JPH11147230A - Method for molding fiber cushion material for seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide fiber cushion materials for seat which can be easily put into a die and a certain amount of which can also be put into a complicated die part such as a curved die part as designed and in which differences in density of the materials can be minimized. SOLUTION: An upper and lower dies 2, 3 have respectively cavities 5, 6 which are provided outside gas-permeable molding parts 2A, 3A respectively. A raw cotton, as fiber raw material, in which thermoplastic low melting point fibers and high melting point fibers are mixed, is put into the die 3 and the dies 2, 3 are clamped together. And while hot air is being passed from one of the cavities to the other one through a molding part defined by the upper and lower dies, the raw cotton, as fiber raw material, is molded by heat, in which the raw cotton is formed into a mat-like shape by pre-molding and cut into cubic forms of predetermined size using a crusher or the like and the crushed materials 20 are measured and put into the die 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a fiber cushion for a seat useful as a cushioning or cushioning material for a vehicle, an office chair, and its components such as a headrest and an armrest.

[0002]

2. Description of the Related Art FIGS. 3 (a) and 3 (b) show an example of a fiber cushion body of this type and a hot air mold used for molding the same. The fiber cushion body 50 is for a seat back constituting a seat, and is designed such that upper and lower portions 50b and 50c located on both sides of the main portion 50a stand up, and a frame with an S spring is arranged inside the main portion 50a. It is. The fiber raw material is raw cotton obtained by mixing a high melting point fiber with a thermoplastic low melting point fiber.

[0003] The molding die structure has a configuration in which a heat treatment is performed while passing hot air through a heating air blowing means to a molding portion 63 formed in a clamped state of the upper and lower dies 61 and 62. The upper and lower dies 61 and 62 are formed of gas-permeable molding portions 61A and 62A that define the molding portion 63, and molding portions 61A and 62A.
A is provided with cavities 64 and 65 provided on the outside of A, and the upper mold 61 is clamped in a state of being housed in the lower mold 62. In addition, the forming part 63 forms a space corresponding to the fiber cushion body 50. The lower mold 62 is supplied with hot air pressure-fed through the heating blower means to the cavity 6.
An inlet 66 for introducing into the 5 is provided. The upper die 61 is provided with an outlet 67 for exhausting the hot air that has reached the cavity 64 from the cavity 65 through the molding portion 63. The hot air exhausted from the outlet 67 is guided to the heating blower, heated to a constant temperature again, sent to the inlet 66 and circulated.

When molding the fiber cushion body 50,
After the raw cotton of the fiber raw material is charged and arranged in the molding portion 62A of the lower die 62, the upper die 61 is moved so as to be accommodated in the lower die 62 and clamped with the compression of the fiber raw material. From that state, the raw cotton of the fiber raw material in the forming part 63 melts the low melting point fiber as the hot air passes from the hollow part 65 to the hollow part 64 through the forming part 63 for a predetermined time. When the fibers or the fibers are bonded together and cooled after the heat treatment, the fibers are kept in a shape corresponding to the molded portion 63.

[0005]

In the above-described forming method, the required amount of, for example, opened or unopened raw cotton as the raw material of the fiber raw material is supplied to the forming portion 62A of the lower mold 62 by the supply means. And heat-treated from a state compressed by mold clamping. Such a molding method has the following problems. When using the opened raw cotton, since the raw cotton naturally becomes light and bulky, the lower mold 62 must be formed deeply in proportion to the bulkiness. 62
A part of the raw cotton put into
It is difficult to control the input amount in each part according to the thickness of the molded product as designed, and the working environment is worsened. On the other hand, when using unspread raw cotton, the fibers are entangled with each other, and the size and density at the time of feeding are varied. In the automatic feeding method, the feeding amount at each part is not stable, and the density of the molded product is low. Partially different, the quality is difficult to stabilize and the yield is poor.

Japanese Patent Application Laid-Open No. 7-2228822 discloses a method of laminating and placing a plurality of flat slivers as fiber raw materials. This method is to cut the flattened material to a predetermined length as a fiber raw material and to prevent problems such as partial density difference of the molded product by laminating, but it also handles relatively thick sliver. It is difficult, automatic feeding to the lower mold is difficult,
When the flat shape is thick, it becomes difficult to adjust to a molded portion having a relatively curvature, so that the thickness is restricted.

The present invention has been developed in view of the above background. Its purpose is to be able to supply a fixed amount to a complicated mold input part such as a curved part as designed and to minimize the density difference etc. It is an object of the present invention to provide a method of forming a seat cushion material that can be formed. Still other objects will be sequentially clarified in the contents described below.

[0008]

According to the present invention, as shown in FIG. 1, the upper and lower dies 2, 3 are formed of gas permeable molding portions 2A, 3A and outer portions of the molding portions 2A, 3A. The raw cotton, which is a fiber raw material in which thermoplastic low-melting fiber and high-melting fiber are mixed, is placed in the lower mold 3 and the upper and lower molds 2 and 3 are formed. After tightening, the hot air is passed from the one hollow portion to the other hollow portion through the inside of the forming portion 4 formed by the upper and lower dies, and the raw cotton of the fiber raw material is heated and formed. After the raw cotton of the fiber raw material is formed into a mat shape by preforming, it is cut into a predetermined square shape by a crusher or the like.
Is measured and charged into the lower mold 3.

Here, as raw cotton as a fiber raw material used in the present invention, for example, a low-melting fiber such as a polyester elastomer and a high-melting fiber such as a polyester polymer excellent in resilience and compression durability are mixed. It was done. The low-melting fiber is a thermoplastic material, and allows for pre-molding, and is heat-treated at a molding temperature at which it can be melted,
Any binder can be used as long as it can bind fibers or fibers together as a binder and maintain the shape of the molded product corresponding to the shape of the molding portion of the molding die. In this case, it is preferable to use a core-sheath type or an eccentric sheath type of a crimped fiber or the like having thermal adhesiveness in order to obtain an excellent cushion structure. The larger the difference between the melting points of the low-melting fiber and the high-melting fiber, the better the molding efficiency is. However, if the temperature is 40 ° C. or more, the cushion properties are satisfied.

[0010] The raw cotton as a raw material of the fiber is preliminarily formed by, for example, a low heat treatment or a weak compression treatment, or a treatment at a temperature lower than the molding temperature and a weak compression force, and is appropriately formed into a mat shape. The dried product is used in a state of a crushed product 20 which is cut into a predetermined size by a crusher or the like. The cut shape is preferably a square shape from the viewpoint of cutability, and is, for example, a hexahedron such as a dice. However, it is only necessary that the shape can be adjusted to a size within a predetermined range. By using the pulverized product 20 as described above, the measurement and the automatic supply can be performed more stably in the case where the opened raw cotton and the unopened raw cotton are used. Therefore, in this structure, since the pulverized product 20 is put into the lower mold 3, even when the fiber cushion body has a complicated shape such as a curved portion, a partial density difference hardly occurs. It has the advantages of being able to improve the moldability into the mold 3 and the working environment, and being able to make the depth of the lower mold 3 relatively small since it is not extremely bulky.

The above-mentioned pulverized product 20 is preferably cut into a size in the range of 5 to 100 mm square in order to ensure the above advantages. In addition, the crushed product 20
Is formed by dividing into a plurality of large and small ranks classified by size. For example, as shown in FIG. 1, a large-rank crushed product 20a corresponding to a substantially flat portion of the fiber cushion body is used.
It is more preferable to use the crushed product 20b of a small rank corresponding to the substantially curved portion of the fiber cushion body. When the pulverized products 20a and 20b are properly used in accordance with the molding part as described above, the workability of the injection can be further improved, and the familiarity with a complicated shape such as a curved portion is improved, and the partial density difference is further improved. Disappears. As another method, for example, when the fiber cushion body is relatively monotonous and becomes thicker in thickness, the crushed products 20a, 20
It is also effective to fill the gaps between the crushed products 20a, which are likely to be generated when the crushed products b are automatically injected into the molding part, with small crushed products 20b.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, although the form described below has various technically preferable limitations,
It does not limit the scope of the invention.

FIG. 1 shows the method of the present invention in a state where a pulverized product is put into a hot-air molding die, and FIG. 2 shows a state of the hot-air molding die during heat molding. In the description of this embodiment, after an example of a hot air molding die used in the method of the present invention is outlined, a specific molding method using the hot air molding die will be described in detail. Figures 1 and 2
The hot air forming mold 1 shown in FIG. 1 has an upper mold 2 and a lower mold 3 and has a structure in which the upper mold 2 is moved so as to be accommodated in the lower mold 3 and is clamped. Can be heat-treated while passing hot air through the heating and blowing means 14 to the formed part 4 formed by the above.

The upper and lower dies 2 and 3 are formed with gas permeable molding portions 2A and 3A defining the molding portion 4 and hollow portions 5 and 6 respectively.
And have both. The lower mold 3 has a container shape with an upper opening, and the substantially entire outer surface is covered with a heat insulating material K. The molded portion 3A is provided so as to divide the internal space of the lower die 3 up and down while lying between the both side portions 3c of the lower die 3. The plate configuration of the molded portion 3A is formed to be gas permeable of the punched metal plate portion. Reference numeral 3a denotes a large number of through holes. A cavity 6 is provided below the molded part 3A between the lower part 3b and the inner bottom surface 3b. Hot air is introduced into the cavity 6 from an inlet 7 provided on one side 3c.

The upper mold 2 has a substantially double lid shape, and is provided in a state where a molded portion 2A is integrated with both side portions 2c projecting from the upper portion 2b. The upper part 2b is provided with an outlet 8 substantially at the center. The lower side of the both sides 2c is provided in a state where the right side is located inside by an amount corresponding to the thickness of the portion 30b of the fiber cushion body 30 (see FIG. 3A),
The right side is the portion 30c of the fiber cushion body 30 (FIG. 3A)
(See FIG. 2). And the part which forms the shaping | molding part 4 between the lower mold | dies 3 among the both sides 2c is formed by gas permeability, ie, a punching metal plate part, like the shaping | molding part 2A.
Reference numeral 2a denotes a large number of through holes. The hollow portion 5 is located outside the molded portion 2A, and includes the upper portion 2b and both side portions 2c.
Are formed. The upper mold 2 can detachably seal the upper opening of the lower mold 3 in a mold-clamped state, and can discharge hot air from the cavity 5 through the outlet 8. The hot air exhausted from the outlet 8 is guided to a heating and blowing means 14 described later, heated to a constant temperature again, sent to the inlet 7 and circulated.

The heating and blowing means 14 comprises a heating mechanism (not shown) for heating up to the molding temperature, a fan mechanism 15 and the like, and sends hot air from the inlet 8 to the cavity 6 through the pipe 16a. Normally, it is connected to the outlet 8 via a pipe 16b, and the hot air exhausted from the outlet 8 is heated again to a constant temperature by the heating mechanism, and is heated by the fan mechanism 15
And circulates to the inlet 7 through the pipe 16a. When recirculating, it has a filtering member or the like for removing impurities from hot air. When the heating mechanism is stopped, it is needless to say that cold air at normal temperature can be circulated.

Next, the embodiment of the method of the present invention will be described in detail by way of an example in which the method is carried out using the above-described hot air forming mold. Here, the used fiber raw material is raw cotton obtained by mixing a low-melting fiber material and a high-melting fiber material, and is formed as a mold packing form as follows. Using a preforming die, the layered product laminated on the web laminate having a predetermined thickness is heated to a temperature several tens of degrees lower than the molding temperature. Was cut into a square shape by a special crusher. The cut crushed product 20 is a dice-shaped hexahedron, and as shown in FIG. 2, a crushed product 20a of 10 to 100 mm square (a hexahedron having a side of 10 to 100 mm).
And a pulverized product 20b of 5 to 10 mm square (a hexahedron having a side of 5 to 10 mm) are ranked according to the size.

In this embodiment, the molding part 4 is formed as shown in FIG.
Fiber cushion body 30 for seat having the same shape as (a)
The pulverized product 20 is charged into the lower mold 3 in the following manner. The injection into the lower mold 3 is performed by using the nozzles 10, 11, and 12 using compressed air,
0 is automatically input from each of the nozzles 10, 11, and 12. Nozzle 10 is used to crush pulverized product 20a of large rank
Nos. 1 and 12 respectively feed the ground products 20b of a small rank. Each of the nozzles 10, 11, and 12 is moved at a constant speed in the X-Y direction by a transfer mechanism on the molding portion 3A of the lower die 3, and has a structure capable of feeding a fixed amount of the corresponding pulverized products 20a and 20b. I have. In FIG. 1, symbols X1, X2, and X3 denote movement amounts of the nozzles 10, 11, and 12 in the X direction.
The directions are omitted. For this input,
The upper part (molding part) of the molding part 3A of the lower mold 3 is the injection area 13
a, 13b, and 13c. For example, the nozzle 10 is assigned to the input area 13a, and the nozzles 11 and 12 are assigned to the corresponding input areas 13b and 13c. , 11 and 12 are designed. The required amount of the crushed products 20a and 20b corresponding to the input areas 13a, 13b and 13c is measured in advance, and the crushed products 20 to be used are supplied by the corresponding nozzles 10, 11, and 12 by the measured amount. You.

In the mold setting operation, first, the upper mold 2
Is removed by a moving mechanism or the like, and the above-mentioned pulverized products 20a and 20b are placed on the molding portion 3A by the dedicated nozzles 10 and 1 respectively.
A predetermined amount is supplied to each of the input areas 13a, 13b, and 13c through the first and the second areas. Thereafter, the upper mold 2 is clamped. In this operation, the upper mold 2 is arranged with a predetermined pressing force while moving into the upper part of the lower mold 3. In this final operation, although not shown, the upper part 2b and the corresponding part of the lower die 2 are detachably fixed. As a result, a forming part 4 having a gap corresponding to the fiber cushion body 30 is formed in the hot-air forming die 1 by the upper and lower dies 2 and 3, and the above-mentioned pulverized products 20 a and 20 b are formed in the forming part 4. It is set in a compressed state according to the mold clamping force.

From the above mold clamping state, the heating and blowing means 14
Is activated. When the heating mechanism is activated, the fan mechanism 1
5 is the heated gas (corresponding to the molding temperature, for example, 2
Hot air heated to 00 degrees) is pumped into the cavity 6 from the inlet 7. When the hot air fed to the cavity 6 reaches a predetermined pressure, it enters the molded part 4 through the through-hole 3a. Molding part 4
The hot wind that has entered the crushed product 20a, 20b rises upward and reaches the cavity 5 through the through-hole 2a,
It is evacuated from outlet 8 and recirculated as before.

When the above heat treatment is performed for a predetermined time, the low-melting-point fibers constituting the pulverized products 20a and 20b are gradually melted to bond between the fibers or to each other, and to form an integral fiber cushion corresponding to the molded portion 4. The body 30 is formed. Thereafter, the operation of the heating mechanism is stopped, and cold air of normal temperature is similarly circulated through the fan mechanism 15 so that the fiber cushion 30
To cool. As a result, the shape of the fiber cushion body 30 is maintained, so that the upper mold 2 is released and taken out. The molded fiber cushion body 30 has the same contour as that of FIG.

In the above-described molding method, the raw cotton as a fiber raw material is kept in its shape by preliminary molding, and is put into the lower mold 3 in the state of crushed products 20a and 20b cut to a predetermined size. Therefore, even when the automatic charging method is adopted, the charging amount in each unit can be structurally uniform. As a result, the formed fiber cushion 30 has a cushion structure having a more uniform density as a whole, and can be more stable in quality. Further, with this structure, the working environment can be favorably maintained without the raw cotton of the fiber raw material being scattered in the charging operation as in the related art. In addition, the lower die 3 can be reduced in size because the raw material input capacity can be reduced in accordance with the compression ratio at the time of preforming the crushed products 20a and 20b.

The above embodiment is a basic example of the present invention, and includes, for example, the specific structure of the upper and lower dies 2, 3 and the heating and blowing means 14, the mold charging method of the crushed product 20, and the crushed products 20a, 20b.
And the like are modified based on the mass production scale, the shape of the fiber cushion body, and the like.

[0024]

As described above, according to the method for molding a fiber cushion body for a seat according to the present invention, the raw cotton of the fiber raw material is put into the lower mold in the state of a crushed product, so that The workability of the injection can be improved, and the injection amount at the molding part can be input as designed. As a result, the density and the like of the obtained fiber cushion body are made uniform, and the quality is further improved. As described above, the method of the present invention uses a crushed product in place of the raw cotton as a fiber raw material, thereby improving the working environment and the handling property, the automatic feeding into the mold and the quantitative feeding property, the lower mold volume or the mold. This makes it possible to greatly improve the form and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of the method of the present invention in a state where a pulverized product is put into a lower mold.

FIG. 2 is a schematic structural view showing the method of the present invention at the time of heat molding.

FIG. 3 is a view showing an example of a fiber cushion body and an example of a hot air molding die for molding the fiber cushion body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hot air forming mold, 2 ... Upper mold, 2A ... Upper mold forming part 3 ... Upper mold, 3A ... Upper mold forming part, 4 ... Molding part 5, 6 ... Hollow part, 14 ... Heating blowing means 10,11 , 12 ... Injection nozzle 20,20a, 20b ... Pulverized product

Claims (3)

[Claims] An upper and lower mold each having a gas-permeable molding portion and a hollow portion provided outside each of the molding portions, and a raw cotton fiber material mixed with a thermoplastic low-melting fiber and a high-melting fiber. Is placed in the lower mold, and after clamping the upper and lower molds, while passing hot air from the one cavity to the other cavity through the molding portion formed by the upper and lower molds, In the molding method of the seat fiber cushion body for heating and molding the raw cotton, the raw cotton of the fiber raw material is formed into a mat shape by preliminary molding, and then cut into a square shape having a predetermined size by a crusher or the like. A method for molding a fiber cushion body for a seat, comprising weighing and pulverizing a pulverized product into the lower mold. 2. The method according to claim 1, wherein the crushed product is cut into a size ranging from 5 to 100 mm square. 3. The pulverized product is divided and formed into a plurality of large and small ranks classified by size, and the one with the large rank corresponding to a substantially flat portion of the fiber cushion body is used. The molding method of a fiber cushion body for a seat according to claim 2, wherein the one having the smaller rank is used corresponding to a substantially curved portion of the fiber cushion body.