JP2003033929A - Manufacturing method for foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a foam which can manufacture the foam easily and economically by using a foaming mold with a simple structure. SOLUTION: After a string-shaped or a belt-shaped member 20 is arranged on a bottom face of a cavity 12 with one end or both ends of it put outside the cavity 12 using a foam mold 10 which consists of a cavity mold 11 with the cavity 12 formed and a lid mold 15, a foaming raw material is poured into the cavity. At mold-releasing time after the molds are opened, the foam P is taken out of the cavity by pulling the cavity-outside portion of the string- shaped or the belt-shaped member outside the cavity.

Description

Detailed Description of the Invention

The present invention relates to a method for manufacturing a foam using a foam molding die including a cavity mold and a lid mold.

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a foam having a predetermined shape, as shown in FIGS. 8 and 9, a cavity mold 41 having a cavity 42 and a lid mold 45 for covering the cavity mold 41 are formed.
Using a foaming mold 40 consisting of
A so-called molding method is often used, in which a foaming raw material is injected into a foamed body to form a foamed body P, and then the mold P is opened to release the foamed body P from the mold.

Conventionally, in this type of molding die 40, in order to easily take out the foam P from the cavity 42, a concave portion 43 is formed on the bottom surface of the cavity 42 and a vertically movable nest 51 is provided in the concave portion 43. After the mold is opened after the foaming, the insert 51 is raised by the elevating member 52 of the ejecting device 50 (ejector), whereby the foam P is lifted from the cavity 42 and taken out.

However, such ejection device 5
Providing 0 in the molding die 40 increases the manufacturing cost of the molding die and its accessory device, and tends to take time to manufacture the molding die. Further, in the method of manufacturing the foam P using the molding die 40 having such a structure, when the foam P is foamed, the foaming raw material enters the boundary between the recess 43 on the bottom surface of the cavity 42 and the nest 51, and is left as it is to foam the foam. If the manufacturing of P is repeated, the lifting and lowering of the insert 51 will be hindered, so that periodic maintenance is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a method for producing a foam which does not complicate the structure of the foaming mold and which is economical and easy to obtain a foam. It is provided.

[0006]

That is, the present invention is
A foaming raw material is injected into a cavity of a foaming mold including a cavity mold having a cavity and a lid mold, and the foaming raw material is foamed to form a foam, and then the mold is opened to demold the foam. In the method for producing a foam, after placing the string-shaped or belt-shaped member on the inner bottom surface of the cavity so that one end or both ends thereof are outside the cavity, the foaming raw material is injected into the cavity, and after the mold is opened. When the mold is removed, the foamed body is taken out of the cavity by pulling the outside portion of the cavity of the cord-shaped or belt-shaped member outward of the cavity.

The invention of claim 2 is characterized in that, in claim 1, the cord-shaped or belt-shaped member is made of a flexible material.

Furthermore, the invention of claim 3 is characterized in that, in claim 1 or 2, the foam is taken out from the cavity by pulling both ends of the cord-shaped or belt-shaped member outward of the cavity.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing a foamed body according to an embodiment of the present invention at the time of manufacturing, FIG. 2 is a perspective view showing the arrangement state of the string-shaped members with a cavity mold omitted, and FIG.
FIG. 4 is a perspective view showing the arrangement state of the belt-shaped member with the cavity mold omitted, FIG. 4 is a perspective view showing the belt-shaped member with the plate-shaped support member further arranged without the cavity mold, and FIG. FIG. 6 is a cross-sectional view showing when the foam is taken out, FIG. 6 is a cross-sectional view showing another time when taken out, and FIG. 7 is a cross-sectional view showing yet another time taken out.

The foaming mold 10 of the embodiment shown in FIG. 1 is a known mold used for molding a foam made of urethane foam or the like, and has a cavity 12 according to a desired product shape. 11 and a lid mold 15 for covering it.

When manufacturing a foam using the foaming mold 10, first, as shown in FIG. 1-A, the foaming mold 10 is opened and the string-shaped or belt-shaped member 20 is attached to one end or both ends thereof. It is arranged on the cavity inner bottom surface 12a so that (both ends in this example) are located outside the cavity 12.
Regarding the direction in which the string-shaped or belt-shaped member 20 is arranged, that is, the longitudinal direction or the lateral direction with respect to the cavity shape, or the position on the cavity inner bottom surface 12a, the material and hardness of the foam P to be manufactured It is appropriately determined depending on the size, the material of the string-shaped or belt-shaped member 20, and the like.

As the string-like or belt-like member 20,
A cord-shaped member 21 as shown in FIG. 2 or a belt-shaped member 25 as shown in FIG. 3 can be used, and they are arranged along the inner surface of the cavity 12 of the cavity mold 11. Further, when the string-like member 21 is used, a plurality of string-like members are provided at predetermined intervals as shown in FIG. 2 so that the cavity bottom side Pa of the foam P can be supported and lifted with a predetermined width when the foam is removed from the mold. 21 is preferably arranged on the bottom surface 12a of the cavity. When a plurality of string-shaped members 21 are arranged in this manner, the plurality of string-shaped members 21 outside the cavity 12 are arranged.
The respective end portions may be appropriately grouped together to facilitate handling of the plurality of cord-shaped members 21 at the same time. On the other hand, when the belt-shaped member 25 is used, the foam P
The width is set to an appropriate width depending on the size of the foamed body P so that the cavity bottom side Pa can be easily supported and lifted with a predetermined width.

The string-shaped or belt-shaped member 20 is not particularly limited to paper, resin, cloth, metal, etc., but it is one that fits in the shape of the cavity 12 and does not damage the foam P when the foam is removed from the mold. Is good. Although the thickness and thickness depend on the material, a thin or thin material having a thickness of 3 mm or less in the case of the string-shaped member 21 and 1 mm or less in the case of the belt-shaped member 25 is a foam that contacts the string-shaped or belt-shaped member 20. It is more preferable because it has less influence on the surface of the body P. Further, as defined in claim 2, the cord-shaped or belt-shaped member 20 is made of a flexible material, for example, a cord-shaped member 21 made of paper cord, resin cord or the like, paper tape, resin or metal film. If the belt-shaped member 25 is made of, for example, it is convenient because the cord-shaped or belt-shaped member 20 can be formed along the cavity 12 without preliminarily shaping it into the shape of the cavity 12. On the other hand, if a resin string, a metal belt, a resin belt or the like having a predetermined thickness and thickness capable of retaining the self-shape is preliminarily formed into a shape that matches the shape of the cavity 12, it can be easily placed in the cavity 12. Become.

Further, the string-like or belt-like member 20.
Is selected to be one that is bonded and left integrally with the foam P when the foam P is foamed, one that is repeatedly used to manufacture the foam P without being adhered to the foam P, or one that is an inexpensive material. It may be replaced with a new one each time. In particular, it is economical when used repeatedly. In that case, the cord-shaped or belt-shaped member 20 is formed of the foam P.
Use a material that is difficult to adhere to or apply a release agent.

A plurality of cord-shaped or belt-shaped members 20 are arranged on the inner bottom surface 12a of the cavity so that the foam P can be more reliably and stably lifted and taken out from the cavity mold 11 when the foam P is released from the mold. In addition, as shown in FIG. 4, a plate-shaped support member 29 is provided on the cord-shaped or belt-shaped member 20 arranged in the cavity 12 to support the cavity bottom side Pa of the foam P with a wider effective area. You may do it. The plate-shaped support member 29 is made of an appropriate material such as a resin plate or a metal plate. The plate-shaped support member 29 is made of a material to which the foam P is difficult to adhere, or is applied with a release agent.

Next, a required amount of foaming material Po such as urethane material is injected into the cavity 12 and the mold is closed by the lid mold 15, and the foaming material Po is reactively foamed to form the foam P in the shape of the cavity 12. At this time, the outer end of the cavity 12 of the string-shaped or belt-shaped member 20 is positioned on the parting surface of the cavity mold 11 and the lid mold 15, or the foam molding mold 1 passes through the parting surface.
It is located outside 0. In addition, when a string-shaped or belt-shaped member 20 having a particularly large thickness is used, a gap corresponding to the thickness of the string-shaped or belt-shaped member 20 can be formed on the parting surfaces of the cavity mold 11 and the lid mold 15. Therefore, it is preferable to prevent the leakage of the foaming raw material Po by using a sealing material or the like at the periphery of the cavity 12 of the cavity mold 11 or the lid mold 15 to enhance the sealing property.

When the foaming is completed, the lid mold 15
To open the cavity 1 of the string-shaped or belt-shaped member 20.
2 Pull the outer part outward of the cavity 12. As a result, the foam body P is supported on the cavity bottom side Pa by the string-shaped or belt-shaped member 20 and lifted from the cavity 12, so that the foam body P can be easily demolded.

There are various methods for pulling the outer portion of the cavity 12 of the string-shaped or belt-shaped member 20 at the time of releasing the mold. In the method shown in FIG. 5, both ends 22 (2
7) is fixed at a predetermined position outside the cavity 12, and one or both of the cavity mold 11 and the fixed both ends 22 (27) is pushed toward the cavity mold 11 as indicated by an arrow y.

In the method shown in FIG. 6, one end of the cord-shaped or belt-shaped member 20 outside the cavity 12 is fixed, and the other end is pulled outward. Further, in the method shown in FIG. 7, both ends 22 (27) of the string-shaped or belt-shaped member 20 are left outside the cavity 12,
Both ends thereof are pulled outward of the cavity 12, respectively. In the case of FIGS. 6 and 7, the direction in which the cord-shaped or belt-shaped member 20 is pulled is not limited to the horizontal direction, and may be an appropriate direction such as directly above, diagonally above or below.

Further, as defined in claim 3, in FIG. 5, the cavity mold 11 and the fixed end portions 22, 22 (27, 2) are fixed.
7) As shown in the case of pressing both in between, or FIG.
As shown in FIG. 4, the foamed body P can be lifted evenly by pulling both ends 22 (27) of the cord-shaped or belt-shaped member 20 outward of the cavity 12 to take out the foamed body P from the cavity 12. Therefore, the interference with the inner surface of the cavity 12 is reduced, and the mold can be released more smoothly.

In the above embodiment, the cord-shaped or belt-shaped member 2
Although the case where both ends of 0 are positioned outside the cavity 12 is shown, the present invention is not limited to this, and only one end of the string-shaped or belt-shaped member is outside the cavity, and the other end is positioned inside the cavity. You may In that case, the end portion of the string-shaped or belt-shaped member located inside the cavity is fixed by adhering it to the foam, or by sandwiching and fixing it between the foam and the inner surface of the cavity. Alternatively, the foam can be released from the mold by pulling the end of the belt-shaped member located outside the cavity to the outside of the cavity.

[0022]

As shown and described above, according to the method for producing a foam of the present invention, the cord-shaped or belt-shaped member is provided on the inner bottom surface of the cavity so that one end or both ends thereof are outside the cavity. After the arrangement, the foaming raw material is injected into the cavity, and when the mold is released after the mold is opened, the foamed body is taken out from the cavity by pulling the outside portion of the cavity of the string-shaped or belt-shaped member to the outside of the cavity. Since it does not require a complicated demolding device, the foaming mold has a simple structure, and it does not require cost or time to manufacture equipment such as a foaming mold, so it is economical to manufacture foams. You can

Further, according to this manufacturing method, it is possible to directly cope with the foaming mold having the conventional structure.
It is a very economical and highly profitable method.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a foamed body according to an embodiment of the present invention during manufacturing.

FIG. 2 is a perspective view showing an arrangement state of a string-shaped member with a cavity mold omitted.

FIG. 3 is a perspective view showing an arrangement state of belt-shaped members with a cavity mold omitted.

FIG. 4 is a perspective view showing a state in which a plate-shaped support member is further arranged on a string-shaped member, with a cavity mold omitted.

FIG. 5 is a cross-sectional view showing when the foamed body is taken out.

FIG. 6 is a cross-sectional view showing another time of taking out.

FIG. 7 is a cross-sectional view showing still another extraction time.

FIG. 8 is a cross-sectional view showing a foam body manufactured by a conventional manufacturing method.

FIG. 9 is a cross-sectional view showing the foam-mold releasing process according to the conventional method.

[Explanation of symbols]

10 Foaming mold 11 cavity type 12 cavities 15 Lid type 20 String-shaped or belt-shaped members 21 String member 22 End of string-like member 25 Belt-shaped member 27 Belt-shaped member end P foam

Claims (3)

[Claims] 1. A foaming raw material is injected into a cavity of a foaming mold having a cavity mold having a cavity formed therein and a lid mold, the foaming raw material is foamed to form a foamed body, and then the mold is opened. In the method for producing a foamed product, the string-shaped or belt-shaped member is placed on the inner bottom surface of the cavity so that one end or both ends of the member are outside the cavity, and then the foaming raw material is injected into the cavity. At the time of releasing the mold after the mold is opened, the foam is taken out of the cavity by pulling an outer portion of the cavity of the string-shaped or belt-shaped member outward of the cavity. 2. The method for producing a foam according to claim 1, wherein the cord-shaped or belt-shaped member is made of a flexible material. 3. The method for producing a foam according to claim 1, wherein the foam is taken out of the cavity by pulling both ends of the cord-shaped or belt-shaped member outward of the cavity.