Method for manufacturing processed yarn, and yarn processing machine

Abstract

To improve heating efficiency while avoiding risk of fusion when yarn breakage occurs during heating and processing the yarn with a heater.SOLUTION: A finished yarn manufacturing method has a step to heat a running yarn Y made of synthetic fibers with a first heater 13. The first heater 13 has a heat source 51 and a heat source 52. The heat source 52 has a contact surface 56 that extends at least in a predetermined extension direction for contacting the running yarn Y. In the manufacturing method, the first heater 13 is disposed so that the contact surface 56 is directed at least downward and tilted angle at cross section in parallel both with a vertical direction and the extension direction falls within the range from -60° to +60° to a horizontal direction of the contact surface 56. Temperature of the contact surface 56 is set to a predetermined temperature of 230°C or higher and 350°C or less. The yarn Y is made to run while contacting the contact surface 56 in this state.SELECTED DRAWING: Figure 5

Description

Technical Field

[0003] , ,

[0001] The present invention relates to a method for manufacturing a processed yarn and a yarn processing machine.

Background Art

[0002] Various heating devices used for processing (such as false twisting) yarns made of synthetic fibers have been conventionally known. For example, Patent Document 1 discloses a heating device (described as a primary heater in Patent Document 1) using Dowtherm (a registered trademark of The Dow Chemical Company) as a heat medium. In yarn processing using this heating device, a contact plate (contact member) for contacting the yarn is heated to a predetermined processing temperature by the heat medium. The yarn is heated to the above processing temperature by the running yarn contacting the contact member (contact method). Also, for example, in the heating device disclosed in Patent Document 2 (described as the first heating device in Patent Document 2), the yarn runs in a yarn running space heated by a sheathed heater as a heat source. Thereby, the yarn is heated by the gas in the yarn running space (non-contact method). In yarn processing using this heating device, by setting the temperature of the yarn running space higher than the above processing temperature and appropriately setting the running speed of the yarn, the yarn passing through the yarn running space is heated to a temperature substantially equal to the processing temperature. Further, for example, in Patent Document 3, in a heating device using a sheathed heater as a heat source, means for switching the heating method between a contact method and a non-contact method has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in contact-type processing, it is recommended to lower the heating temperature (set temperature of the contact member) (for example, 225°C or lower in Patent Document 3). Conversely, in non-contact-type processing, it is recommended to raise the heating temperature (set temperature of the yarn running space) (for example, 420°C or higher in Patent Document 3). The inventor of this application has the following view on the reason for this: If the heating temperature falls within a certain range (hereinafter referred to as the middle range for convenience of explanation), when yarn breakage occurs and the yarn cannot run normally, the yarn melts in the heating device and adheres to the heating device (fusion). In order to remove such adhesion, it becomes necessary to stop the heating device for a long time. However, if the set temperature is sufficiently high, the yarn sublimes easily when breakage occurs, thus avoiding the problem of fusion. For this reason, conventionally, the heating temperature has been set lower than the middle range temperature in contact-type processing and higher than the middle range temperature in non-contact-type processing. On the other hand, in recent years, there has been a demand for yarn processing methods and yarn processing machines with higher heating efficiency.

[0005] The objective of the present invention is to improve heating efficiency while avoiding the risk of fusion when yarn breakage occurs during processing using a heating device. [Means for solving the problem]

[0006] The first invention relates to a method for manufacturing processed yarn, comprising the step of heating a running yarn made of synthetic fibers with a heating device, wherein the heating device comprises a heat source and a heating section heated by the heat source, and the heating section has a contact surface for contacting the running yarn, which extends at least in a predetermined extending direction, wherein the heating device is positioned such that the angle of inclination of the contact surface with respect to the horizontal direction is between -60 and +60° in a cross section parallel to both the vertical direction and the extending direction, with the contact surface at least facing downward, and the temperature of the contact surface is set to a predetermined temperature of 230°C to 350°C, and the yarn is run while in contact with the contact surface.

[0007] In this invention, the temperature range of 230°C to 350°C is referred to as the middle range. Generally, it is believed that there is a risk of fusion when the heating temperature is below 350°C. However, the inventors of this invention believed that by adopting a contact method and setting the heating temperature within the middle range while avoiding the problem of fusion, the yarn could be heated more efficiently. In other words, compared to conventional contact methods, the heating temperature can be set higher, so the heating efficiency can naturally be increased. Furthermore, compared to conventional non-contact heating devices, even at lower heating temperatures, the yarn can be heated more efficiently due to the contact surface (i.e., the heating efficiency can be increased).

[0008] In this invention, even if the temperature of the contact surface (heating temperature) is within a predetermined range in the middle range when the yarn is running normally (normal state), the yarn can be heated to the optimal processing temperature (avoiding the problem of fusion) by appropriately setting the type of yarn, the brand of yarn (thickness), the yarn running speed, and the heating temperature. Furthermore, the contact surface is at least facing downwards, and the inclination angle of the contact surface with respect to the horizontal direction is between -60 and +60° (details of the definition of the inclination angle will be explained in the embodiments described later). As a result, when yarn breakage occurs, the yarn can be quickly separated from the contact surface by its own weight. This prevents the yarn from melting even if yarn breakage occurs.

[0009] The method for manufacturing processed yarn of the second invention is characterized in that, in the first invention, the material of the yarn is polyester, and the predetermined temperature is 250°C or more and 350°C or less.

[0010] In polyester, the likelihood of fusion occurs particularly high when the heating temperature exceeds 250°C. The ability to avoid fusion at such heating temperatures is especially beneficial with the present invention.

[0011] The third invention is a method for manufacturing processed yarn, characterized in that, in the first invention, the material of the yarn is nylon 6, and the predetermined temperature is 230°C or higher and 350°C or lower.

[0012] In nylon 6, the likelihood of fusion occurring increases significantly when the heating temperature exceeds 230°C. The ability to avoid fusion at such heating temperatures is particularly effective with the present invention.

[0013] The fourth invention is a method for manufacturing processed yarn, characterized in that, in the first invention, the material of the yarn is nylon 66, and the predetermined temperature is 260°C or higher and 350°C or lower.

[0014] In nylon 66, the likelihood of fusion occurring increases significantly when the heating temperature exceeds 260°C. The ability to avoid fusion at such heating temperatures is particularly effective with the present invention.

[0015] The fifth invention is a method for manufacturing processed yarn, characterized in that, in any of the first to fourth inventions, the predetermined temperature is 320°C or lower.

[0016] When the heating temperature is 350°C or close to it, depending on conditions such as the type and / or thickness of the yarn, or the yarn running speed, fusion may easily occur. In this invention, by setting the heating temperature to 320°C or lower, fusion can be more reliably avoided.

[0017] The sixth invention is a method for manufacturing processed yarn, characterized in that, in any of the first to fifth inventions, an electric heater is used as the heat source.

[0018] Generally, there are two types of heat sources: those that use a heat transfer medium to heat the contact surface, and those that generate Joule heat using an electric heater to heat the contact surface. With heat sources using a heat transfer medium, there is generally a limit to how high the temperature of the heat transfer medium can rise, making it difficult to raise the temperature of the contact surface. In this invention, the temperature of the contact surface can be easily raised by using an electric heater.

[0019] The seventh invention is a method for manufacturing processed yarn, characterized in that, in the sixth invention, the length of the heating device in the extending direction is 0.4 m or more and 1.6 m or less.

[0020] In the present invention, by using a heating device having an appropriate length in the extending direction, it is possible to cope with various conditions such as the type and / or thickness of the yarn, or the yarn running speed.

[0021] The yarn processing machine of the eighth invention is a yarn processing machine having a heating device for heating a running yarn made of synthetic fiber, the heating device including a heat source, a heating part heated by the heat source, and a control part for controlling the heat source, the heating part having at least a contact surface for contacting the running yarn extending in at least a predetermined extending direction, the contact surface facing at least downward, and the heating device being arranged such that in a cross section parallel to both the vertical direction and the extending direction, the inclination angle of the contact surface with respect to the horizontal direction falls within -60 to +60°, and the control part controls the heat source such that when the yarn is running while contacting the contact surface, the temperature of the contact surface becomes a predetermined temperature of 230°C or more and 350°C or less.

[0022] In the present invention, similar to the first invention, the risk of fusion when yarn breakage occurs can be avoided.

[0023] The yarn processing machine of the ninth invention is characterized in that in the eighth invention, the material of the yarn is polyester and the predetermined temperature is 250°C or more and 350°C or less.

[0024] In the present invention, similar to the second invention, the risk of fusion in polyester can be avoided.

[0025] The yarn processing machine of the tenth invention is characterized in that in the eighth invention, the material of the yarn is nylon 6 and the predetermined temperature is 230°C or more and 350°C or less.

[0026] In the present invention, similar to the third invention, the risk of fusion in nylon 6 can be avoided.

[0027] The yarn processing machine of the 11th invention is characterized in that, in the 8th invention, the yarn material is nylon 66, and the predetermined temperature is 260°C or more and 350°C or less.

[0028] In this invention, as with the fourth invention, the risk of fusion in nylon 66 can be avoided.

[0029] The yarn processing machine of the twelfth invention is characterized in that, in any of the eighth to eleventh inventions, the heat source is an electric heater.

[0030] In this invention, similar to the sixth invention, the temperature of the contact surface can be easily increased.

[0031] The yarn processing machine of the 13th invention is characterized in that, in the 12th invention, the length of the heating device in the extending direction is 0.4 m or more and 1.6 m or less.

[0032] In this invention, similar to the seventh invention, by using a heating device having an appropriate length in the extending direction, it is possible to accommodate various types and / or thicknesses of yarn, or conditions such as yarn running speed. [Brief explanation of the drawing]

[0033] [Figure 1] This is a side view of a false twisting machine for carrying out the manufacturing method of processed yarn according to this embodiment. [Figure 2] This is a schematic diagram showing a false twisting machine deployed along the yarn path. [Figure 3] (a) to (d) are explanatory diagrams showing the first heating device. [Figure 4] This is an explanatory diagram showing the definition of the inclination angle of the contact surface with respect to the horizontal direction. [Figure 5] (a) and (b) are explanatory diagrams showing the limits of the inclination angle of the contact surface with respect to the horizontal direction. [Figure 6] This graph shows the relationship between crimp rate and heating temperature when false-twisting yarn of a predetermined thickness using various heating devices. [Modes for carrying out the invention]

[0034] Next, embodiments of the present invention will be described. In Figure 1, the direction perpendicular to the plane of the paper is defined as the longitudinal direction of the machine base, and the direction from left to right on the plane of the paper is defined as the width direction of the machine base. The direction perpendicular to both the longitudinal direction and the width direction of the machine base is defined as the up-and-down direction (vertical direction) where gravity acts. The longitudinal direction and the width direction of the machine base are directions that are substantially parallel to the horizontal direction.

[0035] (Overall configuration of the false twisting machine) First, the overall configuration of the false twisting machine 1 (yarn processing machine of the present invention) for carrying out the method of manufacturing the processed yarn of this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a side view of the false twisting machine 1. Figure 2 is a schematic diagram of the false twisting machine 1 unfolded along the path (yarn path) of the yarn Y.

[0036] The false twisting machine 1 is configured to perform false twisting on yarn Y made of synthetic fibers (e.g., polyester). Yarn Y is, for example, a multifilament yarn made of multiple filaments. Alternatively, yarn Y may be made of a single filament. The false twisting machine 1 comprises a yarn feeding section 2, a processing section 3, and a winding section 4. The yarn feeding section 2 is configured to supply yarn Y. The processing section 3 is configured to draw yarn Y from the yarn feeding section 2 and perform false twisting. The winding section 4 is configured to wind the yarn Y processed by the processing section 3 onto a winding bobbin Bw. The components of the yarn feeding section 2, processing section 3, and winding section 4 are arranged in multiples along the longitudinal direction of the machine base (see Figure 2). The longitudinal direction of the machine base is the direction perpendicular to the running surface of yarn Y (plane of paper in Figure 1), which is formed by the yarn path from the yarn feeding section 2 through the processing section 3 to the winding section 4.

[0037] The yarn supply unit 2 has a creel stand 7 that holds multiple yarn supply packages Ps and supplies multiple yarns Y to the processing unit 3. The processing unit 3 is configured to draw out multiple yarns Y from the yarn supply unit 2 and process them. The processing unit 3 is configured such that, in order from the upstream side in the yarn travel direction, it includes, for example, a first feed roller 11, a twisting guide 12, a first heating device 13 (heating device of the present invention), a cooling device 14, a false twist device 15, a second feed roller 16, an entanglement device 17, a third feed roller 18, a second heating device 19, and a fourth feed roller 20. The winding unit 4 has multiple winding devices 21. Each winding device 21 winds the yarn Y that has been false twisted in the processing unit 3 onto a winding bobbin Bw to form a winding package Pw.

[0038] The false twisting machine 1 has a main machine base 8 and a winding base 9 that are spaced apart in the machine width direction. The main machine base 8 and the winding base 9 are provided to extend approximately the same length in the machine longitudinal direction. The main machine base 8 and the winding base 9 are arranged to face each other in the machine width direction. The false twisting machine 1 has a unit called a span, which includes one set of main machine bases 8 and winding bases 9. In one span, the devices are arranged so that false twisting can be performed simultaneously on multiple yarns Y running in a line in the machine longitudinal direction. In the false twisting machine 1, these spans are arranged symmetrically on the left and right sides of the paper with respect to the center line C in the machine width direction of the main machine base 8 as the axis of symmetry (the main machine base 8 is common to both the left and right spans). Multiple spans are also arranged in the machine longitudinal direction.

[0039] (Configuration of the processing section) The configuration of the processing unit 3 will be explained with reference to Figures 1 and 2. The first feed roller 11 is configured to unwind the yarn Y from the yarn supply package Ps attached to the yarn supply unit 2 and send it to the first heating device 13. The first feed roller 11 is configured to send one yarn Y to the first heating device 13, for example, as shown in Figure 2. Alternatively, the first feed roller 11 may be configured to send multiple adjacent yarns Y downstream in the yarn travel direction. The twisting guide 12 is configured so that the twist applied to the yarn Y by the false twisting device 15 does not propagate upstream of the twisting guide 12 in the yarn travel direction.

[0040] The first heating device 13 is a device for heating the yarn Y fed from the first feed roller 11 to a predetermined processing temperature. The first heating device 13 is configured to heat two yarns Y, for example, as shown in Figure 2. More details of the first heating device 13 will be described later.

[0041] The cooling device 14 is configured to cool the yarn Y heated by the first heating device 13. The cooling device 14 is configured to cool one yarn Y, for example, as shown in Figure 2. Alternatively, the cooling device 14 may be configured to cool multiple yarns Y simultaneously. The false twisting device 15 is located downstream of the cooling device 14 in the yarn travel direction and is configured to impart twist to the yarn Y. The false twisting device 15 is, for example, a so-called disc friction type false twisting device, but is not limited to this. The second feed roller 16 is configured to send the yarn Y processed by the false twisting device 15 to the entanglement device 17. The conveying speed of the yarn Y by the second feed roller 16 is faster than the conveying speed of the yarn Y by the first feed roller 11. As a result, the yarn Y is stretched and false twisted between the first feed roller 11 and the second feed roller 16.

[0042] The entanglement device 17 is configured to impart entanglement to the yarn Y. The entanglement device 17 has, for example, a known interlacing nozzle that imparts entanglement to the yarn Y by airflow.

[0043] The third feed roller 18 is configured to send yarn Y traveling downstream of the entanglement device 17 in the yarn travel direction to the second heating device 19. For example, as shown in Figure 2, the third feed roller 18 is configured to send one yarn Y to the second heating device 19. Alternatively, the third feed roller 18 may be configured to send multiple adjacent yarns Y downstream in the yarn travel direction. The conveying speed of yarn Y by the third feed roller 18 is slower than the conveying speed of yarn Y by the second feed roller 16. Therefore, the yarn Y is loosened between the second feed roller 16 and the third feed roller 18. The second heating device 19 is configured to heat the yarn Y sent from the third feed roller 18. The second heating device 19 extends along the vertical direction, with one provided in each span. The fourth feed roller 20 is configured to send the yarn Y heated by the second heating device 19 to the winding device 21. The fourth feed roller 20 is configured to feed a single thread Y to the winding device 21, for example, as shown in Figure 2. Alternatively, the fourth feed roller 20 may be configured to feed multiple adjacent threads Y downstream in the thread travel direction. The conveying speed of the thread Y by the fourth feed roller 20 is slower than the conveying speed of the thread Y by the third feed roller 18. As a result, the thread Y is loosened between the third feed roller 18 and the fourth feed roller 20.

[0044] In the processing unit 3 configured as described above, the yarn Y, stretched between the first feed roller 11 and the second feed roller 16, is twisted by the false twisting device 15. The twist formed by the false twisting device 15 propagates to the twist-stopping guide 12, but does not propagate upstream of the twist-stopping guide 12 in the yarn direction. The yarn Y, which has been stretched and twisted, is heated and heat-set in the first heating device 13, and then cooled in the cooling device 14. Downstream of the false twisting device 15 in the yarn direction, the yarn Y is untwisted, but the above-mentioned heat-setting maintains the wavy false twist state of the yarn Y (i.e., the crimp of the yarn Y is maintained).

[0045] The false-twisted yarn Y is loosened between the second feed roller 16 and the third feed roller 18, then entangled by the entanglement device 17, and guided downstream in the yarn direction. Furthermore, the yarn Y is loosened between the third feed roller 18 and the fourth feed roller 20, and then heat-treated by the second heating device 19. Finally, the yarn Y fed from the fourth feed roller 20 is wound up by the winding device 21.

[0046] (Structure of the winding mechanism) The configuration of the winding unit 4 will be explained with reference to Figure 2. The winding unit 4 has a plurality of winding devices 21. Each winding device 21 is configured to wind yarn Y onto one winding bobbin Bw. The winding device 21 has a pivot guide 41, a traverse device 42, and a cradle 43. The pivot guide 41 is a guide that serves as a pivot point when the yarn Y is traversed. The traverse device 42 is configured to allow the yarn Y to be traversed by the traverse guide 45. The cradle 43 is configured to rotatably support the winding bobbin Bw. A contact roller 46 is arranged near the cradle 43. The contact roller 46 contacts the surface of the winding package Pw and applies contact pressure. In the winding unit 4 configured as described above, the yarn Y fed from the fourth feed roller 20 is wound onto the winding bobbin Bw by each winding device 21, and the winding package Pw is formed.

[0047] (1st heating device) Next, the more specific configuration of the first heating device 13 will be explained with reference to Figures 3(a) to (d). Figure 3(a) is a view of the first heating device 13 from the longitudinal direction of the machine base, and the first heating device 13 is depicted such that the direction in which the first heating device 13 extends (the extension direction described later) is oriented in the left-right direction of the paper. Figure 3(b) is a cross-sectional view taken along the Ab-Ab line of Figure 3(a). Figure 3(c) is a cross-sectional view taken along the Ac-Ac line of Figure 3(b). Figure 3(d) is a cross-sectional view taken along the Ad-Ad line of Figure 3(b). The direction perpendicular to both the longitudinal direction of the machine base and the extension direction is defined as the height direction (see Figure 3(b)). In Figures 3(a) to (d), the left side of the paper is one side in the extension direction, and the right side of the paper is the other side in the extension direction. One side in the extension direction may be, for example, the upstream side in the yarn running direction, but is not limited to this. In Figures 3(a) to 3(d), the upper side of the paper is considered one side in the height direction, and the lower side of the paper is considered the other side in the height direction.

[0048] The first heating device 13 is configured to heat the running yarn Y. In this embodiment, the first heating device 13 is configured to heat, for example, two yarns Y (yarns Ya and Yb; see Figure 3(b)). The first heating device 13 extends in a predetermined extending direction perpendicular to the longitudinal direction of the machine base (see Figure 3(a), etc.). The length of the first heating device 13 in the extending direction is preferably 0.4m or more and 1.6m or less. Alternatively, the length of the first heating device 13 in the extending direction may be, for example, 1.0m or more and 1.5m or less. Depending on conditions such as the type and / or thickness of the yarn, or the yarn running speed, it is preferable to select a first heating device 13 having an appropriate length in the extending direction. The first heating device 13 has a heat source 51 and a heating section 52. The first heating device 13 heats the running yarns Ya and Yb simultaneously by bringing the running yarns Ya and Yb into contact with the heating section 52 heated by the heat source 51.

[0049] The heat source 51 is, for example, a known sheath heater (electric heater). A sheath heater is a device having a heating wire (e.g., a coil) and a pipe surrounding the heating wire. A sheath heater generates Joule heat when an electric current flows through the heating wire. The heat source 51 extends along the direction of extension (see Figures 3(a) and (c)). The heat source 51 is electrically connected to a control device 100 (see Figure 3(a); control unit of the present invention) that controls the heating temperature of the first heating device 13. The control device 100 is configured to set the heating temperature of the first heating device 13. The control device 100 controls the first heating device 13 based on the set temperature value of the first heating device 13. The control device 100 may, for example, control the first heating device 13 by considering the set temperature of the first heating device 13 and the detection result by a temperature sensor (not shown) that detects the actual temperature of the heating unit 52. The control device 100 may be electrically connected to other devices that make up the false twisting machine 1, in addition to the first heating device 13.

[0050] The heating section 52 is configured to be heated by the heat generated by the heat source 51. The heating section 52 extends in the extending direction along the heat source 51 (see Figure 3(a)). In the extending direction, the heating section 52 has approximately the same length as the length of the first heating device 13 in the extending direction. For example, if the length of the first heating device 13 in the extending direction is 1.0 m, then the length of the heating section 52 in the extending direction is also 1.0 m. The heating section 52 includes, for example, two heating members 53 (heating members 53a, 53b) and two contact blocks 54 (contact blocks 54a, 54b). Heating member 53a and contact block 54a are members for heating the yarn Ya. Heating member 53b and contact block 54b are members for heating the yarn Yb. The components for heating thread Ya and thread Yb are, for example, positioned on opposite sides of the heat source 51 in the longitudinal direction of the machine base.

[0051] A component for heating the yarn Ya will now be described. The heating component 53a is made of a metal material with a high specific heat, such as brass. The heating component 53a extends in the longitudinal direction along the heat source 51. The heating component 53a is positioned to be in contact with the heat source 51. The heating component 53a is positioned, for example, on one side of the heat source 51 in the longitudinal direction of the machine base (the left side of the paper in Figure 3(b)). The heating component 53a has, for example, a slit 55 (slit 55a) that extends in the longitudinal direction and forms a yarn path. The slit 55a is an inverted U-shaped slit in a cross-section perpendicular to the longitudinal direction. The other side of the slit 55a is open in the height direction. A contact block 54 (contact block 54a) is housed inside the slit 55a.

[0052] The contact block 54a is a member that forms a thread path for the thread Ya to travel. The contact block 54a is, for example, a long member made of SUS (stainless steel). The contact block 54a extends at least in the extending direction. The contact block 54a is housed in the slit 55a. The contact block 54a is fixed to the heating member 53a in contact with the heating member 53a. The contact block 54a is heated by the heat transmitted from the heat source 51 via the heating member 53a. The contact block 54a has a contact surface 56 (contact surface 56a) for contacting the thread Y. The contact surface 56a faces at least the other side in the height direction. In a cross section perpendicular to the longitudinal direction of the machine base, the contact surface 56a is curved, for example, in a roughly U-shape (see Figure 3(d)). When viewed from the extending direction, the contact surface 56a is curved, for example, in an inverted U-shape (see Figure 3(b)).

[0053] Next, we will describe the components for heating the yarn Yb. The heating component 53b is positioned, for example, on the other side of the heat source 51 in the longitudinal direction of the machine base (the right side of the paper in Figure 3(b)). The heating component 53b is in contact with the heat source 51. The heating component 53b has a slit 55b with the same shape as the slit 55a. A contact block 54b with the same structure as the contact block 54a is housed inside the slit 55b. The contact block 54b has a contact surface 56b with the same shape as the contact surface 56a. The contact surface 56b faces at least the other side in the height direction. Further details are omitted.

[0054] Here, the positional relationship between the first heating device 13 and the twisting guide 12, and the positional relationship between the first heating device 13 and the cooling device 14 are appropriately set so that the yarn Y reliably contacts the contact surface 56 when the yarn Y is running normally (hereinafter referred to as the normal state). As a result, a force is applied to the yarn Y running along the contact surface 56, at least in the height direction, toward the contact surface 56. Therefore, in the normal state, it is prevented that the yarn Y will separate from the contact surface 56.

[0055] In the first heating device 13 having the above configuration, under normal conditions, the yarn Y receives heat from the heating section 52 via the contact surface 56 as it travels, by contacting the contact surface 56 (contact method). This heats the yarn Y. By appropriately setting the type of yarn Y, the brand (thickness) of yarn Y, the travel speed of yarn Y, and the heating temperature of the first heating device 13, the temperature of yarn Y can be set to the optimal processing temperature. In the first heating device 13, the heating temperature and the processing temperature do not necessarily coincide. The heating temperature is often set higher than the target value of the processing temperature.

[0056] Conventionally, it has been avoided to set the heating temperature of the first heating device 13 to fall within a certain range (hereinafter referred to as the middle range). The reason for this is that if the heating temperature of the first heating device 13 is set to a temperature within the middle range, there is a risk that if yarn breakage occurs and the yarn Y cannot run normally, the yarn Y may fuse to the device. On the other hand, in recent years, there has been a demand for yarn processing methods and yarn processing machines with higher heating efficiency. Therefore, in order to increase heating efficiency while avoiding the risk of fusion when yarn breakage occurs during processing while heating the yarn with the heating device, the first heating device 13 is configured as follows.

[0057] (Configuration and arrangement of the first heating device) The configuration and arrangement of the first heating device 13 will be explained in more detail with reference to Figures 3(a) to 5(b). Figure 4 is an explanatory diagram showing the definition of the inclination angle of the contact surface 56 with respect to the horizontal direction. Figures 5(a) and 5(b) are explanatory diagrams showing the limits of the inclination angle of the contact surface 56 with respect to the horizontal direction.

[0058] First, the heating temperature of the first heating device 13 (the set temperature of the contact surface 56) can be set to any temperature within at least the middle range (for example, 230 to 350°C in this embodiment). In addition, the heating temperature of the first heating device 13 may be set to a temperature lower than 230°C. Furthermore, the heating temperature of the first heating device 13 may be set to a temperature higher than 350°C.

[0059] As described above, the contact block 54 of the first heating device 13 has a contact surface 56. As shown in Figures 3(b) and (d), the space on the other side (more precisely, the lower side) in the height direction of the contact surface 56 is open. "Open" means that in the first heating device 13, no member is positioned on the extension line below the contact surface 56, and a space is formed in which the thread Y can fall out of the first heating device 13 by its own weight when the thread is cut.

[0060] Furthermore, as shown in Figures 3(d) and 4, for example, in a cross-section perpendicular to the longitudinal direction of the machine base (in other words, a cross-section parallel to both the vertical and extending directions), the contact surface 56 is curved in an inverted U-shape. More specifically, the central part of the contact surface 56 in the extending direction (the part near point P0 shown in Figure 4) is approximately parallel to the extending direction. The outer part of the contact surface 56 in the extending direction is inclined with respect to the extending direction. The parts near one end of the contact surface 56 in the extending direction (the part near point P1 shown in Figure 4) and the part near the other end (the part near point P2 shown in Figure 4) are inclined the most with respect to the extending direction. For example, when the first heating device 13 is positioned so that the extending direction is approximately parallel to the horizontal direction (see Figure 4), in a cross-section perpendicular to the longitudinal direction of the machine base, the part near point P0 is approximately parallel to the horizontal direction. Also, in this case, the parts near point P1 and the parts near point P2 are inclined significantly with respect to the horizontal direction.

[0061] As shown in Figure 4, in a cross section perpendicular to the longitudinal direction of the machine base, angle θ1 is defined as the angle of inclination with respect to the horizontal direction of the portion near point P1. Also, in the same cross section, angle θ2 is defined as the angle of inclination with respect to the horizontal direction of the portion near point P2. The detailed definitions of angles θ1 and θ2 are described below. Angle θ1 is the angle between one portion of the tangent line passing through point P1 of the contact surface 56 in the extending direction (tangent line T1) and a substantially horizontal straight line L1 extending along the width direction of the machine base, in a cross section perpendicular to the longitudinal direction of the machine base. When tangent line T1 is located above straight line L1 (see Figures 4 and 5(a)), angle θ1 is defined as having a positive value. When tangent line T1 is located below straight line L1 (see Figure 5(b)), angle θ1 is defined as having a negative value. Angle θ2 is the angle between one portion of the tangent line passing through point P2 of the contact surface 56 in the extending direction (tangent T2) and a substantially horizontal straight line L2 extending along the width direction of the machine base, in a cross section perpendicular to the longitudinal direction of the machine base. When tangent T2 is located above the straight line L2 (see Figure 5(a)), angle θ2 is assumed to have a positive value. When tangent T2 is located below the straight line L2 (see Figures 4 and 5(b)), angle θ2 is assumed to have a negative value. In a cross section perpendicular to the longitudinal direction of the machine base, the inclination angle of the portion of the contact surface 56 between points P1 and P2 with respect to the horizontal direction is a value between angle θ1 and angle θ2.

[0062] In this embodiment, the inclination angle of the contact surface 56 with respect to the horizontal is between -60 and +60°. More specifically, the inclination angle of the entire portion of the contact surface 56 from point P1 to point P2 (i.e., the entire portion of the contact surface 56 in the extending direction) is between -60 and +60° with respect to the horizontal. In this embodiment, when both angles θ1 and θ2 are between -60 and +60°, the inclination angle of the entire contact surface 56 with respect to the horizontal is between -60 and +60°.

[0063] As described above, in the first heating device 13, the space below (directly below) the contact surface 56 is open, and in a cross-section perpendicular to the longitudinal direction of the machine base, the inclination angle of the contact surface 56 with respect to the horizontal direction is within a predetermined range. Therefore, when yarn breakage occurs during the operation of the false twisting machine 1, the yarn Y is quickly separated from the contact surface 56 by its own weight, and furthermore, the yarn Y can be detached from the first heating device 13. Therefore, even if the set temperature in the first heating device 13 is within the middle range, fusion at the time of yarn breakage can be avoided. In this embodiment, the middle range is the temperature range of 230°C to 350°C, which has conventionally been avoided in setting.

[0064] (Method of manufacturing processed yarn) Next, the method for manufacturing processed yarn in this embodiment (specifically, a method for manufacturing processed yarn that includes a step of heating the yarn Y with a first heating device 13) will be described. In this embodiment, as described above, the contact surface 56 of the first heating device 13 is directed at least downwards. In addition, in a cross section perpendicular to the longitudinal direction of the machine frame (a cross section parallel to both the vertical and extending directions), the inclination angle of the contact surface 56 with respect to the horizontal direction is kept between -60 and +60°. Furthermore, the temperature of the contact surface 56 (heating temperature) is set to a predetermined temperature of 230°C to 350°C. In this state, the yarn Y is run while in contact with the contact surface 56. By heating the yarn Y in this manner, even if yarn breakage occurs for any reason, the yarn Y can be quickly separated from the contact surface 56. Therefore, fusion of the yarn Y at the time of breakage can be avoided, and the yarn Y can not be prevented from adhering to the first heating device 13.

[0065] The thickness of the heated yarn Y can be any thickness. The contact method is particularly effective when the heated yarn Y is thick. In the contact method, even when a thick yarn Y (e.g., 80 dtex or more) is heated, heat can be effectively transferred to the yarn Y via the contact surface 56. Therefore, the yarn Y can be heated uniformly in its radial direction.

[0066] (Comparison with conventional manufacturing methods) Next, a comparison with conventional manufacturing methods will be explained with reference to Figure 6. The inventors of this application actually evaluated, as follows, whether the yarn quality obtained by the yarn manufacturing method using the first heating device 13 of this embodiment is the same as when other conventional heating devices (not shown) are used instead of the first heating device 13.

[0067] Figure 6 is a graph showing the relationship between the crimp contraction of yarn Y and the heating temperature when yarn Y of a predetermined thickness is false-twisted using three types of heating devices described later. The horizontal axis represents the heating temperature, and the vertical axis represents the crimp contraction. Figure 6 shows the relationship between the crimp contraction and the heating temperature when yarn Y of 167 dtex (48 filaments) is heated. The material (yarn material) of yarn Y used in the evaluation is polyester. For reference, the melting point of polyester is 255-260°C. Generally, in false-twist processing, the preferred processing temperature for polyester using the first heating device 13 is approximately 180-200°C. The running speed (processing speed) of yarn Y used in the evaluation was 800 m / min. The relationship between the crimp contraction and the heating temperature can be adjusted as appropriate by changing the running speed of yarn Y (i.e., changing the time that yarn Y is heated by the first heating device 13 while running).

[0068] The outlines of the three types of heating devices are described below. The first type of heating device ("Sheath Heater (Contact) 1.0m" in Figure 6) is a heating device having the same structure as the first heating device 13 described above. "Sheath Heater" indicates the type of heat source. "Contact" indicates that a contact method is employed. "1.0m" indicates that the length of the heating device in the extending direction is 1.0m (the same applies to the second and third types of heating devices below). The relationship between the heating temperature and the crimp rate in the first type of heating device is shown by the filled circular marker in Figure 6. The second type of heating device ("Heat Transfer Medium (Contact) 2.0m" in Figure 6) is a known contact-type heating device using Dowsam, a known heat transfer medium. The second type of heating device is known as a so-called Dowsam heater. The heating temperature in the second heating device is approximately equal to the actual processing temperature of the yarn Y. The relationship between the heating temperature and the crimp rate in the second type of heating device is shown in Figure 6 by a filled square marker. The third type of heating device ("Sheath heater (non-contact) 1.0m" in Figure 6) is a heating device having generally the same structure as the first heating device 13 described above. In the third type of heating device, instead of the contact block 54 in the first heating device 13, a slit guide described in, for example, Japanese Patent Application Publication No. 9-291428 is provided. The third type of heating device is a known non-contact type heating device (mainly using the heat of air heated by the heating unit 52 to heat the yarn Y). The relationship between the heating temperature and the crimp rate in the third type of heating device is shown in Figure 6 by a filled triangle marker.

[0069] The history of the second type of heating device (Dowtham heater) and the third type of heating device (non-contact heating device) described above will be briefly explained. Conventionally, the Dowtham heater described above has been widely used. However, Dowtham heaters have a limitation in the increase of the heating temperature, so when the yarn to be heated becomes thicker, the device becomes larger or it becomes necessary to reduce the running speed of the yarn Y, which is a problem. In addition, Dowtham heaters generally have a large heat dissipation area, so they also have the problem of consuming a lot of power to maintain the heating temperature. Subsequently, heating devices equipped with sheath heaters as a heat source were manufactured. This made it easier to increase the heating temperature and to miniaturize the device, and the increase in power consumption could be suppressed by reducing the area of ​​the heat dissipation area. However, in order to avoid the fusion problem described above, the inventors of this invention consider that it was necessary for the heating temperature to be set sufficiently high in the heating device and for a non-contact method to be adopted so as not to overheat the yarn Y.

[0070] In the first type of heating device described above (the first heating device 13 in this embodiment), by setting the heating temperature to approximately 250-290°C (within the solid line frame shown in Figure 6), a crimp rate almost equivalent to that obtained when the heating temperature was set to approximately 180-200°C (within the dashed line frame shown in Figure 6) in the second type of heating device described above (Dawsam heater) was set. Furthermore, this crimp rate is almost equivalent to that obtained when the heating temperature was set to approximately 420-460°C (within the dashed line frame shown in Figure 6) in the conventional third type of heating device described above (sheath heater and non-contact type). It should be noted that the evaluation results described above are merely a comparison of yarn properties when a specific type and thickness of yarn is run at a specific running speed in the three types of heating devices. Therefore, it should be noted that these evaluation results do not indicate that the heating temperature of the first heating device 13 is limited to approximately 250-290°C.

[0071] As described above, it was found that when using a first type of heating device having the same configuration as the first heating device 13, the same yarn quality as when using the conventional second and third types of heating devices can be obtained. By adopting a contact method and setting the heating temperature to a middle range, the following advantages can be obtained, for example. The first heating device 13 can achieve a higher heating temperature compared to the second type of heating device (Dawsam heater), thus enabling the device to be made more compact and / or heating efficiency to be improved. In addition, the first heating device 13 can achieve a lower heating temperature compared to the third type of heating device (non-contact method), thus reducing the power consumption of the heat source 51. Furthermore, in the first heating device 13 having a contact surface 56, heat can be effectively transferred to the yarn Y via the contact surface 56. Therefore, even when heating a thick yarn Y, the outer and inner parts of the yarn Y in the radial direction can be heated uniformly.

[0072] As described above, under normal conditions, even if the temperature (heating temperature) of the contact surface 56 is within the middle range, the yarn can be heated to the optimal processing temperature (avoiding the problem of fusion) by appropriately setting the type of yarn, the brand (thickness) of the yarn, the yarn running speed, and the heating temperature. Furthermore, the contact surface 56 is at least facing downwards, and the inclination angle of the contact surface 56 with respect to the horizontal is between -60 and +60°. This allows the yarn Y to be quickly separated from the contact surface 56 by its own weight when a yarn break occurs. This prevents the yarn Y from melting even if a yarn break occurs. Therefore, heating efficiency can be increased while avoiding the risk of fusion when a yarn break occurs. In addition, by adopting a contact method and setting the heating temperature within the middle range, as mentioned above, the device can be made more compact and / or power consumption can be reduced.

[0073] Furthermore, in this embodiment, by using a sheathed heater, which is an electric heater, as the heat source 51, the temperature of the contact surface 56 can be easily raised to above the melting point of the yarn material.

[0074] Furthermore, the length of the first heating device 13 in the extending direction is 0.4m or more and 1.6m or less. By using the first heating device 13 having an appropriate length in the extending direction, it is possible to accommodate various types and / or thicknesses of yarn Y, or conditions such as yarn running speed.

[0075] Specifically, for example, when the false twisting device 15 is a known PIN-type false twisting device, the processing speed is 50 to 100 m / min. When the processing speed is low in this way, the first heating device 13 is preferably short in the extending direction (0.4 m). When heating the yarn Y using the Dowsam heater described above under these processing speed conditions, the length of the Dowsam heater in the extending direction is, for example, 1.0 to 1.2 m. Furthermore, when heating a thick yarn Y for industrial materials made of nylon 6, nylon 66, or polyester, for example, the first heating device 13 is preferably long in the extending direction (1.6 m). In this case, the processing speed is 600 to 800 m / min. When heating the yarn Y using the Dowsam heater described above under these processing speed conditions, the length of the Dowsam heater in the extending direction is, for example, 2.0 to 2.5 m.

[0076] Next, modified examples of the above embodiments will be described. However, components having the same configuration as the above embodiments will be denoted by the same reference numerals and their descriptions will be omitted as appropriate.

[0077] (1) In the above embodiment, the space below (directly below) the contact surface 56 of the first heating device 13 is always open. However, this is not the only option. The other end of the first heating device 13 in the height direction may be provided with, for example, an openable / closable or removable cover (not shown) to prevent outside air from entering the thread running space through which the thread Y runs. Even in such a case, the thread Y can be quickly separated from the contact surface 56 when the thread is cut, thus avoiding the problem of fusion.

[0078] (2) The yarn material of yarn Y is not limited to those described above. For example, nylon 6 or nylon 66 may be used as the yarn material.

[0079] (3) In the embodiments described above, the middle range was defined as a temperature range of 230°C to 350°C. However, it is not limited to this. The lower limit of the middle range may be changed according to, for example, the type of yarn material and the temperature at which fusion is likely to occur for each yarn material. For example, the temperature at which fusion is likely to occur for polyester is approximately 250°C or higher. Therefore, for example, for polyester, the lower limit of the middle range may be 250°C or higher. Also, the temperature at which fusion is likely to occur for nylon 6 is approximately 230°C or higher. Therefore, for nylon 6, the lower limit of the middle range may be 230°C or higher. Also, the temperature at which fusion is likely to occur for nylon 66 is approximately 260°C or higher. Therefore, for nylon 66, the lower limit of the middle range may be 260°C or higher. Furthermore, when the heating temperature of the first heating device 13 is 350°C or near that temperature, fusion may be more likely to occur depending on the type and / or thickness of the yarn Y, or the yarn running speed, etc. Therefore, the upper limit of the middle range may be, for example, 320°C. This makes it possible to more reliably avoid fusion. The heating temperature of the first heating device 13 may be a predetermined temperature that falls within the above range.

[0080] (4) In the embodiments described above, a contact block 54 was provided as a member having a contact surface 56. However, it is not limited to this. Instead of the contact block 54, for example, a SUS plate (not shown) that has been sheet metal-processed to be in the shape of an inverted U when viewed from the extending direction may be housed in the slit 55 (see, for example, Japanese Patent Application Publication No. 2002-194631). A contact surface (not shown) may be formed on such a SUS plate.

[0081] (5) In the embodiments described above, the contact surface 56 was assumed to be curved in a cross section perpendicular to the longitudinal direction of the machine base. However, it is not limited to this. The contact surface 56 may be substantially straight in a cross section perpendicular to the longitudinal direction of the machine base.

[0082] (6) In the embodiments described above, the contact block 54 is housed within the slit 55, and the other side of the slit 55 is open in the height direction. However, this is not the only way to do so. For example, when viewed from the extending direction, the position of the other end of the heating member 53 in the height direction and the position of the end of the contact surface 56 in the height direction may be approximately the same. Even in this case, the space below (directly below) the contact surface 56 can be said to be open.

[0083] (7) In the embodiments described above, a first heating device 13 for heating the heating section 52 by a sheath heater was provided in the false twisting machine 1. However, it is not limited to this. Instead of the first heating device 13, the above-described Dowsam heater may be provided in the false twisting machine 1. For example, if there is a yarn material with a low melting point, the processing method (method for manufacturing processed yarn) described above may be carried out in the Dowsam heater.

[0084] (8) In the embodiments described above, the first heating device 13 was configured to be able to heat two threads Y. However, it is not limited to this. The first heating device 13 may be configured to be able to heat one thread Y. Alternatively, the first heating device 13 may be configured to be able to heat three or more threads Y.

[0085] (9) The present invention is not limited to false twisting machine 1, but is also applicable to known false twisting machines (not shown) having other configurations. For example, the present invention may be applied to a false twisting machine (not shown) described in Japanese Patent Application Publication No. 2009-74219. This false twisting machine is configured to be able to combine two threads to form one thread. This false twisting machine is configured to be able to wind one combined thread or two uncombined threads onto a single cradle. For example, the present invention may be applied to such a false twisting machine. Alternatively, the present invention is also applicable to yarn processing machines that process yarn (not shown) while it is running, such as a known air processing machine (not shown), in addition to false twisting machines. [Explanation of Symbols]

[0086] 1. False twisting machine (yarn processing machine) 13 First heating device (heating device) 51 Heat source 52 Heating section 56 Contact surface 100 Control device (control unit) Y thread θ1 angle θ2 angle

Claims

1. A method for manufacturing processed yarn, comprising a step of heating a yarn made of synthetic fibers in motion with a heating device, The heating device comprises a heat source and a heating section heated by the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the thread while it is moving, The contact surface is directed at least downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extension direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. With the temperature of the contact surface set to a predetermined temperature of 230°C to 350°C, the thread is run while in contact with the contact surface. The material of the aforementioned yarn is polyester. A method for manufacturing processed yarn, characterized in that the predetermined temperature is 250°C or higher and 350°C or lower.

2. A method for manufacturing processed yarn, comprising a step of heating a yarn made of synthetic fibers in motion with a heating device, The heating device comprises a heat source and a heating section heated by the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the thread while it is moving, The contact surface is directed at least downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extension direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. With the temperature of the contact surface set to a predetermined temperature of 230°C to 350°C, the thread is run while in contact with the contact surface. The material of the aforementioned yarn is nylon 6. A method for manufacturing processed yarn, characterized in that the predetermined temperature is 230°C or higher and 350°C or lower.

3. A method for manufacturing processed yarn, comprising a step of heating a yarn made of synthetic fibers in motion with a heating device, The heating device comprises a heat source and a heating section heated by the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the thread while it is moving, The contact surface is directed at least downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extension direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. With the temperature of the contact surface set to a predetermined temperature of 230°C to 350°C, the thread is run while in contact with the contact surface. The material of the aforementioned yarn is nylon 66. A method for manufacturing processed yarn, characterized in that the predetermined temperature is 260°C or higher and 350°C or lower.

4. The method for manufacturing processed yarn according to claim 1, characterized in that the predetermined temperature is 320°C or lower.

5. The method for manufacturing processed yarn according to claim 2, characterized in that the predetermined temperature is 320°C or lower.

6. The method for manufacturing processed yarn according to claim 3, characterized in that the predetermined temperature is 320°C or lower.

7. A method for manufacturing processed yarn according to any one of claims 1 to 6, characterized in that an electric heater is used as the heat source.

8. The method for manufacturing processed yarn according to claim 7, characterized in that the length of the heating device in the extending direction is 0.4 m or more and 1.6 m or less.

9. A yarn processing machine having a heating device for heating yarn made of synthetic fibers while it is in motion, The heating device comprises a heat source, a heating section heated by the heat source, and a control unit that controls the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the running thread, The contact surface is at least facing downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extending direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. The control unit, When the thread is moving while in contact with the contact surface, the heat source is controlled so that the temperature of the contact surface reaches a predetermined temperature of 230°C to 350°C. The material of the aforementioned yarn is polyester. A yarn processing machine characterized in that the predetermined temperature is 250°C or higher and 350°C or lower.

10. A yarn processing machine having a heating device for heating yarn made of synthetic fibers while it is in motion, The heating device comprises a heat source, a heating section heated by the heat source, and a control unit that controls the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the running thread, The contact surface is at least facing downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extending direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. The control unit, When the thread is moving while in contact with the contact surface, the heat source is controlled so that the temperature of the contact surface reaches a predetermined temperature of 230°C to 350°C. The material of the aforementioned yarn is nylon 6. A yarn processing machine characterized in that the predetermined temperature is 230°C or higher and 350°C or lower.

11. A yarn processing machine having a heating device for heating yarn made of synthetic fibers while it is in motion, The heating device comprises a heat source, a heating section heated by the heat source, and a control unit that controls the heat source. The heating section has at least a contact surface extending in a predetermined direction for contacting the running thread, The contact surface is at least facing downwards, The heating device is arranged such that, in a cross-section parallel to both the vertical direction and the extending direction, the inclination angle of the contact surface with respect to the horizontal direction falls between -60 and +60°. The control unit, When the thread is moving while in contact with the contact surface, the heat source is controlled so that the temperature of the contact surface reaches a predetermined temperature of 230°C to 350°C. The material of the aforementioned yarn is nylon 66. A yarn processing machine characterized in that the predetermined temperature is 260°C or higher and 350°C or lower.

12. The yarn processing machine according to any one of 9 to 11, characterized in that the heat source has an electric heater.

13. The yarn processing machine according to claim 12, characterized in that the length of the heating device in the extending direction is 0.4 m or more and 1.6 m or less.

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