Screws for tire cord fiber extruders and tire cord fiber extruders
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- THE JAPAN STEEL WORKS LTD
- Filing Date
- 2021-10-21
- Publication Date
- 2026-07-07
- Estimated Expiration
- Not applicable · inactive patent
Smart Images
Figure 0007886138000001 
Figure 0007886138000002 
Figure 0007886138000003
Abstract
Description
Technical Field
[0001] The present invention relates to a screw of an extruder for manufacturing tire cord fibers and an extruder for manufacturing tire cord fibers, which are used in tire cord manufacturing equipment.
Background Art
[0002] A screw used in an extruder that melts resin pellets and discharges molten resin is described in, for example, Patent Document 1. The screw described in Patent Document 1 is provided with a supply section, a melting promotion section, a metering and kneading / mixing section from its proximal end side to its distal end side. Further, in the metering and kneading / mixing section, a first kneading / mixing section and a second kneading / mixing section are provided at intervals in the axial direction of the screw.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Both the first kneading / mixing section and the second kneading / mixing section of Patent Document 1 are kneading / mixing sections of the same shape and were for manufacturing fibers for clothing. High strength and stable quality are required for tire cord fibers (for industrial materials).
[0005] Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.
Means for Solving the Problems
[0006] According to one embodiment, the metering unit has a first mixing unit and a second mixing unit provided upstream of the first mixing unit, wherein the flow resistance of the resin raw material passing through the second mixing unit is smaller than the flow resistance of the resin raw material passing through the first mixing unit. [Effects of the Invention]
[0007] According to one embodiment, it is possible to manufacture resin raw materials that become high-strength fibers used in tire cords with stable quality. [Brief explanation of the drawing]
[0008] [Figure 1] This is a schematic diagram showing an example of equipment used to manufacture tire cord. [Figure 2] This is a partial cross-sectional view showing the structure of an extruder for manufacturing tire cord fibers. [Figure 3] Figure 2 is a plan view showing the screw as a standalone component. [Figure 4] Figure 3 is an enlarged perspective view of the dashed circle A. [Figure 5] Figure 3 is an enlarged perspective view of the dashed circle B. [Figure 6] This graph compares the pressure fluctuations at the metering section of a screw. [Figure 7] This is a table showing the capabilities (specifications) of the screw in the example. [Figure 8] This table shows the capabilities (specifications) of the screws in the comparative example. [Figure 9A] This is an enlarged view showing the mixing section of the modified example 1. [Figure 9B] This is an enlarged view showing the mixing section of the second modified example. [Modes for carrying out the invention]
[0009] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In all the drawings used to describe the embodiment, the same reference numerals are used for components and devices that have the same or substantially the same function, and repeated descriptions will be omitted.
[0010] <Overview of Tire Cord Manufacturing Equipment> The tire cord manufacturing equipment 10 shown in FIG. 1 is equipment for manufacturing a tire cord TC using resin pellets PR as a raw material. Here, the tire cord TC is a reinforcing material for maintaining the shape of the tire TR, and is manufactured through an [extrusion process], a [fiber manufacturing process], a [twisting process], and a [weaving process].
[0011] In the [extrusion process], using an extruder 20 for manufacturing tire cord fibers, a process of melting the solid resin pellets PR into molten resin MR is performed. The extruder 20 for manufacturing tire cord fibers is controlled by a controller that comprehensively controls the entire tire cord manufacturing equipment 10. Thereafter, the molten resin MR is sent to the [fiber manufacturing process].
[0012] In the [fiber manufacturing process], the molten resin MR is passed through a filter to remove (filter) impurities and the like, and at the same time, the molten resin MR is made into a plurality of thin fibers using a spinning machine. Thereafter, these thin fibers are exposed to, for example, cooling air to be cured, whereby a plurality of thin fibers are completed. The cured and completed fibers are wound up by a bobbin.
[0013] In the [twisting process], an operation of twisting a plurality of thin fibers finished in the [fiber manufacturing process] is performed. Specifically, while bundling a plurality of thin fibers, twisting is performed in a right twist or a left twist to obtain twisted yarn. Thereby, it becomes possible to improve the durability of the tire cord TC against the addition of a large repeated load.
[0014] In the [weaving process], the twisted yarn formed through the [twisting process] is pulled out from a creel using a feeder and sent to a loom body. Thereafter, a process of weaving the twisted yarn into a cloth shape using the loom body is performed. Thereby, the tire cord TC is completed.
[0015] Next, the structure of the extruder 20 for manufacturing tire cord fibers will be described.
[0016] <Hopper> As shown in FIGS. 1 and 2, an extruder 20 for manufacturing tire cord fibers includes a hopper 21. The hopper 21 is formed in a substantially cylindrical shape, and an innumerable number of granular resin pellets (polymers) PR are stored therein. The hopper 21 has a pellet inlet 22 and a pellet outlet 23, and the resin pellets PR stored in the hopper 21 are supplied from the pellet outlet 23 to a pellet supply block 35 disposed downstream thereof.
[0017] Here, as shown in FIG. 2, the side where the hopper 21 of the extruder 20 for manufacturing tire cord fibers is disposed (the resin pellet PR side) is the “upstream”, and the side where the nozzle member 36 of the extruder 20 for manufacturing tire cord fibers is disposed (the molten resin MR side) is the “downstream”.
[0018] <Drive unit> Further, the extruder 20 for manufacturing tire cord fibers includes a drive unit 24. The drive unit 24 includes a drive motor 25 as a drive source and a speed reducer 26 that reduces the rotation of the drive motor 25 and increases the torque. The output shaft of the speed reducer 26 is connected to the base end portion of a screw 32 (the screw of the extruder for manufacturing tire cord fibers) that forms a kneading processing unit 30, whereby the screw 32 is rotated in one direction.
[0019] Note that the rotation speed of the screw 32 can be controlled with high precision by controlling the drive motor 25. Here, the extruder 20 for manufacturing tire cord fibers is a single-screw type extruder having only one screw 32.
[0020] <Kneading processing unit> Furthermore, the extruder 20 for manufacturing tire cord fibers includes a kneading processing unit 30. The kneading processing unit 30 has a cylinder 31 formed in a substantially cylindrical shape, and the cylinder 31 is provided on the axis of the drive motor 25 and the speed reducer 26. Inside the cylinder 31, a screw 32 is rotatably accommodated. The screw 32 has a function of conveying the resin pellets PR and the molten resin MR (resin raw materials) supplied to the cylinder 31 while kneading them from upstream to downstream.
[0021] Furthermore, the cylinder 31 is equipped with a total of six heaters 33 arranged in its axial direction. These heaters 33 are formed in a roughly cylindrical shape and are arranged to surround the screw 32. The heaters 33 heat the resin material that is conveyed by the rotation of the screw 32, and the temperature of the heaters 33 is controlled with high precision by a controller.
[0022] Here, the resin pellet PR is heated not only by the heater 33 but also by the heat generated (frictional heat) due to the shear action accompanying the rotation of the screw 32. In other words, the controller balances the rotation speed of the screw 32 and the heating state by the heater 33, thereby enabling high-precision control of the viscosity of the molten resin MR.
[0023] Furthermore, as shown in Figure 2, a transport path 34 for transporting resin pellets PR and molten resin MR is provided inside the cylinder 31 that forms the kneading section 30. The transport path 34 is formed by being surrounded by the inner wall 31a of the cylinder 31, the outer wall 32b of the main body 32a that forms the screw 32, and the flights 32c of the screw 32.
[0024] Here, the flights 32c provided on the screw 32 are arranged spirally in the axial direction of the screw 32 and are capable of sliding against the inner wall 31a of the cylinder 31. As a result, the resin pellets PR and molten resin MR inside the transport path 34 are transported from upstream to downstream of the cylinder 31 as the screw 32 rotates in one direction.
[0025] Furthermore, a pellet supply block 35 is integrally provided upstream of the cylinder 31. The pellet supply block 35 is provided with a supply port 35a, which faces the pellet discharge port 23 of the hopper 21. As a result, the resin pellets PR stored in the hopper 21 are supplied to the cylinder 31 via the supply port 35a and the inside of the pellet supply block 35 and enter the transport path 34.
[0026] Furthermore, a nozzle member 36 is integrally provided downstream of the cylinder 31 (downstream of the transport path 34) to discharge the molten resin MR melted by the rotation of the screw 32. The nozzle member 36 is connected upstream of the transport pipe P, which leads to a filter that filters the molten resin MR, and the molten resin MR discharged from the nozzle member 36 is sent to the transport pipe P. The downstream end of the transport pipe P is connected to the filter.
[0027] The mixing section 30 is equipped with a supply area AR1, a compression area AR2, and a metering area AR3, arranged from upstream to downstream. Correspondingly, the screw 32 housed inside the cylinder 31 is provided with a supply section 32d, a compression section 32e, and a metering section 32f, as shown in Figure 3. In other words, the supply section 32d is located in the supply area AR1, the compression section 32e is located in the compression area AR2, and the metering section 32f is located in the metering area AR3.
[0028] <Supply section> As shown in Figures 2 and 3, the supply unit 32d located in the supply area AR1 transports the resin pellets PR supplied from the hopper 21 toward the compression area AR2 (compression unit 32e) as the screw 32 rotates in one direction, as indicated by arrow M1. In the transport path 34 of the supply unit 32d, the resin pellets PR are crushed. The resin pellets PR are then gradually softened by the heat generated (frictional heat) due to the shearing action and the heating of the heater 33.
[0029] In the supply section 32d, the groove depth G1 of the transport path 34 is constant throughout its entire axial direction to ensure that a sufficient amount of resin pellets PR can be supplied. Furthermore, the supply section 32d has a length L1 sufficient to soften the resin pellets PR.
[0030] <Compression section> The compression unit 32e, located in the compression region AR2, is provided downstream of the supply unit 32d. The compression unit 32e compresses the resin pellets PR that have been transported from the supply unit 32d (supply region AR1) and softened, completely melting the resin pellets PR to form molten resin MR (see Figures 1 and 2). As the screw 32 rotates in one direction, the compression unit 32e transports the resin pellets PR (molten resin MR) toward the metering region AR3 (metering unit 32f) as indicated by arrow M2. In the transport path 34 of the compression unit 32e, the resin pellets PR (molten resin MR) are gradually compressed as they move downstream.
[0031] Specifically, the outer wall 32b of the main body 32a in the compression section 32e is inclined at a gentle angle α° toward the metering section 32f, as shown in Figure 3. As a result, the volume of the transport path 34 in the compression section 32e gradually decreases from upstream to downstream. In other words, the groove depth of the transport path 34 in the compression section 32e gradually becomes shallower (smaller) than the groove depth G1 of the supply section 32d.
[0032] As a result, in the compression section 32e, the softened resin pellets PR are melted starting from the portion in contact with the inner wall 31a of the cylinder 31, and then completely melted downstream of the compression section 32e to become molten resin MR. Here, the length of the compression section 32e is such that L2 is sufficient to completely melt the resin pellets PR into molten resin MR.
[0033] <Measuring section> The metering unit 32f, located in the metering area AR3, is provided downstream of the compression unit 32e. The metering unit 32f homogenizes the molten resin MR that has been melted via the transport path 34 of the compression unit 32e (compression area AR2). As the screw 32 rotates in one direction, the metering unit 32f transports the homogenized molten resin MR toward the nozzle member 36 in a stable state without generating pulsation or other disturbances. Subsequently, the molten resin MR is discharged from the nozzle member 36 toward the transport pipe P as indicated by arrow M3.
[0034] Specifically, the groove depth of the conveyance path 34 in the metering section 32f is a slightly shallower groove depth G2 than the groove depth G1 of the conveyance path 34 in the supply section 32d (G2 < G1). Also, the length of the metering section 32f is a length L3 that enables the molten resin MR to be sufficiently homogenized.
[0035] Here, in the screw 32, the pitch (flight pitch) Pt of the flight 32c is constant throughout the axial direction, and the ratio of the effective length L of the screw 32 to the diameter dimension D of the portion of the flight 32c is
[28] (L / D = 28). Note that the effective length L of the screw 32 is a value obtained by adding the length L1 of the supply section 32d, the length L2 of the compression section 32e, and the length L3 of the metering section 32f (L = L1 + L2 + L3).
[0036] Furthermore, in the metering section 32f, a Maddock type mixing section (first mixing section) 40 and a cross-saw type mixing section (second mixing section) 50 for enhancing the kneading property of the molten resin MR to more homogenize the molten resin MR in the portion of the metering region AR3 are provided. The Maddock type mixing section 40 is provided downstream of the metering section 32f, and the cross-saw type mixing section 50 is provided between the Maddock type mixing section 40 and the compression section 32e. That is, the cross-saw type mixing section 50 is provided upstream of the Maddock type mixing section 40.
[0037] <Maddock type mixing section> The Maddock type mixing section 40 has a shape as shown in FIG. 4. Specifically, the Maddock type mixing section 40 includes a bulging portion 41 that bulges radially outward from the outer wall 32b of the main body portion 32a in the screw 32. Also, a plurality of groove portions 42 and groove portions 43 are provided in the bulging portion 41 so as to extend in the axial direction of the screw 32. These groove portions 42 and groove portions 43 are arranged alternately at equal intervals in the circumferential direction of the screw 32.
[0038] Furthermore, partition walls 44 and 45 are provided between grooves 42 and 43 in the circumferential direction of the screw 32. Partition walls 44 and 45 separate grooves 42 and 43, respectively, and are arranged alternately at equal intervals in the circumferential direction of the screw 32. Partition wall 44 is slightly recessed radially inward relative to partition wall 45 of the screw 32. As a result, the molten resin MR passes between partition wall 44 and the inner wall 31a of the cylinder 31 (see Figure 2).
[0039] Furthermore, an inlet 42a into which molten resin MR flows is provided upstream of groove 42 (left in the figure), and an outlet 43a into which molten resin MR is discharged is provided downstream of groove 43 (right in the figure). As a result, as the screw 32 rotates in one direction, the molten resin MR passing through the Maddock-type mixing section 40 reaches the outlet 43a from the inlet 42a, via groove 42, partition wall 44 and groove 43, as shown by the dashed arrow.
[0040] During this process, the molten resin MR passes through the narrow gap between the partition wall 44 and the inner wall 31a of the cylinder 31, and flows in a crank-like manner in the axial and circumferential directions of the screw 32 (see dashed arrow). This improves the kneading ability of the molten resin MR in the Maddock-type mixing section 40.
[0041] <Cross-saw type mixing unit> The cross-saw type mixing section 50 has the shape shown in Figure 5. Specifically, the cross-saw type mixing section 50 is provided between adjacent flights 32c in the axial direction of the screw 32 and has a plurality of protrusions 51 that bulge radially outward from the outer wall 32b of the main body 32a of the screw 32. The plurality of protrusions 51 are formed in a sawtooth shape with sharp angles CN. This increases the contact area of the plurality of protrusions 51 with the molten resin MR and improves the kneading of the molten resin MR passing through the cross-saw type mixing section 50.
[0042] Furthermore, in the cross-screw mixing section 50, a plurality of groove portions GR (refer to the two-dot chain line in the figure) that are inclined with respect to the axis of the screw 32 are provided so as to cross between the plurality of convex portions 51. Also, the protruding height h1 of the plurality of convex portions 51 is slightly smaller than the protruding height h2 of the flight 32c (h1 < h2).
[0043] As a result, the molten resin MR is more likely to pass through the portion of the cross-screw mixing section 50 than through the portion of the Maddock-type mixing section 40. In other words, as shown in FIG. 3, the flow resistance FR1 of the molten resin MR passing through the cross-screw mixing section 50 is smaller than the flow resistance FR2 of the molten resin MR passing through the Maddock-type mixing section 40 (FR1 < FR2).
[0044] As shown in FIG. 3, the molten resin MR supplied from the compression section 32e (compression region AR2) to the metering section 32f (metering region AR3) is increased to pressure P1 upstream of the cross-screw mixing section 50 and then further increased to pressure P2 upstream of the Maddock-type mixing section 40 (P1 < P2). That is, the pressure inside the metering region AR3 is increased step by step from upstream to downstream.
[0045] Here, as shown in the "pressure (MPa) - time (min) graph" of FIG. 6, the pressure fluctuation in the metering section 32f (metering region AR3) of the screw 32 was analyzed. As a result, in the "comparative example" without the cross-screw mixing section 50 (the right side of FIG. 6), the pressure fluctuation was large when the rotational speed of the screw 32 was high (for example, rotational speed 70 rpm). This is considered to be due to the fact that the molten resin MR flowed into the metering section 32f (metering region AR3) from the compression section 32e (compression region AR2) at once, and thus bubbles were generated inside the molten resin MR. However, if the rotational speed of the screw 32 is low (for example, rotational speed 10 rpm), there is no problem even in the "comparative example" without the cross-screw mixing section 50.
[0046] Thus, in the "comparative example" which does not have a cross-saw type mixing section 50, it was found that when the rotation speed of the screw 32 is increased to improve efficiency (high discharge), air bubbles are generated inside the molten resin MR, resulting in poor mixing. Such poor mixing leads to a decrease in the rigidity of the fibers that are subsequently finished.
[0047] In contrast, in the "Example" equipped with a cross-saw type mixing section 50 (left side of Figure 6), as described above, the internal pressure in the metering section 32f (metering area AR3) is gradually increased from pressure P1 to pressure P2. In other words, in the "Example" equipped with a cross-saw type mixing section 50, it is possible to raise the pressure upstream of the cross-saw type mixing section 50 to a certain level (pressure P1). Therefore, even when the rotation speed of the screw 32 is high (for example, 70 rpm), it was found that the pressure fluctuations are not as large as in the "Comparative Example" which is not equipped with a cross-saw type mixing section 50, and bubbles are less likely to form inside the molten resin MR.
[0048] Furthermore, if the cross-saw type mixing section 50 is changed to the same type as the Maddock type mixing section 40, it will lead to "over-mixing" of the molten resin MR, causing the temperature of the molten resin MR to become too high, resulting in a decrease in the rigidity of the fibers that are subsequently finished. In other words, by combining the Maddock type mixing section 40 and the cross-saw type mixing section 50, even if the rotation speed of the screw 32 is increased to achieve high discharge, it is possible to suppress the temperature of the molten resin MR from becoming too high, and the insufficient mixing of the molten resin MR can be resolved, ultimately making it possible to stably obtain high-strength (high-rigidity) fibers for tire cord TC.
[0049] <Comparison of capabilities between examples and comparative examples> In the "Example" equipped with the cross-saw type mixing unit 50, the data shown in Figure 7 was obtained. In contrast, in the "Comparative Example" without the cross-saw type mixing unit 50, the data shown in Figure 8 was obtained.
[0050] To obtain this data, the viscosity (melt viscosity) of the molten resin MR in the metering unit 32f (metering area AR3) was set to fall within the range of 10,000 [poise] to 30,000 [poise], which is the viscosity required to obtain high-strength fibers suitable for tire cord TC. The molten resin MR with a viscosity within this range was then homogenized in the metering unit 32f. In addition, the temperature (polymer temperature) of the molten resin MR in the metering unit 32f (metering area AR3) was set to 310°C or lower, which is the temperature required to obtain high-strength fibers suitable for tire cord TC.
[0051] In the "Examples," for example, as shown by the asterisk in Figure 7, it was found that in an extruder 20 for manufacturing tire cord fibers with a screw size (diameter) of [90 mmφ], an L / D ratio of
[28] , and a motor capacity of [75 kW], the fibers could be finished without quality problems in the subsequent [fiber manufacturing process] when the rotation speed of the screw 32 was [6~80 rpm] and the discharge capacity was [100~320 kg / h].
[0052] In contrast, in the "Comparative Example," for example, as shown by the asterisk in Figure 8, a tire cord fiber manufacturing extruder 20 with a screw size (diameter) of [90 mmφ], an L / D ratio of
[28] , and a motor capacity of [75 kW], i.e., a tire cord fiber manufacturing extruder 20 of the same size as the "Example," was found to be able to produce fibers without quality problems in the subsequent [fiber manufacturing process] when the screw rotation speed of [6~60 rpm] and the discharge capacity of [70~200 kg / h].
[0053] In other words, when comparing tire cord fiber manufacturing extruders 20 of the same size, the "Example" can accommodate higher speed rotation (higher efficiency) of the screw 32 compared to the "Comparative Example," and consequently, it is possible to increase the discharge capacity of the molten resin MR. Specifically, the "Example" equipped with a cross-saw type mixing section 50 achieved a discharge capacity increase of up to approximately 1.6 times compared to the "Comparative Example" which was not equipped with a cross-saw type mixing section 50.
[0054] Furthermore, comparing the "Example" and the "Comparative Example," as shown in the shaded areas of Figures 7 and 8, when considering a fixed discharge capacity of [70-200 kg / h], it was found that the "Comparative Example" corresponds to an extruder 20 for manufacturing tire cord fibers with a screw size (diameter) of [90 mmφ], an L / D ratio of
[28] , and a motor capacity of [75 kW]. In contrast, the "Example" corresponds to an extruder 20 for manufacturing tire cord fibers with a screw size (diameter) of [75 mmφ], an L / D ratio of
[28] , and a motor capacity of [55 kW].
[0055] In other words, the "Example" makes it possible to miniaturize the tire cord fiber extruder 20 compared to the "Comparative Example," which in turn makes it possible to reduce the cost and power consumption of the tire cord fiber extruder 20.
[0056] In the above comparison, we used a tire cord fiber manufacturing extruder 20 with a screw 32 of size (diameter) of [90mmφ], but the same can be said for tire cord fiber manufacturing extruders 20 with screw 32 of sizes (diameter) of [115mmφ], [125mmφ], [130mmφ], [150mmφ], and [175mmφ] (multiple variations).
[0057] Furthermore, for reference, in an extruder 20 for manufacturing tire cord fibers with a screw 32 size (diameter) of [90 mmφ], it was found that in the "Example," when the rotation speed of the screw 32 was [30~65 rpm], the polymer temperature (temperature of molten resin MR) was [287~296°C], which is below the target of 310°C. In contrast, in the "Comparative Example," which has the same size as the "Example," it was found that when the rotation speed of the screw 32 was [20~45 rpm], the polymer temperature was [295~300°C], which is close to the target of 310°C but below it.
[0058] As described in detail above, according to the screw 32 of the tire cord fiber manufacturing extruder 20 of this embodiment and the tire cord fiber manufacturing extruder 20, the metering section 32f has a Maddock-type mixing section 40 and a cross-saw-type mixing section 50 provided upstream of the Maddock-type mixing section 40, and the flow resistance FR1 of the molten resin MR passing through the cross-saw-type mixing section 50 is smaller than the flow resistance FR2 of the molten resin MR passing through the Maddock-type mixing section 40 (FR1 <FR2)。
[0059] As a result, the tire cord fiber extruder 20 can produce resin raw materials (molten resin MR) that become high-strength fibers used in tire cord TC with stable quality.
[0060] Furthermore, the mixing section (second mixing section) located upstream of the Maddock-type mixing section 40 is not limited to the cross-saw-type mixing section 50; other types of mixing sections can also be used.
[0061] The following describes in detail, with reference to the drawings, a modified version of the second mixing section.
[0062] <Example 1> The second mixing section shown in Figure 9A is a Dalmege-type mixing section 60. The Dalmege-type mixing section 60 comprises a large-diameter section 61 which is larger in diameter than the main body section 32a of the screw 32, and a large-diameter section 62 which has the same shape as the large-diameter section 61. In other words, the Dalmege-type mixing section 60 employs a two-stage structure in which the large-diameter section 61 and the large-diameter section 62 are arranged in the axial direction of the screw 32.
[0063] Each of the large-diameter sections 61 and 62 is provided with multiple inclined grooves 61a and 62a that are inclined with respect to the axis of the screw 32. These inclined grooves 61a and 62a are arranged at equal intervals in the circumferential direction of each large-diameter section 61 and 62. Molten resin MR enters and exits the interior of the multiple inclined grooves 61a and 62a. This improves the kneadability of the molten resin MR in the metering area AR3 (see Figure 2).
[0064] In addition, the diameter dimension d1 of each of the large-diameter portions 61 and 62 is slightly smaller than the diameter dimension D of the portion of the flight 32c of the screw 32 (d1 < D). Also, in the flow resistance FR3 of the molten resin MR passing through the damage-type mixing portion 60, similar to the cross-saw-type mixing portion 50 (see FIG. 3), it is smaller than the flow resistance FR2 of the molten resin MR passing through the Maddock-type mixing portion 40 (FR3 < FR2).
[0065] Even in the damage-type mixing portion 60 of the first modified example formed as described above, the same operational effects as those of the above-described cross-saw-type mixing portion 50 can be achieved.
[0066] <Second Modified Example> The second mixing portion shown in FIG. 9B is a barrier mixing-type mixing portion 70. Specifically, the barrier mixing-type mixing portion 70 includes a sub-flight 71. The sub-flight 71 is provided spirally in the axial direction of the screw 32 and is disposed at a position shifted by approximately half a pitch (≒ Pt / 2) in the axial direction of the screw 32 with respect to the flight 32c. And the upstream end portion 71a and the downstream end portion 71b of the sub-flight 71 are respectively connected to the flight 32c.
[0067] Also, the protruding height h3 of the main body portion 32a of the sub-flight 71 is slightly smaller than the protruding height h2 of the main body portion 32a of the flight 32c (h3 < h2). Further, in the flow resistance FR4 of the molten resin MR passing through the barrier mixing-type mixing portion 70, similar to the cross-saw-type mixing portion 50 (see FIG. 3), it is smaller than the flow resistance FR2 of the molten resin MR passing through the Maddock-type mixing portion 40 (FR4 < FR2).
[0068] In this way, by providing the sub-flight 71 with a shift of approximately half a pitch between the flights 32c, the kneading property of the molten resin MR in the metering region AR3 (see FIG. 2) is enhanced.
[0069] As described above, the barrier mixing type mixing section 70 of the modified example 2 can also achieve substantially the same effects as the cross saw type mixing section 50 described above.
[0070] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention. For example, in the embodiments described above, as shown in Figure 3, a cross-saw type mixing section 50 (Dalmeage type mixing section 60, barrier mixing type mixing section 70) is arranged approximately in the middle between the Maddock type mixing section 40 and the compression section 32e in the metering area AR3, but the present invention is not limited to this.
[0071] For example, depending on the specifications required for the screw 32, the cross-saw type mixing section 50 (Dalmage type mixing section 60, barrier mixing type mixing section 70) may be positioned closer to the compression section 32e, or closer to the Maddock type mixing section 40.
[0072] Furthermore, the material, shape, dimensions, number, and installation location of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited to the above-described embodiments. [Explanation of symbols]
[0073] 10: Tire cord manufacturing equipment 20: Extruder for tire cord fiber manufacturing 21: Hoppa 22: Pellet input port 23: Pellet discharge port 24: Drive unit 25: Drive motor 26: Reducer 30: Mixing Section 31: Cylinder 31a:Inner wall 32: Screw (screw for extruder used in tire cord fiber manufacturing) 32a: Main body 32b: Exterior wall 32c: Flight 32d: Supply section 32e: Compression section 32f:Measuring part 33: Heater 34: Conveyor path 35: Pellet supply block 35a: Supply port 36: Nozzle component 40: Maddock-type mixing section (first mixing section) 41:bulge 42: Groove 42a: Entrance 43: Groove 43a: Exit part 44: Partition wall 45: Partition wall 50: Cross-saw type mixing section (second mixing section) 51: Convex part 60: Dalmaji-type mixing section (second mixing section) 61: Large diameter section 61a: Inclined groove 62: Large diameter section 62a: Inclined groove 70: Barrier mixing type mixing section (second mixing section) 71: Subflight 71a: Upstream end 71b: Downstream end AR1: Supply area AR2: Compressed area AR3:Metric area CN: Acute corner FR1~FR4: Flow resistance GR:Groove L: Effective length MR: Molten resin (resin raw material) P: Conveyor pipe P1: Pressure (low) P2: Pressure (High) PR: Resin pellets (resin raw material) TC: Tire Code TR: Tires
Claims
1. A screw for an extruder used in the manufacture of tire cord fibers, The screw is rotatably housed inside the cylinder. A supply unit that transports resin raw materials, A compression unit is provided downstream of the supply unit and compresses and melts the resin raw material transported from the supply unit, A measuring unit is provided downstream of the compression unit and homogenizes the resin raw material melted in the compression unit, Equipped with, A transport path for transporting the resin raw material is formed on the outer periphery of the supply unit, the compression unit, and the metering unit, respectively. The transport path is formed by being surrounded by the inner wall of the cylinder, the outer wall of the main body that forms the screw, and a flight that is spirally arranged in the axial direction of the screw and is capable of sliding against the inner wall of the cylinder. The groove depth of the transport path upstream of the metering section is deeper than the groove depth of the transport path downstream of the compression section. The aforementioned measuring unit is The first mixing section, A second mixing section is provided upstream of the first mixing section, It has, The flow resistance of the resin raw material passing through the second mixing section is smaller than the flow resistance of the resin raw material passing through the first mixing section. Screw for an extruder used in the manufacture of tire cord fibers.
2. In the screw of the tire cord fiber manufacturing extruder according to claim 1, The measuring unit is capable of homogenizing the resin raw material having a viscosity of 10,000 to 30,000 poises. Screw for an extruder used in the manufacture of tire cord fibers.
3. In the screw of the tire cord fiber manufacturing extruder according to claim 1 or claim 2, The first mixing section is a Maddock-type mixing section, and the second mixing section is a cross-saw-type mixing section. Screw for an extruder used in the manufacture of tire cord fibers.
4. An extruder for manufacturing tire cord fibers, A cylinder into which resin raw materials are supplied, A screw is rotatably housed inside the cylinder and conveys the resin raw material supplied to the cylinder while kneading it. It has, The aforementioned screw is A supply unit for transporting the aforementioned resin raw material, A compression unit is provided downstream of the supply unit and compresses and melts the resin raw material transported from the supply unit, A measuring unit is provided downstream of the compression unit and homogenizes the resin raw material melted in the compression unit, Equipped with, A transport path for transporting the resin raw material is formed on the outer periphery of the supply unit, the compression unit, and the metering unit, respectively. The transport path is formed by being surrounded by the inner wall of the cylinder, the outer wall of the main body that forms the screw, and a flight that is spirally arranged in the axial direction of the screw and is capable of sliding against the inner wall of the cylinder. The groove depth of the transport path upstream of the metering section is deeper than the groove depth of the transport path downstream of the compression section. The aforementioned measuring unit is The first mixing section, A second mixing section is provided upstream of the first mixing section, It has, The flow resistance of the resin raw material passing through the second mixing section is smaller than the flow resistance of the resin raw material passing through the first mixing section. Extruder for manufacturing tire cord fibers.
5. In the extruder for manufacturing tire cord fibers according to claim 4, The measuring unit is capable of homogenizing the resin raw material having a viscosity of 10,000 to 30,000 poises. Extruder for manufacturing tire cord fibers.
6. In the extruder for manufacturing tire cord fibers according to claim 4 or claim 5, The first mixing section is a Maddock-type mixing section, and the second mixing section is a cross-saw-type mixing section. Extruder for manufacturing tire cord fibers.