Mesh structure manufacturing apparatus and method for manufacturing a mesh structure

Abstract

The present invention provides a manufacturing apparatus (1) for a net-like structure, which includes: a nozzle (10) having a discharge hole (11) for extruding molten thermoplastic resin into a line; a water tank (20) disposed below the nozzle (10); a conveying device (30) provided in the water tank (20) for conveying the net-like structure (60) having a linear resin (12); and a gas discharging device (40) provided in the water tank (20) for discharging gas.

Description

[0001] This application is a divisional application of an application with an international filing date of March 7, 2019 (date of entry into the Chinese national phase: September 25, 2020), an international application number of PCT / JP2019 / 009102 (national application number: 201980022277.5), and an invention title of "Device for manufacturing a net-like structure and method for manufacturing a net-like structure". Technical Field

[0002] The present invention relates to a device for manufacturing a net-like structure and a method for manufacturing a net-like structure. Background Art

[0003] Currently, as an elastic cushion material for furniture, bedding such as beds, seats for vehicles such as trains, automobiles, and two-wheelers, a net-like structure is gradually widely used. The net-like structure has the following advantages compared with foamed-crosslinked urethane: it has the same level of durability, excellent moisture permeability, water permeability, and air permeability, and has less heat storage property, so it is not easily stuffy. In addition, the following advantages can also be cited: it is made of a thermoplastic resin, is easy to recycle, has no concern about residual drugs, and is environmentally friendly.

[0004] As a device for manufacturing a net-like structure, there is the following three-dimensional net-like structure manufacturing device. The three-dimensional net-like structure manufacturing device includes: a nozzle head having a plurality of extrusion holes for extruding molten thermoplastic resin downward as a line and allowing it to descend; a water tank for cooling the aggregate of the lines; a pair of conveyor belts provided oppositely below the extrusion holes, and an annular member wound around the conveyor belts has a gap; and a forced convection member provided in the inner region of the conveyor belts, including at least one of a jet hole for jetting cooling water from the gap toward the aggregate and a suction hole for sucking water from near the aggregate via the gap. The aggregate is pulled by the conveyor belts at a speed slower than the descending speed of the lines and cooled by the water tank, thereby forming the aggregate into a three-dimensional net-like structure (for example, refer to Patent Document 1).

[0005] In addition, as a method for manufacturing a net-like structure, there is a method for manufacturing a three-dimensional net-like structure, which is characterized in that the method for manufacturing the three-dimensional net-like structure includes: an extrusion step in which molten thermoplastic resin is extruded downward as a plurality of strands and allowed to descend; a loop formation step in which the strands come into contact with the water surface, or the strands come into contact with a pair of guide members that are opposed to each other with the aggregate of the descending strands interposed therebetween, or come into contact with a conveyor belt that is opposed to the lower side of the guide members, so that the strands are irregularly wound and heat fusion bonding occurs at the winding portion; a traction step in which the aggregate is clamped by the conveyor belt and pulled into the water at a speed slower than the descending speed of the strands; and a cooling step in which a gap is provided in an annular member disposed around the conveyor belt, and cooling water is sprayed from the inner region of the conveyor belt toward the traction region sandwiched by the pair of conveyor belts through the gap, or water is sucked from the traction region through the gap into the inner region of the conveyor belt, thereby causing forced convection of water, and the aggregate is cooled in the water in parallel with the traction step (for example, refer to Patent Document 1).

[0006] Prior art documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-155588 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, in the manufacturing apparatus and manufacturing method of the net-like structure as in Patent Document 1, when manufacturing the net-like structure, cooling water is sprayed toward the net-like structure, and there is a difference in the degree of cooling between the surface portion of the net-like structure in direct contact with the cooling water and the inside of the net-like structure not in contact with the cooling water, resulting in uneven cooling in the thickness direction of the net-like structure. When there is uneven cooling in the manufacturing of the net-like structure, there are the following problems: the residual compressive strain in the interior where cooling is insufficient is large, and in addition, the hardness retention rate after repeated compression becomes small, and the durability of the net-like structure is significantly deteriorated.

[0011] The present invention has been made to solve the above problems of the prior art, and an object thereof is to provide a manufacturing apparatus and a manufacturing method for a net-like structure, by which, when manufacturing the net-like structure, uneven cooling is not likely to occur in the thickness direction of the net-like structure during cooling, and sufficient durability is obtained.

[0012] Solutions for solving the problems

[0013] The first net-like structure manufacturing apparatus of the present invention capable of solving the above-mentioned problems is characterized in that the first net-like structure manufacturing apparatus includes: a nozzle having an ejection hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying a net-like structure having a linear resin; and a gas discharging device provided in the water tank for discharging gas.

[0014] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, the gas discharging device is disposed at a position lower than the conveying device.

[0015] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, the gas discharging device has a gas discharge hole for discharging gas, and the normal direction of the discharge hole faces the water surface of the water tank.

[0016] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, the conveying device is at least composed of a first conveying device and a second conveying device, and there is a net-like structure between the first conveying device and the second conveying device. The gas discharging device has a gas discharge hole for discharging gas, and the normal direction of the discharge hole faces the net-like structure between the conveying devices.

[0017] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, when the amount of resin extruded from the nozzle increases, the amount of gas discharged by the gas discharging device increases.

[0018] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, when the speed of the conveying device increases, the amount of gas discharged by the gas discharging device increases.

[0019] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, the conveying device has a mesh belt and a driving roller.

[0020] Preferably, the first net-like structure manufacturing apparatus of the above technical solution has a net-like structure traction device for pulling the net-like structure on one side of the water tank. The conveying device is at least composed of a first conveying device and a second conveying device, and the gas discharging device is disposed at a position on the side of the net-like structure traction device with respect to a vertical plane including the midpoint between the first conveying device and the second conveying device.

[0021] In the first net-like structure manufacturing apparatus of the above technical solution, preferably, the gas discharging device is at least composed of a first gas discharging device and a second gas discharging device, the conveying device is at least composed of a first conveying device and a second conveying device, the first gas discharging device is disposed below the first conveying device in the vertical direction, and the second gas discharging device is disposed below the second conveying device in the vertical direction.

[0022] Further, a method for manufacturing a first net-like structure according to the present invention that can solve the above problems is characterized in that the method for manufacturing the first net-like structure includes: a step of extruding molten thermoplastic resin into a string; a step of conveying a net-like structure having a string-shaped resin in a water tank by a conveying member; and a step of discharging gas into water in the water tank by a gas discharging device.

[0023] A second net-like structure manufacturing apparatus according to the present invention that can solve the above problems is characterized in that the second net-like structure manufacturing apparatus includes: a nozzle having a discharge hole for extruding molten thermoplastic resin into a string; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying a net-like structure having a string-shaped resin; and a water discharging device provided in the water tank for discharging water in a predetermined direction. The conveying device is at least composed of a first conveying device and a second conveying device. A net-like structure exists between the first conveying device and the second conveying device, and the net-like structure between the conveying devices does not exist on the extension line of the water discharge direction of the water discharging device.

[0024] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the water discharge direction of the water discharging device faces the water surface of the water tank.

[0025] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the water discharge direction of the water discharging device is deflected toward the net-like structure side between the conveying devices compared to the vertical direction.

[0026] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the water discharging device has a discharge hole for discharging water, and the discharge hole is disposed at a position 0.1 mm or more and 400 mm or less below the water surface of the water tank.

[0027] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the water discharging device is disposed inside the conveying device.

[0028] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the conveying device has a mesh belt and a driving roller.

[0029] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, the driving roller is at least composed of an upper driving roller and a lower driving roller. The upper driving roller is disposed above the inside of the conveying device, and the lower driving roller is disposed below the inside of the conveying device. The water discharge direction of the water discharged by the water discharging device is the direction toward the upper driving roller.

[0030] In the second net-like structure manufacturing apparatus of the above technical solution, preferably, when the amount of resin extruded from the nozzle increases, the amount of water discharged by the water discharging device increases.

[0031] In the second net-like structure manufacturing apparatus according to the above technical solution, preferably, when the speed of the conveying device increases, the amount of water discharged by the water discharging device increases.

[0032] In the second net-like structure manufacturing apparatus according to the above technical solution, preferably, the direction of the water discharged by the water discharging device is linked to the amount of resin extruded from the nozzle.

[0033] In the second net-like structure manufacturing apparatus according to the above technical solution, preferably, the direction of the water discharged by the water discharging device is linked to the speed of the conveying device.

[0034] In the second net-like structure manufacturing apparatus according to the above technical solution, preferably, the water discharging device has a discharge hole for discharging water, and the position of the discharge hole from the water surface of the water tank is linked to the amount of resin extruded from the nozzle.

[0035] In the second net-like structure manufacturing apparatus according to the above technical solution, preferably, the water discharging device has a discharge hole for discharging water, and the position of the discharge hole from the water surface of the water tank is linked to the speed of the conveying device.

[0036] Furthermore, the manufacturing method of the second net-like structure of the present invention capable of solving the above problems is characterized in that the manufacturing method of the second net-like structure includes: a step of extruding the molten thermoplastic resin into a line; a step of conveying the net-like structure having the linear resin in the water tank by the first conveying device and the second conveying device; and a step of discharging water by the water discharging device in a direction other than the direction toward the net-like structure between the first conveying device and the second conveying device.

[0037] The third net-like structure manufacturing apparatus of the present invention capable of solving the above problems is characterized in that the third net-like structure manufacturing apparatus includes: a nozzle having a discharge hole for extruding the molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying the net-like structure having the linear resin; and a drain provided at the bottom of the water tank.

[0038] In the third net-like structure manufacturing apparatus according to the above technical solution, preferably, in the water tank, a partition plate is provided around the drain.

[0039] In the third net-like structure manufacturing apparatus according to the above technical solution, preferably, the net-like structure manufacturing apparatus has a heat exchanger for cooling the water discharged from the drain and circulates the water.

[0040] In the third net-like structure manufacturing apparatus according to the above technical solution, preferably, the conveying device has a mesh belt and a driving roller.

[0041] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, the conveying device is composed of at least a first conveying device and a second conveying device, and the drain outlet is provided at a position including the intersection point, which is the point where the perpendicular line drawn from the midpoint between the first conveying device and the second conveying device to the bottom of the water tank intersects the bottom of the water tank.

[0042] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, a net-like structure traction device for traction of the net-like structure is provided on one side of the water tank, the conveying device is composed of at least a first conveying device and a second conveying device, the first conveying device is arranged at a position closer to the net-like structure traction device than the second conveying device, and the drain outlet is provided at a position closer to the net-like structure traction device than the first conveying device.

[0043] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, a net-like structure traction device for traction of the net-like structure is provided on one side of the water tank, the conveying device is composed of at least a first conveying device and a second conveying device, the first conveying device is arranged at a position closer to the net-like structure traction device than the second conveying device, and the drain outlet is provided at a position on the side opposite to the net-like structure traction device side relative to the second conveying device.

[0044] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, the shape of the drain outlet observed from a direction perpendicular to the water surface of the water tank is rectangular.

[0045] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, the third net-like structure manufacturing apparatus has a drainage volume adjustment component for adjusting the drainage volume from the drain outlet.

[0046] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, when the amount of resin extruded from the nozzle increases, the drainage volume adjustment component increases the drainage volume from the drain outlet.

[0047] In the manufacturing apparatus for the third net-like structure of the above technical solution, preferably, when the speed of the conveying device increases, the drainage volume adjustment component increases the drainage volume from the drain outlet.

[0048] In addition, the manufacturing method of the third net-like structure of the present invention capable of solving the above problems is characterized in that the manufacturing method of the third net-like structure has: a step of extruding the molten thermoplastic resin into a strand; a step of conveying the net-like structure having the strand-shaped resin in the water tank by a conveying component; a step of discharging the water in the water tank from a drain outlet provided at the bottom of the water tank; and a step of supplying water to the water tank at a temperature lower than the temperature of the water discharged from the drain outlet.

[0049] In the method for manufacturing the third net-like structure of the above technical solution, preferably, a heat exchanger is used to cool the water discharged from the drain port, and the water is supplied to the water tank to circulate.

[0050] Effects of the invention

[0051] In the first net-like structure manufacturing apparatus according to the present invention, a gas discharging device provided in the water tank discharges gas. Thus, convection can be caused in the water in the water tank, and it is easy to uniformly cool the surface portion and the inside of the net-like structure. Therefore, a net-like structure can be manufactured which is less likely to have uneven cooling in the thickness direction of the net-like structure and has sufficient durability.

[0052] In the second net-like structure manufacturing apparatus according to the present invention, a water discharging device provided in the water tank discharges water, and the net-like structure between the conveying devices does not exist on the extension line of the water discharging direction of the water discharging device. Thus, convection is caused in the water in the water tank, and it is easy to uniformly cool the surface portion and the inside of the net-like structure. As a result, a net-like structure can be manufactured which is less likely to have uneven cooling in the thickness direction of the net-like structure and has sufficient durability.

[0053] In the third net-like structure manufacturing apparatus according to the present invention, a drain port is provided at the bottom of the water tank, and the water in the water tank is discharged from the drain port. Thus, the high-temperature water near the linear resin in the water tank, particularly inside the net-like structure, can be discharged, and the rise in the overall water temperature in the water tank can be prevented. Therefore, it is easy to uniformly cool the surface portion and the inside of the net-like structure, and a net-like structure can be manufactured which is less likely to have uneven cooling in the thickness direction of the net-like structure and has sufficient durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A side view (partial cross-sectional view) showing the first net-like structure manufacturing apparatus in the embodiment of the present invention.

[0055] Figure 2 A side view (partial cross-sectional view) showing an example of the second net-like structure manufacturing apparatus in the embodiment of the present invention.

[0056] Figure 3 A side view (partial cross-sectional view) showing another example of the second net-like structure manufacturing apparatus in the embodiment of the present invention.

[0057] Figure 4 A side view (partial cross-sectional view) showing an example of the third net-like structure manufacturing apparatus in the embodiment of the present invention.

[0058] Figure 5Side view (partial cross-sectional view) showing another example of the third mesh structure manufacturing apparatus in the embodiments of the present invention.

[0059] Figure 6 Side view (partial cross-sectional view) showing yet another example of the third mesh structure manufacturing apparatus in the embodiments of the present invention. Detailed Description of the Invention

[0060] Hereinafter, the present invention will be specifically described with reference to the accompanying drawings. However, the present invention is of course not limited to the illustrated examples, and can be appropriately modified and implemented within the scope that can conform to the gist described above and below, and all of them are included in the technical scope of the present invention.

[0061] The first mesh structure manufacturing apparatus of the present invention will be described below.

[0062] The first mesh structure manufacturing apparatus of the present invention is characterized by including: a nozzle having a discharge hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying a mesh structure having a linear resin; and a gas discharge device provided in the water tank for discharging gas.

[0063] The mesh structure of the present invention is a structure having the following three-dimensional random ring joint structure: a linear resin containing a thermoplastic resin is bent to form a random ring, and each ring is joined in a molten state with each other.

[0064] Figure 1 It is a side view of the first mesh structure manufacturing apparatus in the embodiments of the present invention. The mesh structure manufacturing apparatus 1 has a nozzle 10, a water tank 20, a conveying device 30, and a gas discharge device 40.

[0065] The nozzle 10 has a discharge hole 11 for extruding molten thermoplastic resin into a line. That is, by extruding the thermoplastic resin melted by heating from the discharge hole 11 of the nozzle 10, a linear resin 12 is formed.

[0066] The number of the discharge holes 11 of the nozzle 10 can be one or more. When the nozzle 10 has a plurality of discharge holes 11, the plurality of discharge holes 11 can be arranged in a single row, but are preferably arranged in multiple rows. By having a plurality of discharge holes 11 in the nozzle 10, a plurality of linear resins 12 can be formed simultaneously, and the production efficiency of the mesh structure 60 can be improved. The number of the discharge holes 11 of the nozzle 10 can be adjusted according to the hardness and cushioning properties of the mesh structure 60 to be manufactured.

[0067] The cross-sectional shape of the outlet of the ejection hole 11 is not particularly limited. For example, a circular shape, an elliptical shape, a polygonal shape, etc. may be cited. Among them, the cross-sectional shape of the outlet of the ejection hole 11 is preferably circular or elliptical. By configuring the ejection hole 11 in this way, the cross-sectional shape of the linear resin 12 extruded from the ejection hole 11 also becomes circular or elliptical. Therefore, when forming the above-mentioned three-dimensional random loop joining structure, the contact area between the linear resins 12 can be increased, and a net-like structure body 60 having high elasticity and durability can be manufactured.

[0068] In addition, the cross-sectional shape of the linear resin 12 extruded from the ejection hole 11 can be solid or hollow. In order to make the cross-sectional shape of the linear resin 12 hollow, for example, a structure having a mandrel such as a core part inside the ejection hole 11 may be sufficient. Specifically, for the cross-sectional shape of the outlet of the ejection hole 11, a so-called C-type nozzle in which the inside and outside of the ejection hole 11 are partially connected, a so-called three-point bridge-shaped nozzle in which a bridge part is provided in the ejection hole 11 to divide the ejection hole 11 in the circumferential direction, etc. may be cited.

[0069] The length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 is preferably 0.1 mm or more, more preferably 0.5 mm or more, and still more preferably 1.0 mm or more. By setting the lower limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 in this way, the durability of the net-like structure body 60 can be improved, and a net-like structure body 60 that can withstand repeated compression can be manufactured. In addition, the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 is preferably 10 mm or less, more preferably 7 mm or less, and still more preferably 5 mm or less. By setting the upper limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 in this way, a net-like structure body 60 having good cushioning properties can be manufactured.

[0070] When the nozzle 10 has a plurality of ejection holes 11, the sizes of the cross-sectional shapes of the outlets of the respective ejection holes 11 may be the same or different. If the sizes of the cross-sectional shapes of the outlets of all the ejection holes 11 provided in the nozzle 10 are the same, a net-like structure body 60 with uniform thickness of the linear resin 12 can be formed. In addition, for example, when the size of the cross-sectional shape of the outlet of the ejection hole 11 at the central portion of the nozzle 10 is smaller than the size of the cross-sectional shape of the outlet of the ejection hole 11 at the outer peripheral portion of the nozzle 10, the linear resin 12 inside the net-like structure body 60 is thinner than the linear resin 12 at the surface portion of the net-like structure body 60. Therefore, the temperature inside the net-like structure body 60 becomes easier to drop than that at the surface portion. Therefore, a net-like structure body 60 having a structure that is not likely to cause uneven cooling can be manufactured.

[0071] Examples of the thermoplastic resin extruded from the ejection holes 11 include polyester-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, ethylene-vinyl acetate copolymers, and the like. Among them, the thermoplastic resin preferably contains at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer. By the thermoplastic resin containing at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer, the processability is improved, and it is easy to manufacture the network structure 60. In addition, the thermoplastic resin more preferably contains a polyester-based thermoplastic elastomer. By the thermoplastic resin containing a polyester-based thermoplastic elastomer, the repeated compression residual strain can be made small. In addition, by the thermoplastic resin containing a polyester-based thermoplastic elastomer, the hardness retention rate after repeated compression of the network structure 60 can be increased, and a network structure 60 with high durability can be manufactured.

[0072] The water tank 20 is disposed below the nozzle 10 and is configured to receive the linear resin 12 extruded from the ejection holes 11 of the nozzle 10. The water tank 20 has water for cooling the linear resin 12 extruded from the ejection holes 11 of the nozzle 10. The linear resin 12 extruded from the ejection holes 11 of the nozzle 10 forms a random loop by landing on the water surface in the water tank 20 and bending. The random loops are in contact with adjacent random loops in a molten state, thereby forming a structure in which the random loops are joined to each other in three-dimensional directions. At the same time, the structure is fixed by being cooled by water. Thus, the network structure 60 is obtained.

[0073] The conveying device 30 is provided in the water tank 20 and is used for conveying the network structure 60 having the linear resin 12. That is, the conveying device 30 conveys in the water tank 20 the network structure 60 having the linear resin 12 extruded from the ejection holes 11 of the nozzle 10 and received in the water tank 20. The conveying device 30 preferably conveys the network structure 60 from the water surface of the water tank 20 toward the bottom of the water tank 20. In addition, the conveying device 30 is preferably provided in the water tank 20.

[0074] The type of the conveying device 30 is not particularly limited. For example, conveyors such as belt conveyors, mesh conveyors, and plate conveyors can be cited. The detailed content of the conveying device 30 will be described later.

[0075] The gas release device 40 is provided in the water tank 20 for releasing gas. The gas released by the gas release device 40 is preferably the gas compressed by a device (not shown) for compressing the gas. The gas release device 40 releases gas into the water in the water tank 20, thereby enabling convection of the water in the water tank 20. When convection is caused in the water in the water tank 20, not only the water near the surface portion of the mesh structure 60 in the water tank 20 but also the water inside the mesh structure 60 moves through the gaps of the mesh structure 60, and thus new water is supplied. Therefore, both the surface portion and the inside of the mesh structure 60 in the water tank 20 can be cooled evenly, and uneven cooling is not likely to occur. Since uneven cooling is not likely to occur, in the manufacture of the mesh structure 60, an increase in repeated compressive residual strain caused by insufficient cooling and a decrease in the hardness retention rate after repeated compression can be prevented, and a mesh structure 60 with high durability can be manufactured. As for the type of gas, for example, air, oxygen, nitrogen, etc. can be cited, but air is preferably used.

[0076] The gas release device 40 is preferably provided at a position lower than the conveying device 30. Since the water near the water surface where the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 contacts the water in the water tank 20 becomes the highest temperature, by providing the gas release device 40 at a position lower than the conveying device 30, the water below the conveying device 30, which is at a lower temperature than the water near the water surface, can be sent to the linear resin 12 near the water surface, and the linear resin 12 near the water surface can be cooled efficiently. The gas release device 40 can be provided between the lower end of the conveying device 30 and the bottom of the water tank 20, or can be provided at the bottom of the water tank 20.

[0077] The gas release device 40 has a gas release hole 43 for releasing gas, and the normal direction of the gas release hole 43 preferably faces the water surface of the water tank 20. The normal of the gas release hole 43 refers to the line perpendicular to the plane including the opening of the gas release hole 43. By making the normal direction of the gas release hole 43 face the water surface of the water tank 20, convection of water can be caused from near the gas release device 40 toward the water surface where the water temperature is higher, and the mesh structure 60 can be cooled efficiently. In addition, preferably, when the gas release device 40 has a plurality of gas release holes 43, the normal direction of at least one gas release hole 43 faces the water surface of the water tank 20.

[0078] The number of gas release holes 43 provided in the gas release device 40 can be one or more. If the number of gas release holes 43 is one, it is easy to adjust the direction of the gas released from the gas release hole 43. In addition, if the number of gas release holes 43 is more than one, the gas released from the gas release holes 43 can be diffused to cause greater convection in the water in the water tank 20, and the cooling efficiency of the mesh structure 60 can be improved.

[0079] In addition, as will be described later, it is also preferable that when the conveying device 30 is constituted by at least a first conveying device 31 and a second conveying device 32 and there is a net-like structure 60 between the first conveying device 31 and the second conveying device 32, the normal direction of the gas discharge hole 43 faces the net-like structure 60 between the conveying devices 30. That is to say, it is preferable that the normal direction of the gas discharge hole 43 faces the net-like structure 60 between the first conveying device 31 and the second conveying device 32. By making the normal direction of the gas discharge hole 43 face the net-like structure 60 between the conveying devices 30, it is easier to send water into the inside of the net-like structure 60, and it is easy to cool the inside of the net-like structure 60 where cooling is likely to become insufficient.

[0080] More preferably, the normal direction of the gas discharge hole 43 faces the water surface of the water tank 20 and the net-like structure 60 between the conveying devices 30. By configuring the gas discharge hole 43 in this way, it is possible to generate convection of water from the gas discharge device 40 through the inside of the net-like structure 60 toward the water surface of the water tank 20, and it is not easy to cause uneven cooling in the thickness direction of the net-like structure 60.

[0081] Preferably, when the amount of resin extruded from the nozzle 10 increases, the amount of gas discharged by the gas discharge device 40 increases. That is to say, preferably, the volume of gas (m 3 / min) (measurement value under the conditions of 1 atmospheric pressure and normal temperature) discharged by the gas discharge device 40 is linked to the extrusion amount (g / min) of the resin extruded from the nozzle 10. For example, if the amount of the linear resin 12 extruded from the nozzle 10 is increased in order to improve the resilience of the net-like structure 60, the temperature near the water surface of the water tank 20 is likely to become higher. Therefore, the cooling efficiency of the net-like structure 60 deteriorates. In addition, when the amount of the linear resin 12 extruded from the nozzle 10 is increased, the net-like structure 60 becomes denser. Therefore, it is difficult to cool the inside of the net-like structure 60, and uneven cooling is likely to occur in the thickness direction of the net-like structure 60. Therefore, by increasing the gas discharge amount of the gas discharge device 40 as the amount of the linear resin 12 extruded from the nozzle 10 increases, it is possible to increase the convection of water in the water tank 20 and improve the cooling efficiency of the net-like structure 60, and it is possible to prevent uneven cooling.

[0082] More preferably, the volume of gas (m 3 / min) (measurement value under the conditions of 1 atmospheric pressure and normal temperature) discharged by the gas discharge device 40 is proportional to the extrusion amount (g / min) of the resin from the nozzle 10. By making the volume of gas discharged by the gas discharge device 40 and the extrusion amount of the resin from the nozzle 10 in such a relationship, it is possible to further improve the cooling efficiency of the net-like structure 60 and it is not easy to cause uneven cooling.

[0083] Preferably, when the speed of the conveying device 30 increases, the amount of gas released by the gas releasing device 40 increases. That is to say, preferably, the volume of the gas released by the gas releasing device 40 (m 3 / min) (measurement value under the conditions of 1 atmospheric pressure and normal temperature) is linked to the conveying speed of the mesh structure 60 based on the conveying device 30. If the speed of the conveying device 30 is increased for the purpose of reducing the hardness of the mesh structure 60, such as reducing the density of the mesh structure 60, sometimes the next process may be transferred when the cooling inside the mesh structure 60 is insufficient. If the next process is transferred in a state where the cooling inside the mesh structure 60 is insufficient, it may result in a mesh structure 60 with a large amount of repeated compressive residual strain inside and a small hardness retention rate after repeated compression, and poor durability. Therefore, by increasing the amount of gas released by the gas releasing device 40 as the speed of the conveying device 30 increases, the convection of the water in the water tank 20 can be increased, and the cooling efficiency of the mesh structure 60 can be improved. Not only can the surface part of the mesh structure 60 be sufficiently cooled, but also the inside can be sufficiently cooled.

[0084] More preferably, the volume of the gas released by the gas releasing device 40 (m 3 / min) (measurement value under the conditions of 1 atmospheric pressure and normal temperature) is proportional to the speed (m / min) of the conveying device 30. By making the volume of the gas released by the gas releasing device 40 and the speed of the conveying device 30 in such a relationship, the cooling efficiency of the mesh structure 60 can be further improved, and the occurrence of uneven cooling can be prevented.

[0085] In addition, more preferably, when the amount of resin extruded from the nozzle 10 increases, the amount of gas released by the gas releasing device 40 increases, and when the speed of the conveying device 30 increases, the amount of gas released by the gas releasing device 40 increases. That is to say, more preferably, the volume of the gas released by the gas releasing device 40 (m 3 / min) (measurement value under the conditions of 1 atmospheric pressure and normal temperature) is proportional to both the extrusion amount (g / min) of the resin from the nozzle 10 and the speed (m / min) of the conveying device 30. By setting the amount of gas released by the gas releasing device 40 in this way, for example, even if the amount of the linear resin 12 extruded from the nozzle 10 is increased and the speed of the conveying device 30 is increased for the purpose of improving the productivity of the mesh structure 60, etc., the mesh structure 60 can be sufficiently cooled by increasing the convection of the water in the water tank 20, and uneven cooling in the thickness direction of the mesh structure 60 can be less likely to occur.

[0086] The upper end portion of the conveying device 30 is preferably positioned above the water surface of the water tank 20. By arranging the conveying device 30 in this way, when the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 comes into contact with the water in the water tank 20, it is possible to prevent the linear resin 12 from moving freely on the water surface, and it is possible to prevent the thickness of the net-like structure 60 from becoming too large.

[0087] The conveying device 30 preferably has a conveyor belt 33. Examples of the conveyor belt 33 include a mesh conveyor belt formed by continuously incorporating or weaving a flat belt made of rubber or resin or a metal lead into a grid shape, or a plate conveyor belt in which metal plates are continuously mounted on a conveyor chain.

[0088] Among them, from the viewpoints of good gripping performance and excellent water permeability, the conveyor belt 33 is preferably a mesh conveyor belt. That is, the conveying device 30 is preferably a mesh conveyor conveying device having a grid-shaped belt and a driving roller 34. By configuring the conveying device 30 in this way, water and gas can pass through the conveying device 30, so the conveying device 30 is less likely to interfere with the convection of the water in the water tank 20 caused by the gas discharge device 40, and the cooling efficiency of the net-like structure 60 can be improved.

[0089] The conveyor belt 33 is preferably annular. By configuring the conveyor belt 33 to be annular, the annular conveyor belt 33 can be rotated continuously without interruption by the rotation of the driving roller 34, and the conveying device 30 can be operated continuously. As a result, the net-like structure 60 can be conveyed efficiently.

[0090] There are a plurality of driving rollers 34, which are preferably provided at the upper and lower parts inside the annular conveyor belt 33 respectively. That is, it is preferable to provide an upper driving roller 34a at the upper part inside the conveyor belt 33 and a lower driving roller 34b at the lower part inside the conveyor belt 33. By configuring the driving rollers 34 in this way, the conveyor belt 33 is less likely to be deflected, and the following situation can be prevented: under the rotation of the driving roller 34, the conveyor belt 33 rotates idly, causing malfunction of the conveying device 30.

[0091] Preferably, the conveying device 30 is composed of at least a first conveying device 31 and a second conveying device 32, and a net-like structure 60 is present between the first conveying device 31 and the second conveying device 32. By configuring the conveying device 30 in this way, the net-like structure 60 can be conveyed in a state of being sandwiched between the first conveying device 31 and the second conveying device 32, and therefore, a net-like structure 60 with a neat surface and a constant thickness can be produced.

[0092] The distance between the lower drive roller 34b of the first conveying device 31 and the lower drive roller 34b of the second conveying device 32 is preferably smaller than the distance between the upper drive roller 34a of the first conveying device 31 and the upper drive roller 34a of the second conveying device 32. That is to say, preferably, the distance between the lower first conveying device 31 and the second conveying device 32 is smaller than the distance between the upper first conveying device 31 and the second conveying device 32, and the distance between the first conveying device 31 and the second conveying device 32 narrows as it goes downward. By configuring the conveying device 30 in this way, the net-like structure body 60 can be clamped at the lower part of the conveying device 30. As a result, it is easy to introduce the linear resin 12 and the net-like structure body 60 into the water tank 20, and it is easy to cool the net-like structure body 60.

[0093] Preferably, the net-like structure body manufacturing device 1 has a net-like structure body traction device 50 that traction the net-like structure body 60 and lifts it from the water tank 20. Since the net-like structure body manufacturing device 1 has the net-like structure body traction device 50, the net-like structure body 60 can be automatically lifted from the water tank 20 after cooling the net-like structure body 60 and transferred to the drying process of the net-like structure body 60, so the productivity of the net-like structure body 60 can be improved.

[0094] Preferably, a net-like structure body traction device 50 for traction the net-like structure body 60 is provided on one side of the water tank 20. The conveying device 30 is at least composed of a first conveying device 31 and a second conveying device 32. The gas discharge device 40 is arranged at a position on the side of the net-like structure body traction device 50 with respect to the vertical plane p1 including the midpoint P1 between the first conveying device 31 and the second conveying device 32. Since the net-like structure body 60 exists at a position in the water tank 20 on the side of the net-like structure body traction device 50 with respect to the vertical plane p1, compared with the side of the vertical plane p1 opposite to the side of the net-like structure body traction device 50, it is preferable to cause more water convection on the side of the net-like structure body traction device 50 of the vertical plane p1 in terms of efficiently cooling the net-like structure body 60. Therefore, by arranging the gas discharge device 40 in this way, convection can be more efficiently caused for the water near the net-like structure body 60, and the cooling efficiency of the net-like structure body 60 can be improved.

[0095] Preferably, the gas discharge device 40 is composed of at least a first gas discharge device 41 and a second gas discharge device 42, the conveying device 30 is composed of at least a first conveying device 31 and a second conveying device 32, the first gas discharge device 41 is provided below the first conveying device 31 in the vertical direction, and the second gas discharge device 42 is provided below the second conveying device 32 in the vertical direction. By arranging the first gas discharge device 41 and the second gas discharge device 42 in this way, it is possible to generate a convection of water on both sides of the net-like structure 60, not only enabling the water near the net-like structure 60 to move, but also enabling the water in the entire water tank 20 to move, and further improving the cooling efficiency of the net-like structure 60.

[0096] The normal direction of the gas discharge hole 43 of the first gas discharge device 41 may be the same as or different from the normal direction of the gas discharge hole 43 of the second gas discharge device 42. For example, if the normal direction of the gas discharge hole 43 of the first gas discharge device 41 is the vertical direction and is the direction towards the water surface, and the normal direction of the gas discharge hole 43 of the second gas discharge device 42 is also the vertical direction and is the direction towards the water surface, then it is possible to equally cause a convection of water on both sides of the net-like structure 60 in the water tank 20, and it is possible to generate a convection with good balance using the first gas discharge device 41 and the second gas discharge device 42. In addition, if the normal direction of the gas discharge hole 43 of the first gas discharge device 41 and the normal direction of the gas discharge hole 43 of the second gas discharge device 42 are different, then using the first gas discharge device 41 and the second gas discharge device 42, it is possible to cause a convection of water at different positions, and it is possible to preferentially cause a convection at the positions where a convection is desired.

[0097] As Figure 1 shown, it is also preferable that the normal direction of the gas discharge hole 43 of the first gas discharge device 41 and the normal direction of the gas discharge hole 43 of the second gas discharge device 42 face between the center point of the upper driving roller 34a of the first conveying device 31 and the center point of the upper driving roller 34a of the second conveying device 32. By configuring the first gas discharge device 41 and the second gas discharge device 42 in this way, it is possible to efficiently cause a convection at the position where the water temperature in the water tank 20 is the highest, that is, at the position where the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 contacts the water in the water tank 20, and it is possible to efficiently cool the net-like structure 60.

[0098] The distance from the first gas release device 41 to the bottom of the water tank 20 may be the same as the distance from the second gas release device 42 to the bottom of the water tank 20, or may be different from the distance from the second gas release device 42 to the bottom of the water tank 20. That is to say, the distance from the gas release hole 43 of the first gas release device 41 to the bottom of the water tank 20 may be the same as the distance from the gas release hole 43 of the second gas release device 42 to the bottom of the water tank 20, or may be different from the distance from the gas release hole 43 of the second gas release device 42 to the bottom of the water tank 20. If the distance from the first gas release device 41 to the bottom of the water tank 20 is the same as the distance from the second gas release device 42 to the bottom of the water tank 20, the convection caused by the first gas release device 41 and the convection caused by the second gas release device 42 can be made to the same degree. Therefore, it is possible to cause convection in the water tank 20 well-balancedly by using the first gas release device 41 and the second gas release device 42.

[0099] In addition, in the following case, that is, when the distance from the first gas release device 41 to the bottom of the water tank 20 is different from the distance from the second gas release device 42 to the bottom of the water tank 20, and the first gas release device 41 is arranged on the side where the mesh structure traction device 50 is provided, and the distance from the first gas release device 41 to the bottom of the water tank 20 is greater than the distance from the second gas release device 42 to the bottom of the water tank 20, the first gas release device 41 is arranged close to the linear resin 12. Therefore, it is possible to cause greater convection near the mesh structure 60, and the cooling efficiency of the mesh structure 60 can be improved.

[0100] The amount of gas released by the first gas release device 41 may be the same as the amount of gas released by the second gas release device 42, or may be different from the amount of gas released by the second gas release device 42. If the amount of gas released by the first gas release device 41 is the same as the amount of gas released by the second gas release device 42, it is possible to cause the same degree of convection in the water in the water tank 20 by using the first gas release device 41 and the second gas release device 42, and it is possible to generate convection well-balancedly in the water tank 20.

[0101] In addition, if the amount of gas released by the first gas release device 41 is different from the amount of gas released by the second gas release device 42, and the first gas release device 41 is arranged on the side where the mesh structure traction device 50 is provided, and the amount of gas released by the first gas release device 41 is more than the amount of gas released by the second gas release device 42, it is possible to increase the convection of the water caused by the first gas release device 41 which is closer to the mesh structure 60, and the cooling of the mesh structure 60 can be carried out efficiently.

[0102] Alternatively, the water in the drain tank 20 can be drained and low-temperature water can be supplied to the tank 20 again. When draining the water in the drain tank 20, although not shown, it can be drained by so-called overflow through a pipe or the like provided at the upper part of the tank 20. Specifically, for example, methods such as supplying new low-temperature water to the tank 20 from the lower part of the tank 20 and causing the water with increased temperature to overflow can be cited.

[0103] The manufacturing method of the first net-like structure of the present invention is characterized in that the manufacturing method of the first net-like structure has: a step of extruding the molten thermoplastic resin into a line; a step of conveying the net-like structure having the linear resin in a water tank by a conveying member; and a step of discharging gas into the water in the water tank by a gas discharging device.

[0104] The thermoplastic resin as the material of the net-like structure is heated to be melted, and the resin is extruded in the form of a line. In order to make the resin into a line, it is sufficient to extrude the molten thermoplastic resin from a nozzle or the like having a discharge hole.

[0105] The extruded linear resin is stored in a water tank filled with water. The linear resin forms a random loop by landing on the water surface in the water tank and bending. The random loops are in contact with adjacent random loops in a molten state, thereby forming a structure in which the random loops are joined to each other in three-dimensional directions. At the same time, the structure is fixed by being cooled by water. Thus, a net-like structure is formed.

[0106] The net-like structure is conveyed in the water tank by a conveying member. Preferably, the conveying member conveys the net-like structure downward from the water surface in the water tank. By conveying the net-like structure by such a conveying member, the extruded linear resin is continuously formed into a sheet-like net-like structure, and a net-like structure of an appropriate size for an elastic pad material for bedding or an elastic pad material for a seat can be manufactured. As the conveying member, for example, a conveying device such as the above-described conveyor can be used.

[0107] Gas is discharged into the water in the water tank by a gas discharging device. By discharging gas into the water, convection is generated in the water in the water tank, and the water having a high temperature near the water surface moves to supply low-temperature water. Thereby, the net-like structure is efficiently cooled, and not only the surface portion of the net-like structure can be sufficiently cooled, but also the inside can be sufficiently cooled, and uneven cooling is not likely to occur, and a net-like structure having high durability can be manufactured.

[0108] The net-shaped structure can be manufactured by lifting the cooled net-shaped structure from the water tank and drying it. Preferably, before and after drying the net-shaped structure, a pseudo-crystallization treatment of heating for a certain period of time at a temperature lower than the melting point of the resin used for the material of the net-shaped structure is performed. By performing the pseudo-crystallization treatment on the net-shaped structure, the durability of the net-shaped structure can be improved. It is considered that through the pseudo-crystallization treatment, the hard segments of the resin are rearranged by heating to form a metastable mesophase, and crosslinking points like pseudo-crystallization are formed, improving the durability such as heat resistance and sag resistance of the net-shaped structure.

[0109] As described above, the first net-shaped structure manufacturing apparatus of the present invention is characterized in that the first net-shaped structure manufacturing apparatus includes: a nozzle having a discharge hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying the net-shaped structure having a linear resin; and a gas discharge device provided in the water tank for discharging gas. By configuring the net-shaped structure manufacturing apparatus in such a manner, the gas discharge device provided in the water tank can discharge gas to cause convection in the water of the water tank, and it is easy to efficiently cool the surface portion and the interior of the net-shaped structure. Therefore, a manufacturing apparatus for manufacturing a net-shaped structure can be provided, in which the net-shaped structure is less likely to have uneven cooling in the thickness direction and has sufficient durability.

[0110] The second net-shaped structure manufacturing apparatus of the present invention will be described below.

[0111] The second net-shaped structure manufacturing apparatus of the present invention is characterized in that the second net-shaped structure manufacturing apparatus includes: a nozzle having a discharge hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying the net-shaped structure having a linear resin; and a water discharge device provided in the water tank for discharging water in a predetermined direction. The conveying device is at least composed of a first conveying device and a second conveying device. There is a net-shaped structure between the first conveying device and the second conveying device, and the net-shaped structure between the conveying devices does not exist on the extension line of the water discharge direction of the water discharge device.

[0112] The net-shaped structure of the present invention is a structure having the following three-dimensional random ring joint structure: a linear resin containing a thermoplastic resin is bent to form a random ring, and each ring is joined in a molten state in contact with each other.

[0113] Figure 2 and Figure 3 is a side view of the second net-shaped structure manufacturing apparatus in the embodiment of the present invention. The net-shaped structure manufacturing apparatus 1 has a nozzle 10, a water tank 20, a conveying device 30, and a water discharge device 70.

[0114] The nozzle 10 has a discharge hole 11 for extruding the molten thermoplastic resin into a line. That is, by extruding the thermoplastic resin melted by heating from the discharge hole 11 of the nozzle 10, a linear resin 12 is formed.

[0115] The number of the discharge holes 11 of the nozzle 10 may be one or plural. When the nozzle 10 has plural discharge holes 11, the plural discharge holes 11 may be arranged in a single row, but are preferably arranged in plural rows. By the nozzle 10 having plural discharge holes 11, plural linear resins 12 can be formed simultaneously, and the production efficiency of the net-like structure 60 can be improved. The number of the discharge holes 11 of the nozzle 10 can be adjusted accordingly according to the hardness, cushioning property, etc. of the net-like structure 60 to be manufactured.

[0116] The cross-sectional shape of the outlet of the discharge hole 11 is not particularly limited, and examples thereof include a circular shape, an elliptical shape, a polygonal shape, etc. Among them, the cross-sectional shape of the outlet of the discharge hole 11 is preferably a circular shape or an elliptical shape. By configuring the discharge hole 11 in this way, the cross-sectional shape of the linear resin 12 extruded from the discharge hole 11 also becomes a circular shape or an elliptical shape. Therefore, when forming the above-mentioned three-dimensional random loop joint structure, the contact area between the linear resins 12 can be increased, and a net-like structure 60 having high elastic force and durability can be manufactured.

[0117] In addition, the cross-sectional shape of the linear resin 12 extruded from the discharge hole 11 may be solid or hollow. In order to make the cross-sectional shape of the linear resin 12 hollow, for example, a structure having a core bar such as a core bone part inside the discharge hole 11 may be sufficient. Specifically, for the cross-sectional shape of the outlet of the discharge hole 11, a so-called C-type nozzle in which the inside and outside of the discharge hole 11 are partially communicated, a so-called three-point bridge-shaped nozzle in which a bridge part is provided in the discharge hole 11 to divide the discharge hole 11 in the circumferential direction, etc. can be cited.

[0118] The length in the major axis direction of the cross-sectional shape of the outlet of the discharge hole 11 is preferably 0.1 mm or more, more preferably 0.5 mm or more, and further preferably 1.0 mm or more. By setting the lower limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the discharge hole 11 in this way, the durability of the net-like structure 60 can be improved, and a net-like structure 60 that can withstand repeated compression can be manufactured. In addition, the length in the major axis direction of the cross-sectional shape of the outlet of the discharge hole 11 is preferably 10 mm or less, more preferably 7 mm or less, and further preferably 5 mm or less. By setting the upper limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the discharge hole 11 in this way, a net-like structure 60 having good cushioning property can be manufactured.

[0119] In the case where the nozzle 10 has a plurality of ejection holes 11, the sizes of the cross-sectional shapes of the outlets of the respective ejection holes 11 may be the same or different. If the sizes of the cross-sectional shapes of the outlets of all the ejection holes 11 provided in the nozzle 10 are the same, a network structure 60 with a uniform thickness of the linear resin 12 can be formed. Further, for example, when the size of the cross-sectional shape of the outlet of the ejection hole 11 at the central portion of the nozzle 10 is smaller than the size of the cross-sectional shape of the outlet of the ejection hole 11 at the outer peripheral portion of the nozzle 10, the linear resin 12 inside the network structure 60 is thinner than the linear resin 12 at the surface portion of the network structure 60. Therefore, the temperature inside the network structure 60 drops more easily than that at the surface portion, and a network structure 60 with a structure that is not likely to cause uneven cooling can be manufactured.

[0120] Examples of the thermoplastic resin extruded from the ejection hole 11 include polyester-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, ethylene-vinyl acetate copolymers, and the like. Among them, the thermoplastic resin preferably contains at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer. By the thermoplastic resin containing at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer, the processability is improved, and the network structure 60 is easily manufactured. Further, the thermoplastic resin more preferably contains a polyester-based thermoplastic elastomer. By the thermoplastic resin containing a polyester-based thermoplastic elastomer, the repeated compression residual strain can be made smaller and the hardness retention rate after repeated compression can be made larger, and a network structure 60 with higher durability can be manufactured.

[0121] The water tank 20 is disposed below the nozzle 10 and is configured to be able to receive the linear resin 12 extruded from the ejection hole 11 of the nozzle 10. The water tank 20 has water for cooling the linear resin 12 extruded from the ejection hole 11 of the nozzle 10. The linear resin 12 extruded from the ejection hole 11 of the nozzle 10 forms a random loop by landing on the water surface in the water tank 20 and bending. The random loops are in contact with adjacent random loops in a molten state, whereby a structure in which the random loops are joined to each other in three-dimensional directions is formed, and at the same time, the structure is fixed by being cooled by water. Thus, the network structure 60 is obtained.

[0122] The conveying device 30 is provided in the water tank 20 and is used for conveying the network structure 60 having the linear resin 12. That is, the conveying device 30 conveys in the water tank 20 the network structure 60 having the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 and received in the water tank 20. The conveying device 30 preferably conveys the network structure 60 from the water surface of the water tank 20 toward the bottom of the water tank 20. Further, the conveying device 30 is preferably provided in the water tank 20.

[0123] The conveying device 30 is composed of at least a first conveying device 31 and a second conveying device 32, and a net-like structure body 60 is present between the first conveying device 31 and the second conveying device 32. By configuring the conveying device 30 in this way, it is possible to convey the net-like structure body 60 in a state where the first conveying device 31 and the second conveying device 32 sandwich the net-like structure body 60. Therefore, a net-like structure body 60 with a neat surface and a constant thickness can be produced.

[0124] The type of the conveying device 30 is not particularly limited. For example, conveyors such as belt conveyors, mesh conveyors, and plate conveyors can be cited. The detailed content of the conveying device 30 will be described later.

[0125] The water discharging device 70 is provided in the water tank 20 and is used to discharge water in a predetermined direction. The net-like structure body 60 between the conveying devices 30 does not exist on the extension line of the water discharging direction of the water discharging device 70. Since the water discharging device 70 discharges water into the water in the water tank 20 and the net-like structure body 60 between the conveying devices 30 does not exist on the extension line of the water discharging direction, instead of directly cooling the surface portion of the net-like structure body 60 by bringing water into contact with it, convection is generated in the water in the water tank 20, and the net-like structure body 60 is cooled by using this water. As a result, both the surface portion and the inside of the net-like structure body 60 in the water tank 20 can be cooled evenly, and uneven cooling is not likely to occur. In the case of a conventional manufacturing device that cools by bringing water into contact with the surface portion of the net-like structure body 60, there are the following problems: uneven cooling occurs in the thickness direction of the net-like structure body 60, leading to an increase in the repeated compressive residual strain in the insufficiently cooled part and a decrease in the hardness retention rate after repeated compression. However, in the net-like structure body manufacturing device 1, since uneven cooling is not likely to occur, an increase in the repeated compressive residual strain and a decrease in the hardness retention rate after repeated compression can be prevented, and a net-like structure body 60 with high durability can be manufactured.

[0126] The water discharging direction of the water discharging device 70 preferably faces the water surface of the water tank 20. Since the water near the water surface where the linear resin 12 extruded from the ejection holes 11 of the nozzle 10 comes into contact with the water in the water tank 20 has the highest temperature, by making the water discharging direction face the water surface, water with a temperature lower than that near the water surface can be sent to the vicinity of the water surface, and the net-like structure body 60 can be cooled efficiently.

[0127] Furthermore, the water discharge direction of the water discharge device 70 is more preferably a direction inclined toward the mesh structure 60 side from the vertical direction. That is to say, more preferably, the water discharge direction of the water discharge device 70 is toward the water surface of the water tank 20 and is a direction inclined toward the mesh structure 60 side between the conveying devices from the vertical direction with respect to the water surface of the water tank 20. By setting the water discharge direction of the water discharge device 70 in this way, it is possible to more efficiently send low-temperature water to the vicinity of the water surface where the water reaches the highest temperature and where the linear resin 12 extruded from the ejection holes 11 of the nozzle 10 contacts the water in the water tank 20. As a result, it is easy to uniformly cool the surface portion and the interior of the mesh structure 60.

[0128] The water discharge device 70 has a water discharge hole 73 for discharging water. The water discharge hole 73 is preferably arranged at a position 0.1 mm or more below the water surface of the water tank 20, more preferably at a position 1 mm or more below the water surface of the water tank 20, and further preferably at a position 10 mm or more below the water surface of the water tank 20. By setting the lower limit value of the distance D1 between the water discharge hole 73 and the water surface of the water tank 20 as described above, it is possible to sufficiently cause convection in the water in the water tank 20 and improve the cooling efficiency of the mesh structure 60. In addition, the water discharge hole 73 is preferably arranged at a position 400 mm or less below the water surface of the water tank 20, more preferably at a position 350 mm or less below the water surface of the water tank 20, further preferably at a position 300 mm or less below the water surface of the water tank 20, and most preferably at a position 250 mm or less below the water surface of the water tank 20. By setting the upper limit value of the distance D1 between the water discharge hole 73 and the water surface of the water tank 20 as described above, it is possible to cause convection of water from the water discharge device 70 toward the vicinity of the water surface with a higher water temperature. The vicinity of the water surface is the part where the difference in the cooling degree between the surface portion and the interior of the mesh structure 60 is the largest. By causing convection of water in the vicinity of this water surface, it is possible to more uniformly cool the mesh structure 60. In addition, in the case where the water discharge device 70 has a plurality of water discharge holes 73, preferably, the distance D1 between at least one water discharge hole 73 and the water surface of the water tank 20 is as described above.

[0129] The number of the water discharge holes 73 provided in the water discharge device 70 may be one or plural. If the number of the water discharge holes 73 is one, it is easy to adjust the direction of the water discharged from the water discharge hole 73. In addition, if the number of the water discharge holes 73 is plural, it is possible to diffuse the water discharged from the water discharge holes 73 and cause a large convection in the water in the water tank 20, and improve the cooling efficiency of the mesh structure 60.

[0130] The water discharge device 70 is preferably arranged inside the conveying device 30. By arranging the water discharge device 70 in this way, the water discharged from the water discharge device 70 is not likely to directly contact the mesh structure 60, and it is possible to more efficiently cause convection of water near the water surface where the water temperature becomes higher. Therefore, it is possible to more uniformly and efficiently cool the surface part and the inside of the mesh structure 60.

[0131] The upper end portion of the conveying device 30 is preferably located above the water surface of the water tank 20. By arranging the conveying device 30 in this way, when the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 comes into contact with the water in the water tank 20, it is possible to prevent the linear resin 12 from freely moving on the water surface and prevent the thickness of the mesh structure 60 from becoming too large.

[0132] Preferably, the conveying device 30 includes a conveyor belt 33 and a driving roller 34. Examples of the conveyor belt 33 include a mesh conveyor belt formed by continuously incorporating or weaving a flat belt made of rubber or resin or a metal lead into a grid shape, or a plate conveyor belt in which metal plates are continuously installed on a conveyor chain.

[0133] Among them, considering the aspects of good holding performance and excellent water passing performance, the conveyor belt 33 is preferably a mesh conveyor belt. That is, the conveying device 30 is preferably a mesh conveyor conveying device having a grid-shaped belt and a driving roller. By configuring the conveying device 30 in this way, water can pass through the conveying device 30. Therefore, the conveying device 30 is not likely to hinder the convection of water in the water tank 20 caused by the water discharge device 70, and the cooling efficiency of the mesh structure 60 can be improved.

[0134] The conveyor belt 33 is preferably annular. By configuring the conveyor belt 33 to be annular, the annular conveyor belt 33 can be continuously rotated by the rotation of the driving roller 34, and the conveying device 30 can be continuously operated. As a result, the conveying of the mesh structure 60 can be efficiently performed.

[0135] There are a plurality of driving rollers 34, which are preferably provided at the upper and lower parts inside the annular conveyor belt 33 respectively. That is to say, an upper driving roller 34a is preferably provided at the upper part inside the conveyor belt 33, and a lower driving roller 34b is preferably provided at the lower part inside the conveyor belt 33. By configuring the driving roller 34 in this way, the conveyor belt 33 is not likely to be deflected, and the following situation can be prevented: under the rotation of the driving roller 34, the conveyor belt 33 idles and causes malfunction of the conveying device 30.

[0136] Preferably, the driving roller 34 is at least composed of an upper driving roller 34a and a lower driving roller 34b. The upper driving roller 34a is disposed above the inside of the conveying device 30, and the lower driving roller 34b is disposed below the inside of the conveying device 30. The direction in which the water discharged by the water discharging device 70 goes is the direction towards the upper driving roller 34a. By setting the water discharging direction of the water discharging device 70 in this way, the water discharged from the water discharging device 70 will contact the upper driving roller 34a and cause the water to spread. As a result, convection is likely to occur in the water in the water tank 20, so the cooling efficiency of the net-like structure 60 can be improved.

[0137] The distance between the lower driving roller 34b of the first conveying device 31 and the lower driving roller 34b of the second conveying device 32 is preferably smaller than the distance between the upper driving roller 34a of the first conveying device 31 and the upper driving roller 34a of the second conveying device 32. That is to say, preferably, the distance between the lower first conveying device 31 and the second conveying device 32 is smaller than the distance between the upper first conveying device 31 and the second conveying device 32, and the distance between the first conveying device 31 and the second conveying device 32 narrows as it goes downward. By configuring the conveying device 30 in this way, the net-like structure 60 can be clamped at the lower part of the conveying device 30. Therefore, it is easy to introduce the linear resin 12 and the net-like structure 60 into the water tank 20, and it is easy to cool the net-like structure 60.

[0138] Preferably, when the amount of the resin extruded from the nozzle 10 increases, the amount of the water discharged by the water discharging device 70 increases. That is to say, preferably, the volume of the water discharged by the water discharging device 70 (m 3 / min) is linked with the extrusion amount of the resin from the nozzle 10 (g / min). For example, if the amount of the linear resin 12 extruded from the nozzle 10 is increased in order to improve the resilience of the net-like structure 60, the temperature near the water surface of the water tank 20 is likely to become higher. Therefore, the cooling efficiency of the net-like structure 60 becomes poor. In addition, it is difficult to cool the inside of the net-like structure 60, and cooling unevenness is likely to occur in the thickness direction of the net-like structure 60. Therefore, by increasing the amount of the water discharged by the water discharging device 70 as the linear resin 12 extruded from the nozzle 10 increases, the convection of the water in the water tank 20 can be increased to improve the cooling efficiency of the net-like structure 60, and cooling unevenness can be prevented.

[0139] More preferably, the volume of the water discharged by the water discharging device 70 (m 3 / min) is proportional to the extrusion amount of the resin from the nozzle 10 (g / min). By making the volume of the water discharged by the water discharging device 70 and the extrusion amount of the resin from the nozzle 10 in such a relationship, the cooling efficiency of the net-like structure 60 can be further improved, and cooling unevenness is not likely to occur.

[0140] Also preferably, when the speed of the conveying device 30 increases, the amount of water discharged by the water discharging device 70 increases. That is to say, preferably, the volume of water (m 3 / min) discharged by the water discharging device 70 is linked to the conveying speed of the mesh structure 60 based on the conveying device 30. If the speed of the conveying device 30 is increased for the purpose of reducing the hardness of the mesh structure 60, such as reducing the density of the mesh structure 60, and the transfer to the next process is carried out when the cooling inside the mesh structure 60 is insufficient. If the transfer to the next process is carried out in a state where the cooling inside the mesh structure 60 is insufficient, it may result in a mesh structure 60 with a large amount of repeated compressive residual strain inside the mesh structure 60, a small hardness retention rate after repeated compression, and poor durability. Therefore, by increasing the amount of water discharged by the water discharging device 70 as the speed of the conveying device 30 increases, the convection of water in the water tank 20 can be increased, and the cooling efficiency of the mesh structure 60 near the water surface can be improved. Not only can the surface part of the mesh structure 60 be sufficiently cooled, but also the inside can be sufficiently cooled.

[0141] More preferably, the volume of water (m 3 / min) discharged by the water discharging device 70 is proportional to the speed (m / min) of the conveying device 30. By making the volume of water discharged by the water discharging device 70 and the speed of the conveying device 30 in such a relationship, the cooling efficiency of the mesh structure 60 can be further improved, and the occurrence of uneven cooling can be prevented.

[0142] In addition, more preferably, when the amount of resin extruded from the nozzle 10 increases, the amount of water discharged by the water discharging device 70 increases, and when the speed of the conveying device 30 increases, the amount of water discharged by the water discharging device 70 increases. That is to say, more preferably, the volume of water (m 3 / min) discharged by the water discharging device 70 is proportional to both the extrusion amount (g / min) of the resin from the nozzle 10 and the speed (m / min) of the conveying device 30. By setting the volume of water (m 3 / min) discharged by the water discharging device 70 in this way, for example, even if the amount of the linear resin 12 extruded from the nozzle 10 is increased and the speed of the conveying device 30 is increased for the purpose of improving the productivity of the mesh structure 60, etc., the linear resin 12 can be sufficiently cooled by increasing the convection of water in the water tank 20. As a result, it is possible to less likely cause uneven cooling in the thickness direction of the mesh structure 60.

[0143] Preferably, the direction of the water discharged by the water discharge device 70 is linked to the amount of resin extruded from the nozzle 10. For example, if the amount of the linear resin 12 extruded from the nozzle 10 is increased in order to improve the resilience of the net-like structure 60, the temperature near the water surface of the water tank 20 is likely to become higher, the cooling efficiency of the net-like structure 60 deteriorates, and uneven cooling of the net-like structure 60 is likely to occur. Therefore, by making the discharge direction of the water of the water discharge device 70 approach the central portion of the linear resin 12 near the water surface of the water tank 20 as the linear resin 12 extruded from the nozzle 10 increases, the convection of the water near the water surface, which is likely to become hot, can be increased, so that the inside of the net-like structure 60 can be sufficiently cooled and uneven cooling can be prevented.

[0144] Preferably, the direction of the water discharged by the water discharge device 70 is linked to the speed of the conveying device 30. If the speed of the conveying device 30 is increased for the purpose of reducing the hardness of the net-like structure 60, such as reducing the density of the net-like structure 60, the cooling inside the net-like structure 60 becomes insufficient, and there is a risk that the durability of the net-like structure 60 will decrease. Therefore, by making the discharge direction of the water of the water discharge device 70 approach the central portion of the linear resin 12 near the water surface of the water tank 20 as the speed of the conveying device 30 increases, the cooling efficiency of the linear resin 12 can be improved, and the cooling efficiency of both the surface portion and the inside of the net-like structure 60 can be improved.

[0145] Furthermore, more preferably, the direction of the water discharged by the water discharge device 70 is linked to the amount of resin extruded from the nozzle 10 and the speed of the conveying device 30. By setting the discharge direction of the water of the water discharge device 70 in this way, for example, even if the amount of the linear resin 12 extruded from the nozzle 10 is increased and the speed of the conveying device 30 is increased for the purpose of improving the productivity of the net-like structure 60 or the like, the discharge direction of the water of the water discharge device 70 can be made to approach the central portion of the linear resin 12 near the water surface of the water tank 20, and a large convection of water can be generated in the water tank 20. As a result, the cooling efficiency of the net-like structure 60 near the water surface can be improved, and uneven cooling in the net-like structure 60 can be prevented.

[0146] Preferably, the water discharge device 70 has a water discharge hole 73 for discharging water, and the position of the water discharge hole 73 from the water surface of the water tank 20 is linked to the amount of resin extruded from the nozzle 10. That is, preferably, the position of the water discharge hole 73 of the water discharge device 70 can be moved so that the position of the water discharge hole 73 from the water surface of the water tank 20 moves in a manner linked to the amount of resin extruded from the nozzle 10. For example, if the amount of the linear resin 12 extruded from the nozzle 10 is increased to improve the resilience of the mesh structure 60, the temperature near the water surface of the water tank 20 is likely to become higher, the cooling efficiency of the mesh structure 60 deteriorates, and uneven cooling of the mesh structure 60 is likely to occur. Therefore, by decreasing the distance D1 between the water surface of the water tank 20 and the water discharge hole 73 as the linear resin 12 extruded from the nozzle 10 increases, convection is caused for the high-temperature water near the water surface to move the water, improving the cooling efficiency of the mesh structure 60 near the water surface and preventing uneven cooling in the thickness direction of the mesh structure 60.

[0147] Preferably, the water discharge device 70 has a water discharge hole 73 for discharging water, and the position of the water discharge hole 73 from the water surface of the water tank 20 is linked to the speed of the conveying device 30. If the speed of the conveying device 30 is increased for the purpose of reducing the hardness of the mesh structure 60, such as reducing the density of the mesh structure 60, the cooling inside the mesh structure 60 becomes an insufficient state, and there is a risk that the durability of the mesh structure 60 becomes low. Therefore, by decreasing the distance D1 between the water surface of the water tank 20 and the water discharge hole 73 as the speed of the conveying device 30 increases, the surface portion and the inside of the mesh structure 60 are sufficiently cooled, and uneven cooling of the mesh structure 60 can be prevented.

[0148] Furthermore, more preferably, the position of the water discharge hole 73 of the water discharge device 70 from the water surface of the water tank 20 is linked to the amount of resin extruded from the nozzle 10 and the speed of the conveying device 30. By setting the direction of the water discharged from the water discharge device 70 in this way, for example, even if the amount of the linear resin 12 extruded from the nozzle 10 is increased and the speed of the conveying device 30 is increased for the purpose of improving the productivity of the mesh structure 60 or the like, the cooling efficiency of the mesh structure 60 can be improved by generating a large convection of water in the water tank 20 by decreasing the distance D1 between the water surface of the water tank 20 and the water discharge hole 73, and uneven cooling of the mesh structure 60 can be prevented.

[0149] Preferably, the mesh structure manufacturing apparatus 1 has a mesh structure pulling device 50 that pulls the mesh structure 60 and lifts it from the water tank 20. By having the mesh structure pulling device 50 in the mesh structure manufacturing apparatus 1, the mesh structure 60 can be automatically lifted from the water tank 20 after cooling of the mesh structure 60 and transferred to the drying process of the mesh structure 60, and thus the productivity of the mesh structure 60 can be improved.

[0150] Preferably, a mesh structure traction device 50 for traction of the mesh structure 60 is provided on one side of the water tank 20. The conveying device 30 is composed of at least a first conveying device 31 and a second conveying device 32. The water discharging device 70 is arranged at a position on the side of the mesh structure traction device 50 with respect to the vertical plane p1 including the midpoint P1 between the first conveying device 31 and the second conveying device 32. Since the mesh structure 60 exists at a position on the side of the mesh structure traction device 50 with respect to the vertical plane p1 in the water tank 20, it is preferable in terms of efficiently cooling the mesh structure 60 to cause more water convection on the side of the vertical plane p1 where the mesh structure traction device 50 is located than on the side opposite to the side of the mesh structure traction device 50 of the vertical plane p1. Therefore, by arranging the water discharging device 70 in this way, it is possible to more efficiently cause convection in the water near the mesh structure 60, and the cooling efficiency of the mesh structure 60 can be improved.

[0151] Preferably, the water discharging device 70 is composed of at least a first water discharging device 71 and a second water discharging device 72, the conveying device 30 is composed of at least a first conveying device 31 and a second conveying device 32, the first water discharging device 71 is arranged inside the first conveying device 31, and the second water discharging device 72 is arranged inside the second conveying device 32. By arranging the first water discharging device 71 and the second water discharging device 72 in this way, it is possible to generate water convection on both sides of the mesh structure 60. Therefore, not only can the water near the mesh structure 60 be moved, but also the water in the entire water tank 20 can be moved, and the cooling efficiency of the mesh structure 60 can be further improved.

[0152] The water discharging direction of the first water discharging device 71 may be the same as or different from the water discharging direction of the second water discharging device 72. For example, if the water discharging direction of the first water discharging device 71 is the vertical direction and is the direction towards the water surface, and the water discharging direction of the second water discharging device 72 is also the vertical direction and is the direction towards the water surface, then it is possible to equally cause water convection on both sides of the linear resin 12 in the water tank 20, and it is possible to generate convection with good balance using the first water discharging device 71 and the second water discharging device 72.

[0153] In addition, if the water discharging directions of the first water discharging device 71 and the second water discharging device 72 are different, then using the first water discharging device 71 and the second water discharging device 72, it is possible to cause water convection at different positions, and it is possible to preferentially cause convection at the positions where convection is desired respectively.

[0154] The distance D1 between the water discharge hole 73 of the first water discharge device 71 and the water surface of the water tank 20 may be the same as the distance between the water discharge hole 73 of the second water discharge device 72 and the water surface of the water tank 20, or may be different from the distance between the water discharge hole 73 of the second water discharge device 72 and the water surface of the water tank 20. If the distance D1 between the water discharge hole 73 of the first water discharge device 71 and the water surface of the water tank 20 is the same as the distance between the water discharge hole 73 of the second water discharge device 72 and the water surface of the water tank 20, the convection caused by the first water discharge device 71 and the convection caused by the second water discharge device 72 can be made to be of the same degree, and the first water discharge device 71 and the second water discharge device 72 can be used to cause convection in the water tank 20 with good balance.

[0155] In addition, in the following case, that is, when the distance D1 between the water discharge hole 73 of the first water discharge device 71 and the water surface of the water tank 20 is different from the distance between the water discharge hole 73 of the second water discharge device 72 and the water surface of the water tank 20, and the first water discharge device 71 is arranged on the side where the mesh structure traction device 50 is provided, and the distance D1 between the water discharge hole 73 of the first water discharge device 71 and the water surface of the water tank 20 is greater than the distance between the water discharge hole 73 of the second water discharge device 72 and the water surface of the water tank 20, since the first water discharge device 71 is arranged at a position close to the mesh structure 60, convection can be caused more greatly near the mesh structure 60. Therefore, the cooling efficiency of the mesh structure 60 can be improved.

[0156] The amount of water discharged by the first water discharge device 71 may be the same as the amount of water discharged by the second water discharge device 72, or may be different from the amount of water discharged by the second water discharge device 72. If the amount of water discharged by the first water discharge device 71 is the same as the amount of water discharged by the second water discharge device 72, the first water discharge device 71 and the second water discharge device 72 can be used to cause convection of the same degree in the water in the water tank 20, and convection can be generated in the water tank 20 with good balance.

[0157] In addition, if the amount of water discharged by the first water discharge device 71 is different from the amount of water discharged by the second water discharge device 72, and the first water discharge device 71 is arranged on the side where the mesh structure traction device 50 is provided, and the amount of water discharged by the first water discharge device 71 is more than the amount of water discharged by the second water discharge device 72, the convection of the water caused by the first water discharge device 71 closer to the mesh structure 60 can be increased, and the cooling of the mesh structure 60 can be carried out efficiently.

[0158] It is also possible to drain the water in the water tank 20 and supply low-temperature water to the water tank 20 again. When draining the water in the water tank 20, although not shown, it can be drained by so-called overflow of draining water through a pipe or the like provided at the upper part of the water tank 20.

[0159] The manufacturing method of the second net-like structure of the present invention is characterized in that the manufacturing method of the second net-like structure has: a step of extruding molten thermoplastic resin into a thread; a step of conveying a net-like structure having a thread-like resin in a water tank by a first conveying device and a second conveying device; and a step of discharging water in a direction other than the direction toward the net-like structure between the first conveying device and the second conveying device by a water discharging device.

[0160] Heat the thermoplastic resin, which is the material of the net-like structure, to melt it and extrude the resin in the form of a thread. In order to make the resin into a thread, it is sufficient to extrude the molten thermoplastic resin from a nozzle having an ejection hole or the like.

[0161] Accommodate the extruded thread-like resin in a water tank filled with water. The linear resin forms a random loop by landing on the water surface in the water tank and bending. The random loops are in contact with adjacent random loops in a molten state, thereby forming a structure in which the random loops are joined to each other in three-dimensional directions. At the same time, the structure is fixed by being cooled by water. Thus, a net-like structure is formed.

[0162] Convey the net-like structure in the water tank by a first conveying device and a second conveying device. Preferably, the conveying member conveys the net-like structure downward from the water surface in the water tank. By conveying the net-like structure by the conveying member in this way, the extruded thread-like resin is continuously formed into a sheet-like net-like structure, and a net-like structure of an appropriate size for an elastic pad material for bedding or an elastic pad material for a seat can be manufactured. As the conveying member, for example, the above-described conveyor or the like can be used as the conveying device.

[0163] Discharge water in the water in the water tank by a water discharging device. The water discharging direction of the water discharging device is a direction other than the direction toward the net-like structure between the first conveying device and the second conveying device. Thus, by discharging water in the water, convection is generated in the water in the water tank, and the water that has become high temperature near the water surface moves to supply low-temperature water. Thereby, the net-like structure is efficiently cooled, and not only can the surface portion of the thread-like resin be sufficiently cooled, but also the inside can be sufficiently cooled, and uneven cooling is not likely to occur, and a net-like structure having high durability can be manufactured.

[0164] The net-like structure body can be manufactured by lifting the cooled net-like structure body from the water tank and drying it. Preferably, before and after drying the net-like structure body, a "pseudo-crystallization treatment" of heating for a certain period of time at a temperature lower than the melting point of the resin used for the material of the net-like structure body is performed. By subjecting the linear resin to the pseudo-crystallization treatment, the durability of the net-like structure body can be improved. It is considered that through the pseudo-crystallization treatment, the hard segments of the resin are rearranged by heating to form a metastable mesophase, and crosslinking points like pseudo-crystallization are formed, thereby improving the durability such as heat resistance and sag resistance of the net-like structure body.

[0165] As described above, the second net-like structure body manufacturing apparatus of the present invention is characterized in that the second net-like structure body manufacturing apparatus includes: a nozzle having a discharge hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying the net-like structure body having the linear resin; and a water discharge device provided in the water tank for discharging water in a predetermined direction. The conveying device is at least composed of a first conveying device and a second conveying device. There is a net-like structure body between the first conveying device and the second conveying device, and the net-like structure body between the conveying devices does not exist on the extension line of the water discharge direction of the water discharge device. By adopting such a structure, a manufacturing apparatus for manufacturing a net-like structure body can be provided, in which the surface portion and the inside of the net-like structure body are easily cooled uniformly due to the convection of the water in the water tank, the net-like structure body is not likely to generate uneven cooling in the thickness direction, and has sufficient durability.

[0166] The third net-like structure body manufacturing apparatus of the present invention will be described below.

[0167] The third net-like structure body manufacturing apparatus of the present invention is characterized in that the third net-like structure body manufacturing apparatus includes: a nozzle having a discharge hole for extruding molten thermoplastic resin into a line; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying the net-like structure body having the linear resin; and a drain port provided at the bottom of the water tank.

[0168] The net-like structure body of the present invention is a structure body having the following three-dimensional random ring joint structure: the linear resin containing thermoplastic resin is bent to form random rings, and the rings are joined in a molten state with each other.

[0169] Figures 4 to 6 It is a side view of the third net-like structure body manufacturing apparatus in the embodiment of the present invention. The net-like structure body manufacturing apparatus 1 has a nozzle 10, a water tank 20, a conveying device 30, and a drain port 80.

[0170] The nozzle 10 has ejection holes 11 for extruding the molten thermoplastic resin into a line. That is, by extruding the thermoplastic resin melted by heating from the ejection holes 11 of the nozzle 10, a linear resin 12 is formed.

[0171] The number of ejection holes 11 of the nozzle 10 can be one or more. When the nozzle 10 has a plurality of ejection holes 11, the plurality of ejection holes 11 can be arranged in a single row, but are preferably arranged in multiple rows. By having a plurality of ejection holes 11 in the nozzle 10, a plurality of linear resins 12 can be formed simultaneously, and the production efficiency of the net-like structure can be improved. The number of ejection holes 11 of the nozzle 10 can be adjusted accordingly according to the hardness and cushioning properties of the net-like structure 60 to be manufactured.

[0172] The cross-sectional shape of the outlet of the ejection hole 11 is not particularly limited, and examples thereof include a circular shape, an elliptical shape, a polygonal shape, etc. Among them, the cross-sectional shape of the outlet of the ejection hole 11 is preferably a circular shape or an elliptical shape. By configuring the ejection hole 11 in this way, the cross-sectional shape of the linear resin 12 extruded from the ejection hole 11 also becomes a circular shape or an elliptical shape. Therefore, when forming the above three-dimensional random loop joint structure, the contact area between the linear resins 12 can be increased, and a net-like structure 60 with high elasticity and durability can be manufactured.

[0173] In addition, the cross-sectional shape of the linear resin 12 extruded from the ejection hole 11 can be solid or hollow. In order to make the cross-sectional shape of the linear resin 12 hollow, for example, a structure having a mandrel such as a core bone portion inside the ejection hole 11 is sufficient. Specifically, for the cross-sectional shape of the outlet of the ejection hole 11, examples include a so-called C-type nozzle in which the inside and outside of the ejection hole 11 are partially communicated, and a so-called three-point bridge-shaped nozzle in which a bridge portion is provided in the ejection hole 11 to divide the ejection hole 11 in the circumferential direction.

[0174] The length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 is preferably 0.1 mm or more, more preferably 0.5 mm or more, and still more preferably 1.0 mm or more. By setting the lower limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 in this way, the durability of the net-like structure 60 can be improved, and a net-like structure 60 that can withstand repeated compression can be manufactured. In addition, the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 is preferably 10 mm or less, more preferably 7 mm or less, and still more preferably 5 mm or less. By setting the upper limit value of the length in the major axis direction of the cross-sectional shape of the outlet of the ejection hole 11 in this way, a net-like structure 60 with good cushioning properties can be manufactured.

[0175] In the case where the nozzle 10 has a plurality of ejection holes 11, the sizes of the cross-sectional shapes of the outlets of the respective ejection holes 11 may be the same or different. If the sizes of the cross-sectional shapes of the outlets of all the ejection holes 11 of the nozzle 10 are the same, a reticular structure 60 with a uniform thickness of the linear resin 12 can be formed. Further, for example, when the size of the cross-sectional shape of the outlet of the ejection hole 11 in the central portion of the nozzle 10 is smaller than the size of the cross-sectional shape of the outlet of the ejection hole 11 in the outer peripheral portion of the nozzle 10, the linear resin 12 inside the reticular structure 60 is thinner than the linear resin 12 on the surface portion of the reticular structure 60. Therefore, the temperature inside the reticular structure 60 becomes easier to drop than that of the surface portion, and a reticular structure 60 having a structure less likely to cause uneven cooling can be manufactured.

[0176] Examples of the thermoplastic resin extruded from the ejection hole 11 include polyester-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, ethylene-vinyl acetate copolymers, and the like. Among them, the thermoplastic resin preferably contains at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer. By the thermoplastic resin containing at least any one of a polyester-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, and a polystyrene-based thermoplastic elastomer, the processability is improved, and the reticular structure 60 is easily manufactured. Further, the thermoplastic resin more preferably contains a polyester-based thermoplastic elastomer. By the thermoplastic resin containing a polyester-based thermoplastic elastomer, the repeated compression residual strain can be made smaller and the hardness retention rate after repeated compression can be made larger, and a reticular structure 60 with higher durability can be manufactured.

[0177] The water tank 20 is disposed below the nozzle 10 and is configured to receive the linear resin 12 extruded from the ejection holes 11 of the nozzle 10. The water tank 20 has water for cooling the linear resin 12 extruded from the ejection holes 11 of the nozzle 10. The linear resin 12 extruded from the ejection holes 11 of the nozzle 10 forms a random loop by landing on the water surface in the water tank 20 and bending. The random loops are in contact with adjacent random loops in a molten state, thereby forming a structure in which the random loops are joined to each other in three-dimensional directions, and at the same time, the structure is fixed by being cooled by water. Thus, the reticular structure 60 is obtained.

[0178] The conveying device 30 is provided in the water tank 20 and is configured to convey the reticular structure 60 having the linear resin 12. That is, the conveying device 30 conveys in the water tank 20 the reticular structure 60 having the linear resin 12 extruded from the ejection holes 11 of the nozzle 10 and received in the water tank 20. The conveying device 30 preferably conveys the reticular structure 60 from the water surface of the water tank 20 toward the bottom of the water tank 20. Further, the conveying device 30 is preferably provided in the water tank 20.

[0179] The type of the conveying device 30 is not particularly limited. For example, conveyors such as belt conveyors, mesh conveyors, and plate conveyors can be cited. The detailed content of the conveying device 30 will be described later.

[0180] The drain port 80 is provided at the bottom of the water tank 20 for discharging the water in the water tank 20. By providing the drain port 80 for discharging water at the bottom of the water tank 20, it is possible to discharge the water near the mesh structure 60 that is likely to become high temperature in the water tank 20, especially the water inside the mesh structure 60. By discharging the water that has become high temperature in the water tank 20, the water temperature of the entire water tank 20 can be prevented from rising. In addition, by discharging the water inside the mesh structure 60 that is likely to cause uneven cooling, a large temperature difference is less likely to occur between the surface part and the inside of the mesh structure 60, and both the surface part and the inside of the mesh structure 60 can be cooled evenly, and uneven cooling is less likely to occur. Since uneven cooling is less likely to occur, in the manufacture of the mesh structure 60, an increase in repeated compressive residual strain caused by insufficient cooling and a decrease in the hardness retention rate after repeated compression can be prevented, and a mesh structure 60 with high durability can be manufactured.

[0181] Preferably, after discharging the water in the water tank 20 from the drain port 80 at the bottom of the water tank 20, water having a temperature lower than the water temperature of the discharged water is re-supplied. For the supply of low-temperature water, a water supply pipe or the like may be provided in the water tank 20, and low-temperature water may be put into the water tank from the water supply pipe, which is not shown in the figure. By configuring the mesh structure manufacturing apparatus 1 in this way, after discharging the high-temperature water in the water tank 20 and then supplying low-temperature water, the water temperature of the entire water tank 20 can be prevented from rising. In addition, since water is re-supplied to the water tank 20 after drainage, the water level in the water tank 20 can be prevented from becoming too low.

[0182] Preferably, in the water tank 20, a partition plate 81 is provided around the drain port 80. The drain port 80 has a partition plate 81 around its inner side surface in the water tank 20, whereby the water in the vertical upper part of the drain port 80 can be preferentially discharged, and the discharge of water can be adjusted.

[0183] The partition plate 81 may be provided on a part of the periphery of the drain port 80, but is preferably provided on the entire periphery of the drain port 80. By providing the partition plate 81 around the entire circumference of the drain port 80, it is easier to adjust the discharge of the water in the water tank 20 by the drain port 80.

[0184] Examples of the shape of the drain port 80 as viewed from a direction perpendicular to the water surface of the water tank 20 include a circle, an ellipse, a polygon, etc. Among them, the shape of the drain port 80 is preferably rectangular. By making the shape of the drain port 80 rectangular, the water near the linear resin 12 can be efficiently discharged, and by supplying water at a temperature lower than the temperature of the drained water to the vicinity of the linear resin 12, it becomes easy to uniformly cool the surface portion and the inside of the linear resin 12.

[0185] Although not shown, preferably, the net-like structure manufacturing apparatus 1 has a heat exchanger for cooling the water discharged from the drain port 80 and circulates the water. By configuring the net-like structure manufacturing apparatus 1 in this way, it is possible to reduce the amount of water discarded in the manufacture of the net-like structure 60 by reusing the discharged water, and it is possible to conserve water resources.

[0186] The upper end portion of the conveying device 30 is preferably positioned above the water surface of the water tank 20. By arranging the conveying device 30 in this way, when the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 comes into contact with the water in the water tank 20, it is possible to prevent the linear resin 12 from freely moving on the water surface, and it is possible to prevent the thickness of the net-like structure 60 from becoming too large.

[0187] Preferably, the conveying device 30 includes a conveyor belt 33 and a driving roller 34. Examples of the conveyor belt 33 include a mesh conveyor belt formed by continuously incorporating or weaving a flat belt made of rubber or resin or a metal lead into a grid shape, or a plate conveyor belt in which metal plates are continuously mounted on a conveyor chain.

[0188] Among them, from the viewpoints of good holding performance and excellent water permeability, the conveyor belt 33 is preferably a mesh conveyor belt. That is, the conveying device 30 is preferably a mesh conveyor conveying device having a grid-shaped belt and a driving roller 34. By configuring the conveying device 30 in this way, water can pass through the conveying device 30. Therefore, the conveying device 30 is less likely to interfere with the discharge of the water in the water tank 20 caused by the drain port 80 and the movement of the water accompanying the discharge of the water, and the cooling efficiency of the net-like structure 60 can be improved.

[0189] The conveyor belt 33 is preferably annular. By configuring the conveyor belt 33 to be annular, the annular conveyor belt 33 is continuously rotated by the rotation of the driving roller 34, and the conveying device 30 can be continuously operated. As a result, the conveyance of the net-like structure 60 can be efficiently performed.

[0190] There are a plurality of drive rollers 34, preferably disposed at the upper and lower parts inside the annular conveyor belt 33 respectively. That is, preferably, an upper drive roller 34a is disposed at the upper part inside the conveyor belt 33, and a lower drive roller 34b is disposed at the lower part inside the conveyor belt 33. By configuring the drive rollers 34 in this way, the conveyor belt 33 is not easily deflected, and the following situation can be prevented: under the rotation of the drive rollers 34, the conveyor belt 33 idles, causing malfunction of the conveying device 30.

[0191] Preferably, the conveying device 30 is at least composed of a first conveying device 31 and a second conveying device 32, and there is a mesh structure 60 between the first conveying device 31 and the second conveying device 32. By configuring the conveying device 30 in this way, the mesh structure 60 can be conveyed by the first conveying device 31 and the second conveying device 32 while sandwiching the mesh structure 60. Therefore, a mesh structure 60 with a neat surface and a constant thickness can be manufactured.

[0192] The distance between the lower drive roller 34b of the first conveying device 31 and the lower drive roller 34b of the second conveying device 32 is preferably less than the distance between the upper drive roller 34a of the first conveying device 31 and the upper drive roller 34a of the second conveying device 32. That is, preferably, the distance between the first conveying device 31 and the second conveying device 32 at the lower part is less than the distance between the first conveying device 31 and the second conveying device 32 at the upper part, and the distance between the first conveying device 31 and the second conveying device 32 becomes narrower as it goes downward. By configuring the conveying device 30 in this way, the mesh structure 60 can be clamped at the lower part of the conveying device 30. As a result, the mesh structure 60 can be easily introduced into the water tank 20, and the cooling of the mesh structure 60 is facilitated.

[0193] Preferably, as Figure 4 shown, the conveying device 30 is at least composed of a first conveying device 31 and a second conveying device 32, and a drain port 80 is provided at a position including an intersection point P2, which is the intersection point of a perpendicular line L1 drawn from the midpoint P1 between the first conveying device 31 and the second conveying device 32 to the bottom of the water tank 20 and the bottom of the water tank 20. The water near the water surface where the linear resin 12 extruded from the ejection hole 11 of the nozzle 10 contacts the water in the water tank 20 reaches the highest temperature, and in addition, the temperature of the water vertically below the water surface where the extruded linear resin 12 contacts the water also tends to increase. Therefore, by providing the drain port 80 at such a position, the water that becomes high temperature near the water surface where the extruded linear resin 12 contacts the water and below this part in the vertical direction can be preferentially discharged, and the linear resin 12 and the mesh structure 60 can be efficiently cooled.

[0194] Preferably, the mesh structure manufacturing apparatus 1 includes a mesh structure traction device 50 that traction the mesh structure 60 and lifts it from the water tank 20. By having the mesh structure traction device 50 in the mesh structure manufacturing apparatus 1, the mesh structure 60 can be automatically lifted from the water tank 20 after cooling and transferred to the drying process of the mesh structure 60, thereby improving the productivity of the mesh structure 60.

[0195] It is also preferable that, as Figure 5 shown, a mesh structure traction device 50 for traction the mesh structure 60 is provided on one side of the water tank 20. The conveying device 30 is at least composed of a first conveying device 31 and a second conveying device 32. The first conveying device 31 is arranged at a position closer to the mesh structure traction device 50 than the second conveying device 32, and a drain port 80 is provided at a position closer to the mesh structure traction device 50 than the first conveying device 31. The drain port 80 being provided at a position closer to the mesh structure traction device 50 than the first conveying device 31 means that the end of the drain port 80 on the side opposite to the mesh structure traction device 50 is arranged at a position closer to the mesh structure traction device 50 than the end of the first conveying device 31 on the side opposite to the mesh structure traction device 50. When the mesh structure 60 is tractioned by the mesh structure traction device 50, there is a tendency that the water whose temperature has risen due to cooling the mesh structure 60 also moves along with the mesh structure 60 to the side of the water tank 20 where the mesh structure traction device 50 is located. Therefore, by arranging the drain port 80 at such a position, the water whose temperature has risen in the water tank 20 can be efficiently discharged, and the cooling efficiency of the mesh structure 60 can be improved.

[0196] In addition, it is also preferable that, as Figure 6As shown, on one side of the water tank 20, there is a mesh structure traction device 50 for traction of the strip-shaped resin 12. The conveying device 30 is at least composed of a first conveying device 31 and a second conveying device 32. The first conveying device 31 is arranged at a position closer to the mesh structure traction device 50 than the second conveying device 32, and the drain port 80 is arranged at a position on the side opposite to the mesh structure traction device 50 with respect to the second conveying device 32. That the drain port 80 is arranged at a position on the side opposite to the mesh structure traction device 50 with respect to the second conveying device 32 means that the end of the drain port 80 on the side closer to the mesh structure traction device 50 is arranged at a position on the side opposite to the mesh structure traction device 50 with respect to the end of the second conveying device 32 on the side closer to the mesh structure traction device 50. Depending on the material, wire diameter, density, etc. of the strip-shaped resin 12, sometimes there will be adverse effects such as deformation or damage of the mesh structure 60 caused by the water flow generated by the water discharged from the drain port 80. Therefore, by arranging the drain port 80 at such a position, the influence on the mesh structure 60 is reduced, and the water with an elevated temperature in the water tank 20 is discharged, enabling efficient cooling of the mesh structure 60.

[0197] The number of drain ports 80 can be one or multiple. If the number of drain ports 80 is one, the water above the drain port 80 in the vertical direction can be preferentially discharged. Additionally, if the number of drain ports 80 is multiple, water can be discharged at multiple parts in the water tank 20. In the case where the capacity of the water tank 20 is small and the temperature of the water in the water tank 20 is likely to rise, the high-temperature water in the water tank 20 can be quickly replaced with the newly supplied low-temperature water.

[0198] In Figures 4 to 6 , the front side of the paper surface is referred to as the near side, and the back side of the paper surface is referred to as the depth side. The length from the near-side end to the depth-side end of the drain port 80 is preferably greater than the length from the near-side end to the depth-side end of the conveying device 30. By setting the size of the drain port 80 in this way, the water inside the mesh structure 60 in the water tank 20 that has become high temperature can be sufficiently discharged, thereby preventing the overall water temperature in the water tank 20 from rising and improving the cooling efficiency of the mesh structure 60.

[0199] In Figures 4 to 6In this case, the side where the first conveying device 31 is arranged is referred to as one side, and the opposite side of the side where the second conveying device 32 is arranged is referred to as the other side. The length from one end portion of the drain port 80 to the other end portion is preferably greater than the length from the first conveying device 31 to the second conveying device 32. By the mesh structure 60 coming into contact with the conveying device 30, the temperature of a part of the conveying device 30 in contact with the mesh structure 60 rises, and the temperature of the water near this part of the conveying device 30 also rises. That is to say, the heat of the mesh structure 60 moves to the water that is not in direct contact with the mesh structure 60 via the conveying device 30. By setting the size of the drain port 80 in this way, not only can the water inside the mesh structure 60 in the water tank 20 be drained, but also the water near a part of the conveying device 30 whose temperature has risen due to contact with the mesh structure 60 can be drained. Therefore, the overall water temperature in the water tank 20 is prevented from rising, and the cooling of the mesh structure 60 can be efficiently performed.

[0200] Preferably, the mesh structure manufacturing device 1 has a drainage volume adjusting member 82 for adjusting the drainage volume from the drain port 80. By the mesh structure manufacturing device 1 having the drainage volume adjusting member 82, the amount of water discharged from the drain port 80 and the amount of water supplied to the water tank 20 can be balanced. Specifically, for example, when the amount of water discharged from the drain port 80 is excessive compared to the amount of water supplied to the water tank 20, the drainage volume adjusting member 82 is used to reduce the drainage volume to prevent the water level in the water tank 20 from becoming too low. Additionally, for example, when the amount of water discharged from the drain port 80 is too small compared to the amount of water supplied to the water tank 20, the drainage volume adjusting member 82 is used to increase the drainage volume to prevent water from overflowing from the water tank 20. As the drainage volume adjusting member 82, for example, a valve, a sliding opening / closing lid, a pump, etc. can be used.

[0201] Preferably, when the amount of resin extruded from the nozzle 10 increases, the drainage volume adjusting member 82 increases the drainage volume from the drain port 80. That is to say, preferably, the drainage volume (m 3 / min) and the extrusion amount (g / min) of the resin from the nozzle 10. For example, if the amount of the linear resin 12 extruded from the nozzle 10 is increased in order to improve the resilience of the mesh structure 60, the temperature near the water surface of the water tank 20 is likely to become higher, and thus the cooling efficiency of the mesh structure 60 is deteriorated. In addition, when the amount of the linear resin 12 extruded from the nozzle 10 is increased, the inside of the mesh structure 60 is difficult to be cooled, and uneven cooling is likely to occur in the thickness direction of the mesh structure 60. Therefore, by increasing the amount of water discharged from the drain port 80 as the linear resin 12 extruded from the nozzle 10 increases, the water that has reached a high temperature is quickly discharged from the water tank 20, and the water temperature of the entire water tank 20 is prevented from rising, thereby improving the cooling efficiency of the mesh structure 60 and preventing uneven cooling.

[0202] More preferably, the amount of water discharged from the water outlet 80 regulated by the water discharge regulating member 82 (m 3 / min) is proportional to the amount of resin extruded from the nozzle 10 (g / min). By making the amount of drainage from the drainage port 80 and the amount of resin extruded from the nozzle 10 in such a relationship, the cooling efficiency of the mesh structure 60 can be further improved, and uneven cooling is less likely to occur.

[0203] It is also preferable that the drainage amount adjusting member 82 increases the drainage amount from the drainage port 80 when the speed of the conveying device 30 increases. That is, it is preferable that the drainage amount (m 3 / min) and the conveying speed of the mesh structure 60 based on the conveying device 30. If the speed of the conveying device 30 is increased for the purpose of reducing the density of the mesh structure 60 in order to reduce the hardness of the mesh structure 60, the mesh structure 60 is not sufficiently cooled when the next step is transferred. If the mesh structure 60 is not sufficiently cooled when the next step is transferred, the mesh structure 60 may have a large residual strain of repeated compression inside the mesh structure 60, a small hardness retention rate after repeated compression, and poor durability. Therefore, by increasing the amount of water discharged from the drain port 80 as the speed of the conveying device 30 increases, the water in the water tank 20 that has become high temperature is quickly discharged from the water tank 20, so that the water temperature in the water tank 20 as a whole is prevented from rising, and the cooling efficiency of the mesh structure 60 is improved, so that not only the surface of the mesh structure 60 but also the inside can be fully cooled.

[0204] More preferably, the amount of water discharged from the water outlet 80 regulated by the water discharge regulating member 82 (m 3(m / min) is proportional to the speed of the conveying device 30 (m / min). By making the drainage volume from the drain port 80 and the speed of the conveying device 30 in such a relationship, the cooling efficiency of the mesh structure 60 can be further improved, and the occurrence of uneven cooling can be prevented.

[0205] In addition, more preferably, when the amount of resin extruded from the nozzle 10 increases, the drainage volume from the drain port 80 adjusted by the drainage volume adjusting member 82 increases, and when the speed of the conveying device 30 becomes larger, the drainage volume from the drain port 80 adjusted by the drainage volume adjusting member 82 increases. That is to say, more preferably, the drainage volume (m 3 / min) is proportional to both the extrusion amount (g / min) of the resin from the nozzle 10 and the speed of the conveying device 30 (m / min). By setting the drainage volume (m 3 / min) in this way, for example, even if the amount of the linear resin 12 extruded from the nozzle 10 is increased and the speed of the conveying device 30 is increased for the purpose of improving the productivity of the mesh structure 60, etc., the temperature rise of the entire water in the water tank 20 can be prevented by increasing the discharge speed of the water that becomes high temperature in the water tank 20. Therefore, the mesh structure 60 can be sufficiently cooled, and uneven cooling in the thickness direction of the mesh structure 60 can be less likely to occur.

[0206] In addition to the drain port 80 provided at the bottom of the water tank 20, a drainage member may also be provided. As other drainage members of the drain port 80, although not shown, there may be mentioned so-called overflow members that discharge water from a pipe provided at the upper part of the water tank 20, etc.

[0207] The manufacturing method of the third mesh structure of the present invention is characterized in that the manufacturing method of the third mesh structure has: a step of extruding a molten thermoplastic resin into a line; a step of conveying a mesh structure having a linear resin in a water tank by a conveying member; a step of discharging the water in the water tank from a drain port provided at the bottom of the water tank; and a step of supplying water having a temperature lower than the temperature of the water discharged from the drain port to the water tank.

[0208] The thermoplastic resin as the material of the mesh structure is heated to be melted, and the resin is extruded in the form of a line. In order to make the resin into a line, it is sufficient to extrude the molten thermoplastic resin from a nozzle having a discharge hole, etc.

[0209] The extruded linear resin is stored in a water tank filled with water. The linear resin forms a random loop by landing on the water surface in the water tank and bending. The random loops are in contact with adjacent random loops in a molten state, thereby forming a structure in which the random loops are joined to each other in three-dimensional directions, and at the same time, the structure is fixed by being cooled by water, and at this time, a mesh structure is formed.

[0210] Use a conveying member to convey the net-shaped structure in the water tank. Preferably, the conveying member conveys the net-shaped structure downward from the water surface in the water tank. By conveying the net-shaped structure in this way using the conveying member, the extruded linear resin is continuously formed into a sheet-like net-shaped structure, and a net-shaped structure of appropriate size for an elastic cushion material for bedding or an elastic cushion material for a seat can be manufactured. As the conveying member, for example, a conveying device such as the above-described conveyor can be used.

[0211] Drain the water in the water tank from a drain port provided at the bottom of the water tank. By draining the water in the water tank whose temperature has risen due to the extruded linear resin from the drain port, the temperature rise of the entire water tank is prevented, and the cooling efficiency of the net-shaped structure is not reduced.

[0212] Supply water to the water tank whose temperature is lower than the temperature of the water discharged from the drain port. By supplying low-temperature water into the water tank, the temperature of the entire water tank is lowered. As a result, the net-shaped structure is efficiently cooled, and not only the surface portion of the net-shaped structure can be sufficiently cooled, but also the inside can be sufficiently cooled, and cooling unevenness is less likely to occur, and a net-shaped structure with high durability can be manufactured.

[0213] Preferably, use a heat exchanger to cool the water discharged from the drain port, and then supply it to the water tank for circulation. By reducing the temperature of the water discharged from the drain port, circulating and reusing the discharged water, the amount of water discarded in the manufacture of the net-shaped structure can be reduced, and water resources can be protected.

[0214] By lifting the cooled net-shaped structure from the water tank and drying it, a net-shaped structure can be manufactured. Preferably, before and after drying the net-shaped structure, a so-called pseudo-crystallization treatment is performed in which heating is performed at a temperature lower than the melting point of the resin used for the material of the linear resin for a certain period of time. By performing the pseudo-crystallization treatment on the linear resin, the durability of the net-shaped structure can be improved. It is considered that through the pseudo-crystallization treatment, the hard segments of the resin are rearranged by heating to form a metastable intermediate phase, and crosslinks like pseudo-crystallization are formed, improving the durability such as heat resistance and sag resistance of the net-shaped structure.

[0215] As described above, the third net-like structure manufacturing apparatus of the present invention is characterized in that the third net-like structure manufacturing apparatus includes: a nozzle having ejection holes for ejecting a molten thermoplastic resin in the form of a thread; a water tank disposed below the nozzle; a conveying device provided in the water tank for conveying a net-like structure having a thread-like resin; and a drain port provided at the bottom of the water tank. With such a structure, it is possible to discharge the water that has become hot near the net-like structure in the water tank, particularly inside the net-like structure, from the drain port provided at the bottom of the water tank, and it is possible to prevent the water temperature inside the entire water tank from rising. As a result, it is easy to uniformly cool the surface portion and the inside of the net-like structure, and it is possible to manufacture a net-like structure that is less likely to have uneven cooling in the thickness direction of the net-like structure and has sufficient durability.

[0216] This application claims priority based on Japanese Patent Application No. 2018-063111, Japanese Patent Application No. 2018-063112, and Japanese Patent Application No. 2018-063113, which were filed on March 28, 2018. The entire contents of the specifications of Japanese Patent Application No. 2018-063111, Japanese Patent Application No. 2018-063112, and Japanese Patent Application No. 2018-063113, which were filed on March 28, 2018, are incorporated herein by reference.

[0217] Explanation of reference numerals

[0218] 1. Net-like structure manufacturing apparatus; 10. Nozzle; 11. Ejection holes; 12. Thread-like resin; 20. Water tank; 30. Conveying device; 31. First conveying device; 32. Second conveying device; 33. Conveyor belt; 34. Driving roller; 34a. Upper driving roller; 34b. Lower driving roller; 40. Gas discharging device; 41. First gas discharging device; 42. Second gas discharging device; 43. Gas discharging holes; 50. Net-like structure pulling device; 60. Net-like structure; 70. Water discharging device; 71. First water discharging device; 72. Second water discharging device; 73. Water discharging holes; 80. Drain port; 81. Partition plate; 82. Drainage amount adjusting member; P1. Midpoint between the first conveying device and the second conveying device; L1. Perpendicular line drawn from the midpoint P1 to the bottom of the water tank; P2. Intersection point between L1 and the bottom of the water tank; p1. Vertical plane including the midpoint P1; D1. Distance between the water discharging holes and the water surface of the water tank.

Claims

1. A device for manufacturing a net-like structure, wherein, The device for manufacturing a net-like structure includes: A nozzle having ejection holes for ejecting molten thermoplastic resin into linear resin; A water tank disposed below the nozzle; A conveying device provided in the water tank for conveying the net-like structure having the linear resin; and A water discharging device provided in the water tank for discharging water in a predetermined direction, The conveying device is at least composed of a first conveying device and a second conveying device, There is the net-like structure between the first conveying device and the second conveying device, The net-like structure between the conveying devices does not exist on the extension line of the water discharging direction of the water discharging device, The water discharging direction of the water discharging device faces the water surface of the water tank, and the water discharging direction of the water discharging device is biased toward the side of the net-like structure between the first conveying device and the second conveying device compared with the vertical direction.

2. The device for manufacturing a net-like structure according to claim 1, wherein, The water discharging device has ejection holes for discharging water, The ejection holes are disposed at a position 0.1 mm or more and 400 mm or less below the water surface of the water tank.

3. The device for manufacturing a net-like structure according to claim 1, wherein, The water discharging device is disposed inside the conveying device.

4. The device for manufacturing a net-like structure according to claim 1, wherein, The conveying device has a mesh belt and a driving roller.

5. The device for manufacturing a net-like structure according to claim 4, wherein, The driving roller is at least composed of an upper driving roller and a lower driving roller, The upper driving roller is disposed above the inside of the conveying device, and the lower driving roller is disposed below the inside of the conveying device, The direction of the water discharged by the water discharging device is the direction toward the upper driving roller.

6. The device for manufacturing a net-like structure according to claim 1, wherein, When the amount of resin extruded from the nozzle increases, the amount of water discharged by the water discharging device increases.

7. The device for manufacturing a net-like structure according to claim 1, wherein, When the speed of the conveying device becomes larger, the amount of water discharged by the water discharging device increases.

8. The device for manufacturing a net-like structure according to claim 1, wherein, The direction of the water discharged by the water discharging device is linked with the amount of resin extruded from the nozzle.

9. The device for manufacturing a net-like structure according to claim 1, wherein, The direction of the water discharged by the water discharging device is linked with the speed of the conveying device.

10. The device for manufacturing a net-like structure according to claim 1, wherein, The water discharging device has ejection holes for discharging water, The position of the ejection holes from the water surface of the water tank is linked with the amount of resin extruded from the nozzle.

11. The device for manufacturing a net-like structure according to claim 1, wherein, The water discharging device has ejection holes for discharging water, The position of the ejection holes from the water surface of the water tank is linked with the speed of the conveying device.

12. A method for manufacturing a net-like structure, characterized in that, The method for manufacturing a net-like structure has: A step of extruding the molten thermoplastic resin into a linear resin; A step of conveying a net-like structure having the linear resin in a water tank by a first conveying device and a second conveying device; and A step of discharging water in a direction other than the direction toward the net-like structure between the first conveying device and the second conveying device by a water discharging device, wherein the water discharging direction of the water discharging device faces the water surface of the water tank, and the water discharging direction of the water discharging device is deflected toward the net-like structure side between the first conveying device and the second conveying device more than the vertical direction.

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