JP2002160234A - Mold for molding polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold which can mold a polyurethane foam molding having open cell structure or closed cell structure repeatedly on a level comparable to aluminum casting and to confirm fluidity in a cavity from the outside of the mold. SOLUTION: In the mold for polyurethane foam which comprises a lower mold, an upper mold which is arranged attachably/detachably to cover the open part of the lower mold and forms a closed space between it and the lower molds, and a cavity which is the closed space between the upper and lower molds and is supplied with a material for a polyurethane foam molding, a transparent window of a polycarbonate or an epoxy resin is formed at least in a part of the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polyurethane foam molded article having an open-cell structure or a closed-cell structure, which can be repeatedly molded at a level comparable to that of aluminum casting. The present invention relates to a mold for a polyurethane foam capable of confirming the fluidity of a material.

[0002]

2. Description of the Related Art Aluminum molds are mainly used for molding polyurethane foam.
In addition, cutting from cast iron, forging, and solid aluminum is also known.

In order to examine the moldability of a resin material, a visualization window is installed in a mold to check the actual fluidity of the resin. However, the window material is easily affected by the material. , Its selection is very difficult.

For example, glass, acrylic resin and the like are used for polyurethane foam molding dies, but glass is not suitable for processing and it is difficult to obtain a desired shape. Acrylic resin is vulnerable to heat and easily deformed and clouded by molding heat and vulcanization heat. In addition, acrylic resin has a high affinity with urethane resin, so it is used after applying a release agent, but with the release agent alone, it is not possible to avoid foam adhesion sufficiently, and it can withstand repeated use sufficiently There is no problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to repeatedly mold a polyurethane foam molded article having an open cell structure or a closed cell structure such as a flexible polyurethane foam at a level comparable to that of aluminum casting. It is an object of the present invention to provide a polyurethane foam mold capable of confirming fluidity in a cavity from outside the mold.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and found that when a window material is provided in a mold for molding a polyurethane foam, conventional glass and acrylic resin are used. After examining the materials,
By providing a window made of transparent polycarbonate and epoxy resin on at least part of the mold, good workability,
Polyurethane foam does not adhere, it can be repeatedly molded at a level comparable to conventional aluminum casting, and it is possible to check the fluidity of the resin in the cavity from the outside of the mold and work while checking the moldability. I learned.

Further, the present inventor has further studied and found that a core mold is arranged in a closed space inside a mold like a molding die for a front seat for a vehicle, and an upper surface of the core mold and the above-mentioned core mold are arranged. Forming a large-capacity cavity with the lower mold upper surface, and forming a low-capacity cavity with the core mold upper surface and the upper mold lower surface,
For a complex-shaped mold having a cavity having a structure in which the low-capacity cavity and the large-capacity cavity communicate with each other through a gap, a transparent polycarbonate or epoxy resin window is provided in the mold corresponding to the gap. By this, in particular, since it is possible to observe a portion that has a particular effect on a polyurethane foam molded article of a complicated shape, it was found that the mold would be suitable for observing the molding state,
The present invention has been accomplished.

Accordingly, the present invention provides the following molds for polyurethane foam (1) to (3). (1) A lower mold, an upper mold that is detachably provided to cover an opening of the lower mold, and forms an enclosed space between the lower mold and a closed space between the lower mold and the upper mold. A mold for a polyurethane foam, characterized in that a transparent window made of polycarbonate or epoxy resin is provided in at least a part of the mold, the mold being a cavity to which a material for a foam molded product is supplied. (2) The mold has a core die detachably disposed in the closed space, and when the core die is disposed, a low capacity is formed between the upper surface of the core die and the lower surface of the upper die. A cavity having a structure in which a large-capacity cavity is formed between the lower surface of the core mold and the upper surface of the lower mold, and wherein the low-capacity cavity and the large-capacity cavity communicate with each other through a gap. 2. The polyurethane foam mold according to claim 1, wherein a transparent window is provided on the mold surface facing the gap position. (3) The mold for polyurethane foam according to claim 1 or 2, wherein the entire lower mold and / or upper mold is formed of transparent polycarbonate or epoxy resin.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. The mold for polyurethane foam according to the present invention is, for example, a mold 1 shown in FIGS. In addition, a shape similar to a known mold can be used.

FIG. 1 is a schematic sectional view of a mold 1 of a vehicle front seat exemplified as a mold. The vehicle front seat mold 1 includes a lower mold 2, an upper mold 3 detachably joined to the lower mold 2, and a core disposed between the lower mold 2 and the upper mold 3. And mold 4.

When the lower mold 2 and the upper mold 3 are joined to each other, a large-capacity cavity 5 is formed between the upper surface of the lower mold 2 and the lower surface of the core mold 4. A low-capacity cavity 7 is formed by the upper surface on the tip end side of the core mold 4 and the partitioning projection 6 protruding at a required position on the upper surface of the core mold 4. Communicates through a gap 8 formed between the tip of the core mold 4 and one side wall of the lower mold 2, and is bent at almost 180 ° with respect to the large-capacity cavity 5. 7 are formed so as to be continuous. In addition,
A minute gap 9 is formed between the protrusion 6 and the upper mold 3.

In the mold 1, a portion of the lower mold 2 facing the gap 8 is formed as a transparent window 10 made of a transparent polycarbonate resin or epoxy resin, and the upper mold 3 is provided with a transparent window 10. A portion corresponding to the low-capacity cavity 7 is similarly configured as a transparent window 11 formed of a transparent polycarbonate resin or epoxy resin. In the example of FIG. 1, the other parts of the lower mold 2 and the upper mold 3 and the core mold 4 are made of aluminum, but may be made of other materials. In the figure, 12 is a camera, and 13 is a light source.

The large and low capacity cavities 5, 7
Has a large-capacity cavity 5 forming a seat body that becomes a front surface at the time of mounting, and a low-capacity cavity 7 forms a mounting portion that becomes a back surface at the time of mounting. is there.

Here, the polycarbonate is attached by drilling a predetermined position of the upper die and / or the lower die by machining, fixing the polycarbonate formed into a predetermined shape with a screw, and sealing the periphery with a sealing material. It can be done by stopping. In this case, it is recommended that the screwing portion be reinforced with a metal material and adjusted so that no load is applied to the polycarbonate.

Further, similarly to the polycarbonate, the epoxy resin is attached by drilling a predetermined position of the upper mold and / or the lower mold by machining, pressing gypsum from the inside of the mold, and further adding a note. This can be performed by pouring an epoxy resin material for a mold, providing a window, and filling a gap with a sealing material.

According to the mold, the state of foaming or the like can be observed from the transparent windows 10 and 11 at the time of molding the polyurethane foam. That is, when producing a polyurethane foam, the upper mold is joined to the lower mold after the foaming stock solution is injected into the lower mold. When the foaming solution starts foaming and fills the large-capacity cavity 5 and flows into and fills the low-capacity cavity 7 through the gap 8, the gap 8 becomes narrow, and the low-capacity cavity 7 becomes Usually, since the foam is connected to the large-capacity cavity 5 so as to bend, when the foam communicates through the gap 8 and flows into the low-capacity cavity 7 so as to further go around, the flow mode and flow velocity of the foam are considerably large. However, the transparent window 10 can be used to observe the state when the foam communicates with the gap 8, and the low-capacity cavity can be observed. It is possible to observe the state of flow, whether molding failure has occurred, how it occurred if it occurred, whether there was an abnormality in the flow of foam, etc. Because, it is easy to elucidate the cause of molding defects, which by those likely to also take measures for reduction of molding defects.

Therefore, according to the mold of the present invention, it is possible to confirm the growth of the internal polyurethane foam and the occurrence of defects, and when the defects occur, adjust the internal pressure and temperature, etc. Can be visually confirmed.

Further, since the window material has high heat resistance and can avoid adhesion of the polyurethane foam, it does not require the use of a release agent or the like and can suitably cope with repeated use.

In the present invention, the mold for polyurethane foam may be such that the whole mold is formed of transparent polycarbonate or epoxy resin. In particular,
The thing shown in FIG. 2 can be mentioned.

FIG. 2 is a schematic sectional view of a mold 1 for a vehicle front seat, similar to FIG. In the vehicle front seat mold 1, both the lower mold 22 and the upper mold 23 detachably joined to the lower mold 22 are formed of transparent polycarbonate or epoxy resin. In addition, about the metal mold | die of FIG.
The configuration and the like of the mold other than 3 are the same as those in FIG.

The lower mold 22 and the upper mold 23 shown in FIG. 2 are formed of polycarbonate or epoxy resin as described above, and the production thereof employs a known molding method of ordinary polycarbonate or epoxy resin. Although not particularly limited, it can be manufactured by employing an injection molding method or the like.

In the mold 1 shown in FIG. 2, the lower mold 22 and the upper mold 23 are both formed of a transparent polycarbonate resin or epoxy resin.
It is made up of transparent windows.

Therefore, according to the mold 1 shown in FIG. 2, the state of the material inside can be observed from any position of the lower mold 22 and the upper mold 23 forming surface when the polyurethane foam is molded. In particular, it is possible to observe the internal state of the mold from the time of material introduction, whether the foaming state of the material flowing through the large / low-volume cavity and the molding failure occurred, and if so, how it occurred It is possible to observe in more detail whether or not there is an abnormality in the flow of the foam. For this reason, in the example of FIG. 2 as well, it is easy to find out the cause of the molding failure, and it is easy to take measures to reduce the molding failure. In the illustrated example, transparent polycarbonate or epoxy resin is used for both the upper and lower molds. However, the mold of the present invention is not limited to this, and either the lower mold or the upper mold is used. Only the mold may be transparent.

The molding die of the present invention is applicable to those for obtaining a molded article of polyurethane foam, and is particularly suitable for a mold of a flexible polyurethane foam material, and more specifically, a mold suitable for a vehicle seat. It is.

[0025]

The mold of the present invention can repeatedly mold a polyurethane foam molded article having an open-cell structure or a closed-cell structure at a level comparable to that of aluminum casting, and from inside the cavity to the outside of the mold. Can be confirmed.

[0026]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a mold for polyurethane foam according to one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a mold for polyurethane foam according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mold 2 lower mold 3 upper mold 4 core mold 10,11 transparent window 22 lower mold (formed of transparent material) 23 upper mold (formed of transparent material)

Claims (3)

[Claims] A lower mold, an upper mold detachably disposed over an opening of the lower mold to form a sealed space between the lower mold, and a sealed space between the lower mold and the upper mold. Wherein a transparent window made of polycarbonate or epoxy resin is provided in at least a part of the mold, wherein the mold is a cavity to which a material for a polyurethane foam molded article is supplied. 2. The method according to claim 1, wherein the mold includes a core die detachably disposed in the closed space, and when the core die is disposed, the upper surface of the core die and the lower surface of the upper die are separated. A low-capacity cavity is formed, and a large-capacity cavity is formed by the core mold lower surface and the lower mold upper surface, and a cavity having a structure in which the low-capacity cavity and the large-capacity cavity communicate with each other through a gap. The mold for polyurethane foam according to claim 1, wherein a transparent window is provided on a mold surface facing the gap position. 3. The polyurethane foam mold according to claim 1, wherein the entire lower mold and / or upper mold is formed of a transparent polycarbonate or epoxy resin.