JP2657051B2 - Resin foam molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a resin foam which can prevent a foam molded article foamed in a molding die from being ruptured by internal pressure during demolding.

[0002]

2. Description of the Related Art Foam molded articles using various resin foams such as phenol foam, polystyrene foam and polyethylene foam as heat insulating materials are used for ceilings and walls of houses.

[0003] Conventionally, such a foamed molded article has conventionally been manufactured as shown in FIG.
As shown in FIG. 7, a resin foam material a such as phenol is injected into a molding panel b, and after sealing with a mold c, the resin foam material a is heated as shown in FIG. It is manufactured by foam molding.

[0004]

However, foam molding in a closed mold c requires a considerable amount of time to lower its internal pressure, which not only tends to reduce productivity, but also increases the productivity.
The unevenness of the internal pressure tends to cause a variation in the thickness of the foamed molded body, which causes a problem in quality.

Further, the impact due to the internal pressure when the mold c is removed from the mold is large, and the mold cannot be removed smoothly. In addition, excess gas due to foam molding accumulates inside, and as shown in FIG. As a result, the foamed molded article d may be broken when the internal pressure is released, and may be ruptured when severe.

The present invention is based on the principle that a pin is inserted into a foamed molded product prior to demolding and the gas inside is released, and resin foam capable of reliably preventing cracking and rupture of the foamed molded product due to internal pressure during demolding. The purpose is to provide a body forming method.

[0007]

Means for Solving the Problems To achieve the above object, a resin foam molding method of the present invention is to form a resin foam material into a substantially rectangular flat plate in a mold, and to form at least the foamed molded product . Prior to demolding, a pin is inserted near the four corners of the plane to release the gas inside, and then demolded to take out a foam molded article.

Prior to demolding, a pin is inserted into a foamed article of a resin foam material foamed in a molding die to break air bubbles to make the air bubbles continuous, and the pin is pulled out to remove excess gas inside. Release. Therefore, the internal pressure in the mold can be reduced in a short time before demolding, shortening the molding time and improving the productivity, and suppressing the variation in the thickness of the foam due to uneven internal pressure. Can.

In addition, since the internal pressure is reduced in advance, the impact due to the internal pressure at the time of demolding can be reduced, the demolding can be performed smoothly, and cracks and ruptures of the foam molded article at the time of demolding due to excess gas can be reliably prevented. The quality of the molded product can be ensured in combination with the uniform thickness.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 5, a resin foam molding method according to the present invention comprises foaming a resin foam material 2 such as phenol, polystyrene, or polyethylene in a molding die 3, and This is a method in which the pin 5 is inserted before the mold is released, the gas inside is released, and then the molded article is removed from the mold.

In the present embodiment, as shown in FIG. 2 and the like, the molding die 3 comprises, for example, a work 10 forming a ceiling panel for forming a ceiling in which a surface material 12 is attached to a lower surface of a surrounding frame 11;
An upper die 14 having an upper plate 16 disposed between upper ends of a peripheral plate 15 which can contact the upper surface of the frame 11 of the work 10 by descending.

On the upper plate 16 of the upper die 14, as shown in FIG. 5, there are provided, for example, nine guides 20 for forming holes 19 for inserting the pins 5 at positions near four corners. ,
In other parts, for example, six pieces, a total of 42 pieces, are buried.

Further, as the pin 5 inserted into the molding die 3 from the hole 19, a non-porous rod is used in order to prevent clogging with the resin foam material 2.

In the present invention, first, as shown in FIG.
The resin foam 2 such as phenol is injected into the work 10 of the molding die 3.

Thereafter, as shown in FIG. 3, the upper mold 14 closing the holes 19 with the pins 5 is lowered, and the resin foam 2
Is foamed in the mold 3. The lower end of the pin 5 is positioned at a height equal to or higher than the lower surface of the upper plate 16.

When foaming of the resin foam material 2 is completed and the foam molding 4 is molded in the molding die 3, the mold is released, that is, the upper mold 1 is removed.
4, the pins 5 are inserted into the foam mold 4 as shown in FIG. The insertion of the pins 5 makes it easier for the cells of the foamed molded article 4 to be continuous, thereby making gas release more efficient. However, prior to molding, pin 5
Is excluded in the present invention, because the insertion of a hole in the surface of the pin 5 makes it easy to form a smooth foam molded body 4 having no holes on the surface of the pin 5 and makes it difficult to release gas.

As shown in FIG. 1, by pulling out the pins 5, surplus gas in the foamed molded body 4 in the molding die 3 can be released from the holes 19, and when the mold is subsequently removed, the internal pressure increases. Cracks and rupture of the foam molded article 4 can be prevented. As is clear from the plan view of FIG. 5 and FIGS.
In addition, the foam molded body 4 has a substantially rectangular plate
Pin 5 is inserted at least in the vicinity of four corners of plane of foam molded body 4
It is.

[0018]

As described above, according to the resin foam molding method of the present invention, a pin is inserted into a foam molded article of a resin foam material foam-molded in a mold prior to demolding, and excess gas inside is removed. Release. Therefore, the internal pressure in the mold can be reduced in a short time before demolding, shortening the molding time and improving the productivity, and suppressing the variation in the thickness of the foam due to uneven internal pressure. Can.

Further, since the internal pressure is reduced in advance prior to demolding, the impact due to the internal pressure at the time of demolding can be reduced, and the mold can be smoothly demolded. Damage can be reliably prevented, and the quality of the molded product can be ensured in combination with the uniform thickness.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of the present invention.

FIG. 3 is a sectional view showing one embodiment of the present invention.

FIG. 4 is a sectional view showing an embodiment of the present invention.

FIG. 5 is a plan view showing an example of an arrangement of pin insertion holes of a molding die.

FIG. 6 is a cross-sectional view for explaining a conventional technique.

FIG. 7 is a cross-sectional view for explaining a conventional technique.

FIG. 8 is a cross-sectional view showing cracking and bursting of a foam molded article.

[Explanation of symbols]

 2 Resin foam 3 Mold 4 Foam 5 Pin

Claims (1)

(57) [Claims] 1. A resin foam material is foam-molded into a substantially rectangular plate shape in a molding die, and at least a flat surface of the foam molded article is formed.
A resin foam molding method characterized in that pins are inserted near four corners prior to demolding to release gas inside, and then demolded to take out a foam molded body.