JPH08252145A - Method for manufacturing seat unit formed integrally with surface material - Google Patents

Abstract

PURPOSE: To improve the quality stability, cushioning performance and durability in an integrated process by filling an inner die with foam chips blended with a binder after sucking and forming a surface material and a thermally melting adhesive film, compressing by a lid die, blowing steam from the lid die, and integrating the surface material with foam chips. CONSTITUTION: A woven cloth as a surface material 2 and a thermally melting adhesive film 3 are respectively cut into the inner wall shape of a forming die, placed on a forming die 6, and their edges are fixed by a pressing frame 7. Then, air in the die is evacuated by a vacuum pump through an air sucking hole 10' on the inner wall of the die, and soft polyurethane foam 4 is set thereon. An inner core 8 is set to supplement bulk of the foam chips before compression. Next, polyurethane polymer is mixed into the soft polyurethane foam chips 5', which is filled into the inner die 8, the lid die 9 is descended by means of an air cylinder to compress the foam chips 5'. Steam is introduced at this time into the forming die through a through hole 12 on the lid die 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a seat body integrally molded with a surface material, which is used for automobiles, railway vehicles, furniture and the like.

[0002]

2. Description of the Related Art Conventionally, these seat bodies have been manufactured by the following method, for example. (1) Cushion bodies or foam chips that have been molded into a predetermined shape by sewing, vacuum molding, hot press molding, etc., and then foamed by injecting a foaming undiluted solution and bonded with foam chips are bonded to the molded cushion body. A method of coating by hand or by using an auxiliary device together. (2) A method of integrating a surface material and a cushion body by injecting and foaming a surface material set in a foaming mold with a surface material having a predetermined shape as in (1) and injecting and foaming. (3) A method of vacuum-molding a surface material in which an impermeable film or the like is laminated depending on the material of the surface material, using a concave mold having a seat body shape, injecting a polyurethane unfoamed stock solution into the mold, and performing foaming integration.

However, the above method has the following problems. Regarding (1), not only problems such as cost and delivery time are involved in the steps of forming the surface material, forming the cushion body, and adhering, but also in the final step, At the time of adhesion, there was a problem that the deviation of adhesion and the contamination of the surface material were likely to occur, and the yield deterioration due to defects was unavoidable.

As for (2), a thick wadding material or an impermeable film is used to prevent leakage of the foaming stock solution to the front side of the surface material, stains, and the like. If a wadding material is interposed, a hardened layer will be generated at least partially due to the permeation of the undiluted solution, and the seating feeling will deteriorate, and if an impermeable film is interposed, the breathability necessary for the seat body will be impaired, and sweating problems and sitting There was a problem that made it worse. In addition, the number of laminating processes such as laminating of wadding materials and films is increased, which causes a problem of cost increase.

For (3), in order to utilize vacuum forming, it is necessary to use an impermeable material for the surface material or to laminate an impermeable film on the back surface for the permeable material. was there. Therefore, the completed seat body does not have air permeability on the surface material, and gives discomfort due to sweating or the like when sitting for a long time.

The present invention has been made against the background of such problems of the conventional manufacturing method. There are few intermediate steps, and the manufacturing cost of the product is superior to other manufacturing methods in a consistent process. Furthermore, it is an object of the present invention to manufacture a seat body having excellent quality stability, designability, cushioning property, and durability.

[0007]

A method for manufacturing a surface material-integrated molded seat body according to the present invention is a method in which a surface material and a heat-meltable adhesive film, which are cut into predetermined dimensions, are set in a molding die, and the surface material and the heat-meltable adhesive film are melted. The adhesive adhesive film by suction molding, then set the middle mold in the opening of the mold, fill the foam chip with the binder blended in the mold, then compress the foam chip with the lid mold, In addition to blowing the steam from the lid, the binding agent reacts to bond the foam chips, and the heat-meltable adhesive film is melted to integrate the surface material with the foam chips. It is a body manufacturing method. In addition, a surface material and a heat-meltable adhesive film that have been cut into a predetermined size are set in a molding die, the surface material and the heat-meltable adhesive film are suction-molded, and a soft material prepared to have a substantially inner wall shape of the molding die. The polyurethane sheet is placed on the heat-meltable adhesive film, then the middle mold is set in the opening of the mold, and the mold chip filled with the binder is filled in the mold and then the lid mold is used. The foam chip is compressed, then steam is blown out from the lid mold to react the binder to bond the foam chip and bond it with the soft polyurethane sheet, and at the same time melt the heat-meltable adhesive film to melt the surface material and the soft polyurethane sheet. And a surface material, a soft polyurethane sheet, and a foam chip are integrated with each other to provide a surface material-integrated molded seat body manufacturing method.

The apparatus mold used in the present invention comprises a molding mold, a middle mold and a lid mold. As the material, for example, thermosetting resin such as epoxy resin and silicone resin, iron, aluminum, brass, etc. are used, but cost, workability,
Aluminum is the most suitable in terms of durability.

The mold has a shape of a seat body inside the mold,
It has an opening at the top and suction holes inside for suction molding the surface material and the heat-meltable adhesive film. Further, a pressing frame for fixing and holding the suction-molded surface material and the ends of the heat-meltable adhesive film may be provided around the upper opening. As a result, it is possible to prevent the occurrence of wrinkles due to the displacement of the surface material or the like during the suction molding and to perform the suction molding accurately.

The middle mold is a mold having a substantially cylindrical shape which can be set on the flange of the opening of the molding mold, and the molding mold has a volume for accommodating the bulkiness of the foam chips before compression filled in the molding mold. It is a type for adding. It suffices that the shape is substantially the same as the opening of the molding die, the lid die can be inserted therethrough, and the foam tip can be compressed. Further, the middle mold may have a structure that also serves as a holding frame for a surface material or the like.

The lid mold is a mold for compressing foam chips inside the mold and for introducing steam into the mold. The shape has a compression surface that is substantially the same as the opening of the molding die, and has a steam blowing hole on the compression surface. The number of the blowout holes may be one, but it is preferable that the blowout holes are evenly formed on the entire compression surface in order to blow the vapor onto the entire foam chip. Moreover, it is preferable that the lid mold has a shape that can be inserted into the middle mold. By providing the steam introduction port in the upper portion of the lid mold, it is possible to form an internal structure that causes a hindrance when the medium mold is inserted. Further, by interlocking the lid mold with a pressing device or the like, it is possible to perform work with a constant compression pressure and the like. The foam chips filled in the middle mold are compressed, and then steam is blown from the blowout holes to react the binder to bond the foam chips. At this time, the heat fusible adhesive film is melted by steam heat to adhere the foam chip or the flexible polyurethane foam sheet bonded to the surface material.

As the surface material, any material can be used as long as it is usually used for a seat body, but it is preferable that the elongation rate in suction molding is about 20% or more at the time of breaking. . If it is 20% or less, suction molding may be difficult and wrinkles may easily occur. In particular, it is possible to use breathable knitted fabrics, non-woven fabrics, or even artificial leather or synthetic leather that has breathability by punching or the like without adding any special processing and without losing its breathability. It is possible to It is also possible to use a surface material on which a wadding material such as a flexible polyurethane foam sheet is laminated in advance by laminating or the like.

As the heat-meltable adhesive film, a polyolefin-based, polyamide-based, polyester-based resin film or the like can be used, but a polyolefin-based resin film is preferable from the viewpoint of weldability and cost. The thickness of the heat-meltable adhesive film is preferably 20 to 200 μm, more preferably 30 to 100 μm. If it is 20 μm or less, holes may be opened during suction molding or the adhesive strength between adherends may be insufficient, and if it is 200 μm or more, suction moldability may be deteriorated or it may take time to completely melt, resulting in workability. In addition, the air permeability is impaired, and the cost is not preferable. Further, the heat-meltable adhesive film may be laminated on the surface material in advance. The melting temperature of the heat-meltable adhesive film is preferably one that melts by steam heat and does not exist in a film shape, and is preferably 65 to 135 ° C. 6
If the temperature is 5 ° C or lower, stickiness may occur or dust may be easily attached during handling at room temperature, which may be difficult to handle. Further, if the temperature is 135 ° C. or higher, the heating time becomes long, work efficiency deteriorates, and adverse effects such as melting of the foam chips may occur depending on the material of the chips.

The foam chip preferably has air permeability, heat resistance, adhesiveness, flexibility and cushioning property. For example, soft slab polyurethane foam, molded polyurethane foam, soft polyurethane foam chips obtained by chipping a laminate of a knitted fabric and a foam sheet, and the like are preferably used. Further, the waste material of the soft slab polyurethane foam or the molded polyurethane foam may be collected, made into chips and reused. The foam chip preferably has an average diameter of 10 mm or less, and if the average diameter exceeds 10 mm, it may not be preferable in terms of strength as a cushion body.

The binder is preferably a reactive binder which is cured by the moisture or heat of the steam introduced,
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. If the mixing ratio is less than 10% by weight, the bonding strength between the foam chips may be weak, and the physical properties of the bonded foam chips as a whole may deteriorate.

Foam chips, in the bond-cured state,
40 to 130 kg / cm ³ , preferably 50 to 100 k
It has a good density of about g / cm ³ and is adjusted by the filling amount. Four
If it is less than 0 kg / cm ³ , it may be unfavorable in terms of durability such as fatigue or breakage, while 130 k
If it exceeds g / cm ³ , the hardness becomes high, the sitting comfort and the like deteriorate, the weight becomes heavy, and the cost may increase.

The steam pressure (temperature) introduced from the lid mold into the mold is preferably 0.3 kg / cm ² (about 65).
℃) ~3kg / cm it is ² (about 135 ° C.), more preferably 0.7 kg / cm ² (about 90 ℃) ~2kg / 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, the foam chips may be melted. The steam pressure and the steam introduction time vary depending on the type of the binder, the mixing ratio, the size of the mold, the heat-meltable adhesive film, etc., but are usually about 2 to 5 minutes.

A soft polyurethane foam sheet may be interposed between the hot-melt adhesive film and the foam chip in order to improve the cushioning property of the seat body and the adhesion between the surface material and the foam chip. The thickness of the flexible polyurethane foam sheet is 2 to 10 mm, preferably 3
It may be about 5 mm. If it is less than 2 mm, the workability of mounting on the molding die is poor, and if it exceeds 10 mm, the workability is also poor.
The cost may increase. However, if a wadding material is laminated on the surface material in advance or if there is no problem in cushioning property, this measure need not be taken.

[0019]

[Function] It is not necessary to bond the surface material and the heat-meltable adhesive film in a separate process, and it is possible to shape the inner wall of the mold by suction molding. It is filled in a mold, compressed by a lid mold, and steam is introduced to bond the foam chips to each other, and at the same time, the heat-meltable adhesive film is melted to form the skin material and the foam chips bonded to each other. Because it is integrated and the heat-meltable adhesive film is melted, it does not hinder the air permeability of the surface material, so it is possible to easily obtain a seat body that secures air permeability and has excellent cushioning and durability. Becomes

[0020]

An embodiment of the present invention will be described with reference to the drawings.

As the surface material 2, a knitted cloth having an elongation of 30% and a heat-melting adhesive film 3 made of vinyl acetate resin and having a thickness of 50 μm are cut into a size corresponding to the shape of the inner wall of the mold, and as shown in FIG. Then, the surface material 2 and the end portions of the heat-meltable adhesive film 3 are fixed to the pressing frame 7 on the flange around the opening of the molding die 6 by sequentially placing the surface material 2 and the end portions of the heat-meltable adhesive film 3 on the molding die 6.

Next, through the air suction hole 10 'on the inner wall of the molding die, a vacuum pump is used to suck the surface material 2 and the heat-meltable adhesive film 3 along the inner wall surface of the molding die as shown in FIG. Then, a flexible polyurethane foam 4 having a thickness of 4 mm, which is cut into a predetermined shape in advance, is formed into a heat-meltable adhesive film 3
Set along the top. The middle mold 8 for supplementing the bulkiness of the foam tip before compression is set on the flange around the opening of the mold 6.

Polyurethane prepolymer was added to a soft polyurethane foam chip having an average particle size of about 10 mm so as to be 25% by weight with respect to the chip, and the mixture was mixed by a mixer, and the density of the foam chip after compression was 60 kg / cm.
^An amount of ³ was filled in the middle mold 8 and the mold as shown in FIG.

Next, the lid die 9 which moves up and down by an air cylinder is lowered to put the foam chips in the molding die.
Compressed like. At this time, 1.4 kg / m ² (about 110 ° C.) of steam was introduced into the molding die for 3 minutes and 30 seconds through the through holes on the compression surface of the lid mold 9.

After that, the lid mold 9 is raised, the middle mold 9 and the pressing frame 7 are removed, and the semi-finished product in which the foam chips and the surface material which are mutually bonded are integrated is taken out from the molding die 6.
Residual water in the chip mold was removed in a dry room at 50 ° C.

Next, the end portions of the surface material 2 and the heat-meltable adhesive film 3 were cut to obtain the seat body shown in FIG.

[0027]

According to the present invention, the cushioning property in which the surface material and the foam chip mutually bonded are integrated without impairing the air permeability of the surface material in a simple manufacturing facility and manufacturing process, A highly durable seat body can be efficiently manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a three-view drawing of a seat body according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a molding die according to an embodiment of the present invention and a mounting body such as a surface material.

FIG. 3 is a sectional view of the suction molding according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of a foam chip filling material according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of an embodiment of the present invention during compression and vapor introduction.

[Explanation of symbols]

 1 Seat Body 2 Surface Material 3 Hot Melt Adhesive Film 4 Soft Polyurethane Foam Sheet 5 Mutually Bonded Foam Chips 5'Foam Chips 6 Molds 8 Medium 9 Lids 10 Air Suction Holes 10 'Air Suction Holes 11 Steam Blowout Holes 12 steam pipe

Claims (2)

[Claims] 1. A surface material and a heat-melting adhesive film, which are preliminarily cut into a predetermined size, are set in a molding die, the surface material and the heat-melting adhesive film are suction-molded, and then a middle die is opened in the molding die. After filling the foam chip with the binder blended in the mold, the foam chip is compressed with the lid mold, and then steam is blown from the lid mold to react the binder to form the foam chip. A method of manufacturing a surface material-integrated molded seat body, which comprises bonding the surface material and the foam chip together by melting the heat-meltable adhesive film. 2. A surface material and a heat-melting adhesive film, which are cut into a predetermined size in advance, are set in a molding die, the surface material and the heat-melting adhesive film are suction-molded, and further prepared so as to have a substantially molding inner wall shape. Place the soft polyurethane sheet on the heat-meltable adhesive film, then set the middle mold in the opening of the mold and fill the mold chip with the blended binder, Then, the foam chip is compressed by, then steam is blown from the lid mold to react the binder to bond the foam chip, and the soft polyurethane sheet is bonded, and the heat-meltable adhesive film is melted to form a surface material. A method for producing a surface material-integrated molded seat body, comprising bonding a soft polyurethane sheet to integrate a surface material, a soft polyurethane sheet and a foam chip.