JP2000334763A - Production of foam molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a foamed molded article used as a cushioning material or heat insulating material partially changed in foaming magnification without using a plurality of foaming materials different in foaming magnification. SOLUTION: In a method for producing a foam molding material by charging a foaming material in a mold to foam the same, the foaming material 17a charged in the mold is partially compressed to be partially restricted in its foaming and the foaming magnification of the compressed part of the foaming material 17a is made lower than that of the other part thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a foamed material used as a cushioning material or a heat insulating material, and more particularly, without using a plurality of foamed materials having different expansion ratios.
The present invention relates to a method for producing a foam molding material having a different expansion ratio.

[0002]

2. Description of the Related Art First, a refrigerator will be described as an example, and a cushioning material used for packing the refrigerator will be described with reference to FIG. In FIG. 13, 1 is a refrigerator main body, 2 is a freezer compartment door on the front of the refrigerator, 3 is a refrigerator compartment door on the front of the refrigerator, 4 is a butterfly plate for supporting the freezer compartment door, 5 is a moving wheel 6 and an adjusting leg 7. 8 is a compressor (not shown)
Compressor base plate equipped with a moving wheel 6 at the bottom,
9 is a packing pallet formed by bending four sides of cardboard, 1
Reference numeral 0 denotes a bottom cushioning member formed of styrene foam, which is disposed on the left and right sides of the packing pallet 9 and is located at the bottom of the refrigerator.
Is an upper cushioning material formed of styrene foam which is attached to the upper left and right of the refrigerator body 1, and 12 is an outer corrugated cardboard covering the whole.

FIG. 14 shows the appearance of the upper cushioning material 11. A concave portion 11a is formed in the upper cushioning material 11 for accommodating the upper portions of the freezer compartment door 2 and the butterfly plate 4.
1b (dense spots with a high density) is filled with a material having a lower magnification than other portions of the upper cushioning material 11, and has a compressive strength or breaking strength equal to or higher than that of the other portions even if its thickness is thin. Is configured to obtain.

FIG. 15 is an external view of a packing pallet 9 and a bottom cushioning member 10 disposed on the left and right inside the pallet. The bottom cushioning member 10 is formed with a recess 10a for allowing the front leg 5 of the refrigerator 1 to escape and house it, and a recess 10b for allowing the compressor base plate 8 to escape and house it. These meat portions 10c (high density spots) are also formed. The lower cushioning material 10 is filled with a low-magnification foaming material from other portions, so that the same effect as the upper cushioning material 11 is obtained.

Next, a conventional manufacturing method for the above-described cushioning material will be described. FIG. 16 is a schematic view of a conventional styrofoam molding machine. In FIG. 16, 40 is a styrofoam molding machine, 43a is a movable plate of the molding machine 40, 43b.
Is a fixed plate of the molding machine 40, 44 is a molding die composed of a movable mold 44a attached to the movable plate 43a and a fixed mold 44b attached to the fixed plate 43b, and 45a stores a primary foamed material for high-magnification foaming. A hopper 45b is a hopper for storing the primary foamed material for low-magnification foaming, and a supply pipe 46 is a material supply pipe connecting the hoppers 45a and 45b and the fixed mold 44b of the molding die 44.

[0006] Styrofoam molding using this molding machine 40 is performed as follows. That is, as the foaming material to be foamed in the molding die 44, a material which has been subjected to primary foaming to uniformly fill the mold is used, and a material which has been subjected to primary foaming in advance for high-magnification foaming and low-magnification foaming is used. Are stored in the hoppers 45a and 45b, respectively. These foaming materials are filled into the closed mold 44 of the fixed mold 44b and the movable mold 44a via the supply pipe 46, and the high-magnification foaming material and the low-magnification foaming material are filled depending on the connection position of the supply pipe 46 and the filling amount. The filling position and range are respectively controlled. Furthermore, while the molding die 44 is heated with steam, steam is supplied into the die 44 from the ventilation holes 44i to perform secondary foaming, individual particles are fused and integrated, and after cooling, the molding die 44 Take out the styrofoam molded product.

FIG. 17 is a schematic sectional view showing an example of a combination arrangement of a low-magnification foam material and a high-magnification foam material in a molding die 44 for producing such a cushioning material. In addition,
Here, reference numeral 47a denotes a material for high-magnification foaming supplied into a space in which the fixed mold 44b and the movable mold 44a are closed, and 47b denotes a material for low-magnification foaming.

As described above, at the time of packing, recesses 10a and 10b for allowing the front legs 5 and the compressor base plate 8 of the refrigerator to escape are formed in the front and rear portions of the bottom cushioning member 10, and the upper cushioning member is provided. Since the material 11 is formed with a concave portion 11a for allowing the freezer compartment door 2 and the butterfly plate 4 to escape, the cushioning material is thin at that portion and the product receiving area is reduced. However, since the low-density foam material is filled and foamed around each concave part, it has a high density and is hard and has the strength to withstand handling. It is possible to stably store without. On the other hand, in a portion where such a response is not required, the high-density foamed material is filled to have a low density, thereby reducing the amount of the filled foamed material.

[0009]

As described above, according to the conventional manufacturing method, two kinds of materials having different expansion ratios, which are primarily foamed, are filled in a molding die, thereby simultaneously molding different expansion ratios. However, the primary-foamed low-magnification foam material has a higher specific gravity than the high-magnification foam material and easily falls below the molding die, and it is difficult to fill a predetermined position with the low-magnification foam material. Also, due to its difficulty, there is also a problem that more than a predetermined amount of material must be supplied in order to ensure that the low-ratio foam material is filled in a predetermined range. Furthermore, since two different materials are used, not only is the management of the materials difficult, but also in general molding equipment that uses one type of material, such as a hopper or supply pipe for storing the materials, There is a problem that molding is not possible, and a burden is imposed on equipment.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and a buffer having a partially changed expansion ratio without using a plurality of expansion materials having different expansion ratios. An object of the present invention is to provide a method for producing a foam molded product used for a material or a heat insulating material.

According to the present invention, there is provided a method for producing a foamed molding material in which a foamed material is filled in a mold and foamed to obtain a molded material, wherein the foamed material filled in the mold is partially utilized by using a movable piece. Compressing partially limits the foaming of the foamed material so that the compressed portion of the foamed material has a lower expansion ratio than other portions of the foamed material.

Further, the movable piece is operated by a piston or a rotational force.

[0013] The heating of the mold is performed by using heating steam, and the area of a ventilation hole through which the heating steam passes through the mold is reduced by a unit area per unit area in the compression part of the mold from other locations. Enlarge.

Further, the movable piece is provided with a ventilation hole for passing the heating steam.

Further, a first steam chamber for the heated steam is provided at one end of the movable piece.

Further, a second steam chamber for the heating steam is provided in the operating portion of the movable piece, and the control of the steam passing through the steam chamber is performed independently of the steam passing through the first steam chamber.

Further, a cooling water nozzle for introducing cooling water into the first steam chamber and a cooling water nozzle for introducing cooling water into the second steam chamber are separately provided, and these cooling water nozzles are independently provided. The cooling water is sprayed on the mold under control.

Further, the compression is performed in a process of sucking back the material remaining in the pipe that has supplied the material into the mold.

Further, the space between the movable piece and the mold is set to at least 1.5 times the material diameter after completion of the primary foaming of the foamed molding material, and after the primary foamed molding material is filled, the compression is performed. I do.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a schematic diagram of a styrofoam molding machine used in an embodiment of the present invention. In FIG. 1, reference numeral 30 denotes a styrofoam molding machine, 13a denotes a movable plate of the molding machine 30, and 13b denotes a molding machine 30.
, A molding die 14 filled with a foam material, 15
Reference numeral 16 denotes a hopper for storing a molded foam material which has been primarily foamed for high-magnification foaming. Here, the molding die 14 includes a movable mold 14a attached to the movable plate 13a,
A fixed die 14b attached to the fixed platen 13b;
An opening 14c is formed in a corresponding portion of the fixed mold 14b corresponding to a range in which secondary foaming of a foam material to be performed later is to be limited (or suppressed), and a movable piece driven by hydraulic pressure or the like is formed in the opening 14c. Is inserted and fitted.

Next, a procedure for obtaining a styrofoam molded product using the styrofoam molding machine 30 will be described.

First, a high-magnification foam material 17a, which has been subjected to primary foaming, is stored in the hopper 15. Further, as shown in FIG. 2A, the molding die 14
4d is set at a position where the tip end surface is retracted from the inner side surface of the fixed die 14b. The position setting of the piston 14d is appropriately determined depending on how much the secondary foaming is limited in the secondary foaming to be performed. That is,
The required expansion ratio is controlled by the stroke of the piston 14d. Then, when the molding is started, the foam material 17a is injected into the space inside the molding die 14 closed by the movable die 14a, the fixed die 14b, and the piston 14d via the supply pipe 16. In this case, since the primary foamed materials are all of the same type, they can be easily and uniformly filled in the molding die 14.

Next, as shown in FIG. 2B, the piston 14d is advanced and moved to a position where the distal end surface forms the final shape of the molded product. As a result, the piston 14
The part of the foam material 17a corresponding to the tip end of d is compressed by the stroke of the piston 14d. Next, the molding die 14 is heated with steam to perform secondary foaming. At this time, the portion of the foamed material 17a compressed by the piston 14d is limited in its expansion ratio, and is in a low-ratio expansion state. Then, after cooling the molding die 14, the molding die is opened again, and the styrofoam after secondary foaming is taken out.

In the styrene foam thus obtained, the portion where secondary foaming is restricted and the expansion ratio is low is reduced in compressive strength and breaking strength despite the fact that it is thinner than the other portions. Then, it becomes possible to have necessary strength at the time of packing. Therefore, it is extremely convenient to manufacture a cushioning material having a concave portion used for packing a refrigerator or the like described above by this method.

Embodiment 2 FIG. 3 shows a modification of the molding die 14 used in the styrofoam molding machine 30. Here, the molding die 14 includes a movable mold 14a attached to the movable board 13a and a fixed mold 14b attached to the fixed board 13b, and furthermore, a range in which secondary foaming of the foam material to be performed later is to be suppressed. An opening 14e is formed in a corresponding portion of the movable die 14a in correspondence with the above, and a fan-shaped movable piece 14f that rotates by hydraulic pressure or the like and opens and closes the opening 14e is provided in the opening 14e. That is, this movable piece 1
The secondary foaming of the high-magnification foam material is partially restricted by using the rotational force of 4f, and the secondary foam is made into a low-magnification foam state.

Embodiment 3 FIG. Here, a heat insulating material of the foamed molding material is taken as an example. FIG. 4 is a vertical cross-sectional view of a box constituting a refrigerator when a heat insulating material is filled and foamed. In FIG. 4, 31 is a refrigerator box, 18 is an outer box of a steel plate box 31, 19 is an inner box of a synthetic resin-molded box 31, and 20 is a refrigerator attached to the box 31. Insulated partition made of styrohome for thermal division between storage rooms, 21 is outer box 1
Reference numeral 8 denotes an outer jig for holding the outer surface, 22 denotes an inner jig for holding the inner surface of the inner box 19, and 23 denotes a heat insulating material such as polyurethane filled and foamed between the outer box 18 and the inner box 19. Here, the heat insulating partition 20 utilizes a water receiving portion 20a for receiving defrost water from a cooler (not shown) and an opening formed in the inner box 19 on the back surface of the water receiving portion 20a. And a rear wall 20 b for attaching the heat insulating partition 20 to the inner box 19.

When filling and foaming the heat insulating material 23 in the refrigerator box 31, the foaming pressure of the heat insulating material 23 is reduced by the outer box 18.
The outer jig 21 and the inner jig 22 are supported by the outer jig 21 and the inner jig 22 at the portion where the outer jig 21 and the inner jig 22 are in contact with their wall surfaces. Absent.

On the other hand, as shown in FIG.
Is attached to the inner box 19, and the rear wall 20b is the inner jig 2
Since 2 is not in contact with the back wall 20b, the foaming pressure of the heat insulating material is supported only by the back wall 20b. However, according to the present invention, a heat insulating partition 20 having a back wall 20b that can sufficiently withstand the foaming pressure can be produced.
Hereinafter, the manufacturing method will be described.

FIG. 5 is a schematic sectional view of a molding die portion when the heat insulating partition 20 is manufactured. Note that the configuration of the molding machine main body for forming the heat insulating partition 20 conforms to the styrofoam molding machine described in the first embodiment. In FIG. 5, the molding die 14 has a movable die 14a and a fixed die 14b,
Further, in order to apply pressure to a portion to be the rear wall 20b, a movable piece 14h that rotates about a fulcrum 14g is provided at the open bottom of the molding die 14.

The primary foamed high-magnification foam material 17a filled from the supply pipe 16 into the closed molding die 14 is:
The secondary foaming is performed by heating. At this time, the secondary foaming is restricted in the back wall 20b compressed by the movable piece 14h in accordance with the compressive force, and foaming with a lower magnification is generated as compared with other portions. . In this way, the heat insulating partition 20 taken out of the molding die 14 increases its strength because the rear wall 20b is foamed at a low magnification, and is deformed and damaged by the foaming pressure of the heat insulating material without the support of the inner jig 22. It becomes possible not to make it do.

In each of the above embodiments, the hopper 1
There are provided one to three supply pipes 16 for the foaming material that communicate between the mold 5 and the inside of the fixed mold 14b, but the number thereof can be determined as appropriate according to the shape of the molding die 14. Further, the compression operation of the piston 14d and the movable pieces 14f and 14h may be started simultaneously with the secondary foaming step. further,
The piston 14d and the movable pieces 14f and 14h are not limited to the above embodiment, and may be provided on either the movable mold 14a side or the fixed mold 14b side depending on the type of the molding machine as the main body. Good.

Embodiment 4 FIG. FIG. 6 is a schematic view showing the structure of a mold and a movable compression part of a styrofoam molding machine 30 as shown in FIG. 1 according to a fourth embodiment of the present invention.
Here, as in FIG. 2, the molding die 14 includes a movable mold 14a attached to the movable plate 13a and a fixed mold 14 attached to the fixed plate 13b.
b, and a fixed mold 14b corresponding to a range in which secondary foaming of the foamed material to be performed later is to be restricted (or suppressed).
An opening 14c is formed in a portion corresponding to the above, and a piston 14d driven by hydraulic pressure or the like is inserted and fitted into the opening 14c. Also, the movable mold 14a and the fixed mold 14b
Inner surface 14 in contact with the surface of the Styrofoam molded product
a ′, 14b ′, and the piston 14d are provided with a plurality of ventilation holes 14i arranged in a lattice, for example, so that the heating steam supplied from the heating steam pipe 14m is supplied to the first steam chamber 14a.
Through p, the structure is supplied to the inside of the molding die 14. On the other hand, the heated molding die 14 is cooled by injecting the cooling water supplied from the cooling water pipe 14n into the die 14.

The number of the ventilation holes 14i provided in the piston 14d and the periphery thereof is larger per unit area than the number of the ventilation holes 14i provided in the other parts, so that the heating steam in the compression part is reduced. It is preferable to adopt a structure that further enhances the passage efficiency. As a specific example, an arrangement structure as shown in FIG. 7A is adopted. However, if the area of the piston 14d is small and the ventilation hole 14i cannot be provided in the piston 14d, the arrangement structure shown in FIG. ) As in piston 1
It is good also as a structure which arranges ventilation hole 14i around 4d.

Embodiment 5 FIG. 8 shows still another embodiment of the mold and the movable part. Here, in addition to the first steam chamber 14p, a second steam chamber 14q is provided in a space between the back side of the piston 14d and the fixed mold 14b, and a heating steam pipe 14j and a cooling water pipe 14k are separately provided in the second steam chamber 14q. Has been introduced. The heating steam pipe 14j and the cooling water pipe 14k can be used when the compression ratio is high and the heating and cooling steps need to be performed more efficiently than usual. Further, these are controlled independently of the heating steam pipe 14m and the cooling water pipe 14n originally provided in the first steam chamber 14p for the molding die 14, and adjusted to the optimal operating conditions for each molding condition. Make it possible.

Next, a procedure for obtaining a styrofoam molded product using the molding machine 30 incorporating the configuration of FIG. 8 will be outlined.

First, the material 17a which has been subjected to primary foaming for high-magnification foaming is stored in the hopper 15 in advance. Also, the molding die 14 is such that the tip end surface of the piston 14 d is fixed.
b is set at a position retracted from the inner side surface. And
When molding starts, the foam material 17a is injected into the space inside the molding die 14 closed by the movable die 14a, the fixed die 14b, and the piston 14d via the supply pipe 16. In this case, since the primary foamed materials are all of the same type, they can be easily and uniformly filled in the molding die 14.

Next, at the time of the blowback step (the step of sucking back the raw material in the raw material supply pipe), the piston 14d is advanced and moved until the tip end surface comes to a position constituting the final shape of the molded product. As a result, the foam material 17a corresponding to the piston 14d is compressed by the stroke of the piston 14d.

Further, while the molding die 14 is heated with steam, steam is supplied into the molding die 14 through the ventilation holes 14i to directly heat the foaming material 17a to perform secondary foaming. At this time, a portion where the foam material 17a is compressed by the piston 14d has a reduced foaming ratio and is in a low-foaming state. Here, particularly when it is necessary to increase the compression ratio or when the wall thickness is large, the heating steam pipe 14j or the cooling water pipe 14k provided in the movable part is replaced with the heating steam pipe 14m or cooling water pipe originally provided. By controlling independently of the water pipe 14n, the heating or cooling step can be performed efficiently according to the molding conditions. After heating and cooling of the molding die 14, the molding die 14 is opened again, and the polystyrene foam after the secondary foaming is taken out. The above-described molding process is roughly represented by a flowchart shown in FIG.

Embodiment 6 FIG. Here, a new molding method for a thin portion in a molded product is proposed. Conventionally, as shown in FIG. 10, since a part of the foamed material is thinly molded only by the molding die 44, the mold interval W1 of the thin molded part is set to 3 mm which is the same as the particle diameter of the foamed material after the primary foaming is completed. If it is set, the foam material is not sufficiently filled. For this reason, the interval W needs to be set at least 1.5 times to 2 times the particle diameter of 3 mm, that is, about 4.5 mm or more. Therefore, it is necessary to make the thickness of the thin portion smaller than 4.5 mm. There was a problem. On the other hand, as shown in FIG. 11, which is an embodiment of the present invention, a compression piston 14d is used together with a molding die 14, and a space interval W2 between the molding die 14 and the piston 14d is previously determined by using a foam material. After setting the particle size to 1.5 to 2 times or more and filling the foam material therewith, the piston 14d is compressed and moved to a position where the interval W2 becomes 3 mm to perform secondary foaming. Filling can be performed reliably, and stable molding up to a thickness of about 3 mm, which is almost the same as the particle size of the foamed material, becomes possible.

FIG. 12 shows Embodiment 4 or 5 of the present invention.
FIG. 5 is a distribution diagram based on an experiment of an expansion ratio value in styrofoam obtained by the method according to (1). According to this, the expansion ratio within the compression range is smaller than the expansion ratio outside the compression range as a whole, and the expansion ratio when compressed by 20 mm is substantially smaller than that when compressed by 10 mm. I understand.

[0041]

As described above, according to the present invention, since one kind of primary foamed foam material is used,
The foam material can be uniformly filled in the mold, and wasteful use such as mixing of the material is eliminated. In addition, by using the rotational force of the piston or movable piece to partially compress the foamed material and restrict its secondary foaming, and by setting a predetermined portion to a low foaming ratio state, it is used as a cushioning material and a heat insulating material In this case, the necessary strength can be secured. In addition, although a structure for compressing a predetermined portion in the mold is required, it is not necessary to use a plurality of foaming materials having different expansion ratios. Also, the management of the foamed material becomes easy. The compression by the piston is suitable for compressing a narrow range or increasing the compressive force.On the other hand, the compression of the rotational force of the movable piece compresses the wide range or the compression ratio in the compression range has a slope. It is suitable when you want to have.

Further, since the amount of heated steam introduced into the molding die is increased in the compression portion, it is possible to efficiently perform secondary foaming in that portion.

Further, a steam chamber and a cooling water nozzle corresponding to the entire molding die, and a steam chamber and a cooling water nozzle corresponding to the movable portion of the compression movable piece are provided, and these are controlled independently. Therefore, it is possible to adjust the operating conditions to the optimal ones according to the individual molding conditions.

Further, by compressing the foamed material in the process of sucking back the material remaining in the pipe that has supplied the material into the mold, it is possible to save working time.

Further, the space between the movable piece and the mold is set to at least 1.5 times the material diameter after the completion of the primary foaming of the foamed material, and after filling the primary foamed material,
Since the compression is performed, the filling of the foam material at the time of forming the thin portion can be efficiently performed, and the thin portion having sufficient strength can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a styrofoam molding machine used in an embodiment of the present invention.

FIG. 2A is a schematic cross-sectional view of a molding die according to a first embodiment of the present invention when a material is filled, and FIG. 2B is a piston attached to the molding die according to the first embodiment of the present invention. Schematic sectional view at the time of operation.

FIG. 3 is a schematic diagram showing a molding die according to a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing an example of a box body of a refrigerator at the time of filling and foaming with a heat insulating material.

FIG. 5 is a schematic cross-sectional view of a molding die part at the time of manufacturing a heat insulating partition according to a third embodiment of the present invention.

FIG. 6 is a schematic diagram showing a molding die according to a fourth embodiment of the present invention.

FIG. 7 is an arrangement diagram of ventilation holes in a molding die and a piston according to a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram showing a molding die according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart showing a molding step according to Embodiment 4 or 5 of the present invention.

FIG. 10 is an explanatory view showing a conventional thin part molding method.

FIG. 11 is an explanatory view showing a thin part forming method according to a sixth embodiment of the present invention.

FIG. 12 is an expansion ratio distribution diagram of a molded product according to Embodiment 4 or 5 of the present invention.

FIG. 13 is a longitudinal sectional view showing an example of a packing state of the refrigerator.

FIG. 14 is an external view of an upper cushioning material used for packing in FIG.

FIG. 15 is an external view of a packing pallet and a bottom cushioning material used for the packing of FIG. 13;

FIG. 16 is a schematic view of a conventional styrofoam molding machine.

FIG. 17 is a schematic cross-sectional view of a conventional Styrofoam molding machine when a molding die is filled with a material.

[Explanation of symbols]

1 refrigerator main body, 2 freezer compartment door, 3 refrigerator compartment door, 4 butterfly plate, 5 front legs, 6 wheels, 7 adjusting legs, 8 compressor base plate, 9 packing pallet, 10 bottom cushioning material, 10a,
10b Concave portion of bottom cushioning material, 10c Portion of bottom cushioning material filled with low magnification foam material, 11 Top cushioning material, 11a
Concave portion of upper cushioning material, 11b Portion of upper cushioning material filled with low-magnification foam material, 12 exterior cardboard, 13a movable plate, 13b fixed plate, 14 molding die, 14a movable type, 14b fixed type, 14c opening, 14d piston ,
14e opening, 14f, 14h movable piece, 14i ventilation hole, 14j heating steam pipe, 14k cooling water pipe,
14m heated steam pipe, 14n cooling water pipe, 14
p 1st steam room, 14q 2nd steam room, 15 hoppers,
Reference Signs List 16 supply pipe, 17a high magnification foam material, 20 heat insulating partition, 20a water receiver, 20b back wall, 21 outer jig, 22 inner jig, 30 Styrofoam molding machine.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaru Matsuura 4655-1, Sumiyoshi, Yoshida-cho, Haibara-gun, Shizuoka Pref. UB01 UB22 UC02 UC06 UF50 UH18 UL03 UL06 UL07 UN17

Claims (10)

[Claims] 1. A method of manufacturing a foamed molding material in which a foamed material is filled into a mold and foamed to obtain a molded material, wherein the foamed material filled in the mold is partially compressed using a movable piece. A method for producing a foamed material, wherein the foaming ratio is partially restricted, and the expansion ratio of the compressed portion of the foamed material is made lower than that of the other portions of the foamed material. 2. The method according to claim 1, wherein the movable piece is operated by a piston. 3. The method according to claim 1, wherein the movable piece is operated by a rotational force. 4. The method of heating the mold by using heated steam, wherein the area of a ventilation hole through which the heated steam passes through the mold has a unit area larger than that of another part in a compressed portion of the mold. The method for producing a foamed molded material according to any one of claims 1 and 2, wherein the hitting is increased. 5. The method according to claim 4, wherein the movable piece is provided with a ventilation hole through which the heated steam is passed. 6. The method according to claim 5, wherein a first steam chamber for the heated steam is provided at one end of the movable piece. 7. A second steam chamber for the heating steam is provided in an operation section of the movable piece, and control of steam passing through the steam chamber is performed independently of steam passing through the first steam chamber. The method for producing a foamed material according to claim 5, characterized in that: 8. A cooling water nozzle for introducing cooling water to the first steam chamber and a cooling water nozzle for introducing cooling water to the second steam chamber are separately provided, and these cooling water nozzles are independently controlled. The method for producing a foamed material according to claim 7, wherein cooling water is sprayed on the mold. 9. The foam molding material according to claim 1, wherein the compression is performed in a process of sucking back material remaining in the pipe that has supplied the material into the mold. Manufacturing method. 10. The method according to claim 10, wherein the space between the movable piece and the mold is set to at least 1.5 times the material diameter after the completion of the primary foaming of the foamed molding material, and the compressed material is filled with the primary foamed molding material. 10. The method according to claim 1, wherein
The method for producing a foamed molded material according to any one of the above.