JP2002096341A - Integrated foamed article having different hardness parts and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated foamed article having different hardness parts, wherein two or more foam parts different in hardness are simply integrated at a low cost using a usual foaming mold without separately manufacturing foams or slabs, and a method for manufacturing the same. SOLUTION: A film 2 is set to a mold parting surface 1 so as to cover the cavity part 11 of the split mold 1a related to a foaming mold 1 held to an open state and, subsequently, the mold is closed to demarcate a cavity C by the film 2. Thereafter, foamable raw materials 5a and 5b of a different kind are injected in the demarcated cavity parts 11 and 16 and the film 2 is taken in to integrally mold foams different in hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam of different hardness, in which a bare foam such as a headrest or an armrest is formed from two or more foams having different hardnesses, and a method for producing the same.

[0002]

2. Description of the Related Art Some headrests and the like use a foam having a different hardness to improve the feel when the head is hit by making the head hitting portion softer than other portions. Conventionally, a method of manufacturing a headrest with a different hardness is to manufacture a base foam and a low-repulsion slab separately and then bond them, or set a low-repulsion slab in a mold. After that, there was a method of injecting a foaming raw material into an integrated foamed product (Utility Model Registration No. 251).
No. 5241, Utility Model Registration No. 2515242).

[0003]

However, in the above-mentioned production method, the foam and slab of the base must be separately produced.
In addition, an adhesive must be applied or bonded, which increases the manufacturing cost. Even in the above manufacturing method,
The slab had to be manufactured separately and the special form of the foaming mold had to be used, so the manufacturing cost was still high.

[0004] The present invention solves the above-mentioned problems, and does not require separate production of foams and slabs, and is simple, low-cost, and uses two or more foams having different hardnesses using a normal foaming mold. It is an object of the present invention to provide a foamed article of different hardness in which a body portion is integrated and a method for producing the same.

[0005]

In order to achieve the above object,
The gist of the invention according to claim 1 is that a film in which a cavity is partitioned is provided on a mold dividing surface of a foaming mold, and then different types of foam are formed in the respective cavity portions partitioned by separating the film. A method for producing a foam having a different hardness is characterized by injecting a raw material, taking in the film, and integrally forming a foam having a different hardness. The “film” here is an original film (a planar shape having an extremely thin thickness compared to other dimensions and having a thickness of 250 μm or less).
In addition to the above, a planar shape such as a sheet or a thin plate having a thickness greater than that of a film is included. This is because these also produce the same operation and effect of the present invention as the film in the original meaning. The gist of the invention according to claim 2 is that a film is set on a mold division surface so as to cover a cavity portion of a division mold relating to a foaming mold in a mold open state, and then the mold is closed and a cavity is formed with the film. And then injecting a different kind of foaming material into each of the partitioned cavities, taking in the film, and integrally molding a foam of different hardness, thereby producing a foamed article of different hardness. In the way. The gist of the invention according to claim 3 is that a perforated film is set on a mold dividing surface so as to cover a cavity portion of a divided mold relating to a foaming mold in an open state, and then a hole of the perforated film is formed. Then, a foaming material nozzle is inserted into the cavity portion, and then a foaming material different from the foaming material is injected into the remaining cavity portion. A method for producing a foamed article of different hardness, characterized by molding. The gist of the invention according to claim 4 is that the film is sandwiched between two foam portions having different hardnesses, and that the film is taken as a boundary surface and both foam portions are integrally formed. One of the characteristic foams of different hardness.

According to the first to third aspects of the present invention, if a film in which a cavity is partitioned is provided on a mold dividing surface, each of the cavities partitioned into a film can be prepared without preparing a slab or the like in advance. By injecting different types of foaming raw materials into the portions, it is possible to easily perform integral molding of foams having different hardness. According to the second aspect of the present invention, if a film is set on the mold dividing surface, the cavity is partitioned by closing the mold, so that the production of a foam having a different hardness is facilitated. Since the outer peripheral portion of the film is placed on the mold parting surface, the outer peripheral portion of the film protrudes from the different hardness integrated foam product taken out by demolding. However, since the film is very soft, there is no particular need for post-processing. At the stage of commercialization by covering the skin with the foam of different hardness, the protrusion of the outer peripheral portion of the film cannot be recognized. According to the third aspect of the present invention, when a perforated film is set on the mold dividing surface, the foaming material can be injected into one cavity portion in the mold opened state by using the holes of the perforated film. Easier to remove. As in the invention of claim 4, when the film is sandwiched between two foam portions having different hardnesses, and the film is taken in and used as a boundary surface, and both foam portions are obtained by integral molding, the cost is reduced. Production becomes possible. A film which has not existed in the past is incorporated into a foam of different hardness, but the film is thin and soft and does not cause any trouble.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a foamed article of different hardness and a method for producing the same according to the present invention will be described in detail. (1) Embodiment 1 FIGS. 1 to 4 show one embodiment of a foam of different hardness according to the present invention and a method of manufacturing the same. FIG. 1 shows an insert and a film set on a mold separation surface of a split mold used in the present manufacturing method. FIG. 2 is a longitudinal sectional view showing a state in which molds are closed and different kinds of foaming raw materials are injected into respective cavities, and FIG.
FIG. 4 is a vertical cross-sectional view after the foaming has been completed from the step of FIG. 2, and FIG.
(B) is a perspective view of the foamed article of different hardness obtained by trimming and cutting the outer peripheral portion of the film of (A). Applicable to naked headrest foam without skin as a one-piece foam of different hardness.

The foamed product for headrests, which is a foamed product of different hardness, has a core 32 of the insert 3 embedded therein to integrally form a foamed product 6 of different hardness. The foam part 6b, which is the head, is formed of a softer material than the foam part 6a at the base (rear side of the vehicle), and the two foam parts 6a, 6a,
The film 2 is sandwiched by 6b (FIGS. 3 and 4). Both foam parts 6a, 6b take the film 2 and are integrally formed with the film 2 as the boundary surface K to form a bare headrest foam. The film 2 is disposed so as to divide the head side and the rear side of the vehicle vertically. That is, the film 2 runs in the direction perpendicular to the paper surface of FIG. 3 at the time of molding the foamed product for the headrest, and the main part 21 of the film 2 is formed by the foamed part 6b at the head and the foamed part 6a located at the rear side of the vehicle. The boundary surface K is created. However, in this foamed product for headrest, the film 2 does not exist on the upper portion, and the foam portions 6a and 6b of different hardness are directly bonded on the upper portion, so that the integration of the both is more reliable.

For the foam portions 6a and 6b, for example, a polyurethane foam material is used. The difference in hardness between the head side and the rear side of the vehicle is determined by adjusting the density, the expansion ratio, and the like by mixing the polyurethane foam.
As the film 2, a commercially available plastic film such as polyethylene, polyvinylidene chloride, vinylidene chloride, or polyurethane is used. It is desirable that the film 2 be joined and integrated with the foam portions 6a and 6b during the foam molding of the foam portion 6. If heat is applied during foam molding, the film 2 is required to have heat resistance enough to withstand this temperature. Cavity part 1 partitioned by film 2 during foam molding
Different foaming raw materials 5a and 5b are injected into the base materials 1 and 16 (described later). However, if the film 2 can serve as a partition wall, it is thin (for example, 0.02 mm to 0.03 in thickness).
mm film) is sufficient. A sheet, a thin plate, or the like can be used as the film 2. However, a plastic film thinner than a sheet, a thin plate, or the like is far superior in usability.

[0010] At the time of demolding after the completion of integral molding, a foamed product for a headrest in which the film outer peripheral portion 22 protrudes from the foam 6 is usually trimmed as shown in FIG. Is done. However, thin film 2
Then, the film 2 protrudes outside from the foam 6 in FIG.
Even if the headrest foam is as shown in (a), the film 2 can be eliminated by following the surface of the foam 6 because the film 2 is soft. This is because if a skin is put on the skin to finish it as a headrest product, the existence of the film outer peripheral portion 22 is not recognized from the outside of the skin, and it is possible to obtain a good product.

The above-mentioned foamed article of different hardness (foamed article for headrest) can be manufactured, for example, as follows. First, the film 2 is cut from a roll film or the like into a film 2 having a size capable of covering the cavity portion 11.

Next, the film 2 cut into a predetermined size is placed (set) on the mold dividing surface 10 so as to cover the cavity portion 11 of the foaming mold 1, and the insert 3 is set. Although the cut film 2 may cover the entire surface of the cavity portion 11 with the film 2, the film 2 is not large enough to cover the entire surface, and a portion not covered by the upper portion of the cavity portion 11 as shown in FIG. Can also. This case is also included in the “setting a film on the mold division surface so as to cover the cavity portion of the division mold” in the present invention. The film 2 can be used to partition the cavity C, and the partitioned cavity portions 11,
This is because the foamed material 5 of a different hardness can be integrally molded by injecting the different kinds of foaming raw materials 5 into the foamed material 16.

The foaming mold 1 comprises a pair of split dies 1a, 1
b, and the two split molds 1a and 1b are attached by a hinge 19 so as to be openable and closable. Each split mold 1a (1b) is divided into an upper mold part 1a ₁ (1b ₁ ) and a lower mold part 1a ₂ (1b ₂ ), and these are also attached by a hinge 19 so that they can be opened and closed. The cavity C for the headrest is formed by closing the molds of both the split dies 1a and 1b, and the cavity portions 11 and 16 which partially configure the cavity C are formed in each of the split dies 1a and 1b. The mold dividing surface 10 around the cavity portions 11 and 16 is provided with a mounting groove 13 for the insert 3 and injection grooves 12 and 17 for the foaming raw material 5, but the other portions are flat surfaces.

The film 2 is set on the mold split surface 10 so as to cover the cavity 11 of the split mold 1 as shown in FIG. After that, the core body 32 is arranged in the cavity portion 11, and the insert 3 is set in the mounting groove 13 so that the stay 31 protrudes out of the mold. With respect to the setting of the film 2 and the insert 3 on the mold dividing surface 10, the film 2 is
For example, the film 2 together with the insert 3 can be set on the mold dividing surface 10 by temporarily attaching (within the circle in FIG. 1).

Then, the split molds 1a and 1b are closed.
(FIG. 2). The main part 21 of the film 2 divides the cavity C by closing the mold, and is divided into the head side cavity part 11 and the base side cavity part 16. The outer peripheral portion 22 of the film 2 is held between the two mold separation surfaces 10 and 15 by closing the mold. When the mold is closed, the injection groove 12 becomes an injection hole and communicates with the head side cavity portion 11, and the injection groove 17 also becomes an injection hole and communicates with the base side cavity portion 16.

Subsequently, different kinds of foaming raw materials 5 are injected into each of the partitioned cavity parts 11 and 16 (FIG. 2), and the film 2 is taken in to form foamed bodies 6 of different hardness.
a and 6b are integrally formed (FIG. 3). That is, a liquid foaming raw material 5b such as a polyurethane foam which forms a soft foam 6b in the head side cavity portion 11 is injected from the injection groove 12, while the base side cavity portion 16 is foamed harder than the foam 6b. The liquid foaming raw material 5 a forming the body 6 a is injected from the injection groove 17. Foaming raw materials 5a, 5b
Here, it is more preferable that the head-side foaming raw material 5b is injected and filled first, or simultaneously. Because the insert 3 abuts and supports the film 2 from the base side (FIG. 2), the swelling of the film 2 into the base side cavity portion 16 can be prevented. When the insert 3 is bent or the like, the film 2 can be disposed on the surface of the base-side cavity portion 16 of the stay 31, contrary to FIG. In such a case, the injection of the foaming raw materials 5a and 5b proceeds simultaneously or the base-side foaming raw material 5a is injected and filled first. Thus, the film 2 is taken in, and foams 6a and 6b having different hardness are integrally formed. A bare headrest (one-piece foam with different hardness) in which the soft foam 6b on the head side and the hard foam 6a on the base side are integrated with the film 2 interposed therebetween is formed.

As described above, different kinds of foaming raw materials 5a and 5b are injected into the cavity portions 11 and 16 partitioned by separating the film 2, the film 2 is taken in, and the foams 6a and 6b having different hardness are integrated. After molding, finally,
Perform the cooling and solidification process. After cooling and solidification, the mold is removed and the desired bare headrest is completed (a in FIG. 4). However, in the bare headrest of FIG. 4A, since the outer peripheral portion 22 of the partitioning film 2 of the foam 6 protrudes from the headrest surface, if necessary, as shown in FIG.
Will be commercialized by trimming.

(2) Embodiment 2 This embodiment relates to a foam of different hardness and a method of manufacturing the same as shown in FIGS. 5 to 9. FIG. 5 shows a method of setting an insert and a film on a split surface of a split mold used in the present method. FIG. 6 is a perspective view showing a state in which a nozzle is inserted into a hole formed in a film and a foaming material is injected into a cavity portion.
7 is a perspective view showing a state in which a foaming material different from the foaming material is injected onto the film after the step of FIG. 6, and FIG. 8 is a longitudinal sectional view showing a pattern in which the foaming material is injected from the injection groove by closing the mold. FIG. 9 is a perspective view of a foamed article of different hardness taken out of the mold after the completion of the foam molding. Applied to naked armrest foam without skin as a one-piece foam of different hardness.

In the case of a rear armrest, for example, in the case of a rear armrest, the foamed part 6a used as an armrest has an appropriate hardness (softness) to be applied to an elbow, and stands up without using it as an armrest. The foam part 6b that appears when it is tilted to the seatback side
Has the same hardness (softness) as the seat back. The film 2 is sandwiched between the two foam portions 6a and 6b having different hardnesses, and the foam portion 6a and 6b are integrally formed by taking the film 2 and setting the film main portion 21 as the boundary surface K. More specifically, as shown in FIG. 9 (b), two foam portions 6a and 6b having different hardnesses are vertically formed with the film 2 interposed therebetween. At the center of the substantially rectangular parallelepiped, there is interposed a film 2 which is vertically divided. The upper side of the film 2 is made of a foam 6b having almost the same softness as the seat back, and the lower side of the film 2 is used as an armrest as a hard armrest. The foam 6a is formed into a foamed product for an armrest. In the present embodiment, the film 2 separates the two foam portions 6a and 6b over the entire area, but it is a matter of course that the two may be directly joined partially.

As in the first embodiment, a material such as polyurethane foam is used for the foam part 6, and the difference in hardness between the armrest side and the seat back side is determined by adjusting the density, expansion ratio, etc., by blending the polyurethane foam. It is performed by As the film 2, a plastic film 2 such as polyethylene or polyvinylidene chloride is used.

The foamed product for an armrest is manufactured, for example, as follows. First, a film 2 having a predetermined size is cut from a roll film or the like (FIG. 5). This film 2 is a perforated film 2 having a hole 23 formed therein. The nozzles 91 of the foaming raw material 5 are injected using the holes 23 (described later). The holes of the perforated film 2 may be holes 24 formed by cross-cutting the film 2 as shown in a circle in FIG. The cross-cut hole 24 becomes the perforated film 2 in which the hole 24 is opened only when the nozzle 9 is inserted, and it is possible to prevent the foams 6a and 6b having different hardness from mixing through the hole 24.

Next, the insert 7 and the perforated film 2 are set in one split mold 1d (lower mold in FIG. 5) of the foaming mold 1 in the mold open state. See Insert 7
The support shaft 72 is placed in the support shaft groove 18 of the mold parting surface 10 such that the base 71 is disposed in the cavity portion 11. Thereafter, the perforated film 2 is set such that the cavity portion 11 of the mold dividing surface 10 is covered. When the perforated film 2 is set, the outer peripheral portion 22 of the film rests on the mold dividing surface 10 and completely covers the cavity portion 11. The position of the hole 23 is on the cavity portion 11 (in FIG. 6, substantially at the center of the cavity portion 11). The foaming mold 1 here comprises a pair of split molds 1d and 1e, and both split molds 1d and 1e are attached by a hinge 19 so as to be openable and closable. Further, as shown in FIG.
It is divided into a main body portion 1e ₁ and the lid portion 1e _2. Lid 1
providing the injection hole 17a of the foaming material 5 in e _2. Double split type 1
By closing the molds d and 1e, the cavity C for the armrest is formed, and the cavity portions 11 and 16 which partially configure the cavity C are formed in each of the split molds 1d and 1e. The mold dividing surfaces 10 and 15 around the cavity portions 11 and 16 are provided with grooves 18 for the support shaft of the insert 7, but the other portions are flat surfaces.

Subsequently, the nozzle 91 of the foaming raw material 5 is inserted into the hole 23 of the perforated film 2 so that the lower cavity portion 11 is formed.
The armrest-side foaming raw material 5a is injected into the container (FIG. 6).
After injecting a predetermined amount of the foaming raw material 5a, the nozzle 91 is extracted. Foam 6 on armrest side with insert 7 embedded
a is being formed.

Next, the foaming raw material 5b for seat back is injected into the upper cavity portion 16 (remaining cavity portion). That is, after the foaming material 5a for the armrest side is injected into the lower cavity portion 11, the mold is closed, and then the foaming material 5b for the seatback is injected by inserting the nozzle 92 into the injection hole 17a, and the film 2 is taken in. To integrally form foams 6a and 6b having different hardness. Here, different kinds of foaming raw materials 5a and 5b are not mixed through the holes 23.
As shown in FIG.
It is more preferable to wait for the foaming hardening of the foam material 5a for the armrest side to progress to some extent while dropping b, close the mold, and then inject the foaming material 5b into the upper cavity portion 16 using the injection hole 17a. Of course, even if the different kinds of foaming raw materials 5a and 5b are mixed through the holes 23, there is almost no quality problem because it is inside the foamed article of different hardness. After the insert 7 is buried and integrated molding is completed, a cooling and solidifying process is performed, and if the mold is removed, an armrest as a desired integrally-hardened foamed product is completed.

(3) Effect According to the foamed article with different hardness and the method for manufacturing the same, the cavity C is partitioned by the film 2 so that different types of foamed raw material 5 are formed in the respective cavity portions 11 and 16.
Since a and 5b can be injected and integrally formed, foams 6a and 6b having different hardness can be easily formed integrally. As before,
It is possible to achieve low cost without the trouble of separately producing and storing the slab or the like processed into a predetermined shape. Moreover, the respective cavity portions 11, 1 partitioned by the film 2 are separated.
Since different types of foaming raw materials 5a and 5b can be almost simultaneously injected into 6, the molding can be performed in a short time, and the productivity is improved. The conventional foaming mold 1 can be used almost as it is, and it is sufficient to simply add the work of setting the film 2 on the mold dividing surface 10 so as to cover the cavity portion 11 of the divided mold 1 in the mold open state. It is easy. After the molding of the foamed article with different hardness, the product taken out by demolding has the film outer peripheral portion 22 placed on the mold separation surface 10 protruding from the foamed body 6. There is no problem because the skin is covered on the foamed product. Since the film 2 is soft, it can easily come into contact with the foam 6 if it is stroked. When a product such as a headrest covered with an epidermis is made, the film 2 is indistinct because it is soft and thin. Of course, since the film 2 is thin and easy to handle, the film outer peripheral portion 22 protruding from the foam 6 can be easily trimmed and removed. The headrest can be integrally molded into a product having a softened portion that hits the head while using an inexpensive material on the rear side of the vehicle, thereby achieving cost reduction and high quality.
Even for products such as armrests, the usual foaming mold 1
When used as an armrest, the same hardness as that of the seat back appears, and when it is used as an armrest, a foam of different hardness, which is a flexible foam 6 having good repulsion, can be easily integrally molded, greatly reducing cost. To contribute.

It should be noted that the present invention is not limited to the embodiment described above, but can be variously modified within the scope of the present invention depending on the purpose and application. The shape, size, number, material, and the like of the foaming mold 1, the film 2, the foaming raw material 5, and the foam 6 can be appropriately selected according to the application.

[0027]

As described above, the foamed article with different hardness and the method of manufacturing the same according to the present invention can integrate two or more foamed parts having different hardnesses without separately producing a foam or a slab. The product can be made easily and at low cost, which is extremely beneficial.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a state in which an insert and a film are set on a split surface of a split mold according to a first embodiment.

FIG. 2 is a longitudinal sectional view showing a state in which a mold is closed and different kinds of foaming raw materials are injected into respective cavity portions.

FIG. 3 is a vertical cross-sectional view that has proceeded from the step of FIG. 2 and has completed foam molding.

FIG. 4 is a partial cross-sectional view showing a state where blow molding from FIG. 3 has advanced.

FIG. 5 is a perspective view showing a state in which an insert and a film are set on a split surface of a split mold according to a second embodiment.

FIG. 6 is a perspective view showing a state in which a foaming material is injected into a cavity by inserting a nozzle into a hole formed in a film.

FIG. 7 is a perspective view showing a state in which a foaming material different from the foaming material is injected onto a film after the process of FIG. 6 is completed.

FIG. 8 is a view showing a pattern of closing a mold and injecting a foaming material from an injection groove.

FIG. 9 is a perspective view of a foamed article of different hardness taken out of the mold after completion of the foam molding.

[Explanation of Signs] 1 Foaming mold 1a, 1b, 1d, 1e Split mold 10, 15 Mold splitting surface 11, 16 Cavity part 2 Film (perforated film) 23, 24 Hole 5, 5a, 5b Foaming material 6, 6a , 6b foam (foam part) 91 nozzle C cavity

Claims (4)

[Claims] A film having a cavity defined on a mold dividing surface of a foaming mold is provided, and then different kinds of foaming raw materials are injected into respective cavity portions partitioned by separating the film. A method for producing a foam of different hardness, comprising taking a film and integrally molding a foam of different hardness. 2. A film is set on a mold division surface so as to cover a cavity portion of a division mold relating to a foaming mold in an open state, and then the mold is closed to partition a cavity with the film. A method for producing a foam of different hardness, which comprises injecting different kinds of foaming raw materials into the partitioned cavity portions, taking in the film, and integrally molding a foam of different hardness. 3. A perforated film is set on a mold dividing surface so as to cover a cavity portion of a divided mold relating to a foaming mold in an open state, and a nozzle of a foaming material is inserted into a hole of the perforated film. Inserting and injecting a foaming material into the cavity portion, then injecting a foaming material different from the foaming material into the remaining cavity portion, taking in the film, and integrally molding a foam of different hardness. Manufacturing method of foamed products with different hardness. 4. A film of different hardness, characterized in that a film is sandwiched between two foam portions having different hardnesses, and the film is taken in, and the foam portion is formed integrally with the film as a boundary surface. Foam products.