JP6891853B2 - Cavity mold for bead method foamable synthetic resin molding mold, bead method foamable synthetic resin molding mold, and method for manufacturing bead method foamable synthetic resin molded product - Google Patents

Description

The present invention is a mold for molding a bead method foamable synthetic resin used for a heat insulating container, a packaging material, etc., and a bead method foamable synthetic resin molding for producing a molded product of the foamable synthetic resin using the mold. Regarding the manufacturing method of goods.

The bead method foamable synthetic resin molding mold is composed of a cavity mold (concave mold) and a core mold (convex mold) (for example, the concave mold 4 and the convex mold 5 of Patent Document 1 and the cavity mold 2 of Patent Document 2). And core mold 3, and female mold 4 and male mold 5 of Patent Document 3).
In the bead method foamable synthetic resin molding, a molding space (cavity) formed by a cavity mold and a core mold is filled with foamable beads of a thermoplastic resin, and the foamable beads are heated with steam to be fused and cooled. And it is dried to obtain a molded product of a foamable synthetic resin having a required shape.

The cavity mold and the core mold are plate-shaped inner plates having a mounting surface in a direction orthogonal to the mold opening / closing direction, which is used to prevent damage to the mold and the frame of the molding apparatus main body due to thermal expansion (for example, Patent Document 1). 1 and 2b of FIGS. 1 and 4 and reference numerals 6 and 9 of FIG. 1 of Patent Document 3 in the above frame (for example, reference numerals 7 and 8 of Patent Document 1 and reference numeral 10 of Patent Document 2). , And reference numerals 7 and 10 of Patent Document 3).
The cavity mold includes a mounting flange (see, for example, the flange portion 2a of Patent Document 2 and the flange portion 13 of Patent Document 3) that projects outwardly orthogonal to the mold opening / closing direction. The cavity type is attached to the inner plate by screwing a bolt passed through a through hole provided in the mounting flange into the screw hole of the inner plate.

Japanese Unexamined Patent Publication No. 2003-033938 Japanese Unexamined Patent Publication No. 2003-31770 Japanese Unexamined Patent Publication No. 2013-071248

The inventors of the present application have diligently studied the structure of a mold for molding a foamable synthetic resin by the bead method, mainly in order to meet the demand for energy saving in recent years.
As a result, the present invention has been completed by focusing on the cavity-type mounting structure on the inner plate.

An object to be solved by the present invention is to provide a cavity mold for molding a bead method foamable synthetic resin, which can mainly save energy.

The gist of the present invention is as follows.
[1] A cavity mold for molding a foamable synthetic resin by the bead method, which is attached to the frame of the main body of the molding apparatus via an inner plate.
The inner plate is
It is a plate-shaped object with a mounting surface in the direction orthogonal to the mold opening / closing direction.
The cavity type
A mounting portion that comes into contact with the mounting surface of the inner plate from the molding space side is provided.
The inner plate is
It has a through hole that penetrates so as to face the screw hole provided in the cavity type mounting portion.
It is attached to the inner plate by screwing a bolt passed through the through hole of the inner plate into the cavity type screw hole.
Cavity mold for molding foamable synthetic resin by bead method.

[2] The bead method foamable synthetic resin molding die provided with the cavity mold of the bead method foamable synthetic resin molding die according to claim 1 according to the above [1].

[ 3 ] The molding space formed by the bead method foamable synthetic resin molding mold according to the above [2] is filled with foamable beads of a thermoplastic resin, and the foamable beads are heated by steam and fused. A bead method for producing a molded product of a foamable synthetic resin having a required shape by cooling and drying the molded product.

According to the bead method foamable synthetic resin molding mold and the method for producing a bead method foamable synthetic resin molded product according to the present invention, the following effects are exhibited.
(1) The cavity mold does not have a mounting flange that projects outwardly orthogonal to the mold opening / closing direction, and the cavity mold is placed in contact with the inner plate from the molding space side with the mounting portion provided for the cavity mold. Can be attached to.
(2) As a result, the length of the cavity mold in the mold opening / closing direction is shortened, and the volume of the mounting portion can be made smaller than that of the mounting flange projecting outwardly orthogonal to the mold opening / closing direction. Becomes smaller.
(3) As a result, the heat capacity of the cavity type is reduced, so that the heating time and the cooling time can be shortened, so that energy saving can be achieved and the molding cycle can be shortened.
(4) In addition, the manufacturing cost can be reduced by saving energy, and the manufacturing cost can be further reduced by reducing the material cost by reducing the weight of the cavity type.

FIG. 5 is a schematic vertical cross-sectional view showing the circumference of a mold for molding a bead method foamable synthetic resin according to an embodiment of the present invention. Similarly, it is a schematic view of an enlarged vertical cross section of a main part. It is an exploded perspective view which shows the cavity mold of the bead method foaming synthetic resin molding mold which concerns on embodiment of this invention. It is a schematic enlarged vertical cross-sectional view of a main part which shows the circumference of the mold for molding the conventional bead method foaming synthetic resin. It is an exploded perspective view which shows the cavity mold of the mold for molding the conventional bead method foaming synthetic resin.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
In the following, FIGS. 1 to 3 showing the bead method foamable synthetic resin molding die according to the embodiment of the present invention, and FIGS. 4 and 5 showing the conventional bead method foamable synthetic resin molding die. Steam holes (core vents driven into the vent holes, or the mold itself) that communicate with the inside and outside of the mold, which are necessary for supplying steam from the outside into the molding space and discharging steam from the inside of the molding space to the outside. The description of the slit-shaped steam holes directly formed in the above) is omitted.

<Mold for molding foamable synthetic resin by bead method>
As shown in the schematic view of the vertical cross section of FIG. 1 and the enlarged vertical cross section of the main part of FIG. 2, the bead method foamable synthetic resin molding die A according to the embodiment of the present invention is made of, for example, an aluminum alloy. Yes, it consists of a cavity type (concave type) 4 and a core type (convex type) 5.

In the bead method foamable synthetic resin molding mold A that requires heating and cooling, if the thickness of the cavity mold 4 and the core mold 5 constituting the mold A is thick, a larger amount of steam and cooling are required. I need water. Therefore, from the viewpoint of energy saving, in recent years, there has been a tendency toward the cavity type 4 and the core type 5 which are thinner and lighter. Also in the present invention, better effects can be obtained by adopting the lighter weight cavity type 4 and core type 5.
For example, the wall thickness of the cavity mold 4 and the core mold 5 is set to 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, etc. within the range of about 4 mm to 10 mm, and the required mold strength, manufacturing efficiency, and manufacturing cost, and The bead method is appropriately selected and used based on requirements such as molding efficiency of foamable synthetic resin molding.
A more preferable range of the wall thickness of the cavity type 4 and the core type 5 is about 4 mm to 8 mm.

The cavity mold 4 is attached to the frame 1 of the molding apparatus main body via the inner plate 2, and the core mold 5 is attached to the frame 1 of the molding apparatus main body via the inner plate 3.
The inner plates 2 and 3 have a plate-like shape having a mounting surface in a direction orthogonal to the mold opening / closing direction B, and are used to prevent damage to the mold A and the frame 1 of the molding apparatus main body due to thermal expansion.

<Cavity type>
As shown in the exploded perspective view of FIG. 3, the cavity type 4 is composed of the main body 4A and the bottom plate 4B, and the screw holes 4a, 4a of the main body 4A are passed through the through holes 4b, 4b, ... Assemble the bottom plate 4B to the main body 4A by screwing into ,.
The cavity type 4 is provided with a mounting portion 6 on a side portion opposite to the side portion to which the bottom plate 4B is assembled.
The inner plate 2 has through holes 2a, 2a, ... That penetrate in the mold opening / closing direction B so as to face the screw holes 6a, 6a, ... Provided in the mounting portion 6 of the cavity mold 4.

As shown in the schematic view of the vertical cross section of FIG. 1 and the enlarged vertical cross section of the main part of FIG. 2, the mounting portion 6 of the cavity mold 4 is brought into contact with the mounting surface of the inner plate 2 from the molding space C side. Then, the cavity type 4 is attached to the inner plate 2 by screwing the bolts 7, 7, ... Passed through the through holes 2a, 2a, ... Of the inner plate 2 into the screw holes 6a, 6a, ... Of the cavity type 4. Be done.

<Bead method foamable synthetic resin molding>
In the bead method foamable synthetic resin molding, a molding apparatus is used to enter the molding space C formed by the bead method foamable synthetic resin molding mold A from the raw material filling ports 9, 9, ... (FIG. 3). By filling the foamable beads of resin, heating the foamable beads with steam to fuse them, cooling and drying them, and then inserting and extruding the mold release pins from the mold release pin openings 10, 10, ... A molded product of a foamable synthetic resin having a required shape is obtained.
The effervescent beads to be filled in the mold are a concept including pre-expanded beads obtained by pre-foaming the effervescent beads.

As the foamable synthetic resin used for the bead method foamable synthetic resin molding, for example, a foamable polyolefin resin or a foamable polystyrene resin is used.
When the foamable synthetic resin is a foamable polyolefin resin, a molded product having excellent strength and heat resistance as well as oil resistance and chemical resistance by using the bead method foamable synthetic resin molding mold A. Can be molded.
When the foamable synthetic resin is a foamable polystyrene-based resin, a bead method foamable synthetic resin molding mold A is used to mold a molded product having excellent heat insulation and shock absorption, as well as being lightweight and low-cost. it can.

<Cavity type mounting structure to the conventional inner plate>
For molding of a conventional foamable synthetic resin by the bead method, which forms a molding space C having the same shape and size as the molding space C shown in the schematic view of the vertical cross section of FIG. 1 and the schematic view of the enlarged vertical cross section of FIG. An example around the mold is shown in the enlarged vertical cross-sectional view of the main part of FIG. 4, and an example of the conventional cavity mold is shown in the exploded perspective view of FIG.
Here, in FIGS. 4 and 5, the same reference numerals as those in FIGS. 1 to 3 indicate the same or corresponding portions, and thus detailed description thereof will be omitted.
In the conventional example shown in the schematic view of the enlarged vertical cross section of the main part of FIG. 4, the embodiment of the present invention shown in the schematic view of the enlarged vertical cross section of the main part of FIG. 2 is the inner plate 2'and the main body 4A of the cavity type 4'. 'Is different.

The conventional cavity mold 4'has a mounting flange 11 projecting outwardly orthogonal to the mold opening / closing direction B, and the mounting flange 11 has through holes 11a, 11a, ... Have.
Bolts 7', which are passed through the through holes 11a, 11a, ... Of the mounting flange 11 in a state where the mounting flange 11 of the cavity type 4'is in contact with the mounting surface on the side opposite to the molding space C of the inner plate 2'. The cavity type 4'is attached to the inner plate 2'by screwing 7', ... Into the screw holes 2b, 2b, ... Of the inner plate 2'.

<Comparison between the cavity type of the present invention and the conventional cavity type>
The cavity type 4 of the present invention shown in the schematic view of the enlarged vertical cross section of the main part of FIG. 2 and the conventional cavity type 4'shown in the schematic view of the enlarged vertical cross section of the main part having the same molding space C in shape and size. The cavity mold 4 of the present invention does not have a mounting flange 11 projecting outwardly orthogonal to the mold opening / closing direction B as in the conventional cavity mold 4', and the mounting portion 6 provided in the cavity mold 4 is provided. Can be attached to the inner plate 2 in a state where the cavity mold 4 is in contact with the inner plate 2 from the molding space C side.

As a result, the cavity mold 4 of the present invention has a shorter length in the mold opening / closing direction B than the conventional cavity mold 4'. Moreover, the mounting portion 6 of the cavity type 4 of the present invention can have a smaller volume than the mounting flange 11 of the conventional cavity type 4'.
Therefore, the volume of the cavity type 4 of the present invention is smaller than that of the conventional cavity type 4'. For example, when the inner diameter of the cavity type is 450 mm × 250 mm and the height is about 120 mm, the wall thickness is 7 mm or 9 mm, and the cavity type 4 of the present invention has a volume (weight) of 10 more than the conventional cavity type 4'. It becomes smaller by about 15%.

As a result, the cavity type 4 of the present invention has a smaller heat capacity than the conventional cavity type 4', so that the heating time and the cooling time can be shortened, so that energy saving can be achieved and the molding cycle can be shortened. it can.
Moreover, by using the cavity type as in the present invention, the manufacturing cost can be reduced by saving energy, and the manufacturing cost can be further reduced by reducing the material cost by reducing the weight of the cavity type.

Further, the cavity mold 4 of the present invention shown in the exploded perspective view of FIG. 3 is a mounting flange projecting outwardly orthogonal to the mold opening / closing direction B like the cavity mold 4'shown in the exploded perspective view of FIG. Since there is no 11, the area in the plane direction orthogonal to the mold opening / closing direction B becomes small.
As a result, more molds for bead method foamable synthetic resin molding can be arranged on the frame of the molding apparatus main body, so that the number of products taken in one shot increases, and productivity can be improved.

Further, in the conventional cavity type 4', the mounting flange 11 may interfere with a tool such as a drill when forming a vent hole for driving the core vent into the main body 4A'in the exploded perspective view of FIG.
On the other hand, in the cavity type 4 of the present invention, when forming a vent hole for driving the core vent into the main body 4A in the exploded perspective view of FIG. 3, the mounting portion 6 does not interfere with a tool such as a drill. A vent hole can be easily formed in the mounting portion 6 itself.

Further, in the conventional cavity mold 4', when a slit-shaped steam hole is formed in the main body 4A'in the exploded perspective view of FIG. 5 in the mold opening / closing direction B, the mounting flange 11 is cut with a metal saw or the like. The bead method is that steam and air leak into the parting surface of the foamable synthetic resin molding mold, making it impossible to release the product.
On the other hand, in the cavity mold 4 of the present invention, when a slit-shaped steam hole is formed in the main body 4A in the exploded perspective view of FIG. 3 in the mold opening / closing direction B, even if the mounting portion 6 is cut with a metal saw or the like. Since steam and air do not leak to the parting surface of the bead method foamable synthetic resin molding die shown in FIG. 2, the product can be released.

All the descriptions of the above embodiments are examples, and the present invention is not limited thereto. Various improvements and modifications can be made without departing from the scope of the present invention.

1 Frame 2, 2', 3 Inner plate 2a Through hole 2b Screw hole 4, 4'Cavity type 4A, 4A' Main body 4a Screw hole 4B Bottom plate 4b Through hole 5 Core type 6 Mounting part 6a Screw hole 7, 7', 8 Bolt 9 Raw material filling port 10 Opening for release pin 11 Mounting flange 11a Through hole A Bead method foamable synthetic resin Mold for molding B Mold opening / closing direction C Molding space

Claims (3)

It is a cavity mold for bead method foaming synthetic resin molding that is attached to the frame of the molding machine body via an inner plate.
The inner plate is
It is a plate-shaped object with a mounting surface in the direction orthogonal to the mold opening / closing direction.
The cavity type
A mounting portion that comes into contact with the mounting surface of the inner plate from the molding space side is provided.
The inner plate is
It has a through hole that penetrates so as to face the screw hole provided in the cavity type mounting portion.
It is attached to the inner plate by screwing a bolt passed through the through hole of the inner plate into the cavity type screw hole.
Cavity mold for molding foamable synthetic resin by bead method. The bead method foamable synthetic resin molding die provided with the cavity mold of the bead method foamable synthetic resin molding die according to claim 1. The molding space formed by the bead method foamable synthetic resin molding mold according to claim 2 is filled with foamable beads of a thermoplastic resin, and the foamable beads are heated with steam to be fused, cooled, and cooled. Bead method for producing a molded product of a foamable synthetic resin having a required shape by drying. A method for manufacturing a molded product of a foamable synthetic resin.

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