JP6473173B2 - Molding material supply system and molding material supply method - Google Patents

Description

  The present invention relates to a molding material supply system and a molding material supply method for supplying a molding material to a heating cylinder of a molding machine.

  Conventionally, a system for transporting a molding material from a material source to a supply unit that supplies the molding material to a heating cylinder of a synthetic resin molding machine such as an injection molding machine is known. The molding material supplied to such a synthetic resin molding machine is generally dried using a drying hopper that ventilates heated outside air before being supplied to the synthetic resin molding machine. Further, for example, Patent Document 1 below discloses a dehumidifying and drying apparatus configured to provide a vacuum pump and perform dehumidifying and drying by vacuum and heat treatment while allowing outside air to pass through.

Japanese Patent Laid-Open No. 6-14834

  By the way, as a molding material, it may be carried into a molding factory etc. in the state which made appropriate tempering etc. and was sealed, ie, the state which does not require a drying process etc. If such a molding material is dried as described above, the molding material is exposed to the outside air for a long period of time, and moisture and oxygen in the outside air are easily adsorbed on the surface of the molding material. If such a molding material is melted (plasticized) in the heating cylinder, molding failure due to generation of gas such as water vapor, deterioration due to oxidation, and the like may occur.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a molding material supply system and a molding material supply method capable of suppressing the occurrence of molding defects.

In order to achieve the above object, a molding material supply system according to the present invention includes a material source storage unit that is decompressed by a vacuum generation source and configured to store a molding material in an airtight state with respect to outside air, and a synthetic resin. A supply unit connected so as to communicate with a material inlet of a heating cylinder of a molding machine, decompressed by a vacuum generation source including the heating cylinder, and supplying the molding material to the heating cylinder in an airtight state with respect to outside air; A configuration capable of collecting the molding material transported from the material source storage unit and replenishing the supply unit with the molding material so that the degree of decompression of the supply unit decompressed by the vacuum generation source is substantially maintained. The molding material is transported by gas from the material source reservoir to the collection supply unit so that the degree of decompression of the material source reservoir and the material source reservoir decompressed by the vacuum generation source is substantially maintained. Possible gas transport Includes the material transport passage of the gas transport unit, said material source reservoir, at least one of the collecting supply unit and the supply unit, and a inert gas supply section supplying an inert gas The inert gas supply unit is configured to supply an inert gas as a transport gas of the gas transport unit to a material transport path of the gas transport unit, and the gas transport unit is supplied to the material transport path. In addition, a gas return path for circulating the inert gas is provided .

In order to achieve the above object, the molding material supply method according to the present invention is stored in a material source storage section configured to store the molding material in an airtight state against the outside air by reducing the pressure by a vacuum generation source. The formed molding material is gas-transported toward the collection and replenishment unit so that the degree of decompression of the material source storage unit is generally maintained, and the molding material collected in the collection and replenishment unit is transferred to the synthetic resin molding machine. The pressure reduction degree of the supply part is generally maintained in the supply part that is connected to communicate with the material inlet of the heating cylinder, is decompressed by a vacuum generation source including the heating cylinder, and is airtight with respect to the outside air. supplemented as being configured for supplying a molding material into the heating cylinder from the supply unit, and the molding material in the material transport passage of the gas transport unit for gas transport towards the collecting supply unit, the Pass the inert gas supplied to the material transport path through the gas return path And supplying an inert gas as a transport gas while circulating Te.

  Since the molding material supply system and the molding material supply method according to the present invention are configured as described above, the occurrence of molding defects can be suppressed.

It is a schematic system block diagram which shows typically an example of the molding material supply system which concerns on one Embodiment of this invention. It is a schematic time chart which shows typically an example of basic operation (molding material supply method) performed in the molding material supply system. It is a schematic system block diagram which shows typically an example of the molding material supply system which concerns on other embodiment of this invention. It is a schematic system block diagram which shows typically an example of the molding material supply system which concerns on further another embodiment of this invention. It is a schematic time chart which shows typically an example of basic operation (molding material supply method) performed in the molding material supply system. It is a schematic system block diagram which shows typically an example of the molding material supply system which concerns on further another embodiment of this invention. It is a schematic time chart which shows typically an example of basic operation (molding material supply method) performed in the molding material supply system.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, FIG. 3, FIG. 4, and FIG. 6, a part of a pipe (pipe) that is a path through which a molding material, gas, and the like pass is schematically shown by a solid line.
In the graphs of FIGS. 2, 5, and 7, the horizontal axis is the time axis and the vertical axis is the pressure change in each part, and the transition is schematically shown. In addition, the schematic time charts in FIGS. 2, 5, and 7 schematically show ON / OFF, opening / closing operation, and the like of each device.

1 and 2 are diagrams schematically showing an example of a molding material supply system according to the first embodiment and a molding material supply method executed using the molding material supply system.
As shown in FIG. 1, the molding material supply system 1 according to the present embodiment gas transports a molding material from a material source storage unit 10 as a material source by a gas transport unit 20, and collects and replenishes a supply unit 30. It is set as the structure supplied to the heating cylinder (cylinder) 4 of the synthetic resin molding machine 3 via the part 35, and comprises a molding system with the synthetic resin molding machine 3. FIG. The molding material supply system 1 also supplies the inert gas to at least one of the material transport path 22, the material source storage unit 10, the collection supply unit 30, and the supply unit 35 of the gas transport unit 20. Gas supply units 16 and 36 are provided.

Here, the molding material is a raw material of the synthetic resin molded product, and examples thereof include natural materials (virgin materials), pulverized materials, master batch materials, and various additives. In addition, the molding material may be, for example, powder / granular resin pellets, fibrous resin fiber pieces, or the like, and may include a reinforcing fiber such as glass fiber or carbon fiber.
Further, the molding material may be a molding material that has been appropriately tempered, that is, a molding material that does not require a drying process in principle. As shown in FIG. It is good also as what was accommodated in the accommodating body 2 which can be accommodated in.

  The synthetic resin molding machine 3 has a configuration in which a material input port 5 into which a molding material is supplied from the supply unit 35 of the molding material supply system 1 according to the present embodiment is provided on the proximal end side of the heating cylinder 4. . In addition, a screw 6 is provided in the heating cylinder 4 to transfer the molding material charged through the material charging port 5 to the tip side (nozzle side) of the heating cylinder 4. Although not shown, a heating unit such as a band heater is provided around the heating cylinder 4. In addition, on the base end side of the screw 6, a motor that rotates the screw 6, a hydraulic cylinder that advances the screw 6, and the like are provided. The synthetic resin molding machine 3 is not limited to a screw type, and may be a plunger type or any type.

  In such a synthetic resin molding machine 3, the screw 6 is operated and appropriate molding cycles, that is, metering, injection, holding pressure, cooling, and the like are executed. Further, the nozzle at the tip of the heating cylinder 4 communicates with a cavity or the like formed by the fixed mold and the movable mold of the mold 7 and is melted (plasticized) by the heating cylinder 4 (molded resin). Is injected into the cavity of the mold 7 from the nozzle and filled, and the molded products are sequentially molded. The synthetic resin molding machine 3 is not limited to such an injection molding machine, and may be another molding machine such as an extrusion molding machine or a compression molding machine.

The material source storage unit 10 is configured to be able to store the molding material in an airtight state against the outside air by being decompressed by a vacuum generation source (material source vacuum generation source) 15. The material source storage unit 10 is configured to be able to prevent the introduction of outside air at least during storage except when the molding material is charged or discharged.
In addition, the material source storage unit 10 is configured such that a lid 13 is provided at the upper end of a hopper-shaped storage main body 11 for closing and closing the charging port for charging the molding material in an openable / closable manner. . In the illustrated example, the upper end of the storage main body 11 is used as an input port that is opened over the entire body, and an example in which the molding material can be input from the container 2 described above is shown. Moreover, although the example which made the lid 13 detachable with respect to the storage main body 11 is shown in the example of a figure, what was connected with respect to the storage main body 11 so that rotation was possible, and it was hold | maintained slidably. It is good also as things.

The material is not limited to the mode in which the lid 13 is opened and the molding material is charged and replenished as described above, and the material is charged upstream of the material source storage unit 10 via an appropriate on-off valve. It is good also as an aspect etc. which provided the hopper etc.
Further, the capacity of the material source storage unit 10 may be a capacity that can store the entire amount of the molding material stored in the container 2, and the capacity of the container 2 so as not to cause a short feed to the supply side. It may be larger than the capacity. Moreover, you may make it provide the translucent window etc. which can visually recognize the inside of the material former storage part 10. FIG. Further, the material source storage unit 10 may be provided with a material sensor or the like that outputs a material request signal if the amount of molding material stored in the material source storage unit 10 reaches a predetermined level.

In addition, a suction pipe line 14 connected to a material source vacuum generation source 15 is connected to the material source storage unit 10. In the illustrated example, an example in which the connection portion of the suction conduit 14 is provided at the upper end portion of the side peripheral wall of the storage main body 11 is shown, but an aspect in which the connection portion of the suction conduit 14 is provided in the lid 13 or the like may be employed. .
The material source vacuum generation source 15 may be a vacuum pump having a drive motor (electric motor) as a rotation drive unit. The material source vacuum generation source 15 is connected to the suction line 14 on the suction side. Note that the material source vacuum generation source 15 may adopt a material that can achieve the ultimate degree of vacuum corresponding to a desired pressure range, or may be a vacuum generation source provided with a plurality of vacuum pumps in multiple stages. Good. Further, an air release valve, a filter, or the like may be provided at an appropriate position on the suction side of the material source vacuum generation source 15. Moreover, you may provide pressure detection parts, such as a pressure sensor and a pressure gauge, which detect the pressure in the material origin storage part 10 in the suction pipe line 14 or the material origin storage part 10. Further, the material source vacuum generation source 15 is not limited to a vacuum pump, and may be an ejector device or the like.

Further, the discharge port 12 at the lower end of the material source reservoir 10 constitutes the gas transport unit 20 and discharges the molding material in the material source reservoir 10 so that the degree of decompression of the material source reservoir 10 is generally maintained. The discharge unit 24 is configured to be connected to the discharge unit 24. That is, the discharge unit 24 is configured to be able to discharge the molding material of the material source storage unit 10 without greatly changing (vacuum break) the pressure in the material source storage unit 10.
In the present embodiment, the discharge unit 24 is a fixed discharge valve 24 including a slide valve 25 and a valve container 26 connected to the slide valve 25.
The slide valve 25 is slid by a valve body drive unit such as an air cylinder, and has a configuration in which a through hole 28 communicating with the discharge port 12 of the material source storage unit 10 is provided at a substantially central portion in the slide direction. The slide valve 25 has a configuration in which closing portions are provided on both sides of the through hole 28 in the sliding direction.
The valve container 26 is connected to the slide valve 25 so that the upper end opening thereof communicates with the through hole 28 of the slide valve 25. In addition, a gas introduction connection portion 27 that allows gas to be introduced into the valve vessel 26 is provided at the lower end portion of the valve vessel 26. Further, an appropriate filter or the like is provided inside the valve container 26 of the gas introduction connection portion 27. In addition, this valve container 26 is good also as what enabled adjustment of the capacity | capacitance.

Further, the fixed discharge valve 24 is provided with a transport path connecting portion 29 to which a material transport path 22 for transporting the molding material in the gas direction toward the supply side is connected. The transport path connection portion 29 is provided in a valve body housing that slidably holds the slide valve 25 so as to be spaced from the discharge port 12 of the material source storage portion 10 in the sliding direction.
In the fixed amount discharge valve 24 configured as described above, if the slide valve 25 is positioned on the storage unit side so that the through hole 28 is in a position communicating with the discharge port 12 of the material source storage unit 10, the material source The reservoir 10 and the valve container 26 communicate with each other, and a predetermined amount of molding material is accommodated in the valve container 26. In this state, the transport path connecting portion 29 is closed by one closing portion of the slide valve 25.
Moreover, in this fixed quantity discharge valve 24, if the slide valve 25 is positioned on the transport side so that the through hole 28 is in a position where it communicates with the transport path connecting portion 29, the material transport path 22 and the valve container 26 are connected. The communicating state enables the molding material in the valve container 26 to be transported. In this state, the discharge port 12 of the material source storage unit 10 is closed by the other closing unit of the slide valve 25.

Moreover, in this embodiment, the inert gas supply part 16 which supplies an inert gas to the material former storage part 10 decompressed by the material former vacuum generation source 15 is provided. Further, an inert gas supply unit 16 that supplies an inert gas as a transport gas of the gas transport unit 20 to the material transport path 22 of the gas transport unit 20 is provided. In the present embodiment, the material source inert gas supply unit 16 as an inert gas supply unit that supplies an inert gas to the material source storage unit 10 and the material transport path 22 is made common. Further, the gas transport section 20 is provided with a gas return path 23 for circulating the inert gas supplied to the material transport path 22.
The material source inert gas supply unit 16 is configured such that a gas supply valve 19 for supplying / blocking an inert gas is provided in a gas pipe line 18 connected to an inert gas supply source 17.
The inert gas may be a gas having an extremely low oxygen content (substantially zero) including nitrogen and argon. The inert gas supply source 17 may be a storage container (cylinder) filled with an inert gas, or may be an inert gas (nitrogen) generator including a compressor or a storage container using a membrane separation system or a PSA system. Good.

  In the present embodiment, the gas pipe line 18 of the material source inert gas supply unit 16 is connected to the gas return path 23 connected to the gas introduction connection unit 27 at the lower end of the valve container 26 of the fixed discharge valve 24. Yes. That is, the inert gas from the material source inert gas supply unit 16 can be selectively supplied to either the material source storage unit 10 or the material transport path 22 via the valve container 26 of the quantitative discharge valve 24. Yes. In other words, the material source storage unit 10 is configured to be able to prevent the introduction of outside air at least during storage except when the molding material is charged or discharged, but is configured to allow the introduction of an inert gas. Yes. The inert gas introduced into the material source reservoir 10 may be in an amount such that the material source reservoir 10 depressurized by the material source vacuum generation source 15 is in a reduced pressure state, or the material source reservoir 10 It is good also as what becomes atmospheric pressure temporarily.

Further, the gas transport unit 20 is provided with a transport gas source 21 such as a blower. In the illustrated example, an example in which a transport gas source 21 is provided in the gas return path 23 is shown. In addition, a filter 23 a is provided at an appropriate position on the upstream side (suction side) of the transport gas source 21 in the gas return path 23. In addition, a pressure regulating valve (relief valve) 23b for maintaining the pressure in the system to be substantially constant is provided at appropriate positions of the material transport path 22 and the gas return path 23, which are pipes for circulating the transport gas. Yes. In the illustrated example, an example in which a pressure regulating valve 23 b is provided on the upstream side of the transport gas source 21 in the gas return path 23 is shown.
In addition, a transport gas opening / closing valve 23c is provided at appropriate positions of the material transport path 22 and the gas return path 23, which are pipes for circulating the transport gas. The transport gas opening / closing valve 23 c is provided between the downstream side (blow-out side) of the transport gas source 21 and the valve container 26 and in the gas return path 23 on the transport gas source 21 side than the connection portion of the gas pipe 18. It has been. That is, if the transport gas on-off valve 23c is closed and the valve container 26 (slide valve 25) is positioned on the storage section side, the material source storage section 10, the material transport path 22 and the gas return path 23 are shut off. It becomes a state. Moreover, if the gas supply valve 19 is opened in this state, the inert gas can be introduced into the material source storage unit 10.

The collection replenishment unit 30 collects the molding material transported from the material source storage unit 10 and replenishes the supply hopper 35 with the molding material so that the degree of decompression of the supply hopper 35 as a supply unit described later is generally maintained. Possible configuration. That is, the collection supply unit 30 is configured to be able to supply the molding material to the supply hopper 35 without significantly changing (vacuum break) the pressure in the supply hopper 35.
The collection replenishment unit 30 includes a collection unit 31 to which the material transport path 22 and the gas return path 23 of the gas transport unit 20 are connected, and a preliminary decompression hopper 33 that receives the molding material collected in the collection unit 31. It is equipped with.
The collection unit 31 is configured to collect the molding material transported via the material transport path 22 separately from the transport gas. Such a collection part 31 includes a connection part to which the material transport path 22 is connected and a connection part to which the gas return path 23 is connected, and a filter for separating the molding material from the transport gas is used as the material transport path 22. It is good also as what was set as the structure provided between the connection part to which this is connected, and the connection part to which the gas return path 23 is connected. In the example shown in the figure, a cylindrical collection unit 31 is shown.

In addition, the lower end portion of the collection portion 31 is connected to the upper end portion of the preliminary decompression hopper 33 via the first on-off valve 32. If the first on-off valve 32 is opened, the collection unit 31 and the preliminary decompression hopper 33 are communicated with each other, and if closed, the collection unit 31 and the preliminary decompression hopper 33 are hermetically separated. It is said that. As such a first on-off valve 32, a slide damper or the like provided with a slide valve body that is slid by a drive unit such as an air cylinder may be employed, and various other on-off mechanisms may be employed. May be.
The preliminary decompression hopper 33 is configured to be decompressed by the vacuum generation source 40 so that the degree of decompression of the supply hopper 35 is substantially maintained when the supply material is supplied to the supply hopper 35. In this embodiment, the vacuum generation source 40 is the same as the supply destination vacuum generation source 40 that depressurizes the supply hopper 35.

In addition, a preliminary suction line 42 is provided so that the upper end portion of the preliminary decompression hopper 33 communicates with a suction line 41 connected to a supply destination vacuum generation source 40 which will be described later. A filter is appropriately provided at an appropriate place such as a connection portion of the preliminary suction line 42 in the preliminary pressure reducing hopper 33. The preliminary suction line 42 is provided with a preliminary pressure reducing valve 43 that opens and closes the preliminary suction line 42. The preliminary suction line 42 and the preliminary decompression hopper 33 may be provided with a pressure sensor such as a pressure sensor or a pressure gauge for detecting the pressure in the preliminary decompression hopper 33.
Further, the preliminary decompression hopper 33 is provided with a first level sensor 44 that detects the presence / absence of a material (outputs a material request signal). As such a first level sensor 44, it may be possible to detect that the molding material of the preliminary decompression hopper 33 has dropped to a predetermined material requirement level. For example, a non-contact sensor such as a capacitance type sensor, Further, a contact sensor having a limit switch or the like may be used.

In the present embodiment, a supply destination inert gas supply unit 36 that supplies an inert gas to the preliminary pressure reduction hopper 33 that is depressurized by the supply destination vacuum generation source 40 is provided.
As described above, the supply destination inert gas supply unit 36 is configured such that a gas supply valve 39 for supplying / blocking an inert gas is provided in a gas pipe line 38 connected to an inert gas supply source 37. In the illustrated example, the gas pipe line 38 is connected to the side peripheral wall of the preliminary decompression hopper 33. Note that the inert gas supply source 37 of the supply destination inert gas supply unit 36 may be the same as the inert gas supply source 17 of the material source inert gas supply unit 16 described above. That is, for example, the gas pipe 18 may be branched upstream of the gas supply valve 19, and this branch pipe may be used as the gas pipe 38 of the supply destination inert gas supply unit 36.

Further, the lower end portion of the preliminary decompression hopper 33 is connected to the upper end portion of the supply hopper 35 through a second on-off valve 34 similar to the first on-off valve 32 described above.
The supply hopper 35 is connected so as to communicate with the material charging port 5 of the heating cylinder 4 of the synthetic resin molding machine 3, is decompressed by the supply destination vacuum generation source 40 including the heating cylinder 4, and is airtight with respect to the outside air. Thus, the molding material is supplied to the heating cylinder 4.
The supply hopper 35 is connected with a suction line 41 connected to a supply destination vacuum generation source 40. In the illustrated example, the suction pipe 41 is connected to the upper end portion of the side peripheral wall of the supply hopper 35. A filter is appropriately provided at an appropriate place such as a connection portion of the suction pipe 41 in the supply hopper 35. Note that the suction line 41 and the supply hopper 35 may be provided with a pressure sensor such as a pressure sensor for detecting the pressure in the supply hopper 35 or a pressure gauge.

Further, the supply destination vacuum generation source 40 may be a vacuum pump or an ejector device, similarly to the material source vacuum generation source 15 described above. The supply source vacuum generation source 40 may be the same as the material source vacuum generation source 15 described above. The vacuum generation sources 15 and 40 are not limited to those provided in the molding material supply system 1, and may be provided in a factory or the like where the molding material supply system 1 is installed.
The supply hopper 35 is provided with a second level sensor 45 that detects the presence or absence of a material (outputs a material request signal). As described above, the second level sensor 45 may detect that the molding material of the supply hopper 35 has decreased to a predetermined material requirement level as described above.
The supply unit 35 is not limited to a supply hopper having a hopper shape, and may be a cylindrical shape. Further, the supply unit 35 is not limited to the configuration in which the molding material is supplied to the heating cylinder 4 in a drooping manner as shown in the figure. For example, the supply unit 35 is configured to include a supply amount adjusting unit that adjusts the supply amount of the molding material supplied to the heating cylinder 4, and the porosity becomes larger than the state in which the heating cylinder 4 is filled with the molding material. It is good also as what was set as the structure which can be supplied in this way, what is called the structure which can be supplied as a starvation.

Moreover, it is good also as a structure which further provided the inert gas supply part which supplies an inert gas to the supply part 35 (heating cylinder 4) pressure-reduced by the supply destination vacuum generation source 40. FIG.
Further, the pressure indicated by the pressure detection unit for detecting the pressure in the heating cylinder 4 decompressed by the supply destination vacuum generation source 40 is an arbitrary pressure from the pressure most decompressed by the supply destination vacuum generation source 40 to the atmospheric pressure. It is good also as a structure etc. which provided the pressure adjustment part which makes adjustment possible.
Further, the molding material supply system 1 is provided with a control unit that is connected to each of the above-described devices via a signal line or the like, controls each device according to a predetermined program set in advance, and executes a basic operation described later. It has been. The control unit is provided with a control circuit such as a CPU, a storage unit configured by a memory or the like and storing various operation programs and the like.

  The molding material supply method according to the present embodiment, which is executed using the molding material supply system 1, is configured to be able to store the molding material in an airtight state with respect to the outside air by being decompressed by the material source vacuum generation source 15. The molding material stored in the material source storage unit 10 is configured to gas transport toward the collection supply unit 30 so that the degree of decompression of the material source storage unit 10 is generally maintained. Further, the molding material supply method is such that the molding material collected in the collection supply unit 30 is connected so as to communicate with the material inlet 5 of the heating cylinder 4 of the synthetic resin molding machine 3 and is supplied including the heating cylinder 4. The supply hopper 35 that has been decompressed by the pre-vacuum generation source 40 and is airtight with respect to the outside air is replenished so that the degree of decompression of the supply hopper 35 is generally maintained, and the molding material is supplied from the supply hopper 35 to the heating cylinder 4. It is set as the structure which supplies. The molding material supply method is configured to supply an inert gas to at least one of the material transport path 22, the material source storage unit 10, the collection supply unit 30, and the supply hopper 35 of the gas transport unit 20. ing. In this embodiment, it is set as the structure which supplies an inert gas to the material transport path 22, the material former storage part 10, and the collection supply part 30 of the gas transport part 20 among these.

Hereinafter, an example of the molding material supply method according to the present embodiment executed using the molding material supply system 1 will be described with reference to FIG.
When the molding material supply system 1 is activated, the vacuum generation sources 15 and 40 and the inert gas supply sources 17 and 37 are activated (ON). The vacuum generation sources 15 and 40 and the inert gas supply sources 17 and 37 may be always ON while the molding material supply system 1 is in operation. Further, the gas supply valve 19 of the material source inert gas supply unit 16 may be always opened.
Further, when the molding material supply system 1 is started up, no molding material is stored in the supply side preliminary decompression hopper 33 and the supply hopper 35, and both level sensors 44 and 45 output a material request signal. It is in the state. When the molding material supply system 1 is started, the first on-off valve 32, the gas supply valve 39 of the supply destination inert gas supply unit 36, the preliminary pressure reducing valve 43, and the transport gas on-off valve 23c are closed, and the second on-off valve is opened. The valve 34 is in an open state. Moreover, the slide valve 25 of the fixed amount discharge valve 24 is in a state of being positioned on the storage unit side.
Thereby, the pressure in the supply hopper 35 including the material source storage unit 10, the valve container 26, the preliminary decompression hopper 33, and the heating cylinder 4 gradually decreases from the atmospheric pressure and becomes a predetermined decompressed state.

  If each part is in a predetermined pressure-reduced state as described above, or if a predetermined time has elapsed from the start of the molding material supply system 1 (or the vacuum generation source 15 or 40), the material source storage unit 10 and the supply side The molding material is transported in the gas direction. First, the second on-off valve 34 is closed so that the pressure reduction degree of the supply hopper 35 is maintained. Then, the gas supply valve 39 is opened so that the inside of the preliminary decompression hopper 33 becomes atmospheric pressure, and an inert gas is supplied to the preliminary decompression hopper 33. Then, the first open / close valve 32 is opened, the slide valve 25 of the fixed discharge valve 24 is switched from the storage side to the transport side, the transport gas source 21 is turned on, and the transport gas on / off valve 23c is opened. Thereby, the molding material accommodated in the valve container 26 is gas-transported toward the collection part 31 of the collection supply part 30 by the inert gas as a transport gas. In addition, after starting the said molding material supply system 1, you may make it replace with external air by supplying an inert gas suitably in the material conveyance path 22 and the gas return path 23 used as the circulation path of an inert gas.

By the gas transport as described above, the molding material is stored in the preliminary decompression hopper 33 via the collection unit 31, and the first level sensor 44 detects the presence of the material. That is, in the present embodiment, the molding material collected in the collection unit 31 is stored in the preliminary decompression hopper 33. According to this, as compared with a configuration in which the on-off valve or the like is opened after being collected in the collection hopper as in the third embodiment to be described later and then put into the preliminary decompression hopper 33, the supply side The molding material can be transported more rapidly toward the vehicle.
Then, the transport gas source 21 is turned off (stopped), the transport gas on-off valve 23c is closed, the slide valve 25 of the fixed discharge valve 24 is switched from the transport side to the storage section side, and the first on-off valve 32 is closed. . The transport gas source 21 and the transport gas on-off valve 23c may be kept on and open so that the entire amount of the molding material accommodated in the valve container 26 can be transported.
If the slide valve 25 of the fixed discharge valve 24 is switched from the transport side to the storage part side, the valve container 26 and the material source storage part 10 communicate with each other, the molding material is stored again in the valve container 26, and the material source storage part Inert gas is introduced into 10. At this time, the pressure in the material source storage unit 10 slightly increases, but the capacity of the valve container 26 is smaller than the capacity of the material source storage unit 10, so that the predetermined pressure reduction state is relatively early. In place of such a mode, for example, before connecting the valve container 26 to a vacuum generation source for decompressing the inside of the valve container 26 and switching the slide valve 25 of the fixed discharge valve 24 from the transport side to the storage unit side, For example, the inside of the valve container 26 may be decompressed.

Then, the preliminary pressure-reducing valve 43 is opened so that the pressure in the vacuum-reduced preliminary pressure-reducing hopper 33 is reduced. At this time, in this embodiment, since the vacuum generation source 40 of the preliminary decompression hopper 33 and the supply hopper 35 is the same, the pressure in the supply hopper 35 slightly increases. In addition, it is good also as an aspect which provided separately the vacuum generation source which decompresses the preliminary | backup pressure reduction hopper 33, and the vacuum generation source 40 which decompresses the supply hopper 35 instead of such an aspect.
Further, the preliminary pressure reducing valve 43 may be kept open so that the pressure in the preliminary pressure reducing hopper 33 becomes a predetermined reduced pressure state.
When the inside of the preliminary decompression hopper 33 is in a decompressed state, the second opening / closing valve 34 is opened, and the molding material is supplied to the supply hopper 35. Thus, the molding machine 3 may be activated (ON) when the second level sensor 45 detects the presence of material and preparation for molding is completed. In the illustrated example, the second level sensor 45 detects the presence of material and the first level sensor 44 also detects the presence of material, that is, the preliminary pressure reduction even when the molding material is supplied to the supply hopper 35. The state where the molding material exists in the lower layer side in the hopper 33 is illustrated.

If the material level in the supply hopper 35 decreases with the consumption of the molding material in the molding machine 3 and the second level sensor 45 detects the absence of material, that is, outputs a material request signal, the material is the same as above. Gas is transported from the original storage unit 10 to the collection unit 31, and replenishment from the preliminary decompression hopper 33 to the supply hopper 35 is performed. In the illustrated example, the first level sensor 44 outputs a material request signal, the second level sensor 45 outputs a material request signal, and the gas transport operation as described above is started after a predetermined delay time has elapsed. It is said.
The basic operation described above is merely an example, and various modifications can be made. For example, instead of the mode in which the inert gas is supplied to the material source storage unit 10 at all times (in this operation example, when the fixed discharge valve 24 is in the state of the storage unit side excluding the state of the transport side), intermittent It is good also as an aspect which supplies an inert gas, or it is good also as an aspect etc. which supply an inert gas until predetermined time passes after injection | throwing-in of a molding material. Further, the supply mode of the inert gas to the preliminary decompression hopper 33 may be substantially the same as the supply mode intermittently. Further, when the molding material supply system 1 is stopped after completion of the molding, the supply destination vacuum generation source 40 may be stopped after the temperature in the heating cylinder 4 is lowered to a predetermined temperature.

Since the molding material supply system 1 and the molding material supply method according to the present embodiment are configured as described above, the occurrence of molding defects can be suppressed.
That is, the molding material can be stored in the material source storage unit 10 that is decompressed by the vacuum generation source (material source vacuum generation source) 15 and can store the molding material in an airtight state with respect to the outside air. Thereby, for example, it is possible to store the molding material appropriately tempered or the like without exposing it to the outside air for a long period of time. Further, it is connected so as to communicate with the material input port 5 of the heating cylinder 4 of the synthetic resin molding machine 3 and is decompressed by the vacuum generation source (supply destination vacuum generation source) 40 including the heating cylinder 4 and is airtight against the outside air. The molding material can be supplied to the heating cylinder 4 by the supply section (supply hopper) 35 in a state. Thereby, it is possible to suppress the molding material in the supply hopper 35 and the heating cylinder 4 from being exposed to the outside air for a long period of time, and volatile gases such as water vapor and additives generated in the heating cylinder 4 can be reduced. It can be removed by suction, and it is possible to suppress the occurrence of molding defects such as silver stripes and cavities in the molded product. In addition, the molding material stored in the material source storage unit 10 can be gas transported toward the collection supply unit 30 so that the degree of decompression of the material source storage unit 10 is generally maintained. Thereby, when discharging a molding material from the material origin storage part 10, it can suppress that the inside of the material origin storage part 10 is exposed to external air over a long period of time. In addition, the molding material collected in the collection supply unit 30 can be supplied to the supply hopper 35 so that the degree of decompression of the supply hopper 35 is generally maintained. Accordingly, when the molding material is supplied from the collection supply unit 30 to the supply hopper 35, it is possible to prevent the supply hopper 35 and the heating cylinder 4 from being exposed to the outside air for a long time.

  Further, an inert gas can be supplied to at least one of the material transport path 22, the material source storage unit 10, the collection supply unit 30, and the supply hopper 35 of the gas transport unit 20. As a result, in the place where the inert gas is supplied, the water vapor and oxygen present around the molding material, and the water vapor and oxygen adsorbed on the surface of the molding material can be replaced with the inert gas. It is possible to reduce the amount of water and oxygen in the vicinity of the water.

  Moreover, in this embodiment, the inert gas can be supplied as a transport gas to the material transport path 22 of the gas transport unit 20 by the inert gas supply unit (material source inert gas supply unit) 16. Thereby, compared with what used outside air etc. as transport gas, it can reduce more effectively that a molding material is exposed to outside air, for example. That is, it can be transported by the inert gas from the material source reservoir 10 that is airtight to the outside air toward the supply hopper 35 side that is airtight to the outside air. It is possible to substantially eliminate exposure of the molding material after storage to the outside air. As a result, the above-described drying process or the like is suitable as a system for supplying an unnecessary molding material in principle. In addition, this can reduce the necessity of heating the molding material stored in the material source storage unit 10 for drying or the like, and heating from the material source storage unit 10 as in the present embodiment. It is also possible not to provide a heater for heating the molding material until immediately before being supplied to the cylinder 4. Thereby, the molding material without a heat history can be supplied, and deterioration of the molding material can be more effectively suppressed.

  In the present embodiment, the gas transport unit 20 includes a gas return path 23 that circulates the inert gas supplied to the material transport path 22. Therefore, for example, the amount of inert gas used can be reduced and the load on the surrounding environment can be reduced compared to a configuration in which an inert gas used as a transport gas is released. it can. In addition, instead of such a mode, a compressed inert gas is supplied to the material transport path 22, the molding material is pumped, and the inert gas used as the transport gas is released at the transport destination side. Also good.

In the present embodiment, the inert gas supply units 16 and 36 are used as at least one of the material source storage unit 10, the collection supply unit 30, and the supply hopper 35 that are decompressed by the vacuum generation sources 15 and 40. An inert gas is supplied to the material source storage unit 10 and the collection supply unit 30. Therefore, by supplying an inert gas to the part to be decompressed, the inert gas is instantaneously diffused, and water vapor and oxygen existing around the molding material by suction by the vacuum generation sources 16 and 36, or the surface of the molding material The water vapor and oxygen adsorbed by the gas can be replaced with the inert gas more effectively, and the amount of water and oxygen around the molding material can be reduced more effectively.
In addition, since the inert gas can be supplied to the material source storage unit 10, even when the inside of the material source storage unit 10 is exposed to the outside air when the molding material is charged into the material source storage unit 10. The water vapor and oxygen existing around the molding material and the water vapor and oxygen adsorbed on the surface of the molding material are replaced with the inert gas by the supply of the inert gas and the suction by the material source vacuum generation source 15. it can.

Further, in this embodiment, since the inert gas can be supplied to the preliminary decompression hopper 33 of the collection supply part 30, the former stage of the supply hopper 35 communicating with the heating cylinder 4, that is, the molding immediately before the supply destination. Water vapor or oxygen present around the material, or water vapor or oxygen adsorbed on the surface of the molding material can be replaced with an inert gas, and the occurrence of molding defects can be more effectively suppressed.
In addition, for example, an inert gas may be intermittently supplied to at least one of the material source storage unit 10, the collection supply unit 30, and the supply hopper 35 that are decompressed by the vacuum generation sources 15 and 40. Good. With such a configuration, the supply of the inert gas and the suction by the vacuum generation sources 15 and 40 are repeated, and water vapor and oxygen can be more effectively replaced with the inert gas.

Next, another embodiment according to the present invention will be described with reference to the drawings.
FIG. 3 is a diagram schematically illustrating an example of a molding material supply system according to the second embodiment.
Note that differences from the first embodiment will be mainly described, and the same components will be denoted by the same reference numerals, and description thereof will be omitted or briefly described.

As shown in FIG. 3, the molding material supply system 1 </ b> A according to the present embodiment is mainly different from the first embodiment in the configuration of the material source reservoir 10 </ b> A and the material source inert gas supply unit 16 </ b> A.
In this embodiment, it is set as the structure which provided the heating means 11a in 10 A of material source storage parts. In the illustrated example, an example in which an outer peripheral heater 11a such as a band heater as a heating unit is provided so as to cover the outer peripheral side of the storage main body 11 of the material source storage unit 10A. In addition, as a heating means which covers such an outer peripheral side, it is good also as what provided the flow path through which heated fluids, such as warm water and warm air, distribute | circulate. Moreover, it replaces with the aspect which provided the heating means so that the outer peripheral side of the storage main body 11 of 10 A of raw material storage parts may be covered, and heat transfer fins etc. which transmit the heat | fever from an appropriate heater in the raw material storage part 10A. It is good also as an aspect etc. which provided the heat part.

Moreover, in this embodiment, it is set as the structure which provided the heater 18a which heats inert gas in the raw material inert gas supply part 16A. In the illustrated example, a heater 18 a is provided in the gas pipe 18 A on the downstream side of the gas supply valve 19.
If it is set as the structure which provided such a heater 18a, the inert gas introduce | transduced in 10 A of material source storage parts can be heated. Moreover, the inert gas as a transport gas supplied to the material transport path 22 can be heated. In addition, instead of or in addition to the aspect in which the heater 18a for heating the inert gas is provided in the material source inert gas supply unit 16A, the inert gas that supplies the inert gas to the preliminary decompression hopper 33 and the supply hopper 35. It is good also as an aspect which provided the heater which heats the inert gas from a supply part.

Also in the molding material supply system 1A according to the present embodiment, it is possible to execute a molding material supply method as an example of a basic operation that is substantially the same as that of the first embodiment.
Further, the above-described outer peripheral heater 11a and heater 18a may be appropriately ON / OFF controlled. For example, ON / OFF may be performed in conjunction with the vacuum generation source 15 or the inert gas supply source 17.
In addition, the molding material supply system 1A according to the present embodiment and the molding material supply method executed using the system also have substantially the same effects as those of the first embodiment.
In the present embodiment, the heating unit 11a is provided in the material source reservoir 10A, and the heater 18a for heating the inert gas is provided in the material source inert gas supply unit 16A. It is good also as a structure which provided either.

Next, still another embodiment according to the present invention will be described with reference to the drawings.
4 and 5 are diagrams schematically illustrating an example of a molding material supply system according to the third embodiment and a molding material supply method executed using the molding material supply system.
Note that differences from the first embodiment will be mainly described, and the same components will be denoted by the same reference numerals, and description thereof will be omitted or briefly described.

As shown in FIG. 4, the molding material supply system 1 </ b> B according to the present embodiment is mainly different from the first embodiment in the configuration of the collection supply part 30 </ b> A.
In this embodiment, it is set as the structure which provided 31 A of hopper-shaped collection hoppers as a collection part of 30 A of collection supply parts. Further, instead of the preliminary decompression hopper 33, the collection hopper 31A is provided with a first level sensor 44A similar to the above for detecting the presence or absence of a material (outputting a material request signal).

Next, an example of the molding material supply method according to this embodiment that is executed using the molding material supply system 1B will be described with reference to FIG.
Note that differences from the first embodiment will be mainly described, and description of similar operations will be omitted or simplified.
In the present embodiment, the aspect of controlling the transport of the molding material from the material source storage unit 10 to the preliminary decompression hopper 33 is mainly different from that of the first embodiment. In the present embodiment, the molding material collected in the collection hopper 31 </ b> A is introduced into the preliminary pressure-reducing hopper 33 by opening the first on-off valve 32.

That is, with the first on-off valve 32 provided between the collection hopper 31A and the preliminary decompression hopper 33 closed, the slide valve 25 of the metering discharge valve 24 is switched from the reservoir side to the transport side, and the transport gas The source 21 is turned on and the transport gas on / off valve 23c is opened. Thereby, the molding material accommodated in the valve container 26 is gas-transported toward the collection hopper 31A of the collection supply part 30A by the inert gas as the transport gas, and the first level sensor 44A detects the presence of the material. .
Then, the second open / close valve 34 is closed so that the pressure reduction degree of the supply hopper 35 is maintained, and the gas supply valve 39 is opened so that the pressure in the preliminary pressure reduction hopper 33 becomes atmospheric pressure. Supply inert gas. Then, the first on-off valve 32 is opened, and the molding material for the collection hopper 31 </ b> A is put into the preliminary pressure-reducing hopper 33. Thereby, the first level sensor 44A detects the absence of material.

Thereafter, as in the first embodiment, the preliminary pressure reducing valve 43 is opened so that the pressure in the vacuum-reduced preliminary pressure reducing hopper 33 is reduced, and the pressure inside the preliminary pressure reducing hopper 33 is reduced. For example, the second opening / closing valve 34 is opened, and the supply material is supplied to the supply hopper 35. As a result, when the second level sensor 45 detects the presence of material and preparation for molding is completed, the molding machine 3 is activated (ON) as described above, and the material in the supply hopper 35 is consumed as the molding material is consumed in the molding machine 3. If the level is lowered and the second level sensor 45 detects the absence of material, that is, outputs a material request signal, transport control is performed in the same manner as described above.
The basic operation described above is merely an example, and various modifications can be made.
The molding material supply system 1B according to the present embodiment and the molding material supply method executed using the molding material supply system 1B have substantially the same effects as those of the first embodiment.

Next, still another embodiment according to the present invention will be described with reference to the drawings.
6 and 7 are diagrams schematically illustrating an example of a molding material supply system according to the fourth embodiment and a molding material supply method executed using the molding material supply system.
Note that differences from the above embodiments are mainly described, and the same components are denoted by the same reference numerals, and description thereof is omitted or simplified.

As shown in FIG. 6, the molding material supply system 1 </ b> C according to the present embodiment is mainly different from the above embodiments in the configuration of the gas transport unit 20 </ b> A. In the present embodiment, the collection supply part 30A has the same configuration as that of the third embodiment.
Further, in the present embodiment, the discharge portion 24A configured to be able to discharge the molding material in the material source reservoir 10 so that the degree of decompression of the material source reservoir 10 is substantially maintained is the above-described embodiment. It has a different configuration.

  The discharge unit 24 </ b> A includes a hopper-shaped discharge container 26 </ b> A that temporarily stores the molding material discharged from the material source storage unit 10 and is decompressed by the vacuum generation source 15. In the illustrated example, the vacuum generation source 15 of the discharge container 26A is the same as the material source vacuum generation source 15 that depressurizes the material source storage unit 10. A preliminary suction line 28A is provided so that the upper end of the discharge container 26A communicates with the suction line 14 connected to the material source vacuum generation source 15. A filter is appropriately provided at an appropriate place such as a connection portion of the preliminary suction line 28A in the discharge container 26A. Further, the preliminary suction line 28A is provided with a material source side preliminary pressure reducing valve 29A for opening and closing the preliminary suction line 28A. A pressure sensor such as a pressure sensor or a pressure gauge for detecting the pressure in the discharge container 26A may be provided in the preliminary suction line 28A or the discharge container 26A.

The upper end portion of the discharge container 26A is connected to the discharge port 12 at the lower end of the material source storage unit 10 via a cut-off valve 25A. If the cut-off valve 25A is opened, the material source storage unit 10 and the discharge container 26A are communicated with each other, and if closed, the material source storage unit 10 and the discharge container 26A are hermetically separated. Has been.
In addition, a discharge valve 27A that discharges the molding material toward the connection portion 22b with the material transport path 22A is provided at the lower end of the discharge container 26A. If the discharge valve 27A is opened, the discharge container 26A and the material transport path 22A are communicated. If closed, the discharge container 26A and the material transport path 22A are hermetically separated. .

In the present embodiment, the transport gas of the gas transport unit 20A is the outside air. In other words, in the present embodiment, the supply of supplying the inert gas only to the preliminary decompression hopper 33 without the configuration capable of selectively supplying the inert gas to either the material source reservoir 10 or the material transport path 22. A pre-inert gas supply unit 36 is provided.
In the illustrated example, the transport gas is exhausted without being circulated. That is, the suction pipe 23A connected to the collection hopper 31A is connected to the suction side of the transport gas source 21A, and the blowout side is opened to the atmosphere. Moreover, the example which provided the filter 22a which introduces external air upstream from the connection part 22b of 22 A of material transport paths is shown. Instead of the suction transport mode as shown in the figure, a compressed air source as a transport gas source that introduces compressed air may be connected to the upstream side of the connection portion 22b of the material transport path 22A and pumped. .

Next, an example of the molding material supply method according to the present embodiment executed using the molding material supply system 1C will be described with reference to FIG.
Note that differences from the above embodiments will be mainly described, and description of similar operations will be omitted or simplified.
In the present embodiment, the aspect of controlling the transportation of the molding material from the material source storage unit 10 to the collection hopper 31A is mainly different from the third embodiment. In the present embodiment, the molding material of the material source storage unit 10 is temporarily stored in the decompressed discharge container 26A and then gas transported toward the collection supply unit 30A.

That is, as described above, when the material source vacuum generation source 15 and the like are activated, the material source side preliminary pressure reducing valve 29A is also opened, and the inside of the discharge container 26A is decompressed. And in the state which closed the discharge valve 27A, the cut-off valve 25A is opened, and the molding material of the material former storage part 10 is cut out to the discharge container 26A. Thereby, the molding material of the material source storage part 10 is discharged | emitted, without making the pressure in the material source storage part 10 fluctuate | variate significantly (vacuum fracture). The opening control of the cut-off valve 25A may be opened until a predetermined time elapses, or an appropriate material sensor is provided in the discharge container 26A, and the cut-off valve 25A is closed based on the detection of the material sensor. It is good also as an aspect etc. to be made.
If the cut-off valve 25A is opened, the material source side preliminary pressure reducing valve 29A is closed. Then, the cut-off valve 25A is closed while the material source side preliminary pressure reducing valve 29A is closed, the transport gas source 21A is turned on, and the discharge valve 27A is opened. Thereby, the molding material of discharge container 26A is gas-transported toward the collection hopper 31A of the collection supply part 30A by the outside air as the transport gas. When the molding material of the discharge container 26A is transported, the discharge valve 27A is closed, the material source side preliminary pressure reducing valve 29A is opened, and the pressure reducing hopper 33 and the supply hopper 35 are molded as in the third embodiment. Material is transported sequentially.
The basic operation described above is merely an example, and various modifications can be made.

The molding material supply system 1C according to this embodiment and the molding material supply method executed using the molding material supply system 1C have substantially the same effects as those of the first embodiment.
In the present embodiment, the transport gas for transporting the molding material from the material source side to the supply destination side is the outside air. However, the transport time and the time collected in the collection hopper 31A are stored in the material source storage unit 10. It is comparatively shorter than the time to be stored and the time to be stored after the preliminary decompression hopper 33, and even when such a mode is adopted, it is possible to prevent the molding material from being exposed to the outside air for a long time. I can. Further, in this embodiment, the molding material after being transported to the outside air is exposed to an inert gas atmosphere in the preliminary decompression hopper 33, and even when water vapor or oxygen is adsorbed on the surface of the molding material or the like during transportation. , Can be replaced with an inert gas. In this case, an inert gas may be intermittently supplied while decompressing in the preliminary decompression hopper 33.

In addition, different configurations and operations described in the above embodiments may be combined or rearranged as appropriate.
Moreover, the supply aspect to each part of the above-mentioned inert gas is an example, and various deformation | transformation are possible.
In addition, a mode in which the molding material is transported by gas from the material source reservoirs 10 and 10A so that the degree of decompression of the material source reservoirs 10 and 10A is substantially maintained, and supply is performed so that the degree of decompression of the supply unit 35 is substantially maintained. The aspect in which the molding material is supplied to the portion 35 is also an example, and various modifications are possible.
Moreover, although the example using the molding material supply system 1, 1A, 1B, 1C according to each of the above-described embodiments is shown in the example of the molding material supply method according to each of the above-described embodiments, the molding according to each of the embodiments is illustrated. The material supply method can be implemented using various molding material supply systems.

1, 1A, 1B, 1C Molding material supply system 10, 10A Material source storage unit 15 Material source vacuum source 16, 16A Material source inert gas supply unit 20, 20A Gas transport unit 22, 22A Material transport channel 23 Gas return channel 30, 30A Collection supply unit 35 Supply hopper (supply unit)
36 Destination inert gas supply unit 40 Destination vacuum generation source 3 Synthetic resin molding machine 4 Heating cylinder 5 Material inlet

Claims (4)

A material source storage section that is decompressed by a vacuum generation source and configured to store a molding material in an airtight state with respect to the outside air,
A supply connected to the material inlet of the heating cylinder of the synthetic resin molding machine, supplying the molding material to the heating cylinder in an airtight state against the outside air, including the heating cylinder, being decompressed by a vacuum generation source And
The molding material transported from the material source storage unit is collected, and the supply unit can be replenished with the molding material so that the degree of decompression of the supply unit is reduced by the vacuum generation source. A collection and supply department,
Gas transport configured to transport the molding material from the material source reservoir to the collection supply unit so that the degree of decompression of the material source reservoir decompressed by the vacuum source is substantially maintained. And
An inert gas supply unit that supplies an inert gas to at least one of the material transport path of the gas transport unit, the material source storage unit, the collection supply unit, and the supply unit , and
The inert gas supply unit is configured to supply an inert gas as a transport gas of the gas transport unit to a material transport path of the gas transport unit, and the gas transport unit is configured to supply the inert gas supplied to the material transport path. A molding material supply system comprising a gas return path for circulating an active gas . In claim 1 ,
The inert gas supply unit is configured to supply an inert gas to at least one of the material source storage unit, the collection supply unit, and the supply unit that are decompressed by a vacuum generation source. Characteristic molding material supply system. In claim 2 ,
The molding material supply system, wherein the inert gas supply unit is configured to supply an inert gas to the collection replenishment unit that is decompressed by a vacuum generation source. The molding material stored in the material source reservoir that is decompressed by the vacuum generation source and configured to store the molding material in an airtight state with respect to the outside air is maintained so that the degree of decompression of the material source reservoir is substantially maintained. The molding material collected in the collection and replenishment part is connected to communicate with the material inlet of the heating cylinder of the synthetic resin molding machine, and includes the heating cylinder. A supply part that has been depressurized by a vacuum generation source and is airtight with respect to the outside air is replenished so that the degree of decompression of the supply part is substantially maintained, and a molding material is supplied from the supply part to the heating cylinder. It is configured and
Inert gas as transport gas while circulating the inert gas supplied to the material transport path through the gas return path to the material transport path of the gas transport section for transporting the molding material by gas toward the collection and replenishment section A molding material supply method comprising: supplying a molding material.

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