JPS6036426Y2 - Columnar body for steam holes used in foam molding equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a columnar body for steam holes used in a foam molding device, and attempts to obtain a columnar body suitable for preventing water from penetrating through the steam holes and entering the mold.

It is equipped with a foam molding device in which expandable thermoplastic resin particles are filled into the mold cavities between the molds, and the particles are heated and expanded using steam as a heating medium so that they are thermally fused to each other to form a bottom shape. Conventionally, as a means for forming steam holes, the first
As shown in the figure, a slit part 1 (core vent) with a steam slit 2 formed at the tip is used, and in places where it is difficult to drive and fit this slit part 1 into the molds 4 and 5, a drilled hole of 1 to 2 rIrInφ is used. 3 was drilled directly into the mold.

As is clear from FIGS. 2 and 3, which show the mounting state of the slit component 1, the drawbacks of the above conventional method include:
Water collects in the slit part 1 located on the top surface of the mold, and ice collects on the lower inner surface of the slit part 1 on the side of the mold, and when the foamed molded product 6 is removed, this collected water enters the mold. was.

On the other hand, even in the case of using the drilled holes 3 illustrated in FIG. 4, it takes time and effort to drill a large number of drilled holes 3, and it is difficult to drill small holes (0.3 to 0.8 mmφ). However, since the drill hole 3 has to be made large, it is difficult to prevent water from entering.

When water easily enters the inner surface of the mold through the steam holes, filling of the raw material is inhibited, so extra cracking is taken and filling is carried out while blowing out the water.

However, if cracking occurs frequently, the weight of the foamed molded product becomes heavier, and both heating time and cooling time become longer, which also causes an increase in product cost.

Therefore, it is necessary to provide the inner surface of the mold with steam holes that prevent water from leaking out.The columnar body for steam holes according to this invention can be provided in a foam molding device by eliminating these conventional drawbacks. and its composition is 0.8TrrI
It is characterized by being a columnar body such as a cylinder having a large number of small holes of nφ or less formed through it, and having a length equal to or greater than the thickness of the foaming mold.

Next, embodiments of this invention will be illustrated below with reference to FIGS. 5 to 7.

Reference numeral 10 denotes a columnar body for a steam hole formed in the shape of a cylinder or the like, and 20 denotes a large number of small holes formed through the columnar body 10 to serve as steam holes, each having a diameter of 0.8TrrInφ or less.

The steam hole columnar body 10 is formed to have a length equal to or greater than the thickness of the foam mold 30, 40 (usually formed by a mold) to which it is attached.

The steam hole columnar body 10 is used by being driven and fitted into the insertion hole of the mold 30.40, but in the fitted state, since it has the length as described above, the part facing the molded product 50 is the inner surface of the mold. It is preferable that the matching and opposing portions of the outer surface of the mold are provided either to coincide with the mold surface or to slightly protrude from the mold surface.

Experimental results show that not only does the columnar body 10 protrude slightly on the outside of the mold, but also that the small pores 20 are smaller than 0.8rIrIrLφ, so unless the inner surface of the mold is opened, the surface tension of water will cause the small pores 20 to become smaller. We were also able to confirm that water did not get inside.

The inner surface of the mold is filled with particles of foamed polystyrene and the like that have foaming power for fusion, so there is no risk of the mold becoming open.

Furthermore, since the columnar body 10 for the steam hole can be processed separately as an independent part separated from the mold, it is easier to process than a case where the hole is drilled directly into the mold.
It becomes easy to form countless small holes of φ or less, preferably 0.5 Mφ or less.

Note that it is convenient to form a slip prevention part 60 by knurling grooves or other processing on the outer periphery of the columnar body 10 on the side closer to the outer surface of the mold, and the shape of the columnar body 10 also A cylindrical shape is best because it is easy to implement, but
It is also possible to use other columnar shapes.

Steam supply holes, cooling water supply holes, and drain holes are omitted in the mold shown in the figure.

By using a columnar body for steam holes as described above,
As mentioned above, since moisture will not infiltrate into the mold, it is possible to fill the raw material without cracking during molding.Although it varies somewhat depending on the wall thickness of the foam molded product, it is approximately 5~
It can result in raw material savings of 7%.

For example, when foam molding a plate-shaped body with a thickness of 30TIrIn,
If cracking of mm is removed, there will be about 10% overfilling, so the effect of being able to fill the raw material without cranking is extremely large.

In addition, the columnar body for steam holes of this invention has a higher unit price than conventional products.
Even if it were doubled, the price increase would be limited to about 1% for the proportion of the entire mold, so the economic advantage of saving raw materials each time they are sequentially used in foam molding is far greater.

Furthermore, in terms of foam molding, as an advantage in terms of molding amount, this invention has an advantage of 0.2 to 0.3 Tr compared to conventional slits.
Since it is also possible to form small holes of rInφ, the residue caused by the contact of the molded product surface with the steam holes becomes almost invisible.
Beautiful surface molding is promoted.

As an example of the use of the columnar body for steam holes according to this invention, the diameter is 10 mm.
1rrIrLφ, length 12rrrIn steam hole columnar body with 8 holes of 0.5wnφ installed as small holes at a pitch of 45wIL in the mold thickness 10mm (9, 8 ~ 9
．． Drill a hole of 9rIrrnφ and click), molded product dimensions are external dimensions 350X 500mm, 150rIrInH1
A mold capable of molding a molded product with an average wall thickness of 25TrrIn and 5mm foam was fabricated and tested. Conventionally, cracking of 3rIrIn was removed before filling the raw material, but when using this design height, the inner surface of the mold became wet. Because of this, it can be molded without cracking. Conventionally, the heating time was 3 hoes, the cooling time was 47 seconds, and the weight of the molded product was 203 g, but with this design, the heating time was 3, the cooling time was 41 seconds, and the weight of the molded product was 185 g.
g, down was 16% in the heating time, 13% in the cooling time, and 18g in weight of the molded product.

From these results, it is possible to provide a columnar body for steam holes that can maintain the inner surface of the mold in a dry state, allowing raw materials to be filled without cracking, controlling the weight of the molded product, and shortening the heating time. It is clear that the cooling time can be shortened and the profitability of foam molding technology can be greatly improved.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional slit part, Figure 2 is a schematic diagram of the device to which the previous Surin I/part was installed, Figure 3 is an enlarged cross-sectional view of part A during molding, and Figure 4 is the conventional Fig. 5 is a perspective view of a columnar body for steam holes according to this invention, Fig. 6 is a schematic cross-sectional view of an apparatus equipped with this invention, and Fig. 7 is part B of the previous section. FIG. 3 is an enlarged cross-sectional view during molding. 10... Columnar body for steam hole, 20... Small hole, 60... Anti-slip part.

Claims (1)

[Scope of Claim for Utility Model Registration] A columnar body such as a cylinder having a large number of small holes of 10.8rrrInφ or less formed through it, and having a length equal to or greater than the thickness of the foam mold. A columnar body for a steam hole used in a foam molding device, characterized in that: 2. A steam hole for use in a foam molding device as set forth in claim 1 of the above-mentioned utility model registration claim, in which a non-slip portion such as a knurled groove is formed within the required length of one end of the length of the columnar body. columnar body.