JP3769681B2 - Manufacturing method of foam molding material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the production of foamed molding materials used for cushioning materials and heat insulating materials, and more particularly, to produce foamed molding materials having different foaming ratios without using a plurality of foaming materials having different foaming ratios. On how to do.
[0002]
[Prior art]
First, taking a refrigerator as an example, the cushioning material used for the packaging will be described based on FIG. 13 showing the packaging form. 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 that pivotally supports the freezer compartment door, and 5 is a moving wheel 6 and an adjustment leg 7. The front leg of the refrigerator provided, 8 is a compressor base plate equipped with a compressor (not shown) and provided with a moving wheel 6 at the bottom, 9 is a packaging pallet formed by bending four sides of the cardboard, 10 is a packaging pallet 9 A bottom cushioning material formed by foamed polystyrene located on the left and right sides of the refrigerator and molded at the bottom of the refrigerator, 11 is an upper cushioning material molded by foamed polystyrene attached to the upper left and right of the refrigerator body 1, and 12 is an exterior cardboard covering the whole.
[0003]
Furthermore, the external appearance of the upper buffer material 11 is shown in FIG. The upper cushioning material 11 is formed with a concave portion 11a for accommodating the upper part of the freezer compartment door 2 and the butterfly plate 4, and the meat portion 11b (dense spot portion) is more than the other parts of the upper cushioning material 11. The material is filled with a low-magnification foamed material, and is configured so as to obtain a compressive strength and fracture strength equal to or higher than those of other portions even when the wall thickness is thin.
[0004]
In FIG. 15, the external view of the bottom cushioning material 10 arrange | positioned at the packing pallet 9 and the right and left of the inside is shown. The bottom cushioning material 10 is formed with a recess 10a for escaping and storing the front leg 5 of the refrigerator 1, and a recess 10b for escaping and storing the compressor base plate 8, and these meat portions 10c (dense spot portions) are also formed. The bottom cushioning material 10 is filled with a material having a lower magnification than the other parts of the bottom cushioning material 10 and is configured to obtain the same effect as the upper cushioning material 11.
[0005]
Next, a conventional manufacturing method for the cushioning material as described above will be described.
FIG. 16 is a schematic view of a conventional polystyrene foam molding machine. 16, 40 is a polystyrene foam molding machine, 43a is a movable platen of the molding machine 40, 43b is a fixed platen of the molding machine 40, 44 is a movable die 44a attached to the movable platen 43a, and a fixed die 44b attached to the fixed platen 43b. 45a is a hopper for storing a primary foamed material for high-magnification foaming, 45b is a hopper for storing a primary foamed material for low-magnification foaming, and 46 is a molding die for these hoppers 45a and 45b. This is a material supply pipe that communicates with 44 fixed molds 44b.
[0006]
Molding of polystyrene foam 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 be uniformly filled in the die is used, and a material which has been subjected to primary foaming for high-magnification foaming and low-magnification foaming in advance. Are stored in the hoppers 45a and 45b, respectively. These foam materials are filled into the closed mold 44 of the fixed mold 44b and the movable mold 44a through the supply pipe 46, and the high-magnification foam material and the low-magnification foam material are changed depending on the connection position of the supply pipe 46 and the filling amount. The filling position and range are each controlled.
Further, the mold 44 is heated with steam, and steam is supplied into the mold 44 from the vent holes 44i to perform secondary foaming, and the individual particles are fused and integrated. Take out the molded product of polystyrene foam.
[0007]
FIG. 17 is a schematic cross-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 manufacturing such a cushioning material. Here, 47a indicates a high-magnification foaming material supplied in a space where the fixed mold 44b and the movable mold 44a are closed, and 47b indicates a low-magnification foaming material.
[0008]
As seen earlier, at the time of packing, the front and rear portions of the bottom cushioning material 10 are formed with recesses 10a and 10b for escaping the front leg 5 and the compressor base plate 8 of the refrigerator. Since the recess 11a for allowing the freezer compartment door 2 and the butterfly plate 4 to escape is formed, the buffer material is thin at that portion, and the product receiving area is also reduced. However, since the low-magnification foam material is filled and foamed around each recess, it has a high density and strength to withstand the handling of the load, and the amount of crushing is small even when compressed from the top, and the product tilts. And stable storage. On the other hand, in the portion where such a countermeasure is unnecessary, the high-magnification foam material is filled and has a low density, thereby reducing the amount of the foam material filled.
[0009]
[Problems to be solved by the invention]
As described above, in the conventional manufacturing method, two types of materials having different primary foaming ratios are filled in a molding die to perform simultaneous molding with different foaming ratios. Since the material has a higher specific gravity than the high-magnification foam material, it tends to fall to the lower side of the molding die, and it is difficult to fill the predetermined position with the low-magnification foam material. In addition, due to the difficulty, in order to ensure the filling of the low-magnification foamed material within a predetermined range, there is a problem that more material than a predetermined amount must be supplied.
In addition, because two different types of materials are used, not only is the management of the material difficult, but this is also the case with general molding equipment that uses one type of material in terms of hoppers and supply pipes that store the materials. There is a problem that it cannot be molded, and there is a burden in terms of equipment.
[0010]
[Means for Solving the Problems]
The present invention has been made to solve these problems, and does not use a plurality of foam materials having different foaming ratios, and is a molded foam product used for a cushioning material or a heat insulating material in which the foaming ratio is partially changed. The manufacturing method of this is provided.
[0011]
In the present invention, when foaming material filled in a mold is heated and foamed by using heating steam, the foaming material is partially compressed by using a movable piece to partially restrict the foaming. In the method for producing a foamed molding material in which the foaming ratio of the compressed portion of the foamed material is lower than that of the other part of the foamed material, heating steam is passed through the mold from the ventilation hole provided in the movable piece, The passing efficiency of the heating steam per unit area in the compressed part of the foam material is made higher than that in the other part of the foam material.
Also, a first steam chamber that communicates with the inside of the mold formed outside the mold, and a second steam that communicates with the interior of the mold formed between the inner side surface of the mold and the back side surface of the movable piece. And the steam passing through these two steam chambers are controlled independently.
In addition, 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 the cooling water nozzles are independently controlled to control the metal The cooling water is sprayed on the mold.
The compression is performed in the 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 foam molding material, and after the primary foamed molding material is filled, the compression is performed. It is a thing.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a schematic view of a polystyrene foam molding machine used in the embodiment of the present invention. In FIG. 1, 30 is a foamed polystyrene molding machine, 13a is a movable board of the molding machine 30, 13b is a stationary board of the molding machine 30, 14 is a molding die filled with foaming material, and 15 is primary foaming for high-magnification foaming. A hopper 16 for storing the molded foam material is a foam material supply pipe that communicates between the hopper 15 and the inside of the fixed mold 14b.
Here, the molding die 14 includes a movable die 14a attached to the movable platen 13a and a fixed die 14b attached to the fixed platen 13b, and further restricts (or suppresses) secondary foaming of the foam material to be performed later. An opening 14c is formed in a corresponding portion of the fixed mold 14b corresponding to the range to be intended, and a piston 14d as a movable piece driven by hydraulic pressure or the like is inserted and fitted into the opening 14c.
[0021]
Next, a procedure for obtaining a foamed polystyrene molded product using this foamed polystyrene molding machine 30 will be described.
[0022]
First, the high-magnification foam material 17 a that has been subjected to primary foaming in advance is stored in the hopper 15. Further, as shown in FIG. 2A, the molding die 14 is set at a position where the tip surface of the piston 14d is retracted from the inner surface of the fixed die 14b. The position 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.
When molding is started, the foam material 17a is injected through the supply pipe 16 into the space in the molding die 14 closed by the movable die 14a, the fixed die 14b, and the piston 14d. At this time, since the first foamed materials are all the same type, the molding die 14 can be easily and uniformly filled.
[0023]
Next, as shown in FIG. 2 (b), the piston 14d is advanced and moved to a position where the tip surface constitutes the final shape of the molded product. As a result, the foam material 17a corresponding to the tip of the piston 14d 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 in a state of low-magnification foaming with its foaming rate limited. And after cooling the molding die 14, the molding die is opened again, and the expanded polystyrene after secondary foaming is taken out.
[0024]
In the polystyrene foam obtained in this way, the secondary foaming is limited and the part that is in the state of low foaming ratio is packed in terms of compressive strength and breaking strength even though the thickness is thinner than other parts. It is possible to have the necessary strength. Therefore, it is very convenient to manufacture the cushioning material having the concave portion used for packing such as the refrigerator described above by this method.
[0025]
Embodiment 2. FIG.
FIG. 3 shows a modification of the molding die 14 used in the polystyrene foam molding machine 30. Here, the molding die 14 includes a movable die 14a attached to the movable platen 13a and a fixed die 14b attached to the fixed platen 13b, and further, a range in which secondary foaming of the foaming material to be performed later is to be suppressed. The opening 14e is formed in the corresponding portion of the movable die 14a, and a fan-shaped movable piece 14f that opens and closes the opening 14e is provided in the opening 14e portion by rotation by hydraulic pressure or the like. That is, the rotational force of the movable piece 14f is used to partially limit the secondary foaming of the high-magnification foamed material so that it is in a low-magnification foamed state.
[0026]
Embodiment 3 FIG.
Here, the heat insulating material in the foam molding material is taken as an example.
FIG. 4 is a longitudinal sectional view at the time of filling and foaming a heat insulating material to a box constituting the refrigerator. 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 box 31 made of synthetic resin, and 20 is a refrigerator attached to the box 31. A heat insulating partition made of stylohome that partitions the storage chambers, 21 is an outer jig that holds the outer surface of the outer box 18, 22 is an inner jig that holds the inner surface of the inner box 19, and 23 is a foam filled between the outer box 18 and the inner box 19. Heat insulating material such as polyurethane. Here, the heat insulating partition 20 uses a water receiving part 20a that receives defrosted water from a cooler (not shown) and an opening formed in the inner box 19 on the back surface of the water receiving part 20a. And a back wall 20b for attaching the heat insulating partition 20 to the inner box 19.
[0027]
When the heat insulating material 23 is filled in the box 31 of the refrigerator and foamed, the foaming pressure of the heat insulating material 23 is applied to the outer box 18 and the inner box 19, but the outer jig 21 and the inner jig 22 are applied to their wall surfaces. In the contact portion, the outer box 18 and the inner box 19 are not deformed by the support of the outer jig 21 and the inner jig 22.
[0028]
On the other hand, as shown in FIG. 4, the back wall 20b portion where the heat insulating partition 20 is attached to the inner box 19 has the inner jig 22 not in contact with the back wall 20b, so that the foam pressure of the heat insulating material can be increased only by the back wall 20b. I will support it. However, according to the present invention, the heat insulating partition 20 having the back wall 20b that can sufficiently withstand the foaming pressure can be made. The manufacturing method will be described below.
[0029]
FIG. 5 is a schematic cross-sectional view of a molding die portion when the heat insulating partition 20 is manufactured. In addition, the structure of the molding machine main body for making the heat insulation partition 20 shall apply to the polystyrene foam molding machine shown in Embodiment 1. FIG. In FIG. 5, the molding die 14 has a movable die 14a and a fixed die 14b. Further, a fulcrum 14g is provided at the open bottom of the molding die 14 in order to apply pressure to the portion that becomes the back wall 20b. The movable piece 14h that rotates about the center is provided.
[0030]
The primary foamed high-magnification foam material 17a filled from the supply pipe 16 into the closed molding die 14 is heated to perform secondary foaming. At this time, in the back wall 20b compressed by the movable piece 14h, Secondary foaming is limited according to the compression force, and low-magnification foaming occurs as compared with other parts.
In this way, the heat insulating partition 20 taken out from the molding die 14 increases its strength because the back wall 20b is foamed at a low magnification, and causes deformation and breakage due to the foaming pressure of the heat insulating material without the support of the inner jig 22. It is possible not to let it.
[0031]
In each of the above embodiments, one to three foam material supply pipes 16 are provided to communicate between the hopper 15 and the inside of the fixed mold 14b. The number of pipes 16 depends on the shape of the molding die 14 and the like. It can be determined as appropriate.
Further, the compression operation of the piston 14d and the movable pieces 14f and 14h may be started simultaneously with the secondary foaming process.
Further, the piston 14d and the movable pieces 14f and 14h are not limited to the above-described embodiment, and are provided on either the movable mold 14a side or the fixed mold 14b side according to the type of the molding machine as the main body. May be.
[0032]
Embodiment 4 FIG.
FIG. 6 is a schematic view showing the structure of the mold and compression movable part of the fourth embodiment of the present invention in the expanded polystyrene molding machine 30 as shown in FIG.
Here, the molding die 14 includes a movable die 14a attached to the movable platen 13a and a fixed die 14b attached to the fixed platen 13b as in FIG. 2, and further restricts secondary foaming of the foam material to be performed later ( Alternatively, an opening 14c is formed in a corresponding portion of the fixed mold 14b corresponding to a range to be suppressed, and a piston 14d driven by hydraulic pressure or the like is inserted and fitted into the opening 14c. Further, the inner side surfaces 14a ′ and 14b ′ in contact with the surfaces of the polystyrene foam molded products of the movable mold 14a and the fixed mold 14b, and the piston 14d are provided with a plurality of ventilation holes 14i arranged in a lattice shape, for example, and a heating steam pipe The heating steam supplied from 14m is supplied to the inside of the molding die 14 through the first steam chamber 14p. On the other hand, the heated molding die 14 is cooled by injecting cooling water supplied from the cooling water pipes 14n onto the die 14.
[0033]
In addition, the number of ventilation holes 14i provided in the piston 14d and the periphery thereof is made larger per unit area than the number of ventilation holes 14i provided in other parts, so that the passing efficiency of the heating steam in the compression part is increased. A higher structure is preferable. As a specific example, the arrangement structure shown in FIG. 7A is adopted. However, when the area of the piston 14d is small and the ventilation hole 14i cannot be provided in the piston 14d, the arrangement shown in FIG. It is good also as a structure which arrange | positions the ventilation hole 14i around the piston 14d like FIG.
[0034]
Embodiment 5. FIG.
Still another embodiment of the mold and the movable part is shown in FIG. Here, in addition to the first steam chamber 14p, a second steam chamber 14q is provided in the 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. It 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 processes 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 optimum operating conditions for each molding condition. Make it possible.
[0035]
Next, a procedure for obtaining a foamed polystyrene molded product using the molding machine 30 incorporating the configuration of FIG. 8 will be outlined.
[0036]
First, the material 17a that has finished primary foaming for high-magnification foaming is stored in the hopper 15 in advance. The molding die 14 is set at a position where the tip surface of the piston 14d is retracted from the inner surface of the fixed die 14b.
When molding is started, the foam material 17a is injected through the supply pipe 16 into the space in the molding die 14 closed by the movable die 14a, the fixed die 14b, and the piston 14d. At this time, since the first foamed materials are all the same type, the molding die 14 can be easily and uniformly filled.
[0037]
Next, at the time of the blow back process (raw material sucking back process in the raw material supply pipe), the piston 14d is advanced and moved until the tip end surface thereof reaches a position constituting the final shape of the molded product. Thereby, the foam material 17a corresponding to the piston 14d is compressed by the stroke of the piston 14d.
[0038]
Further, the molding die 14 is heated with steam, and the secondary foaming is performed by supplying the steam into the molding die 14 through the ventilation holes 14i and directly heating the foaming material 17a. At this time, the portion where the foamed material 17a is compressed by the piston 14d is in a state of low-magnification foaming with its foaming rate limited. Here, especially when the compression ratio needs to be high or when the wall thickness is thick, the heating steam pipe 14j and the cooling water pipe 14k provided in the movable part are replaced with the heating steam pipe 14m and the cooling water pipe originally provided. By controlling independently from the water pipe 14n, it becomes possible to perform a heating or cooling process efficiently according to molding conditions.
After heating and cooling the molding die 14, the molding die 14 is opened again, and the expanded polystyrene after secondary foaming is taken out.
The above molding process is roughly represented by the flowchart shown in FIG.
[0039]
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 foam material is thin-molded only by the molding die 44, the mold interval W1 of the thin-wall molding part is set to 3 mm which is the same as the particle diameter of the foam material after the primary foaming is finished. If set, the foam material is not sufficiently filled. For this reason, this interval W must be set to at least 1.5 to 2 times the particle size of 3 mm, that is, about 4.5 mm or more. There was a problem.
On the other hand, as shown in FIG. 11 which is an embodiment of the present invention, the compression piston 14d is used together with the molding die 14, and the space interval W2 between the molding die 14 and the piston 14d is set in advance of the foam material. If the particle size is set to 1.5 to 2 times or more and filled with a foam material, the piston 14d is compressed and moved to a position where the interval W2 is 3 mm to perform secondary foaming. Filling can be performed reliably, and stable molding up to a wall thickness of about 3 mm, which is almost the same as the particle size of the foamed material, is possible.
[0040]
FIG. 12 is a distribution diagram based on experiments of foaming magnification values in the polystyrene foam obtained by the method according to Embodiment 4 or 5 of the present invention. According to this, the expansion ratio within the compression range is generally smaller than the expansion ratio outside the compression range, and the expansion ratio when compressed by 20 mm is generally smaller than that when compressed by 10 mm. I understand.
[0041]
【The invention's effect】
As described above, according to the present invention, since one kind of foamed material that has undergone primary foaming is used, the foamed material can be uniformly filled in the mold, and useless use such as mixing of materials is eliminated. In addition, by using the rotational force of the piston or movable piece, the foamed material is partially compressed to limit its secondary foaming, and the prescribed part is used for cushioning materials and heat insulating materials by making it low foaming magnification. The strength required for doing so can also 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 foam materials having different foaming ratios, and the configuration of the molding machine is simplified from this aspect. In addition, management of the foam material is also facilitated. The compression by the piston is suitable for compressing a narrow range or increasing its compressive force, while the compression of the rotational force of the movable piece compresses a wide range or inclines the compression ratio of the compression range. Suitable for holding.
[0042]
Further, since the introduction of the heating steam into the molding die is increased at the compression portion, it is possible to efficiently perform the secondary foaming at that portion.
[0043]
Moreover, since the steam chamber and the cooling water nozzle corresponding to the entire molding die and the steam chamber and the cooling water nozzle corresponding to the movable part of the compression movable piece are respectively provided, they are controlled independently. It is possible to adjust to the optimum operating conditions according to the individual molding conditions.
[0044]
Moreover, it is possible to save working time by compressing the foam material in the process of sucking back the material remaining in the pipe that has supplied the material into the mold.
[0045]
Furthermore, since the space between the movable piece and the mold is at least 1.5 times the material diameter after completion of the primary foaming of the foam material, the primary foamed material is filled and then compressed. In addition, it is possible to efficiently fill the foamed material when forming the thin portion, and to obtain a thin portion having sufficient strength.
[Brief description of the drawings]
FIG. 1 is a schematic view of a polystyrene foam molding machine used in an embodiment of the present invention.
2A is a schematic cross-sectional view when a material is filled into a molding die according to Embodiment 1 of the present invention, and FIG. 2B is a piston attached to the molding die according to Embodiment 1 of the present invention. FIG.
FIG. 3 is a schematic view showing a molding die according to a second embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing an example of a refrigerator box body filled with heat insulating material.
FIG. 5 is a schematic cross-sectional view of a molding die portion at the time of manufacturing a heat insulating partition according to Embodiment 3 of the present invention.
FIG. 6 is a schematic view showing a molding die according to Embodiment 4 of the present invention.
FIG. 7 is a layout view of ventilation holes in a molding die and a piston according to Embodiment 4 of the present invention.
FIG. 8 is a schematic view showing a molding die according to a fifth embodiment of the present invention.
FIG. 9 is a flowchart showing a molding process 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 molding method according to Embodiment 6 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 refrigerator packaging state.
14 is an external view of an upper cushioning material used in the packaging of FIG.
15 is an external view of a packing pallet and a bottom cushioning material used in the packing of FIG.
FIG. 16 is a schematic view of a conventional polystyrene foam molding machine.
FIG. 17 is a schematic cross-sectional view when filling a material of a molding die of a conventional polystyrene foam molding machine.
[Explanation of symbols]
1 refrigerator body, 2 freezer compartment door, 3 refrigerator compartment door, 4 butterfly plate, 5 front leg, 6 wheel, 7 adjustment leg, 8 compressor base plate, 9 packing pallet, 10 bottom cushioning material, 10a, 10b bottom cushioning material Concave part, part of 10c bottom cushioning material filled with low-magnification foam material, 11 upper cushioning material, 11a concave part of top cushioning material, 11b part of top cushioning material filled with low-magnification foaming material, 12 exterior cardboard, 13a movable board,
13b Fixed platen, 14 Mold, 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 Heating steam pipe , 14n cooling water pipe, 14p first steam chamber, 14q second steam chamber, 15 hopper, 16 supply pipe, 17a high-magnification foam material, 20 heat insulation partition, 20a water receiving part, 20b back wall, 21 outer jig, 22 inside Jig, 30 Styrofoam molding machine.

Claims (5)

When the foaming material filled in the mold is heated and foamed using heating steam, the foaming material is partially compressed using a movable piece to partially restrict the foaming, and the foaming is performed. In the method for producing a foam molding material in which the expansion ratio of the compressed portion of the material is lower than the other portions of the foam material,
Heating steam is passed through the mold from the ventilation hole provided in the movable piece, and the passage efficiency of the heating steam per unit area in the compressed portion of the foam material is higher than that in the other portion of the foam material. A method for producing a foam molding material. A first steam chamber that communicates with the interior of the mold formed outside the mold, and a first steam chamber that communicates with the interior of the mold formed between the operating portion of the movable piece of the mold and the back side surface of the movable piece. The method for producing a foam molding material according to claim 1, further comprising: two steam chambers, wherein steam passing through the two steam chambers is controlled independently.   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 provided separately, and these cooling water nozzles are independently controlled to the mold. The method for producing a foamed molding material according to claim 2, wherein the cooling water is sprayed.   The said compression is performed in the process of sucking back the material remaining in the pipe which supplied the material in the said metal mold | die, The manufacturing method of the foaming molding material in any one of Claims 1-3 characterized by the above-mentioned.   The space between the movable piece and the mold is set to at least 1.5 times the material diameter after completion of primary foaming of the foam molding material, and after the primary foamed molding material is filled, the compression is performed. The manufacturing method of the foaming molding material in any one of Claims 1-4 characterized by the above-mentioned.

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