JP2000316677A - Cushion body, manufacturing method and manufacturing apparatus - Google Patents

Abstract

(57) [Problem] To provide a cushion body composed of a three-dimensional random loop network structure which is lightweight and easy to manufacture. SOLUTION: This cushion body 1 is constituted by a three-dimensional three-dimensional random loop network structure 3.
The outside of the network structure 3 is covered with a cover member 5.
The reticulated structure 3 has a fineness of 300 to 1 made of a thermoplastic resin.
The apparent density obtained by winding a large number of 0000 denier continuous linear bodies 2 in a loop shape and fusing the contact portions to each other is 0.005 to 0.2 g / cm ³ .
By cutting the reticulated structure 3 into a desired three-dimensional shape using a heater wire or the like, the desired cushion body product shape can be formed in a non-compressed or partially compressed state without using a hot press.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion body suitable for seats mounted on vehicles such as vehicles, ships and aircraft, or furniture such as sofas and beds, and a method and apparatus for manufacturing the same.

[0002]

2. Description of the Related Art For example, a synthetic resin foam such as urethane foam has been widely used as a cushion body used for a vehicle seat or the like.
Alternatively, from the viewpoint of reusing by re-melting, a cushion body having a three-dimensional network structure using a thermoplastic resin as disclosed in, for example, US Pat. No. 5,639,543 has also been proposed. I have.

The mesh-structured cushion body is formed by guiding a large number of continuous fibers obtained by discharging molten thermoplastic resin from a large number of nozzles to a cooling tank while passing between a pair of left and right flat conveyors. The continuous fiber is meandered in a loop shape and the contact portions of the loops are fused to obtain a rectangular parallelepiped cushion body (net-like block).

In order to form the mesh block into a desired cushion shape, the mesh block is conventionally housed between an upper mold and a lower mold having a large number of holes, such as punched metal. Then, the mesh block is compressed and deformed by heating means such as blowing hot air into a volume of about 1/2, and then cooled and solidified by cold air to obtain a desired shape (final product shape as a cushion body). I'm trying to get.

[0005]

When the mesh block is compression-molded by a hot press, the deformation shape and density of the loop of the mesh block are hard to be constant by the hot press. Is not constant, and the apparent density becomes unnecessarily large.

In order to solve the above-mentioned disadvantage, a block construction method in which the mesh block is cut into a plurality of block pieces having different sizes from each other and these block pieces are arranged in accordance with a desired cushion body product shape may be considered. In this block method, an adhesive such as a hot-melt non-woven fabric is inserted between each block piece, thermally deformed by hot pressing with an upper mold and a lower mold, and then cooled and solidified to form a cushion body having a desired shape. obtain.

[0007] However, when molding by such a block method, many man-hours and work time are required.
The cost is high. In addition, when heat is supplied to a hot press mold, uneven temperature does not result in a uniform cushion body, so that there is a problem that heat supply control requires a lot of equipment costs.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cushion body capable of efficiently producing a lightweight cushion body having a three-dimensional network structure that can be easily recycled, and a method and apparatus for producing the cushion body.

[0009]

According to the present invention, there is provided a cushion body having a block-shaped three-dimensional loop network structure formed by a heater wire, a water jet or a cutter blade without using a hot press mold. Is cut into a desired shape with substantially no compression or only partial compression.

[0010] That is, the cushion body of the present invention has an apparent density obtained by winding a plurality of continuous linear bodies made of a thermoplastic resin and having a fineness of 300 to 100,000 deniers in a loop shape and fusing the contact portions of each other. 0.005-
A cushion body having a three-dimensional network structure of 0.2 g / cm ³ , which is obtained by cutting the network structure into a desired cushion body product shape.

The "desired cushion body product shape" referred to in this specification means, for example, in the case of a vehicle seat cushion, a shape including side support portions called so-called bank portions on both left and right sides, furniture such as sofas and the like. In the case of a kind of chair, a seat or a backrest shape suitable for the purpose is used, and in the case of a bed such as a bed, a flat mat shape or the like is used, which means a product shape corresponding to the purpose of use.

[0012] The cushion body of the present invention includes a cover member that covers the net-like structure, and also includes compressing a part of the net-like structure (for example, a side support portion of a seat cushion) with the cover member. I have. In addition, it includes smoothing the cut surface layer by deforming the loop cut portion of the cut surface layer of the net structure in a direction along the cushion body surface.

[0013] The present invention provides a three-dimensional net-like structure by discharging a softened thermoplastic resin from a plurality of nozzles, thereby winding a plurality of continuous linear bodies in a loop shape and fusing the contact portions of each other. Means for forming a structure, means for cooling the mesh structure, and means for cutting the mesh structure into a desired cushion product shape by a cutting machine such as a heater wire or a water jet are provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

A cushion body 1 shown in FIG. 1 has a continuous linear body 2 of 300 denier or more mainly made of a thermoplastic elastic resin, winding in a random loop shape and fusing the mutual contact portions of each loop. Made of a three-dimensional network structure 3 having an apparent density of 0.005 to 0.20 g /
cm ³ range. This cushion body 1 is used, for example, for a seat or a backrest of a vehicle seat (seat) of an automobile or the like, and a main part 1a to which a load of a seated person is applied, and a main part 1a.
And a raised side support portion 1b located on both left and right sides of the vehicle.

The outside of the network structure 3 is covered by a cover member 5. The cover member 5 is covered with a tension member 6 such as a hanging wire while the side support portion 1b of the cushion body 1 is compressed to some extent. Further, as shown by a two-dot chain line M1 in FIG. 1, the outer dimension of the net-like structure 3 of the side support portion 1b before covering is larger than the outer dimension after covering by, for example, about 20 mm. By doing so, the cover member 5
As a result, the net-like structure 3 of the side support portion 1b is compressed, and the appearance of the side support portion 1b is improved, and the holdability is improved.

As shown by a two-dot chain line M2 in FIG.
The outer dimension of the ridge 9 where the side 7 on the side of the occupant and the outer surface 8 of the side support portion 1b intersect beforehand is formed to some extent larger (for example, H = about 20 mm), and the larger ridge 9 is formed. You may compress by covering with the cover member 5. By doing so, the appearance of the side support portion 1b is improved, and the hold performance is also improved.

The net-like structure 3 has an apparent density of 0.0
If it is less than 05 g / cm ³ , the resilience will be lost and it is not suitable as a cushion body. 0.2g / c apparent density
Since more than m ³ and resilient becomes too strong comfort is poor, also it becomes unsuitable as a cushion body. More preferable apparent density is 0.01 g / cm ³ or more,
It is 0.05 g / cm ³ or less.

On the other hand, if the fineness of the continuous linear body 2 is less than 300 denier, the strength is reduced and the repulsive force is reduced, which is not preferable. If the fineness exceeds 100,000 denier, the number of the continuous linear bodies 2 per unit volume decreases, and the compression characteristics deteriorate. That is, it is 300 denier or more, and preferably 400 denier or more and 100,000 denier or less, and more preferably 500 to 50,000, at which a preferable repulsion force is obtained as a cushion body.
Denier.

As the thermoplastic elastic resin which is the material of the continuous linear body 2, a polyester elastomer, a polyamide elastomer, a polyurethane elastomer, or the like can be used. The polyester elastomer is, for example, a polyester ether block copolymer having a thermoplastic polyester as a hard segment and a polyalkylene diol as a soft segment, or a polyester ether block copolymer having an aliphatic polyester as a soft segment. Examples of the polyamide-based elastomer include those having a hard segment of nylon and a soft segment of polyethylene glycol or polypropylene glycol.

A thermoplastic inelastic resin may be combined with the thermoplastic elastic resin. The thermoplastic inelastic resin is, for example, polyester, polyamide, polyurethane or the like. The combination of the inelastic resin and the thermoplastic elastic resin is preferably a resin of the same type from the viewpoint of recycling use, for example, a combination of a polyester elastomer and a polyester resin, or a polyamide elastomer and a polyamide resin. Or a combination of a polyurethane-based elastomer and a polyurethane-based resin is recommended.

Reticulated structure 3 used for cushion body 1
FIG. 6 shows a net-like body manufacturing apparatus 10 conceptually shown in FIG.
And a cutting machine 31 shown in FIG. An example of the mesh body manufacturing apparatus 10 includes an extruder 15 and a nozzle unit 16. The extruder 15 converts the thermoplastic elastic resin raw material supplied from the material supply port 17 to a temperature higher by 10 ° C. to 80 ° C. than its melting point (for example, 40 ° C.).
While being heated to a high temperature, it is extruded toward the nozzle portion 16.

The thermoplastic elastic resin heated to the above-mentioned temperature is discharged downward from the nozzle portion 16 and continuously drops linearly without interruption. If the melting temperature of the thermoplastic elastic resin at the time of discharge is set to a temperature higher by 30 ° C. to 50 ° C. than the melting point of the resin, a random three-dimensional loop is easily formed, and the contact portions between the loops are fused to each other. This is preferable because it can be kept in an easy state.

The nozzle section 16 has a predetermined size (for example, 60
cm × 5 cm), and the nozzle effective surface 18 has a large number of nozzles 16 having a hole diameter of about 0.5 mm.
a are provided at a predetermined hole pitch (for example, pitch: 5 mm). The extruder 15 discharges the thermoplastic elastic resin from the nozzle 16a such that the discharge amount per nozzle is 0.5 g to 1.5 g / min. The nozzle effective surface 18 may open the nozzle 16a only in a region corresponding to the cross-sectional shape of the cushion body 1 to be formed.

A liquid surface 20a of a cooling liquid 20 such as water, which functions as a cooling means in the present invention, is located below the nozzle section 16 at a distance of, for example, about 50 cm from the nozzle section 16. This cooling liquid 20 is heated, for example, to a temperature of about 70 ° C. A guide means 21 is provided below the nozzle portion 16.
Is provided. The guide means 21 includes a pair of endless belts 22 and 23 made of a metal net made of, for example, stainless steel having a width of 70 cm and provided on the both sides 3 a and 3 b in the thickness direction of the net-like structure 3.
4, 25, etc. An example of the distance between the opposing surfaces between the belts 22 and 23 is 14 cm. Each belt 2
The upper portions of the cooling liquid 20 and 23 are exposed on the liquid surface 20 a of the cooling liquid 20. These belts 22 and 23 run endlessly continuously between rollers 24 and 25 by a drive mechanism using a motor or the like as a drive source.

The three-dimensional random loop network structure 3 manufactured by the network manufacturing apparatus 10 is cut into a desired cushion body product shape by a cutting machine 31 having a heater wire 30 as shown in FIG. The cutting machine 31 moves the reticulated structure 3 in its longitudinal direction (the direction indicated by the arrow F in FIG. 6).
And a heater wire moving mechanism 33 capable of moving the heater wire 30 in the thickness direction of the net-like structure 3 (the direction indicated by the arrow T). By flowing, the heater wire 30 is heated to a temperature at which the network structure 3 can be melted.

As the cutting means, other than using the above-described heater wire 30, cutting by water jet, cutting by a press die, or cutting by a rotating disk-shaped blade (so-called vertical cutter) may be used. .

Next, a process of manufacturing the cushion body 1 by the cushion body manufacturing apparatus will be described. The raw material of the thermoplastic elastic resin is supplied to the extruder 15 of the reticulated body manufacturing apparatus 10, and is heated to a temperature about 40 ° C. higher than the softening temperature of the resin raw material to be softened. Then, the molten thermoplastic elastic resin raw material is discharged from each nozzle 16a of the nozzle portion 16 and falls naturally between the belts 22 and 23.

The melted thermoplastic elastic resin is applied to the belt 22,
23, the number of continuous linear bodies 2 corresponding to the number of nozzles 16a is formed, and the belts 22 and 2 are formed.
3, and a random loop is generated while winding. That is, these continuous linear bodies 2 form loops in a direction intersecting with the direction A (for example, the direction of arrow B) while continuing in the direction of arrow A in FIG.

In this case, the pitch of the nozzles 16a is set so that the loops can come into contact with each other, so that the belt 2
By bringing the loops into contact with each other between 2 and 23 and fusing the contact portions between the loops, a three-dimensional network structure 3 is obtained. By maintaining the temperature of the cooling liquid 20 at the annealing temperature (pseudo-crystallization acceleration temperature) of the network structure 3, the pseudo-crystallization treatment of the network structure 3 can be simultaneously performed.

The reticulated structure 3 in which the loops are fused is drawn into the coolant 20 at a speed of about 1 m / min while the both sides 3a and 3b in the thickness direction are regulated by the belts 22 and 23. And the fusion portion of each loop is fixed, whereby the network structure 3 is continuously manufactured.

As shown in FIG. 5, the network structure 3 is pseudo-crystallized at a temperature lower than the melting point of the thermoplastic elastic resin by 10 ° C. or more as required, and then cut into a predetermined size. A block-like network structure 3 is obtained. The net-like structure 3 is formed by connecting the continuous linear bodies 2 of the number corresponding to the number of the nozzles 16a without interruption while drawing a random loop.

Then, for example, as shown in FIG.
0, the net-like structure 3 is formed into a desired cushion body shape, for example, the main portion 1a and the side support portion 1.
Cut into a shape with b. In the case of this embodiment, for example, while moving the mesh structure 3 in the direction of arrow F by the feed mechanism 32, the mesh structure 3 is
The inside is cut as shown by a two-dot chain line M3. At the time of this cutting, the heater wire 30 may be moved by the heater wire moving mechanism 33 according to the outer shape of the cushion body 1 to be cut.

By the steps described above, a net-like structure 3 having a desired shape as shown in FIG. 2 was obtained. The density of the network structure 3 is 0.05 g / cm ³ , and the size is 500 m in length and width.
mx 550 mm, thickness 140 mm, weight 1.31 kg, good appearance. Regarding the hardness of the central part,
It was 240 N in a compression test based on JIS6400. The cushion body 1 is completed by covering the outside of the mesh structure 3 with the cover member 5.

As shown in FIG. 8, in the cut surface portion 3c of the net-like structure 3, the loop cut portion 2 of the continuous linear body 2 is formed.
Since a is in a stab-like state, if the user sits down as it is, the loop cutting portion 2a may strike the skin, causing a foreign-body sensation. In order to eliminate such a foreign-body sensation, it is preferable to smooth the cut surface layer portion 3c of the mesh structure 3 by using a finishing die 40 as shown in FIG.

The finishing die 40 has a molding surface 41 corresponding to the final product shape of the cushion body 1, and a built-in heater 42 is used to cut the surface section 3 c of the reticulated structure 3.
Above the softening temperature of the continuous linear body 2 (for example, around 200 ° C.)
By pressing the cut surface surface portion 3c with the molding surface 41, the loop cut portion 2a is tilted in the direction along the surface of the cushion body as shown in FIG. 10, and the loop cut portion 2a is extended. Thus, the cut surface layer 3c is smoothed.

When the temperature of the molding surface 41 of the finishing die 40 is 160 ° C. and the contact time between the mesh structure 3 and the molding surface 41 is 30 seconds, the change in the loop size is 2 mm, There was a feeling. When the temperature of the molding surface 41 is 160
When the contact temperature with the net-like structure 3 was 90 seconds, the change in the loop size was 4 mm, again giving a feeling of foreign matter.

On the other hand, the temperature of the molding surface 41 is set to 200
When the contact time with the network structure 3 was 30 seconds, the change in the loop size was 6 mm, and the feeling of foreign matter was reduced. Forming surface 4
1 was 200 ° C. and the contact time with the network 3 was 90 °.
In the case of seconds, the change in the loop size was 8 mm, and the feeling of foreign matter was eliminated.

As shown by a two-dot chain line M1 in FIG.
When the reticulated structure 3 of the side support portion 1b formed larger is compressed by the cover member 5, the appearance of the side support portion 1b is improved, and the compression load (φ100 mm indentation load) is improved by about 23 N (Newton). The holdability of the side support portion 1b has been improved. Also, as shown by a two-dot chain line M2 in FIG. 3, when the relatively large ridge line portion 9 is compressed by covering it with the cover member 5, the appearance of the side support portion 1b is improved and the support performance is also improved.

The reticulated structure 3 of the cushion body 1 of the above embodiment forms a large number of random three-dimensional loops by winding a continuous linear body 2 of 300 denier or more mainly composed of a thermoplastic elastic resin. The loops are brought into contact with each other in a molten state, and most of the contact portions are fused with each other to form a three-dimensional network structure 3 having a three-dimensional random loop. For this reason, even if a large deformation is given by a large stress when the cushion body 1 is used, the entire network structure 3 absorbs the stress while deforming three-dimensionally with each other, and when the stress is released, the thermoplastic elastic resin Due to the rubber elasticity, the network structure 3 can be restored to the original shape.

Moreover, the net-like structure 3 of the cushion body 1
Is composed of the continuous linear body 2 continuous in the longitudinal direction of the net-like structure 3, so that it does not fray or collapse in shape.
Since the continuous linear bodies 2 are fused to each other in a molten state, no binder is required. Since the continuous linear bodies 2 are made of a single thermoplastic resin, they can be easily recycled by re-melting.

[Comparative Example] A block (density 0.05 g / cm ³ ) of a network structure manufactured by the network manufacturing apparatus 10 (shown in FIG. 4) similar to that of the above embodiment was subjected to heat as shown in FIG. It is housed in an aluminum mold 50 for pressing, and this network 3 ′ is compressed to two-thirds of its volume, and the inside of the network 3 ′ is heated to 130 ° C. to 160 ° C. Hot pressing was performed by blowing in hot air, and then cooling and demolding were performed to obtain a cushion body having a desired shape. The mold 50 is
A large number of holes having a hole diameter of 2 to 3 mm are formed at intervals of 10 to 20 mm.

In this comparative example, as shown in Table 1 below, three types of net-like structures (140 mm, 120 mm, and 105 mm) having different thicknesses before compression were used. The product was hot-pressed so as to have a thickness of 140 mm, and the appearance and hardness of the product were examined.

[0044]

[Table 1]

As shown in Table 1, the thickness before compression was 14
The comparative product 1 using the 0-mm net-like structure block has a good product appearance, but has a disadvantage of being too heavy. Comparative product 3 using a mesh block having a thickness of 105 mm before compression
Was light, but the product appearance was poor.

[0046]

According to the first aspect of the present invention, it is possible to provide a low-cost cushion body having a desired shape formed of a lightweight three-dimensional loop network structure having good air permeability, excellent set resistance, and light weight. Can be. In addition, this cushion does not require a binder, and is easy to recycle. According to the invention described in claim 2, the appearance of the cushion body can be improved by the cover member. According to the invention described in claim 3, the appearance of the cushion body used for the seat of the vehicle or the like can be improved. According to the fourth aspect of the present invention, it is effective in eliminating the feeling of foreign matter on the cut surface of the mesh structure, and the riding comfort is further improved.

According to the fifth aspect of the present invention, a cushion made of a lightweight three-dimensional loop net structure having good air permeability, excellent set resistance, and a desired shape in a non-compressed or partially compressed state. Production can be performed efficiently, and a molding step for finishing that is performed as necessary can be simplified, and the production cost can be reduced. According to the invention described in claim 6, the surface layer of the cut surface of the net-like structure is smoothed, and the sitting comfort and the like can be further improved.

According to the seventh aspect of the present invention, the cushion body composed of the mesh structure can be continuously and efficiently manufactured, and the manufacturing cost can be reduced. According to the invention described in claim 8, the desired cushion body product shape can be continuously and efficiently formed without generating chips. The invention described in claim 9 is effective in eliminating the feeling of foreign matter.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cushion body showing one embodiment of the present invention.

FIG. 2 is a perspective view of a mesh structure forming the cushion body shown in FIG. 1;

FIG. 3 is a sectional view of a part of the cushion body shown in FIG. 1;

FIG. 4 is a side view of an apparatus for manufacturing the mesh structure of the cushion body shown in FIG. 1;

FIG. 5 is a perspective view of a net-like structure made by the manufacturing apparatus shown in FIG. 4;

FIG. 6 is a perspective view showing a cutting machine.

FIG. 7 is a perspective view schematically showing a cut portion of the net-like structure.

FIG. 8 is an enlarged side view showing a state before a smoothing process on a surface section of a cut surface of the network structure.

FIG. 9 is a sectional view showing a finishing mold.

FIG. 10 is an enlarged side view showing a state after a smoothing process of a cut surface layer portion of the network structure.

FIG. 11 is a sectional view showing a molding apparatus for performing a conventional hot press.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cushion body 1b ... Side support part 2 ... Continuous linear body 3 ... Net-like structure 5 ... Cover member 10 ... Net-like body manufacturing apparatus 31 ... Cutting machine 40 ... Mold for finishing

Claims (9)

[Claims] A fineness of a thermoplastic resin of 300 to 100.
A three-dimensional net-like structure having an apparent density of 0.005 to 0.2 g / cm ³ , in which a plurality of continuous linear bodies of 000 denier are meandered in a loop shape and their contact parts are fused together. A cushion body, wherein the net-like structure is cut into a desired cushion body product shape. And a cover member for covering said net-like structure.
The cushion body according to claim 1, wherein a part of the mesh structure is compressed by the cover member. 3. The cushion body according to claim 2, wherein the portion compressed by the cover member is a side support portion of the seat cushion body. 4. The cushion body according to claim 1, wherein a loop-cut portion of a surface layer of the cut surface of the network structure is deformed in a direction along a surface of the cushion body to smooth the surface layer of the cut surface. . 5. A three-dimensional net-like structure by discharging a softened thermoplastic resin from a plurality of nozzles, thereby winding a plurality of continuous linear bodies in a loop shape and fusing their contact portions with each other. Forming a net, a step of cooling the net-like structure, and a step of cutting the net-like structure into a desired cushion body product shape. 6. A step of heating the cut surface portion of the network structure by using a mold at a temperature equal to or higher than the softening temperature of the continuous linear body and pressing the loop cut portion to smooth the cut surface portion. The method for manufacturing a cushion body according to claim 5, wherein 7. A three-dimensional structure in which a plurality of continuous linear bodies obtained by continuously discharging a softened thermoplastic resin from a plurality of nozzles are bent in a loop shape and their contact portions are fused to each other. A nozzle unit for obtaining a typical net-like structure, cooling means for hardening the continuous linear body by cooling, and cutting means for cutting the net-like structure into a desired cushion body product shape. Characteristic cushion body manufacturing equipment. 8. The cushion body manufacturing apparatus according to claim 7, wherein said cutting means is a heater wire. 9. A finishing mold for smoothing the surface portion of the cut surface by heating the surface portion of the cut surface of the network structure to a temperature equal to or higher than the softening temperature of the continuous linear body and pressing the loop cut portion. The cushion body manufacturing apparatus according to claim 7, comprising: