JP3733411B2 - Cushion material molding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a fiber assembly (hereinafter simply referred to as “fiber assembly”) in which a heat-fusible binder fiber having a melting point lower than that of the matrix fiber is dispersed and mixed in the matrix fiber is thermoformed into a cushion material. The present invention relates to a method for forming a cushioning material.
[0002]
[Prior art]
In general, inexpensive urethane foam has been widely used as a cushioning material for seats having complicated shapes such as automobiles and aircraft. However, since urethane foam has problems such as poor breathability and easy stuffiness and difficulty in recycling, a molding material alternative to this has been eagerly desired.
[0003]
Because of these problems, in recent years, cushion materials using the above-described fiber assembly as a material for replacing urethane foam have attracted attention as materials that can solve these problems. This cushion material is formed by filling a fiber assembly into a cavity of a mold and melting the binder fiber contained in the fiber assembly by thermoforming it to bond the fibers in the fiber assembly. It is formed.
[0004]
As a method of manufacturing the cushion material, the mold is made of a material having air permeability, the fiber aggregate is filled in the mold cavity along with the conveying air flow, and then the fiber aggregate filled in the mold cavity is filled. For example, Japanese Patent Laid-Open No. 7-324266 proposes a method of forming a cushion material by letting heating air and cooling air flow through (hereinafter referred to as “air blowing method”). In addition, filling into a mold cavity using an automatic machine such as a hand lay-up or a robot is usually performed.
[0005]
However, in such a conventional molding method, when a mold assembly having inclined end surfaces 3a ′ facing substantially parallel to each other is filled with a fiber assembly and molded, a cushioning material having excellent quality is used. It has a problem that it cannot be molded. This point will be described below with reference to FIG.
[0006]
In FIG. 5, FIG. 5A is a front cross-sectional schematic diagram schematically illustrating the state of completion of filling of the fiber assembly into the mold cavity by the air blowing method, and FIG. FIG. 2 is a schematic front cross-sectional view schematically illustrating a state after compression of a packed fiber assembly.
[0007]
In such a conventional technique, as illustrated in FIG. 5A, after filling the mold cavity C ′, the upper mold 1 ′ is moved downward as illustrated in FIG. 5B. The fiber assembly F ′ filled by moving is compressed. At that time, the compression direction (the direction of the arrow in the figure) is compression of the upper mold 1 ′ and / or the lower mold 2 ′ for compressing the fiber assembly F ′ filled in the mold cavity C ′. A direction orthogonal to the surface 1a ′ and / or 2a ′ is employed.
[0008]
However, as illustrated in FIG. 5B, when the shape of the two end faces located at both ends of the side portion of the mold cavity C ′ has inclined surfaces 3a ′ that face each other in parallel. There is a problem in that the inclined surface 3a ′ (the portion indicated by the reference symbol A ′ in FIG. 5B) has a higher compression ratio than the other portions. In this way, when the compression ratio of the inclined portion is increased, only this portion becomes harder as a result of higher bulk density compared to other portions, and the quality of the molded cushion material Cause the problem of damage.
[0009]
[Problems to be solved by the invention]
In view of the above-mentioned problems, the problem to be solved by the present invention is that “when the end surfaces of the mold cavities have inclinations facing each other in parallel, the fiber assembly filled in the inclined end surface portions of the mold cavities. It is an object of the present invention to provide a method for molding a body and a fiber assembly filled in other parts to a predetermined bulk density, thereby forming a cushion material having excellent quality.
[0010]
In addition, as a molding method of the cushion material, there are problems such as filling spots and molding spots of the fiber assembly in the mold cavity, particularly when adopting a conventional method of filling the mold cavity by the air blowing method. Is also going to solve.
[0011]
[Means for Solving the Problems]
Here, as means for solving the problems of the prior art, according to the present invention, according to the present invention, “ (1) Gold filled with a fiber aggregate in which binder fibers having heat-fusibility are dispersed and mixed in matrix fibers” An upper mold and a lower mold of an upper mold and a lower mold which are divided into upper and lower parts in order to compress the fiber assembly up and down in the mold cavity, and (2) the upper mold and the lower mold The vertical direction of the compression surface that surrounds the fiber assembly filled in between from the side and is formed by the upper mold wall surface and / or the lower mold wall surface that are separated from both ends and face each other in parallel Using the molds (1) and (2) that are at least composed of side molds having inclined surfaces that are inclined with respect to the both ends, the compression direction of the fiber assembly is inclined at both ends of the side molds fiber to compress the fiber aggregate at the upper and lower molds so as to parallel to the plane Adjust the bulky density of the aggregate, forming method of the cushion, characterized in that thermally fusing the finally compressed fibers "is provided.
[0012]
In the above-described method of the present invention, when the fiber assembly is filled in the mold cavity, it is possible to reduce the molding time by adopting a method in which the fiber assembly is transferred to the mold cavity along with the conveying airflow. It is preferable when manufacturing the cushioning material excellent in quality. At that time, the direction in which the fiber assembly is blown into the mold cavity is made parallel to the compression surface of the mold for compressing the fiber assembly, as the fiber assembly is blown into the mold cavity. It is important to solve the various problems described above.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail together with the operation thereof with reference to the drawings.
[0014]
FIG. 1 is a schematic front cross-sectional view schematically illustrating an apparatus for carrying out the method of the present invention.
In FIG. 1, reference symbol F indicates a fiber assembly used in the present invention. Here, the fiber assembly F of the present invention refers to a fiber in which “matrix fibers” and “binder fibers” are uniformly mixed.
[0015]
In this case, the synthetic fiber material constituting the former “matrix fiber” is not particularly limited, and polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly 1,4-dimethylcyclohexane terephthalate. , Short fibers composed of short fibers composed of polypivalactone, or a copolymerized ester thereof, to a mixed fiber aggregate of these fibers, or composite fibers (conjugate fibers) composed of two or more of the above polymer components, etc. It can be illustrated.
[0016]
Further, the cross-sectional shape of the short fiber may be any of a circular shape, a flat shape, an irregular shape, and a hollow shape. Furthermore, it is preferable that crimps are imparted to the short fibers of the synthetic fiber in this case, and as such crimps, it is particularly preferable that the crimps are manifest. This actual crimping can be obtained by a mechanical method using a crimper or the like, a method using anisotropic cooling during spinning, a method of heating a side-by-side type or eccentric sea core type composite fiber, or the like.
[0017]
On the other hand, examples of the latter “binder fiber” include fibers composed of polymers of polyurethane elastomers and polyester elastomers, and in particular, composite fibers in which these polymers are exposed on a part of the fiber surface can be suitably used. . Needless to say, an appropriate amount of the binder fiber is dispersed and mixed in the matrix fiber in accordance with the required performance of the product to be molded.
[0018]
Next, the fiber assembly F made of the material as described above is filled into the mold cavity C as shown in FIG. The mold cavity C is surrounded by an upper mold represented by reference numeral 1, a lower mold represented by reference numeral 2, and a mold frame represented by reference numeral 3 in FIG. It is an area.
[0019]
The mold frame 3 also serves as a “side mold”, and the upper mold 1, the lower mold 2, and the mold frame (side mold) 3 are punched plates. It is comprised with the air permeable material which has many apertures like. The mold frame 3 that also serves as a side mold is provided with a raw material supply port 4 for supplying a fiber assembly F that is a molding raw material of the cushion material.
[0020]
Here, the upper mold 1 and the lower mold 2 are connected to a driving means (not shown) that moves in the vertical direction when the mold is compressed and / or opened, and independently moves up and down. It can be configured. In addition, as such a drive means (not shown), well-known means, such as a hydraulic cylinder driven by air pressure or hydraulic pressure, or an electric motor that performs linear motion provided with a rack and a pinion, can be used. .
[0021]
By doing in this way, as mentioned above, the molds 1 and 2 can be individually and individually used when the fiber assembly F is compressed, when the molded cushion material is taken out, when the molding device is repaired, etc. It can be moved up and down. Moreover, although description is abbreviate | omitted, for the purpose of adjustment of the compression amount of the fiber assembly F by the metal mold | dies 1 and 2, and ensuring the dimensional stability of a cushioning material, the metal mold | dies 1 and 2 are respectively predetermined positions, respectively. Needless to say, a known positioning means such as a stopper is provided so that positioning can be stopped accurately in multiple stages.
[0022]
In the embodiment of FIG. 1 (a), the air blowing method described above is employed as a method for filling the fiber cavity F into the mold cavity C. Needless to say, a method of filling a mold cavity using a machine can be adopted.
[0023]
Thus, the method for filling the mold cavity C with the fiber assembly F is not particularly limited. However, the air blowing method is a method for performing the method of the present invention. This is preferable in that the filling time of the mold cavity C can be shortened as compared with other methods. This is because, according to the air blowing method, for example, the molds 1 and 2 are completely opened and the fiber assembly F (usually in the form of a pre-shaped web or the like) is placed in the mold cavity C. Then, the operator is released from the process of closing the molds 1 and 2 after that, so that the manual filling process can be omitted.
[0024]
Then, the filling process of the fiber assembly F by the air blowing method which has the above advantages is demonstrated easily, referring the said Fig.1 (a). As shown in FIG. 1A, this filling process starts by supplying a predetermined amount of the fiber assembly F onto the conveyor 5. Next, a certain amount of the fiber assembly F placed on the conveyor 5 is conveyed to the opening machine represented by reference numeral 6 by the conveyor 5, and a desired opening is achieved by passing through the opening machine 6. Done.
[0025]
In this way, the fiber assembly F opened by the spreader 6 is transported by a composite airflow of the transported airflow from the blower represented by reference numeral 7 and the accompanying airflow generated by the rotational movement of the spreader 6. It is conveyed in the transfer duct represented by reference numeral 8 by the air current, and is filled into the mold cavity from the raw material supply port 4.
[0026]
In this case, it is possible to fill the fiber assembly F into the mold cavity C only with the accompanying air flow of the fiber spreader 6, but the flow state of the air flow that conveys the fiber assembly F that has become a small lump is adjusted. In this sense, it is desirable to use a carrier airflow from the blower 7 in combination. That is, the fiber assembly F can be filled into the mold cavity C only by the accompanying airflow generated by the rotational movement of the opening cylinder of the fiber opening machine 6, but the fiber assembly F is evenly and shortly filled in the mold cavity C. From the viewpoint of efficiently filling in time, it is preferable to use an air flow supplied from the blower 7 in combination.
[0027]
According to the present invention, two end faces (that is, both end faces) separated from each other at both side ends are parallel to each other in the vertical direction of the compression surface of the fiber assembly formed by the wall surfaces of the upper mold and the lower mold. When filling the mold cavity forming the inclined surfaces facing each other with the fiber assembly and compressing the filled fiber assembly to a predetermined bulk density, the compression direction is parallel to the inclined end surface. It is a major feature. In the following description, such “ both end surfaces of the side of the mold cavity in which inclined surfaces facing each other in parallel are formed” are referred to as “inclined end surfaces”.
[0028]
Therefore, in the present invention, as schematically illustrated in FIGS. 1A and 1B, the inclined end surface 3a of the mold cavity C is substantially formed of the mold frame 3 (side mold). It is made up of mold walls. Therefore, the inclined end surface 3a of the mold cavity C substantially forms a vertical surface as shown.
[0029]
On the other hand, as a result of changing the inclined end surface 3a of the mold cavity C in the vertical direction, the compression surfaces 1a and / or 2a of the fiber assembly F of the upper mold 1 and / or the lower mold 2 that maintained the horizontal plane are Conversely, an inclined surface that is inclined at a constant angle with respect to a horizontal plane is formed. And the direction which compresses the fiber assembly F maintains the previous perpendicular direction (namely, the up-down direction of FIG. 1), and does not change this direction. For this reason, the compression direction of the fiber assembly F is substantially the same vertical direction as the inclined end surface 3a of the mold cavity C that forms a vertical surface (that is, a direction parallel to the inclined end surface 3a).
[0030]
Therefore, taking the mold cavity C having a parallelogram illustrated as an example in the schematic cross-sectional view of FIG. 1 as an example, as shown in FIG. 1B, the mold catty C is filled. The fiber assembly F can be compressed at a certain ratio in each part of the mold cavity C.
[0031]
By doing so, the inclined end portion 3a of the mold cavity C is not compressed at a particularly large ratio, and this portion does not become harder than other portions. That is, as in the case of the conventional example shown in FIG. 5 incorporated in the description section of the prior art, the inclined end surface 3a ′ of the cushion material to be finally thermoformed is particularly hard even when compared with other portions. The situation of becoming can be avoided.
[0032]
In this case, the problem is that the compression control of the fiber assembly F at the inclined end surface 3a portion of the mold cavity C cannot be achieved as intended, and the hardness of the inclined end surface 3a portion of the cushion material can be freely set as designed. It is a situation that cannot be controlled. Therefore, when a situation arises in which the hardness of the central portion and the end of the cushion material to be molded is intentionally different, the upper mold 1 and / or the lower mold is applied to the portion for which the hardness is to be individually controlled. What is necessary is just to respond | correspond by using the division mold which divided | segmented the type | mold 2. FIG.
[0033]
This is because by using the split molds in this way, it is possible to individually control the moving distance (compression distance) of each of the divided molds in the compression direction. This is because the hardness and softness of the cushion material can be locally changed for each portion corresponding to each divided mold depending on the degree of compression.
[0034]
By the way, in the method of the present invention, when the above-described air blowing method is adopted, at least when the fiber assembly F is blown and filled into the mold cavity C, at least the air blowing direction (fiber assembly blowing). It is preferable to make it parallel to the compression surfaces 1 a and / or 2 a of the upper mold 1 and / or the lower mold 2.
[0035]
In this case, as in the embodiment illustrated in FIGS. 1A and 1B, both the spreader 6 and the transfer duct 8 are connected to the compression surfaces 1 a and / or the upper mold 1 and / or the lower mold 2. You may make it incline according to the inclination of 2a. Further, as in the embodiment illustrated in FIG. 2A and FIG. 2B, the opening machine 6 is not inclined, and only the transfer duct 8 is connected to the upper mold 1 and / or the lower mold 2. You may make it incline according to the inclination of the compression surface 1a and / or 2a.
[0036]
In that case, it is important to match the blowing direction of the conveying air conveying the fiber assembly F with the inclination direction of the compression surfaces 1a and / or 2a of the upper mold 1 and / or the lower mold 2. . By doing in this way, the peculiar problem resulting from the air blowing method mentioned below can be avoided.
[0037]
Therefore, this point will be described in detail below with reference to FIG. First, FIG. 3 will be briefly described. FIG. 3A is a schematic front cross-sectional view schematically showing a state when compression of the fiber assembly F is completed. FIGS. 2B and 2C are front sectional schematic diagrams schematically illustrating the case where the opening of the upper mold 1 is reduced and the case where the opening of the upper mold 1 is increased, respectively. Show.
[0038]
In addition, these FIG. 3 (a), (b), and (c) inclined the blowing direction of the conveyance air of the fiber assembly F as already demonstrated in detail using FIG.1 and FIG.2. It is a figure for demonstrating the problem which arises when letting it not let it be along the compression surfaces 1a and / or 2a of the upper metal mold | die 1 and / or the lower metal mold | die 2.
[0039]
Here, when the fiber assembly F is placed in the conveying airflow and filled in the mold cavity C in a state where the opening of the upper mold 2 is reduced as illustrated schematically in FIG. 3B, the compression of the upper mold 2 is performed. Since the surface 2a is inclined, the fiber assembly F once collides with the compression surface 2a of the upper mold 2 and then is filled in the mold cavity C.
[0040]
As described above, once the fiber assembly F collides with the mold wall and then the mold cavity C is filled, the lamination state of the fiber assembly F in the mold cavity C is normally controlled. This makes it difficult to cause filling spots, and as a result, causes a loss of thickness in the cushion material after molding.
[0041]
Therefore, in order to solve such a problem, it is conceivable to increase the degree of opening of the upper mold 2 as illustrated in FIG. However, in such a case, if a predetermined amount of the fiber assembly F is to be filled into the mold cavity C while avoiding the collision of the fiber assembly F with the upper mold 1, the raw material supply port 4 There will be a situation in which the upper die cavity Ca is not filled with the fiber assembly F.
[0042]
If such a situation occurs, insufficient filling of the fiber assembly F is caused in the portion Ca that is difficult to be filled with the fiber assembly F, and the bulk density decreases in this portion. In the cushion material, the soft and soft spots to be avoided are generated inside.
[0043]
Therefore, as described above, when the air blowing method is employed, the fiber assembly in the mold cavity C is performed on the compression surfaces 1a and / or 2a of the upper mold 1 and / or the lower mold 2. It is necessary to make the blowing direction of the body F parallel.
[0044]
In addition, as shown in FIGS. 1 to 3, all the above-described embodiments have shown examples in which the inclined end surfaces 3 a of the mold cavities C that face each other substantially in parallel are erected in the vertical direction. However, in the embodiment of the present invention, the inclined end surface 3a of the mold cavity C is not set in the vertical direction as shown in the schematic cross-sectional schematic diagram schematically illustrated in FIGS. 4 (a) and 4 (b). In addition, as in the prior art, the compression surfaces 1a and / or 2a of the upper mold 1 and / or the lower mold 2 may be horizontal.
[0045]
In this case, only the wall surface forming the mold frame (side mold) 3 is inclined along the inclined end surface 3a of the mold cavity C, so that the upper mold 1 and / or the lower mold are used. The two compression surfaces 1a and / or 2a remain in a horizontal plane. Therefore, in this embodiment, although not shown in FIG. 4, it is not necessary to incline the spreader 6 that opens the fiber assembly F and the transfer duct 8 that transfers the opened fiber assembly F. It can be installed horizontally on the street.
[0046]
When the process of filling the mold cavity C with the fiber assembly F and compressing the filled fiber assembly F to a predetermined bulk density is completed as described above, the compressed fiber assembly F is thermoformed. The process of converting into a cushion material is performed. In this step, first, in order to fuse the fibers in the fiber assembly F, heated air that melts the binder fibers contained in the fiber assembly F is allowed to flow. Then, the cooling air is allowed to flow through the fiber assembly F to solidify the melted binder fiber, thereby bonding the fibers constituting the fiber assembly F and finally thermoforming the cushioning material. .
[0047]
【The invention's effect】
According to the present invention described above, "when the end surface of the side of the mold cavity with parallel opposed inclined to each other, and the fiber aggregate filled in the inclined end face portion of the mold cavity, other portions It is possible to provide a method for forming a cushioning material having excellent quality by compressing the fiber assembly filled in the container to a predetermined bulk density.
[Brief description of the drawings]
FIG. 1 is a schematic front cross-sectional view schematically illustrating an apparatus for carrying out the method of the present invention.
FIG. 2 is a front cross-sectional schematic diagram schematically illustrating an apparatus for carrying out a method according to another embodiment of the present invention.
FIG. 3 is a view for explaining another embodiment of the present invention, in which FIG. (A) shows a state at the time when compression of the fiber assembly F is completed, and FIG. (B) and FIG. (C). And are respectively schematic cross-sectional schematic diagrams schematically illustrating a state where the opening of the upper mold 1 is reduced and a state where the opening of the upper mold 1 is increased.
FIG. 4 is a diagram for explaining another embodiment of the present invention, in which FIG. (A) shows a state at the time when the filling of the fiber assembly F into the mold cavity is completed, and FIG. ) Is a front cross-sectional schematic diagram schematically illustrating the state at the time when compression of the fiber assembly F is completed.
FIG. 5 (a) is a front cross-sectional schematic diagram schematically illustrating the state of completion of filling of a fiber assembly into a mold cavity by an air blowing method, and FIG. It is the front cross-section schematic diagram which illustrated typically the mode after the compression of the fiber assembly packed into the mold.
[Explanation of symbols]
1 Upper mold 1a Upper mold compression surface 2 Lower mold 2a Lower mold compression surface 3 Mold frame (side mold)
3a Inclined end face 4 Raw material supply port 5 Conveyor 6 Opening machine 7 Blower 8 Transfer duct C Mold cavity F Fiber assembly

Claims (3)

(1) Upper die divided into upper and lower parts in order to compress the fiber assembly up and down in a mold cavity filled with a fiber assembly in which binder fibers having heat-fusibility are dispersed and mixed in matrix fibers And (2) two end faces that surround the fiber assembly filled between the upper mold and the lower mold from the side and that are separated from each other and face each other in parallel. Using the molds (1) and (2) at least composed of side molds having inclined surfaces inclined with respect to the vertical direction of the compression surface formed by the upper and lower mold wall surfaces , the fiber assembly The fiber assembly is compressed by the upper and lower molds so that the compression direction of the body is parallel to the inclined end faces of the side molds, and the bulk density of the fiber assembly is adjusted, and finally the compressed fibers A method for forming a cushioning material, comprising heat-sealing each other . 2. The method for molding a cushion material according to claim 1, wherein the fiber assembly is transferred to the mold cavity while being accompanied by a conveying airflow. Wherein the direction of transferring the mold cavity to the fiber assembly, characterized by a flat row against compression surface of the mold to compress the fiber aggregate, molding method of a cushion material according to claim 2, wherein.

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