the start of production are also carried out, but diagrams regarding these other preparations are omitted. Once the recovery process is complete, spinning equipment 1 will operate normally and begin production.

[0101] The timing for starting the supply of cooling air CF to the spinning cylinder 31 is not limited to when the spinning beam 21 and the cooling device 3 come into contact and the upward movement of the cooling device 3 stops. For example, if a crosswind SF released from the air nozzle 62 is flowing between the spinning device 2 and the cooling device 3 in the vertical direction, the supply of cooling air CF to the spinning cylinder 31 may be started when the cooling device 3 is at its lower end. If the supply of cooling air CF to the spinning cylinder 31 is started when the cooling device 3 is at its lower end, there is a possibility that the cooling air CF will flow from the upper opening of the spinning cylinder 31 toward the die 24. However, since the crosswind SF released from the air nozzle 62 acts as a barrier, the decrease in the temperature of the die 24 and its surroundings can be suppressed.

[0102] [2-3-7. Effects and Effects] In the modified maintenance process described above, the supply of cooling air CF to the spinning cylinder 31 is stopped at least when the cooling device 3 is moved downward relative to the spinning beam 21. Therefore, the cooling air CF directed from the upper opening of the spinning cylinder 31 toward the spinneret 24 can be stopped. As a result, the decrease in temperature of the spinneret 24 and its surroundings can be suppressed.

[0103] In the modified maintenance process described above, the explanation was based on the premise that the supply of cooling air CF to the spinning cylinder 31 is stopped. However, instead of stopping the supply of cooling air CF to the spinning cylinder 31, the amount of cooling air CF supplied to the spinning cylinder 31 may be reduced. Reducing the amount of cooling air CF supplied to the spinning cylinder 31 reduces the amount of cooling air CF that flows from the upper opening of the spinning cylinder 31 toward the spinneret 24, thereby suppressing the decrease in the temperature of the spinneret 24 and its surroundings. The reduction in the amount of cooling air CF supplied to the spinning cylinder 31 should be at least reduced compared to during production, i.e., before the spinning of the molten polymer P is stopped.

[0104] Incidentally, if the supply of cooling air CF to the spinning cylinder 31 is stopped or reduced when performing maintenance on the spinning equipment 1, the molten polymer P spun from the die 24 will not cool and solidify, which may make it difficult to thread the yarn into the spinning cylinder 31 after the maintenance is completed. However, the crosswind SF released from the air nozzle 62 flows in a direction that intersects with the yarn path of the molten polymer P spun from the die 24, making it possible to cool and solidify the molten polymer P spun from the die 24. As a result, it becomes possible to easily thread the yarn into the spinning cylinder after the maintenance is completed while suppressing the decrease in the temperature of the die 24 and its surroundings. Consequently, it becomes possible to shorten the time it takes for the temperature of the die 24 and its surroundings to return to the original temperature after returning to operation, and the amount of yarn that is discarded can be reduced.

[0105] [3. Verification results of the maintenance process according to the present invention or a modified example] When maintenance is performed using the maintenance process according to the present invention or the modified maintenance process described above, it is possible to shorten the time it takes for the yarn properties to return to normal after returning to the operational state. Figure 28 is a schematic diagram showing the results of circular knitting dye evaluation that change over time after maintenance is performed using the maintenance process according to the present invention and the system returns to the operational state. Figure 29 is a graph showing an example of the results of the thermal stress and untwist tension of the yarn that change over time after returning to the operational state, in the case where maintenance is performed using the conventional maintenance process and the modified maintenance process.

[0106] As shown in Figure 28, the circular knitting dye evaluation results show that the color becomes close to BM approximately 15 minutes after returning to operation, and the yarn is judged to be normal. In this way, it is possible to significantly reduce the time required to determine that the yarn is normal compared to when maintenance is performed using conventional maintenance processes.

[0107] Furthermore, as shown in Figure 29, it is clear that both the untwisting tension and thermal stress are better when maintenance is performed using the modified maintenance process than when maintenance is performed using the conventional maintenance process.

[0108] Figure 30 is a graph showing an example of the change in surface temperature of the nozzle 24 over time from the start of maintenance in a conventional maintenance process, the maintenance process of the present invention, and a modified maintenance process. Figure 30(a) shows an example of the change in surface temperature of the nozzle 24 over time from the start of maintenance in a conventional maintenance process. Figure 30(b) shows an example of the change in surface temperature of the nozzle 24 over time from the start of maintenance in the maintenance process according to the present invention. Figure 30(c) shows an example of the change in surface temperature of the nozzle 24 over time from the start of maintenance in a modified maintenance process.

[0109] As shown in Figure 30, it can be seen that in all of the conventional maintenance process, the maintenance process of the present invention, and the modified maintenance process, the surface temperature of the spinneret 24 decreases when the cooling device 3 is lowered relative to the spinning beam 21. However, the time it takes for the surface temperature of the spinneret 24 to return to its original temperature after the maintenance is completed and the cooling device 3 is raised is shorter in the maintenance process of the present invention and the modified maintenance process compared to the conventional maintenance process. This is thought to be because, when maintenance is performed using the conventional maintenance process, the temperature of the spinneret 24 and its surroundings drops significantly due to the cooling air CF directed upward from the upper opening of the spinning cylinder 31 when the cooling device 3 is raised. In this respect, in the maintenance process of the present invention, since no cooling air CF is supplied to the spinning cylinder 31, there is either no cooling air CF directed upward from the upper opening of the spinning cylinder 31, or the amount of cooling air CF directed upward from the upper opening of the spinning cylinder 31 is suppressed, thus suppressing the decrease in the surface temperature of the spinneret 24. Furthermore, in the modified maintenance process, although the cooling air CF supplied to the spinning cylinder 31 is directed upward, this cooling air CF is blocked by the crosswind SF released from the air nozzle 62 of the cooling device 3, thereby suppressing the decrease in the surface temperature of the spinneret 24. [Explanation of Symbols]

[0110] 1. Spinning equipment 3 Cooling device 5 Air Cylinder 6. Blower 7 Control device 21 Spinning beam 23 Spinning Pack 24 nozzles 31 Spinning cylinder P molten polymer CF cooling air Sw workspace

Claims

1. A spinning beam into which a spinning pack is inserted to spin molten polymer downwards from the die, A cooling device is provided, which is positioned below the spinning beam and has a spinning cylinder that extends vertically to surround the molten polymer spun from the die, and cools the molten polymer with cooling air supplied from the circumferential direction of the spinning cylinder. A moving mechanism capable of moving the cooling device downward relative to the spinning beam so that a gap is formed between it and the spinning beam, A temperature drop suppression means for suppressing a temperature drop in the die, at least when the cooling device is moved downward relative to the spinning beam, Equipped with, The aforementioned temperature drop suppression means is The control device includes at least control over the supply of cooling air to the spinning cylinder, The control device is At least when the cooling device is moved downward relative to the spinning beam, it is possible to perform control to stop the supply of cooling air to the spinning cylinder, or control to suppress the amount of cooling air supplied to the spinning cylinder compared to the state before the spinning of the molten polymer was stopped. A spinning apparatus characterized by the following features.

2. The aforementioned temperature drop suppression means is The system includes a blower that blows air between the spinning beam and the cooling device, and in a direction intersecting the thread path of the molten polymer spun from the die, The spinning apparatus according to feature 1.

3. The aforementioned blower device is The operation stops when the spinning beam and the cooling device come into contact. The spinning apparatus according to feature 2.

4. A spinning beam into which a spinning pack is inserted to spin molten polymer downwards from the die, A cooling device is provided, which is positioned below the spinning beam and has a spinning cylinder that extends vertically to surround the molten polymer spun from the die, and cools the molten polymer with cooling air supplied to the spinning cylinder. A spinning apparatus equipped with, A preparation step of moving the cooling device downward relative to the spinning beam so that a gap is formed between it and the spinning beam, A temperature drop suppression step to suppress the temperature drop of the die, at least when the cooling device is moved downward relative to the spinning beam, After performing maintenance by moving the cooling device downward relative to the spinning beam, a return step is performed in which the cooling device is moved upward relative to the spinning beam while suppressing the temperature drop of the die, Execute, The aforementioned temperature drop suppression step is The process includes a step of stopping the supply of cooling air to the spinning cylinder, or a step of suppressing the amount of cooling air supplied to the spinning cylinder compared to the state before the preparation step was performed. A spinning apparatus characterized by the following features.

5. The aforementioned temperature drop suppression step is The process includes a blowing step of blowing air between the spinning beam and the cooling device, and in a direction intersecting the thread path of the molten polymer spun from the die, The spinning apparatus according to feature 4.

6. The aforementioned blowing process is, After the maintenance is performed, the airflow is terminated during or after the recovery process is completed. The spinning apparatus according to feature 5.

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