JP3625890B2 - Manufacturing method of seat body integrally molded seat body - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for manufacturing a surface material-integrated seat body used for automobiles, railway vehicles, furniture, and the like.
[0002]
[Prior art]
Conventionally, these seat bodies have been manufactured by the following method, for example.
(1) Preliminarily formed into a predetermined shape by sewing, vacuum forming, hot press molding, etc., and bonded to a molded cushion body or foam chip formed by injecting and foaming a foaming stock solution and bonding it with a binder. A method of coating by hand or using an auxiliary device in combination with an agent.
(2) A method of integrating a surface material and a cushion body by injecting and foaming a foam stock solution into a surface material obtained by setting a surface material having a predetermined shape in a foaming mold as in (1).
(3) A method in which a surface material obtained by laminating an air-impermeable film or the like is vacuum-formed by a seat body-shaped concave mold depending on the material of the surface material, and a polyurethane unfoamed undiluted solution is injected into the mold to perform foam integration.
[0003]
However, the above method has the following problems.
For (1), the surface material creation process, cushion body formation process, bonding process and process become complicated, and there are not only problems such as cost and delivery time, but also the surface material and cushion body in the final process. During the bonding, there is a problem in that the bonding shift and the surface material are easily stained, and the yield is deteriorated due to defects.
[0004]
For (2), a thicker wadding material or an air-impermeable film is used to prevent the foaming stock solution from leaking to the surface side of the surface material. If it is interposed, a hardened layer will be generated at least partially due to the permeation of the undiluted solution, and the seating feeling will be deteriorated. There was a problem. In addition, a laminating process such as laminating a wadding material and a film has increased, and there has been a problem of an increase in cost.
[0005]
For (3), in order to utilize vacuum forming, it was necessary to use an air-impermeable material for the surface material or to laminate an air-impermeable film on the back surface of the air-permeable material. . Therefore, the completed seat body has no breathability in the surface material, and gives discomfort due to sweating or the like when sitting for a long time.
[0006]
The present invention has been made against the background of the problems of the conventional manufacturing method as described above. There are few intermediate processes, and the manufacturing cost of the product is superior to other manufacturing methods in an integrated process. The object is to produce a seat body that is excellent in stability, design, cushioning, and durability.
[0007]
[Means for solving problems]
The manufacturing method of the surface material integrated molding seat body of the present invention includes setting a surface material and a heat-meltable adhesive film, which have been preliminarily cut to a predetermined size, in a mold, suction molding the surface material and the heat-meltable adhesive film, Then, after setting the middle mold in the opening of the mold and filling the foam chip with the binder blended in the mold, the foam chip is compressed with the lid mold, and then the steam is blown out from the lid mold. A method of manufacturing a surface material-integrated seat body, wherein a foam chip is bonded by reacting a binder, and a heat-melt adhesive film is melted to integrate the surface material and the foam chip.
In addition, the surface material and the heat-meltable adhesive film that have been preliminarily cut to a predetermined size are set in a mold, the surface material and the heat-meltable adhesive film are suction-molded, and a soft material prepared to have a substantially inner shape of the mold The polyurethane sheet is placed on the hot-melt adhesive film, and then the middle mold is set in the opening of the mold and filled with foam chips in which the binder is blended. The foam chip is compressed, then steam is blown out from the lid mold, the binder is reacted to bond the foam chip and adhere to the soft polyurethane sheet, and the hot melt adhesive film is melted to make the surface material and the soft polyurethane sheet. Is bonded, and the surface material, the flexible polyurethane sheet and the foam chip are integrated, and the manufacturing method of the surface material integrally formed seat body.
[0008]
The device mold used in the present invention includes a mold, a middle mold, and a lid mold. For example, thermosetting resin such as epoxy resin or silicone resin, iron, aluminum, brass or the like is used as the material, but aluminum is most suitable in terms of cost, workability, durability, and the like.
[0009]
The molding die has a seat body shape inside the die, has an opening at the top, and has suction holes inside for suction molding the surface material and the hot-melt adhesive film. Moreover, you may have the press frame which fixes and hold | maintains the edge part of the surface material and heat-meltable adhesive film which were suction-molded around the upper opening part. As a result, generation of wrinkles due to displacement of the surface material or the like during suction molding can be prevented and suction molding can be performed accurately.
[0010]
The middle mold is a substantially cylindrical mold that can be set to the flange of the opening of the mold to add a volume for storing the bulk of the foam chip before compression filled in the mold. Of the type. As long as the shape substantially coincides with the opening of the mold, the lid can be inserted, and the foam chip can be compressed. In addition, the middle mold may also have a structure that also serves as a pressing frame for a surface material or the like.
[0011]
The lid mold is a mold for compressing the foam chip inside the mold and for introducing steam into the mold.
The shape has a compression surface substantially the same as the opening of the mold, and the compression surface has a steam blowing hole. The number of the blowout holes may be one, but in order to blow the steam over the entire foam chip, it is preferable that the blowout holes are uniformly over the entire compression surface. Moreover, it is preferable that a lid | cover type | mold is a shape which can be penetrated to a middle mold | type. By providing a steam inlet in the upper part of the lid mold, it is possible to provide a troublesome inner structure when inserted into the middle mold. In addition, it is possible to perform an operation with a constant compression pressure or the like by interlocking the lid mold with a press device or the like.
The foam chip filled in the middle mold is compressed, and then steam is blown from the blowing holes to react the binder to bond the foam chips. At this time, the heat-meltable adhesive film is melted by steam heat to adhere the foam chip or the flexible polyurethane foam sheet bonded to the surface material.
[0012]
As the surface material, any material can be used as long as it is normally used for a seat body. However, it is preferable that the elongation is about 20% or more at the time of breakage in terms of suction molding. If it is 20% or less, suction molding may be difficult, and wrinkles and the like may easily occur.
In particular, it is possible to use breathable knitted fabric, non-woven fabric, or artificial leather or synthetic leather that has breathability by punching processing, etc., without adding special processing, and without losing its breathability Is possible.
It is also possible to use a surface material in which a wadding material such as a flexible polyurethane foam sheet is laminated in advance by laminating or the like.
[0013]
The heat-melt adhesive film can be a polyolefin-based, polyamide-based, or polyester-based resin film, but a polyolefin-based resin film is preferable in terms of weldability and cost.
The thickness of the heat-meltable adhesive film is preferably 20 to 200 μm, and more preferably 30 to 100 μm. If it is 20 μm or less, holes may be formed at the time of suction molding or adhesion between the adherends may be insufficient. If it is 200 μm or more, suction moldability is deteriorated or it takes time to completely melt, and workability is increased. In addition, the air permeability is hindered and the cost is not so favorable. Further, the hot-melt adhesive film may be previously laminated on the surface material.
The melting temperature of the heat-meltable adhesive film is preferably one that melts with steam heat and does not exist in a film shape, and is preferably 65 to 135 ° C. When the temperature is 65 ° C. or less, stickiness may occur during handling at room temperature, and dust or the like may be easily attached, which may be difficult to handle. Further, if it is 135 ° C. or higher, a long heating time is required and work efficiency is deteriorated, and depending on the material of the chip, there is a case where an adverse effect such as melting of the foam chip may occur.
[0014]
The foam chip preferably has air permeability, heat resistance, adhesiveness, flexibility, and cushioning properties. For example, a soft slab polyurethane foam, a molded foamed polyurethane foam, or a soft polyurethane foam chip in which a laminate of a woven fabric and a foam sheet is used as a chip is preferably used. Also, waste of soft slab polyurethane foam or molded foamed polyurethane foam may be collected, chipped and reused.
The size of the foam chip is preferably 10 mm or less in average diameter, and if the average diameter exceeds 10 mm, it may not be preferable in terms of strength as a cushion body.
[0015]
The binder is preferably a reactive binder that is cured by moisture or heat of the introduced steam. For example, a polyurethane prepolymer having an isocyanate group at the terminal is preferable in terms of work efficiency.
The mixing ratio of the binder to the foam chip is 10 to 35% by weight, preferably 15 to 30% by weight. When the mixing ratio is less than 10% by weight, the bonding force between the foam chips is weak, and the physical properties of the bonded foam chips as a whole may be deteriorated.
[0016]
The foam chip is bonded and cured, and has a density of about 40 to 130 kg / cm ³ , preferably about 50 to 100 kg / cm ³ , and is adjusted by the filling amount. If it is less than 40 kg / cm ³ , it may be unfavorable in terms of durability such as sag and breakage. On the other hand, if it exceeds 130 kg / cm ³ , the hardness increases, the seating comfort etc. deteriorates and the weight is also heavy. This may increase the cost.
[0017]
The vapor pressure (temperature) introduced from the lid mold into the mold is preferably 0.3 kg / cm ² (about 65 ° C.) to 3 kg / cm ² (about 135 ° C.), more preferably 0.7 kg. / Cm ² (about 90 ° C.) to ² kg / cm ² (about 120 ° C.). Is less than 0.3 kg / cm ^2, may melt the hot melt adhesive film may be insufficient in adhesion failure and breathable hinder, or impair the appearance of the surface material exceeds 3 kg / cm ^2, chips Depending on the material, foam chips may be melted.
The steam pressure and steam introduction time vary depending on the type of binder, the mixing ratio, the size of the mold, the hot-melt adhesive film, etc., but it is usually about 2 to 5 minutes.
[0018]
In order to improve the cushioning property of the seat body and the adhesion between the surface material and the foam chip, a flexible polyurethane foam sheet may be interposed between the hot-melt adhesive film and the foam chip.
The thickness of the flexible polyurethane foam sheet may be about 2 to 10 mm, preferably about 3 to 5 mm. If it is less than 2 mm, the mounting workability to the mold is poor, and if it exceeds 10 mm, the workability is still bad and the cost may increase. However, if the surface material is laminated with a wadding material in advance or if there is no problem in cushioning properties, it is not necessary to take this measure.
[0019]
[Action]
There is no need to bond the surface material and the heat-meltable adhesive film in a separate process, and it is possible to form the inner wall shape of the mold by suction molding. The foam chip mixed with the binder is put into the mold. Filling, compressing with a lid mold, introducing steam, bonding foam chips to each other at the same time, melting the hot-melt adhesive film, and integrating the skin chip and the foam chips bonded together, Furthermore, since the heat-meltable adhesive film is melted, the air permeability of the surface material is not hindered, so that the air permeability is ensured and a seat body excellent in cushioning and durability can be easily obtained.
[0020]
【Example】
An embodiment of the present invention will be described with reference to the drawings.
[0021]
As the surface material 2, a 50 μm-thick hot-melt adhesive film 3 made of a knitted fabric having an elongation rate of 30% and a vinyl acetate resin is cut into a size corresponding to the shape of the inner wall of the mold, and as shown in FIG. The end portions of the surface material 2 and the hot-melt adhesive film 3 are fixed to the press frame 7 on the flange around the opening of the mold 6.
[0022]
Next, the air suction hole 10 'on the inner wall of the mold is taken and sucked with a vacuum pump, and the surface material 2 and the hot-melt adhesive film 3 are shaped along the inner wall of the mold as shown in FIG. Then, the flexible polyurethane foam 4 having a thickness of 4 mm, which has been cut into a predetermined shape in advance, is set along the hot-melt adhesive film 3.
The middle mold 8 for compensating the bulk of the foam chip before compression is set on the flange around the opening of the mold 6.
[0023]
A polyurethane prepolymer is added to a flexible polyurethane foam chip having an average particle size of about 10 mm so as to be 25% by weight with respect to the chip, mixed by a mixer, and the density of the compressed foam chip becomes 60 kg / cm ^3. The amount was filled in the middle mold 8 and the mold as shown in FIG.
[0024]
Next, the lid mold 9 moving up and down by the air cylinder was lowered, and the foam chip was compressed into the mold as shown in FIG. At this time, 1.4 kg / m ² (about 110 ° C.) of steam was introduced into the mold from the through hole in the compression surface of the lid mold 9 for 3 minutes and 30 seconds.
[0025]
Thereafter, the lid mold 9 is raised, the middle mold 9 and the holding frame 7 are removed, and the semi-finished product in which the foam chip and the surface material combined with each other are integrated is taken out from the mold 6 and is dried in an atmosphere at 50 ° C. Residual moisture in the chip mold was removed.
[0026]
Subsequently, the edge part of the surface material 2 and the heat-meltable adhesive film 3 was cut, and the seat body of FIG. 1 was obtained.
[0027]
【The invention's effect】
According to the present invention, the surface material and the foam chip combined with each other are integrated without compromising the air permeability of the surface material in a simple production facility and production process, and excellent in cushioning and durability. The seat body can be manufactured efficiently and at low cost.
[Brief description of the drawings]
FIG. 1 is a three-side view of a seat body according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a mold according to an embodiment of the present invention and a mounting body such as a surface material.
FIG. 3 is a cross-sectional view of suction molding in an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a foam chip filling according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of the embodiment of the present invention at the time of compression and steam introduction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seat body 2 Surface material 3 Hot melt adhesive film 4 Soft polyurethane foam sheet 5 Foam chip | tip 5 'mutually couple | bonded Foam chip 6 Molding die 8 Middle mold | type 9 Lid type | mold 10 Air suction hole 10' Air suction hole 11 Vapor blowing hole 12 Steam pipe

Claims (2)

Set the surface material and heat-meltable adhesive film cut in advance to the specified dimensions in the mold, suck and mold the surface material and heat-meltable adhesive film, and then set the middle mold in the opening of the mold. After filling the foam chip in which the binder is blended, the foam chip is compressed by the lid mold, and then the steam is blown out from the lid mold to react the binder to bond the foam chip and heat. A method for manufacturing a surface material-integrated seat body comprising melting a meltable adhesive film to integrate a surface material and a foam chip. A flexible polyurethane sheet prepared by setting a surface material and a heat-meltable adhesive film, which have been preliminarily cut into predetermined dimensions, into a mold, suction-molding the surface material and the heat-meltable adhesive film, and further forming an approximately inner wall shape of the mold Is placed on the hot-melt adhesive film, and then the middle mold is set in the opening of the mold and filled with the foam chip in which the binder is blended. Next, steam is blown out from the lid mold, the binder is reacted to bond the foam chip and adhere to the flexible polyurethane sheet, and the hot-melt adhesive film is melted to bond the surface material and the flexible polyurethane sheet. A surface material, a flexible polyurethane sheet, and a foam chip are integrated.

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