Method for manufacturing a cushion

Abstract

To provide a method capable of easily manufacturing a cushion formed of filament three-dimensional conjugate by adequately smoothing a lateral face that is a cut surface and forming into a desired shape.SOLUTION: A method for manufacturing a cushion that supports a user in a thickness direction by using a substantially tabular filament three-dimensional conjugate in which a plurality of filaments made from thermoplastic resin are partially fused. The manufacturing method includes a compression treatment for compressing and deforming a lateral face of the filament three-dimensional conjugate by compressing the lateral face with air-permeable pressurization member in a direction including a vertical direction component with respect to the thickness direction, and a heat treatment for heating the compressed and deformed lateral face by feeding a heat medium toward the compressed and deformed lateral face from outside of the air-permeable pressurization member.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a cushion using a filament three-dimensional assembly.

Background Art

[0002] In recent years, a filament three-dimensional assembly cushion obtained by three-dimensionally fusion-bonding filaments made of a thermoplastic resin has attracted attention. Since it is easy to make the porosity of the filament three-dimensional assembly cushion 90% or more, it has excellent breathability, is less likely to get stuffy, and can be washed with water.

[0003] As a method for manufacturing such a filament three-dimensional assembly (three-dimensional network structure), for example, in Patent Document 1, a plurality of molten filaments (molten thermoplastic resin) having a diameter of around 1 mm discharged from a plurality of nozzles arranged vertically downward are dropped into cooling water, and while forming a loop of the molten filaments by the buoyancy of water, the contact points between the molten filaments generated by the bending during loop formation are fusion-bonded to manufacture a filament three-dimensional assembly (three-dimensional network structure). The obtained filament three-dimensional assembly can be used as a cushion such as a pillow or a cushion by cutting it to a desired size using a saw cutter or the like.

[0004] Further, Patent Document 2 describes a method of changing the thickness of a filament three-dimensional assembly (three-dimensional structure) by heating the filament three-dimensional assembly (three-dimensional structure) while compressing it in the thickness direction with a female mold and a male mold and then cooling it.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, when cutting the filament three-dimensional aggregate, problems such as the exposed cut ends of the filaments on the side surface which is the cut surface occur. Therefore, it is desirable to smooth the cut surface. Also, there may be cases where the side surface of the filament three-dimensional aggregate is shaped as desired, such as being curved, so that it can be used better as a cushion.

[0007] However, in order to smooth and curve the side surface which is the cut surface of the filament three-dimensional aggregate, if a method of compressing and heating the filament three-dimensional aggregate in the thickness direction using a female mold and a male mold is adopted, a part near the cut surface of the filament three-dimensional aggregate is compressed and hardened (burrs) while being sandwiched between the female mold and the male mold, and there are problems such as a space being formed near the contact point between the female mold and the male mold, making it difficult to form a smooth end surface.

[0008] In view of the above problems, an object of the present invention is to provide a manufacturing method capable of easily manufacturing a cushion composed of a filament three-dimensional aggregate in which the side surface which is the cut surface is more appropriately smoothed and shaped as desired.

Means for Solving the Problems

[0009] A method for manufacturing a cushion according to the present invention is a method for manufacturing a cushion that supports a user in the thickness direction using a substantially plate-shaped filament three-dimensional aggregate in which a plurality of filaments made of a thermoplastic resin are partially fused. The method includes a compression process of compressing and deforming the side surface of the filament three-dimensional aggregate by compressing the side surface with a ventilation pressurizing member in a direction including a direction component perpendicular to the thickness direction, and a heating process of supplying a heat medium from the outside of the ventilation pressurizing member toward the compressed and deformed side surface to heat the compressed and deformed side surface.

[0010] According to this manufacturing method, it becomes possible to easily manufacture a cushion made of a filament three-dimensional conjugate having a desired shape while more appropriately smoothing the side surface which is the cut surface. Here, the "side surface" refers to the side surface exposed in the direction orthogonal to the thickness direction of the filament three-dimensional conjugate which is substantially plate-shaped.

[0011] More specifically as the above manufacturing method, the heat treatment may be a manufacturing method which is a process of supplying the heat medium, which is at a temperature equal to or higher than the softening temperature at which plastic deformation of the raw material occurs and equal to or lower than the melting point of the raw material, to the side surface subjected to the compression deformation. Further more specifically as the manufacturing method, the temperature of the heat medium may be in the range from 30°C lower than the melting point of the raw material to 5°C lower than the melting point.

[0012] More specifically as the above manufacturing method, the heat treatment may be a manufacturing method of supplying the heat medium toward the side surface subjected to the compression deformation while supplying a cooling medium toward the filament three-dimensional conjugate excluding the vicinity of the side surface subjected to the compression deformation. Further more specifically as the manufacturing method, the heat medium may be hot air or steam.

[0013] More specifically as the above manufacturing method, the ventilation pressurizing member is formed of a metal plate provided with a plurality of ventilation holes, and it is a manufacturing method of supplying the heat medium to the side surface through the ventilation holes, and the inner diameter of each of the plurality of holes is 0.2 mm or more and 5 mm or less, and the thickness of the metal plate is 1 mm or more and 5 mm or less.

Advantages of the Invention

[0014] According to the manufacturing method of the cushion according to the present invention, it becomes possible to easily manufacture a cushion made of a filament three-dimensional conjugate having a desired shape while more appropriately smoothing the side surface which is the cut surface.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0016] Each embodiment of the present invention will be described below with reference to the respective drawings. In the following description, the up-down, left-right, and front-back directions (directions orthogonal to each other) are as shown in each figure. These directions are merely defined for convenience in the description.

[0017] 1. First Embodiment First, the first embodiment of the present invention will be described. FIG. 1 is a schematic flowchart of a method for manufacturing a cushion according to the first embodiment. As shown in FIG. 1, in this embodiment, a filament three-dimensional conjugate manufacturing step (step S1) for manufacturing a filament three-dimensional conjugate, a cutting process (step S2) for cutting the manufactured filament three-dimensional conjugate into an appropriate size, a cut surface compression heating process (step S3) for heating while compressing the cut surface of the filament three-dimensional conjugate, and a corner compression heating process (step S4) for heating while compressing the corners of the filament three-dimensional conjugate are sequentially performed to manufacture a cushion. Hereinafter, these steps and processes will be specifically described.

[0018] FIG. 2A is a schematic diagram of a manufacturing apparatus 1 for a filament three-dimensional conjugate used in the filament three-dimensional conjugate manufacturing step (step S1). FIG. 2B is a cross-sectional view taken along the line A-A' of the manufacturing apparatus 1 shown in FIG. 2A.

[0019] The manufacturing apparatus 1 for a filament three-dimensional conjugate includes a molten filament supply unit 10 that discharges a molten filament group MF composed of a plurality of molten filaments having a diameter in the range of 0.3 mm to 3 mm downward in the vertical direction, and a fusion bonding forming unit 20 that three-dimensionally entangles the molten filament group MF, fuses and bonds the contact points, and then cools and solidifies to form a filament three-dimensional conjugate.

[0020] The molten filament supply unit 10 includes a pressure melting unit 11 (extruder) and a filament discharge unit 12 (die). The pressure melting unit 11 includes a material input unit 13 (hopper), a screw 14, a screw motor 15 that drives the screw 14, a screw heater 16, and a plurality of temperature sensors (not shown). Inside, a cylinder 11a is formed for conveying the thermoplastic resin or thermoplastic elastomer (hereinafter, these may be collectively referred to as "thermoplastic resin, etc.") supplied from the material input unit 13 while heating and melting it with the screw heater 16.

[0021] Inside the cylinder 11a, the screw 14 is rotatably accommodated. At the downstream end of the cylinder 11a, a cylinder discharge port 11b is formed for discharging the thermoplastic resin, etc. toward the filament discharge unit 12. The heating temperature of the screw heater 16 is controlled based on, for example, the detection signal of the temperature sensor provided in the molten filament supply unit 10.

[0022] The filament discharge unit 12 includes a nozzle unit 16, a die heater 18, and a plurality of temperature sensors (not shown). Inside, a flow guide path 12a is formed for guiding the molten thermoplastic resin, etc. discharged from the cylinder discharge port 11b to the nozzle unit 16.

[0023] The nozzle unit 16 is a thick metal plate in the shape of a substantially rectangular parallelepiped and is provided at the lower part of the filament discharge unit 12 corresponding to the most downstream part of the flow guide path 12a. A plurality of nozzle openings for discharging the molten filament are formed in the nozzle unit 16. As an example, the nozzle openings are arranged in a staggered pattern in the front-back, left-right directions, and the distance (pitch) between adjacent nozzle openings is about 10 mm. However, the specific form of the nozzle openings is not particularly limited.

[0024] A plurality of die heaters 18 (six in the example shown in FIG. 2B) are provided in the left-right direction to heat the filament discharge unit 12. The heating temperature of the die heater 18 is controlled based on, for example, the detection signal of the temperature sensor provided in the filament discharge unit 12.

[0025] Examples of thermoplastic resins and the like that can be used as materials for the filament three-dimensional composite include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon 66, polyvinyl chloride resin, or thermoplastic resins such as polystyrene resin, and thermoplastic elastomers such as styrene-based elastomers, vinyl chloride-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, nitrile-based elastomers, polyamide-based elastomers, or fluorine-based elastomers.

[0026] The thermoplastic resin and the like supplied from the material input section 13 are heated and melted in the cylinder 11a, and are extruded by, for example, the screw 14, and supplied as a molten thermoplastic resin and the like from the cylinder discharge port 11b to the flow path 12a of the filament discharge section 12. Thereafter, a molten filament group MF composed of a plurality of molten filaments is discharged so as to translate downward from each of the plurality of nozzle openings of the nozzle section 16.

[0027] The fusion bonding formation section 20 includes a cooling water tank 23, a pair of front and rear conveyors 24, a plurality of conveying rollers 25a to 25h, and a pair of front and rear receiving plates 21 that regulate the thickness of the filament three-dimensional composite. The cooling water tank 23 is a water tank for storing cooling water W. Inside the cooling water tank 23, the conveyor 24 and a plurality of conveying rollers 25a to 25h are disposed. The pair of conveyors 24a and 24b and the plurality of conveying rollers 25a to 25h are driven by a drive motor (not shown).

[0028] In addition, in this embodiment, a cooling water supply device 22 for supplying cooling water to the receiving plate 21 is provided. The receiving plate 21 is a metal plate having a bent portion including a flat inclined surface 21a that slopes downward and a flat vertical surface 21b that extends vertically downward from the lower end of the inclined surface 21a. The receiving plate 21 guides the end portions in the thickness direction of the molten filament group MF toward the central portion by the front and rear inclined surfaces 21a, thereby reducing the front-rear dimension of the molten filament group MF to the interval between the front and rear vertical surfaces 21b, and smoothing the surface while increasing the density of the end portions in the thickness direction of the molten filament group MF.

[0029] The molten filament group MF discharged from the nozzle portion 17 is adjusted in thickness (front-rear dimension) by the receiving plate 21 as described above, is bent by the buoyancy action of the water W in the cooling water tank 23, and each molten filament therein forms a random loop. The random loops are three-dimensionally intertwined in a molten state with adjacent random loops, and the contact points are fusion-bonded to form a three-dimensional filament aggregate (filament three-dimensional aggregate 3DF).

[0030] The filament three-dimensional aggregate 3DF is conveyed while being cooled by the water W in the cooling water tank 23 by the conveyor 24 and a plurality of conveying rollers 25a to 25h, and is finally discharged to the outside of the cooling water tank 23. In this way, the filament three-dimensional aggregate 3DF is formed by the manufacturing apparatus 1, and the filament three-dimensional aggregate manufacturing process (step S1) is completed.

[0031] Next, a cutting process (step S2) is executed on the filament three-dimensional aggregate 3DF manufactured in the filament three-dimensional aggregate manufacturing process (step S1). The cutting process (step S2) is a process of cutting the filament three-dimensional aggregate 3DF in the front-rear direction and the left-right direction, for example, with a saw cutter or the like according to the size of the cushion (product), etc. By this process, the filament three-dimensional aggregate 30 illustrated in FIG. 3 is obtained.

[0032] The filament three-dimensional conjugate body 30 obtained in this way has a rectangular parallelepiped shape (plate shape) having cut surfaces 30a and 30c at the front-rear direction (length direction) ends, cut surfaces 30b and 30d at the left-right direction (width direction) ends, and high-density smooth surfaces 30m and 30n at the upper-lower direction (thickness direction) ends. The upper-lower direction of the filament three-dimensional conjugate body 30 corresponds to the thickness direction of the filament three-dimensional conjugate body 3DF formed by the manufacturing apparatus 1.

[0033] At the boundaries between the cut surfaces 30a, 30b, 30c, and 30d, four corner edges (bending lines) 30e, 30f, 30g, and 30h are formed. The cut surface 30a and the cut surface 30b are in contact with each other at the corner edge 30f, the cut surface 30b and the cut surface 30c are in contact with each other at the corner edge 30g, the cut surface 30c and the cut surface 30d are in contact with each other at the corner edge 30h, and the cut surface 30d and the cut surface 30a are in contact with each other at the corner edge 30e.

[0034] Next, a cut surface compression heat treatment (step S3) is performed on the filament three-dimensional conjugate body 30 obtained by the cutting process (step S2). FIG. 4 shows a state in which the cut surface compression heat treatment is performed. (A) to (D) in FIG. 4 are shown as cross-sectional views when the filament three-dimensional conjugate body 30 is cut by a plane that bisects it in the left-right direction.

[0035] FIG. 4(A) shows a state before the cut surfaces 30a and 30c at the front-rear direction ends of the filament three-dimensional conjugate body 30 are subjected to a compression heat treatment using four ventilation pressurizing members 31aa, 31ab, 31ac, and 31ad having ventilation holes. Details of these ventilation pressurizing members 31aa, 31ab, 31ac, and 31ad will be described later with reference to FIG. 5.

[0036] Figure 4(B) shows a state in which the cut surfaces 30a and 30c, which are the side surfaces of the filament three-dimensional assembly 30 shown in Figure 4(A), are compressed using four air-permeable pressing members 31aa, 31ab, 31ac, and 31ad, causing the cut surface 30a to deform into the curved surface 30aa and the cut surface 30c to deform into the curved surface 30ca. In the present application, the side surface of the filament three-dimensional assembly refers to the side surface that is exposed in the direction orthogonal to the thickness direction of the filament three-dimensional assembly, which is substantially plate-shaped, unless otherwise specified.

[0037] In the example shown in Figure 4(B), as schematically indicated by the white arrow P, the air-permeable pressing member 31aa is moved obliquely downward and rearward, and the air-permeable pressing member 31ab is moved obliquely upward and rearward to hold down the cut surface 30a. At the same time, the air-permeable pressing member 31ac is moved obliquely downward and forward, and the air-permeable pressing member 31ad is moved obliquely upward and forward to hold down the cut surface 30c, thereby compressing the cut surface 30a and the cut surface 30c. The deformation of the filament three-dimensional assembly 30 at this time is elastic deformation.

[0038] In this way, by using the air-permeable pressing members 31aa, 31ab, 31ac, and 31ad to compress inward in the direction including the direction component (the front-rear direction component shown in Figure 4) perpendicular to the vertical direction (thickness direction) of the filament three-dimensional assembly 30, the cut surfaces 30a and 30c, which are the side surfaces of the filament three-dimensional assembly 30, are compressed and deformed inward, forming the curved surfaces 30aa and 30ca. As a form of compressing the cut surface 30a and the cut surface 30c, it is also possible to adopt a form in which the joined members of the two air-permeable pressing members 31aa and 31ab are moved rearward to hold down the cut surface 30a, and the joined members of the two air-permeable pressing members 31ac and 31ad are moved forward to hold down the cut surface 30b.

[0039] Figure 4(C) shows a state where the four breathable pressing members 31aa, 31ab, 31ac, 31ad shown in Figure 4(B) and the filament three-dimensional conjugate body 30 are fixed using a pair of parallel upper and lower thickness-direction pressing plates 32a, 32b, and a heat medium HA is supplied through ventilation holes from the outside of the breathable pressing members 31aa, 31ab, 31ac, 31ad to the curved surfaces 30aa, 30ca for heat treatment. By being sandwiched and fixed between the upper thickness-direction pressing plate 32a and the lower thickness-direction pressing plate 32b, the state in which the cut surfaces 30a, 30c are compressed and deformed by the breathable pressing members 31aa, 31ab, 31ac, 31ad is maintained.

[0040] As the thickness-direction pressing plates 32a, 32b, a breathable mold with a thickness of 5 mm or more and 50 mm or less provided with a plurality of ventilation holes 32ah, 32bh through which a heat medium HA such as hot air or a cooling medium CA such as cold air can pass can be used. In the example shown in Figure 4(C), six ventilation holes 32ah are provided in the upper thickness-direction pressing plate 32a and six ventilation holes 32bh are provided in the lower thickness-direction pressing plate 32b in the front-rear direction, respectively. The hole diameters of the ventilation holes 32ah, 32bh are preferably in the range of 5 to 20 mm.

[0041] The thickness-direction pressing plates 32a, 32b may be provided with engaging protrusions (not shown) for engaging with the ventilation holes of the breathable pressing members 31aa, 31ab, 31ac, 31ad. By providing the engaging protrusions, the breathable pressing members 31aa, 31ab, 31ac, 31ad can be engaged with the ventilation holes so that they do not move outward in the front-rear direction. Further, thereby, the compressive force applied by the thickness-direction pressing plates 32a, 32b to the filament three-dimensional conjugate body 30 in the thickness direction through the breathable pressing members 31aa, 31ab, 31ac, 31ad can be maintained without excessively increasing, and the compression of the filament three-dimensional conjugate body 30 inward in the front-rear direction by the breathable pressing members 31aa, 31ab, 31ac, 31ad can be maintained.

[0042] In addition, in the situation shown in FIG. 4(C), recesses may be provided in the thickness-direction pressing plates 32a and 32b so as to minimize the vertical gap between the thickness-direction pressing plates 32a and 32b and the filament three-dimensional conjugate body 30. For example, recesses substantially equivalent to the plate thickness of the ventilation-pressure members 31aa, 31ab, 31ac, and 31ad may be provided in the portions of the thickness-direction pressing plates 32a and 32b facing the ventilation-pressure members 31aa, 31ab, 31ac, and 31ad.

[0043] As the heat medium HA, hot air, water vapor, warm water, or the like can be used. The heat medium HA passes through the ventilation holes of the ventilation-pressure members 31aa, 31ab, 31ac, and 31ad and heats the vicinity of the curved surfaces 30aa and 30ca of the filament three-dimensional conjugate body 30 to cause plastic deformation. As a result, the curved surfaces 30aa and 30ca are maintained even after the ventilation-pressure members 31aa, 31ab, 31ac, and 31ad are removed.

[0044] The heat medium HA that has passed through the vicinity of the curved surfaces 30aa and 30ca is naturally discharged to the outside through the ventilation holes 32ah of the thickness-direction pressing plate 32a. However, in order to prevent plastic deformation from occurring in portions of the filament three-dimensional conjugate body 30 other than the vicinity of the curved surfaces 30aa and 30ca due to contact with the high-temperature heat medium HA, for example, it is preferable to provide a blower (not shown) above the thickness-direction pressing plate 32a to promote the discharge of the heat medium HA from the ventilation holes 32ah. Furthermore, in order to prevent portions of the filament three-dimensional conjugate body 30 other than the vicinity of the curved surfaces 30aa and 30ca from rising to a temperature equal to or higher than the softening point, it is preferable to forcibly supply a cooling medium CA such as cold air to the filament three-dimensional conjugate body 30 from below the ventilation holes 32bh of the thickness-direction pressing plate 32b.

[0045] In the example shown in FIG. 4(C), the cooling medium CA is supplied in this manner, and the heat medium HA and the cooling medium CA are discharged to the outside through the ventilation holes 32ah. The heat treatment in this example is in a form in which the cooling medium CA is supplied to the filament three-dimensional conjugate body 30 except for the vicinity of the side surfaces (curved surfaces 30aa and 30ca) that have been compression-deformed, while the heat medium HA is supplied toward the compression-deformed side surfaces.

[0046] The temperature of the heat medium HA is preferably within a range that is equal to or higher than the softening temperature at which plastic deformation occurs in raw materials such as thermoplastic resins used for the filament three-dimensional conjugate, and equal to or lower than the melting point of the raw material. More preferably, it is within a range from 30°C lower than the melting point of the raw material to 5°C lower than the melting point. By setting the temperature of the heat medium HA within the above temperature range, it is possible to prevent the raw material from melting and forming films, or to prevent a decrease in the air permeability (resistance to stuffiness) and water permeability (ease of washing) of the cushion. As the cooling medium CA, cold air, mist, or cold water can be used.

[0047] Figure 4(D) shows a filament three-dimensional conjugate 30αi formed by subjecting the cut surface compression heat treatment (mainly the treatment shown in Figures 4(B) to (C)) described above. In the filament three-dimensional conjugate 30αi, smooth curved surfaces 30aa and 30ca are formed by subjecting the cut surfaces 30a and 30c to compression heat treatment.

[0048] In Figure 4, an example is shown of a method of smoothly curving the cut surfaces 30a and 30c at the front and rear ends of the filament three-dimensional conjugate 30 into curved surfaces 30aa and 30ca by heating while compressing them with the air permeability pressurizing members 31aa, 31ab, 31ac, and 31ad. By the same method, the cut surfaces 30b and 30d at the left and right (width direction) ends of the filament three-dimensional conjugate 30 can be smoothly curved into curved surfaces 30ba and 30da by heating while compressing them with the air permeability pressurizing members 31aa, 31ab, 31ac, and 31ad. In this way, by smoothly curving all four cut surfaces 30a to 30d of the filament three-dimensional conjugate 30, a filament three-dimensional conjugate 30α shown in Figure 6(A) described later can be obtained.

[0049] FIG. 5 is a perspective view of the air-permeable pressing members 31aa and 31ab used for the cross-sectional compression heat treatment shown in FIG. 4. FIG. 5(A) shows a state in which the two air-permeable pressing members 31aa and 31ab are joined, and FIG. 5(B) shows a state in which the two air-permeable pressing members 31aa and 31ab are separated. Since the shapes of the air-permeable pressing members 31aa, 31ab, 31ac, and 31ad are the same, the illustration of the air-permeable pressing members 31ac and 31ad is omitted.

[0050] Each of the four air-permeable pressing members 31aa, 31ab, 31ac, and 31ad has a shape in which one end of a rectangular plate is curved so that its cross-sectional shape is in the shape of the letter "J" of the alphabet, and at the end of the planar portion K1, the end of a curved surface portion K2 having a shape generally corresponding to a part of a cylinder (corresponding to a central angle of 90°) is connected.

[0051] Also, each of the four air-permeable pressing members 31aa, 31ab, 31ac, and 31ad is formed of a rigid member having a plurality of ventilation holes (not shown) through which a heat medium such as hot air can pass. As such a rigid member, an air-permeable metal plate (such as punching metal) or a metal mesh having a thickness of 1 mm or more and 5 mm or less can be used.

[0052] The pore diameter of each of the plurality of ventilation holes in the air-permeable pressing members 31aa, 31ab, 31ac, and 31ad is preferably 0.2 mm or more and 5 mm or less. Further, so that the filaments (such as the cut ends of the filaments generated by cutting the filament three-dimensional conjugate body 30) constituting the filament three-dimensional conjugate body 30 do not enter the ventilation holes, the pore diameter of each of the plurality of ventilation holes is preferably smaller than the diameter of the filament.

[0053] Each of the two ventilation pressure members 31aa, 31ab and the two ventilation pressure members 31ac, 31ad becomes a joined body with a cross-sectional shape of a "U" shape in the alphabet by joining. Each of the ventilation pressure members 31aa, 31ab and the ventilation pressure members 31ac, 31ad in the states shown in FIGS. 4(B) and 4(C) is in such a joined body state, and the cut surfaces 30a, 30c of the filament three-dimensional conjugate 30 can be deformed into a curved surface shape.

[0054] After the above-described cut surface compression heat treatment (step S3) is executed, a corner compression heat treatment (step S4) is further executed. FIG. 6 shows how the corner compression heat treatment is performed. Note that FIGS. 6(A) to 6(D) are shown as a plan view of the filament three-dimensional conjugate 30α viewed from above.

[0055] FIG. 6(A) shows the filament three-dimensional conjugate 30α used for the corner compression heat treatment. The filament three-dimensional conjugate 30α has curved surfaces 30aa, 30ba, 30ca, 30da formed by the above-described cut surface compression heat treatment. Four corner curves 30ea, 30fa, 30ga, 30ha are formed at the boundaries between the four curved surfaces 30aa, 30ba, 30ca, 30da. The curved surfaces 30aa and 30ba are in contact with each other at the corner curve 30ea, the curved surfaces 30ba and 30ca are in contact with each other at the corner curve 30fa, the curved surfaces 30ca and 30da are in contact with each other at the corner curve 30ga, and the curved surfaces 30da and 30aa are in contact with each other at the corner curve 30ha.

[0056] FIG. 6(B) shows a state before the corner compression heat treatment of the vicinity of the four corner curves 30ea, 30fa, 30ga, 30ha of the filament three-dimensional conjugate 30α using the four corner ventilation pressure members 41c. Details of the corner ventilation pressure member 41c will be described later with reference to FIGS. 7 and 8.

[0057] FIG. 6(C) shows a state in which the vicinity of the four corner curves 30ea, 30fa, 30ga, and 30ha of the filament three-dimensional conjugate body 30α is subjected to corner compression heat treatment using four corner ventilation pressurizing members 41c.

[0058] In the example shown in FIG. 6(C), as schematically indicated by the white arrow P, each of the corner ventilation pressurizing members 41c arranged in the vicinity of each corner of the filament three-dimensional conjugate body 30α is moved in the direction (a direction orthogonal to the thickness direction) toward the center of the upper view of the filament three-dimensional conjugate body 30α, thereby compressing the vicinity of the four corner curves 30ea, 30fa, 30ga, and 30ha of the filament three-dimensional conjugate body 30α. The deformation of the filament three-dimensional conjugate body 30α at this time is elastic deformation. Further, in the compressed state like this, the vicinity of the four corner curves 30ea, 30fa, 30ga, and 30ha is heated.

[0059] In this way, by the four corner ventilation pressurizing members 41c, the vicinity of the four corner curves 30ea, 30fa, 30ga, and 30ha is heated while being pressurized toward the central portion side in the direction (in all directions of up, down, left, and right in the drawing of FIG. 6) orthogonal to the thickness direction (the direction perpendicular to the paper surface of FIG. 6) of the filament three-dimensional conjugate body 30α, and plastic deformation occurs. Note that the heat treatment of the vicinity of each of the corner curves 30ea, 30fa, 30ga, and 30ha can be performed by the same method as the heating method shown in FIG. 4(C), that is, by supplying the heat medium HA to the vicinity of the four corner curves 30ea, 30fa, 30ga, and 30ha through the ventilation holes from the outside of the corner ventilation pressurizing member 41c.

[0060] FIG. 6(D) shows a filament three-dimensional conjugate body cushion 30β obtained by subjecting the four corner curves 30ea, 30fa, 30ga, and 30ha of the filament three-dimensional conjugate body 30α to corner compression heat treatment. The filament three-dimensional conjugate body cushion 30β has corner curved surfaces 30eb, 30fb, 30gb, and 30hb in which the vicinity of the corner curves 30ea, 30fa, 30ga, and 30ha is curved in accordance with the shape inside the corner ventilation pressurizing member 41c.

[0061] FIG. 7 is a plan view of the corner ventilation pressurizing member 41c shown in FIG. 6. FIG. 8 is a sectional view taken along the line B-B' of the corner ventilation pressurizing member shown in FIG. 7.

[0062] The corner ventilation pressurizing member 41c has an upper surface shape in which the right-angled vertex portion of an isosceles right triangle is rounded. Further, the corner ventilation pressurizing member 41c has an inner wall that is curved into a "C" shape in a sectional view, and the filament three-dimensional conjugate body 30α can be inserted into the internal space in contact with the inner wall. Furthermore, the corner ventilation pressurizing member 41c is formed of a rigid member having a plurality of ventilation holes (not shown) through which a heat medium such as hot air can pass. As such a rigid member, a ventilated metal plate (such as punching metal) or a metal mesh having a thickness of 1 mm or more and 5 mm or less can be used.

[0063] The aperture diameter of each of the plurality of ventilation holes in the corner ventilation pressurizing member 41c is preferably 0.2 mm or more and 5 mm or less. Further, in order that the filaments constituting the filament three-dimensional conjugate body 30 do not enter the ventilation holes, the aperture diameter of each of the plurality of ventilation holes is preferably smaller than the diameter of the filaments.

[0064] FIG. 9 is a perspective view of the filament three-dimensional conjugate body cushion 30β formed by performing a cut surface compression heat treatment and a corner compression heat treatment. The filament three-dimensional conjugate body cushion 30β has high-density smooth surfaces 30m, 30n at the upper and lower (thickness) ends, curved surfaces 30aa, 30ca at the front and rear (length) ends, curved surfaces 30ba, 30da at the left and right (width) ends, and corner curved surfaces 30eb, 30fb, 30gb, 30hb.

[0065] In this way, the filament three-dimensional conjugate cushion 30β is processed such that the cut surface is smoothed and the side surfaces and corners are rounded. In particular, it can be comfortably used as a cushion that supports the user in the thickness direction (for example, a cushion laid under the buttocks or a cushion that can be placed behind the back for reclining). Note that the filament three-dimensional conjugate cushion 30β can also be used covered with a cover or the like.

[0066] 2. Second Embodiment Next, a second embodiment of the present invention will be described. The second embodiment is basically the same as the first embodiment except for matters related to the cut surface compression heat treatment. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0067] FIG. 10 shows a state in which the cut surface compression heat treatment in the second embodiment is performed. Note that (A) to (C) in FIG. 10 are represented as cross-sectional views when the filament three-dimensional conjugate 30 is cut by a plane that bisects it in the left-right direction.

[0068] FIG. 10(A) shows a state before the cut surfaces 30a and 30c at the front-rear direction ends of the filament three-dimensional conjugate 30 are compression heat-treated using two ventilation pressurizing members 51a and 51b. The ventilation pressurizing members 51a and 51b have a shape in which the central part of a rectangular plate is bent at about 45 degrees, and are formed of a rigid member having a plurality of ventilation holes (not shown) through which a heat medium such as hot air can pass. As such a rigid member, a ventilation metal plate (such as punching metal) with a thickness of 1 mm or more and 5 mm or less or a metal mesh can be used.

[0069] The aperture diameter of each of the plurality of ventilation holes in the ventilation pressurizing members 51a and 51b is preferably 0.2 mm or more and 5 mm or less. Further, it is preferable that the aperture diameter of each of the plurality of ventilation holes is smaller than the diameter of the filament constituting the filament three-dimensional conjugate 30 so that the filament does not enter the ventilation holes.

[0070] Figure 10(B) shows a state in which, by performing a compression process on cut surfaces 30a and 30c, which are side surfaces of the filament three-dimensional aggregate 30, using two ventilation pressurizing members 51a and 51b, the cut surface 30a is deformed into an inclined surface 30ab, and the cut surface 30c is deformed into an inclined surface 30cb.

[0071] In this way, by compressing inward in a direction including a direction component (front-rear direction shown in Fig. 10) perpendicular to the vertical direction (thickness direction) of the filament three-dimensional aggregate 30 using the ventilation pressurizing members 51a and 51b, the cut surfaces 30a and 30c, which are side surfaces of the filament three-dimensional aggregate 30, are compressed and deformed inward, and smooth inclined surfaces 30ab and 30cb are formed. In the example shown in Fig. 10(B), as schematically indicated by the white arrow P, the ventilation pressurizing member 51a is moved obliquely downward and rearward to press the cut surface 30a, and the ventilation pressurizing member 51b is moved obliquely downward and forward to press the cut surface 30c, thereby compressing the cut surface 30a and the cut surface 30c. The deformation of the filament three-dimensional aggregate 30 at this time is elastic deformation.

[0072] Figure 10(C) shows a state in which, while fixing the two ventilation pressurizing members 51a and 51b and the filament three-dimensional aggregate 30 in the state shown in Fig. 10(B) using a pair of parallel upper and lower thickness-direction pressurizing plates 32a and 32b, a heat medium HA is supplied to the inclined surfaces 30ab and 30cb through ventilation holes from the outside of the ventilation pressurizing members 51a and 51b for heat treatment. By being sandwiched and fixed between the upper thickness-direction pressurizing plate 32a and the lower thickness-direction pressurizing plate 32b, the state in which the cut surfaces 30a and 30c are compressed and deformed by the ventilation pressurizing members 51a and 51b is maintained.

[0073] As the thickness-direction pressurizing plates 32a and 32b, a ventilation mold having a thickness of 5 mm or more and 50 mm or less, provided with a plurality of ventilation holes 32ah and 32bh through which a heat medium HA such as hot air or a cooling medium CA such as cold air can pass, can be used. The pore diameters of the ventilation holes 32ah and 32bh are preferably in the range of 5 to 20 mm.

[0074] The thickness-direction pressing plates 32a and 32b may be provided with engaging protrusions (not shown) for engaging with the ventilation holes of the ventilation-pressure members 51a and 51b. By providing the engaging protrusions, the engaging protrusions are engaged with the ventilation holes so that the ventilation-pressure members 51a and 51b do not move outward in the front-rear direction, and the compression force applied to the filament three-dimensional conjugate 30 in the thickness direction is not excessively increased, and the compression of the filament three-dimensional conjugate 30 inward in the front-rear direction by the ventilation-pressure members 51a and 51b can be maintained.

[0075] As the heat medium HA, hot air, water vapor, warm water, or the like can be used. The heat medium HA passes through the ventilation holes of the ventilation-pressure members 51a and 51b and heats the vicinity of the inclined surfaces 30ab and 30cb of the filament three-dimensional conjugate 30 to cause plastic deformation. Thereby, the inclined surfaces 30ab and 30cb are maintained even after the ventilation-pressure members 51a and 51b are removed.

[0076] The heat medium HA that has passed through the vicinity of the inclined surfaces 30ab and 30cb is naturally discharged to the outside through the ventilation holes 32ah of the thickness-direction pressing plate 32a. However, in order to prevent plastic deformation from occurring in portions other than the vicinity of the inclined surfaces 30ab and 30cb in the filament three-dimensional conjugate 30 due to contact with the high-temperature heat medium HA, for example, it is preferable to provide a blower (not shown) above the thickness-direction pressing plate 32a to promote the discharge of the heat medium HA from the ventilation holes 32ah. Furthermore, in order to prevent portions other than the vicinity of the inclined surfaces 30ab and 30cb of the filament three-dimensional conjugate 30 from rising to a temperature equal to or higher than the softening point, it is preferable to forcibly supply a cooling medium CA such as cold air to the filament three-dimensional conjugate 30 from below the ventilation holes 32bh of the thickness-direction pressing plate 32b. In the example shown in FIG. 10(C), the cooling medium CA is supplied in this manner, and the heat medium HA and the cooling medium CA are discharged to the outside through the ventilation holes 32ah.

[0077] In FIG. 10, an example is shown of a method of smoothly chamfering the inclined surfaces 30ab and 30cb by heating while compressing the cut surfaces 30a and 30c at the front and rear ends of the filament three-dimensional conjugate 30 with the ventilation pressure members 51a and 51b. By the same method, the cut surfaces 30b and 30d at the left and right (width) ends of the filament three-dimensional conjugate 30 can be smoothly chamfered to inclined surfaces 30bb and 30db by heating while compressing them with the ventilation pressure members 51a and 51b.

[0078] 3. Third Embodiment Next, a third embodiment of the present invention will be described. The third embodiment is basically the same as the first embodiment except for matters related to the cut surface compression heat treatment. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0079] FIG. 11 shows a state in which the cut surface compression heat treatment in the third embodiment is performed. Note that (A) to (C) in FIG. 10 are shown as cross-sectional views when the filament three-dimensional conjugate 30 is cut by a plane that bisects it in the left-right direction.

[0080] FIG. 11(A) shows a state before the cut surfaces 30a and 30c at the front and rear ends of the filament three-dimensional conjugate 30 are subjected to compression heat treatment using two ventilation pressure members 131a and 131b. Details of these ventilation pressure members 131a and 131b will be described later with reference to FIG. 12. In the third embodiment, before compressing the cut surfaces 30a and 30c using the ventilation pressure members, a pair of upper and lower thickness direction pressure plates 32a and 32b are arranged so as to be in contact with the upper and lower surfaces of the filament three-dimensional conjugate 30.

[0081] FIG. 11(B) shows a state in which the cut surfaces 30a and 30c, which are the side surfaces of the filament three-dimensional conjugate 30 shown in FIG. 11(A), are compressed using two ventilation pressure members 131a and 131b, so that the cut surface 30a is deformed into a smooth curved surface 30aa and the cut surface 30b is deformed into a smooth curved surface 30ca.

[0082] In the example shown in FIG. 11(B), as schematically indicated by the white arrow P, by moving the ventilation pressure member 131a rearward to press the cut surface 30a and moving the ventilation pressure member 131b forward to press the cut surface 30c, the cut surfaces 30a and 30c are compressed. The deformation of the filament three-dimensional conjugate 30 at this time is elastic deformation.

[0083] In this way, by using the ventilation pressure members 131a and 131b to compress inward in the direction including the direction component (front-rear direction shown in FIG. 11) perpendicular to the vertical direction (thickness direction) of the filament three-dimensional conjugate 30, the cut surfaces 30a and 30c, which are the side surfaces parallel to the thickness direction of the filament three-dimensional conjugate 30, are compressed and deformed inward, and smooth curved surfaces 30aa and 30ca are formed.

[0084] Also, in the state shown in FIG. 11(B), the ventilation pressure members 131a and 131b are sandwiched and fixed between the upper and lower thickness-direction pressure plates 32a and 32b, so that the state in which the cut surfaces 30a and 30c are compressed and deformed can be maintained. The thickness-direction pressure plates 32a and 32b may be provided with engaging protrusions (not shown) for engaging with the ventilation holes of the ventilation pressure members 131a and 131b. By providing the engaging protrusions, the engaging protrusions are engaged with the ventilation holes so that the ventilation pressure members 131a and 131b do not move outward in the front-rear direction, and the compression of the filament three-dimensional conjugate 30 inward in the front-rear direction by the ventilation pressure members 131a and 131b can be maintained without excessively increasing the compression force applied in the thickness direction of the filament three-dimensional conjugate 30.

[0085] FIG. 11(C) shows a state in which the ventilation pressure members 131a and 131b and the filament three-dimensional conjugate 30 are fixed using the thickness-direction pressure plates 32a and 32b, and a state in which a heat medium HA is supplied from the outside of the ventilation pressure members 131a and 131b to the curved surfaces 30aa and 30ca for heat treatment.

[0086] As the thickness-direction pressing plates 32a and 32b, a ventilation mold with a thickness of 5 mm or more and 50 mm or less provided with a plurality of ventilation holes 32ah and 32bh through which a heat medium HA such as hot air or a cooling medium CA such as cold air can pass can be used. The pore diameter of the ventilation holes 32ah and 32bh is preferably 5 to 20 mm.

[0087] As the heat medium HA, hot air, steam, warm water, etc. can be used. The heat medium HA passes through the ventilation holes of the ventilation pressure members 131a and 131b and heats the vicinity of the curved surfaces 30aa and 30ca of the filament three-dimensional conjugate body 30, causing plastic deformation. As a result, the curved surfaces 30aa and 30ca are maintained even after the ventilation pressure members 131a and 131b are removed.

[0088] The heat medium HA that has passed through the vicinity of the curved surfaces 30aa and 30ca is naturally discharged to the outside through the ventilation holes 32ah of the thickness-direction pressing plate 32a. However, in order to prevent plastic deformation from occurring in the portions of the filament three-dimensional conjugate body 30 other than the vicinity of the curved surfaces 30aa and 30ca due to contact with the high-temperature heat medium HA, for example, it is preferable to provide a blower (not shown) above the thickness-direction pressing plate 32a to promote the discharge of the heat medium HA from the ventilation holes 32ah. Furthermore, in order to prevent the portions of the filament three-dimensional conjugate body 30 other than the vicinity of the curved surfaces 30aa and 30ca from rising to a temperature above the softening point, it is preferable to forcibly supply a cooling medium CA such as cold air to the filament three-dimensional conjugate body 30 from below the ventilation holes 32bh of the thickness-direction pressing plate 32b. In the example shown in Fig. 11(C), the cooling medium CA is supplied in this manner, and the heat medium HA and the cooling medium CA are discharged to the outside through the ventilation holes 32ah.

[0089] In FIG. 11, an example of a method is illustrated in which the cut surfaces 30a and 30c at the front and rear ends of the filament three-dimensional assembly 30 are heated while being compressed by the ventilation pressure members 131a and 131b to be smoothly curved into the curved surfaces 30aa and 30ca. By the same method, the cut surfaces 30b and 30d at the left and right (widthwise) ends of the filament three-dimensional assembly 30 are heated while being compressed by the ventilation pressure members 131a and 131b, so that the cut surfaces 30b and 30d can be smoothly curved into the curved surfaces 30ba and 30da.

[0090] FIG. 12 is a perspective view of the ventilation pressure members 131a and 131b used for the cut surface compression heat treatment shown in FIG. 11. The ventilation pressure members 131a and 131b have a shape in which a rectangular plate is bent into a shape of the alphabet letter "C" in its cross-sectional shape, and are formed of a rigid member having a plurality of ventilation holes (not shown) through which a heat medium such as hot air can pass.

[0091] As such a rigid member, a ventilation metal plate (such as punching metal) or a metal mesh having a thickness of 1 mm or more and 5 mm or less can be used. The hole diameter of each of the plurality of ventilation holes in the ventilation pressure members 131a and 131b is preferably 0.2 mm or more and 5 mm or less. Further, it is preferable that the hole diameter of each of the plurality of ventilation holes is smaller than the diameter of the filament so that the filaments constituting the filament three-dimensional assembly 30 do not enter the ventilation holes.

[0092] As shown in Fig. 11, both end portions of the ventilation pressure members 131a and 131b in a "C" shape in cross-section are sandwiched between the thickness direction pressure plates 32a and 32b and the filament three-dimensional conjugate body 30 when the cut surface compression heat treatment is performed. Therefore, in order to minimize the step difference between the upper surface 30m and the bottom surface 30n of the filament three-dimensional conjugate body 30 after the cut surface compression heat treatment, the thickness of both end portions of the ventilation pressure members 131a and 131b in the "C" shape is made as thin as possible, and both end portions are sharpened. As another method for minimizing such a step difference, a part of the thickness direction pressure plates 32a and 32b (the part sandwiching both end portions of the ventilation pressure members 131a and 131b) may be made thinner by the thickness of both end portions of the ventilation pressure members 131a and 131b.

[0093] Fig. 13 shows each modification example of the ventilation pressure members 131a and 131b used for the cut surface compression heat treatment of the present embodiment. Figs. 13(A) to (C) are shown as cross-sectional views when the filament three-dimensional conjugate body 30 is cut by a plane that bisects the filament three-dimensional conjugate body 30 in the left-right direction in a state where the filament three-dimensional conjugate body 30 is compressed and deformed.

[0094] The ventilation pressure members 141a and 141b shown in Fig. 13(A) have a shape in which only both ends of a rectangular plate are bent. The ventilation pressure members 151a and 151b shown in Fig. 13(B) have a shape in which a rectangular plate is bent so that its cross-section is in a "く" shape. The ventilation pressure members 161a and 161b shown in Fig. 13(C) have a shape in which a rectangular plate is bent so that its cross-section is in a "C" shape of the alphabet.

[0095] 4. Fourth Embodiment Next, the fourth embodiment of the present invention will be described. The fourth embodiment is basically the same as the first embodiment except that the cut surface compression heat treatment for the filament three-dimensional conjugate body provided with the opening is performed. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0096] In the fourth embodiment, after the corner compression heat treatment (step S4) is performed, further, after a process of forming an opening in the filament three-dimensional conjugate body 30β is performed, an opening cut surface compression heat treatment is executed. FIG. 14 shows how these processes are performed. Note that (A) to (E) in FIG. 14 are represented as plan views (views from above).

[0097] FIG. 14(A) shows the filament three-dimensional conjugate body 30β used for the opening cut surface compression heat treatment. The filament three-dimensional conjugate body 30β is equivalent to that shown in FIG. 9, and has curved surfaces 30aa, 30ba, 30ca, 30da formed by the cut surface compression heat treatment on the cut surfaces 30a, 30b, 30c, 30d at the front-rear and left-right ends, and four corner curved surfaces 30eb, 30fb, 30gb, 30hb formed by the corner compression heat treatment at the boundaries of the four curved surfaces 30aa, 30ba, 30ca, 30da.

[0098] FIG. 14(B) shows the filament three-dimensional conjugate body 30γi in which a central opening 30p is formed by circularly cutting and removing the central portion of the filament three-dimensional conjugate body 30β with a cutter or the like. The filament three-dimensional conjugate body 30γi has a central opening 30p, and the peripheral surface of the central opening 30p is an opening cut surface 30pa which is a cut surface generated by cutting with a cutter or the like.

[0099] FIG. 14(C) shows a state in which the central opening 30p of the filament three-dimensional conjugate body 30γi is heated while being compressed outward from the center of the central opening 30p in a direction perpendicular to the thickness direction of the filament three-dimensional conjugate body 30γi (the left-right direction of this drawing sheet, as indicated by the white arrow P in FIG. 14(C)) using two ventilation pressurizing members 41d for openings.

[0100] By compressing and heating the central opening 30p, the cut surface 30pa of the opening of the filament three-dimensional conjugate body 30γi is compressed and deformed to form a smooth curved surface 30ra. The heat treatment can be performed by supplying the heat medium HA to the cut surface 30pa of the opening through the ventilation holes of the ventilation and pressure member 41d for the opening in the same manner as the heating method shown in FIG. 4C. Details of the ventilation and pressure member 41d for the opening will be described later with reference to FIGS. 15 and 16.

[0101] FIG. 14(D) shows a state in which the central opening 30p of the filament three-dimensional conjugate body 30γi is heated while being compressed outward from the center of the central opening 30p in a direction perpendicular to the thickness direction of the filament three-dimensional conjugate body 30γi (the vertical direction of the paper surface of this figure, as indicated by the white arrow P in FIG. 14(D)) using two ventilation and pressure members 41d for the opening.

[0102] By compressing and heating the central opening 30p, the cut surface 30pa of the opening of the filament three-dimensional conjugate body 30 is compressed and deformed to form a curved surface 30ra. The heat treatment can be performed by supplying the heat medium HA to the cut surface 30pa of the opening through the ventilation holes of the ventilation and pressure member 41d for the opening in the same manner as the heating method shown in FIG. 4C.

[0103] FIG. 14(E) shows the filament three-dimensional conjugate body 30γ after the cut surface of the opening is compressed and heat-treated. Thus, the cut surface 30pa of the opening in the filament three-dimensional conjugate body 30γi is processed into an opening curved surface 30ra which is a smooth curved surface by the above-described cut surface compression and heat treatment of the opening. In the example of the present embodiment, as the cut surface compression and heat treatment of the opening, as shown in FIGS. 14(C) and 14(D), the pressing direction is changed and it is performed in two steps, but it may be performed three or more times.

[0104] Note that the opening cut surface compression heat treatment of the present embodiment is not limited to the filament three-dimensional conjugate body subjected to the cut surface compression heat treatment (step S3) or the corner compression heat treatment (step S4), and can be carried out on various filament three-dimensional conjugate bodies provided with openings by cutting using a cutter or the like.

[0105] FIG. 15 is a plan view of the ventilation pressurizing member 41d for the opening shown in FIG. 14. FIG. 16 is a cross-sectional view taken along the line C-C' of the ventilation pressurizing member 41d for the opening shown in FIG. 14. The ventilation pressurizing member 41d for the opening has a shape obtained by cutting a donut shape in a quarter in a top view (a partial shape of a sector with a central angle of 90°), and has a cross-sectional shape in the shape of the letter "C" of the alphabet, and its cross-section is in a form opened toward the outside (the outside in the radial direction of the sector).

[0106] The ventilation pressurizing member 41d for the opening is formed of a hard member having a plurality of ventilation holes (not shown) through which a heat medium such as hot air can pass. As such a hard member, a ventilation metal plate (such as punching metal) or a metal mesh having a thickness of 1 mm or more and 5 mm or less can be used. The aperture diameter of each of the plurality of ventilation holes in the ventilation pressurizing member 41d for the opening is preferably 0.2 mm or more and 5 mm or less. Further, it is preferable that the aperture diameter of each of the plurality of ventilation holes is smaller than the diameter of the filament so that the filaments constituting the filament three-dimensional conjugate body 30γi do not enter the ventilation holes.

[0107] FIG. 17 is a perspective view of the filament three-dimensional conjugate body cushion 30γ after the opening cut surface compression heat treatment is performed. The filament three-dimensional conjugate body cushion 30γ has high-density smooth surfaces 30m and 30n at the upper and lower (thickness direction) ends, curved surfaces 30aa and 30ca at the front and rear (length direction) ends, curved surfaces 30ba and 30da at the left and right (width direction) ends, corner curved surfaces 30eb, 30fb, 30gb, and 30hb, and an opening curved surface 30ra.

[0108] 5. Others As described above, the manufacturing method according to the present embodiment is a manufacturing method for manufacturing a cushion using a substantially plate-shaped filament three-dimensional conjugate in which a plurality of filaments made of a thermoplastic resin or a thermoplastic elastomer are partially fused. The method includes a compression process of compressing a side surface of the filament three-dimensional conjugate in a direction including a component perpendicular to the thickness direction (a direction perpendicular to the thickness direction or a direction inclined by less than 90° from this direction) with a ventilation pressurizing member to compress and deform the side surface, and a heating process of supplying a heat medium from the outside of the ventilation pressurizing member toward the compressed and deformed side surface to heat the compressed and deformed side surface.

[0109] Therefore, according to the manufacturing method of the present embodiment, it is possible to easily manufacture a cushion made of a filament three-dimensional conjugate in which the side surface, which is a cut surface, is more appropriately smoothed and has a desired shape. That is, in this manufacturing method, since the side surface of the filament three-dimensional conjugate is compressed and heated in a direction including a component perpendicular to the thickness direction with a ventilation pressurizing member, as in Patent Document 2 described above, a part near the cut surface of the filament three-dimensional conjugate is compressed and hardened while being sandwiched between a female mold and a male mold (burrs) are generated, and a space is generated near the contact point between the female mold and the male mold, and it is difficult to form a smooth end surface. It is possible to smooth the side surface, which is the cut surface, while avoiding such problems. From the viewpoint of more sufficiently avoiding this problem, it is desirable that the direction in which the ventilation pressurizing member is moved in the compression process is a direction perpendicular to the thickness direction of the filament three-dimensional conjugate or a direction inclined by 60° or less from this direction, and it is more desirable that the direction is a direction perpendicular to the thickness direction or a direction inclined by 45° or less from this direction.

[0110] Furthermore, according to the manufacturing method of the present embodiment, by appropriately setting the shape of the inner wall of the ventilation pressure member, it is possible to smooth the side surface which is the cut surface and make it into a desired shape (substantially the same shape as the inner wall). For example, when making the side surface as rounded as possible, the ventilation pressure members 31aa and 31ab of the first embodiment may be adopted. When making the side surface an inclined surface, the ventilation pressure members 51a and 51b of the second embodiment may be adopted. Depending on the shape of the side surface which is the cut surface, by appropriately adjusting the shape of the ventilation pressure member (particularly, the shape of the inner wall in contact with the side surface), it is possible to make the side surface into a desired shape. Note that the cushion made of the filament three-dimensional conjugate body manufactured by the manufacturing method according to each embodiment is suitable as a cushion for supporting a user in the thickness direction, but the use of the cushion is not particularly limited.

[0111] As described above, the embodiments of the present invention have been described. However, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. That is, the above embodiments should be considered as illustrative in all respects and not restrictive. The technical scope of the present invention is shown not by the description of the above embodiments but by the claims, and it should be understood that all modifications belonging to the meaning and scope equivalent to the claims are included.

Industrial Applicability

[0112] The present invention can be used in the manufacturing method of cushions for various applications.

Explanation of Reference Numerals

[0113] 1 Manufacturing apparatus 10 Melted filament supply section 11 Pressurized melting section 11a Cylinder 11b Cylinder discharge port 12 Filament discharge section 12a Flow guide path 13 Material input section 14 Screw 15 Screw motor 16 Screw heater 17 Nozzle part 18 Die heater 20 Fusing and bonding formation part 21 Receiving plate 21a Inclined surface 21b Vertical surface 22 Cooling water supply device 23 Cooling water tank 24 Conveyor 25a~25h Conveyor rollers 30, 30α, 30β, 30γ Filament three-dimensional assemblies 30αi, 30γi Filament three-dimensional assemblies 31aa, 31ab, 31ac, 31ad Ventilation pressure members 32a, 32b Thickness direction pressure plates 41c Corner part ventilation pressure member 41d Opening part ventilation pressure member 51a, 51b Ventilation pressure members 131a, 131b Ventilation pressure members 141a, 141b Ventilation pressure members 151a, 151b Ventilation pressure members 161a, 161b Ventilation pressure members

Claims

1. A manufacturing method for producing a cushion using a substantially plate-shaped filament three-dimensional conjugate body in which a plurality of filaments made of a thermoplastic resin or a thermoplastic elastomer are partially fused, a compression process of compressing and deforming a side surface of the filament three-dimensional conjugate body by compressing the side surface with a ventilation pressurizing member in a direction including a direction component perpendicular to the thickness direction; a heating process of supplying a heat medium from the outside of the ventilation pressurizing member toward the compressed and deformed side surface and heating the compressed and deformed side surface, The heating process is a process of supplying the heat medium toward the compressed and deformed side surface while supplying a cooling medium toward the filament three-dimensional conjugate body except in the vicinity of the compressed and deformed side surface, wherein the cooling medium is supplied from one side in the thickness direction of the filament three-dimensional conjugate body.

2. The heating process is a process of supplying the heat medium toward the compressed and deformed side surface while supplying a cooling medium toward the filament three-dimensional conjugate body sandwiched in the thickness direction by each thickness-direction pressurizing plate, The manufacturing method according to claim 1, wherein the cooling medium is supplied toward the filament three-dimensional conjugate body through a hole provided in one of the thickness-direction pressurizing plates, and the cooling medium is discharged together with the heat medium through a hole provided in the other.

3. The heating process is a process of supplying the heat medium, which is at a temperature equal to or higher than the softening temperature at which plastic deformation of the raw material occurs and equal to or lower than the melting point of the raw material, to the compressed and deformed side surface.

4. The temperature of the heat medium is in the range from 30°C lower than the melting point of the raw material to 5°C lower than the melting point.

5. The production method according to any one of claims 1 to 4, wherein the heat medium is hot air or steam.

6. The production method according to any one of claims 1 to 5, wherein the ventilation pressurizing member is formed of a metal plate provided with a plurality of ventilation holes, and the heat medium is supplied to the side surface through the ventilation holes. The inner diameter of each of the plurality of holes is 0.2 mm or more and 5 mm or less. The production method is characterized in that the thickness of the metal plate is 1 mm or more and 5 mm or less.

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