CN109605645B - Foam molding system, mold, material feeder, and foam molding method - Google Patents
Foam molding system, mold, material feeder, and foam molding method Download PDFInfo
- Publication number
- CN109605645B CN109605645B CN201811219603.5A CN201811219603A CN109605645B CN 109605645 B CN109605645 B CN 109605645B CN 201811219603 A CN201811219603 A CN 201811219603A CN 109605645 B CN109605645 B CN 109605645B
- Authority
- CN
- China
- Prior art keywords
- mold
- gas
- inner mold
- pressure
- cavity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000010097 foam moulding Methods 0.000 title claims abstract description 65
- 239000000463 material Substances 0.000 title claims abstract description 24
- 239000002184 metal Substances 0.000 claims abstract description 118
- 239000012530 fluid Substances 0.000 claims abstract description 101
- 239000011347 resin Substances 0.000 claims abstract description 75
- 229920005989 resin Polymers 0.000 claims abstract description 75
- 239000000919 ceramic Substances 0.000 claims abstract description 50
- 238000005187 foaming Methods 0.000 claims abstract description 38
- 239000007789 gas Substances 0.000 claims description 76
- 238000000034 method Methods 0.000 claims description 40
- 230000008569 process Effects 0.000 claims description 24
- 238000001816 cooling Methods 0.000 claims description 22
- 239000003570 air Substances 0.000 claims description 19
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 16
- 230000006837 decompression Effects 0.000 claims description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 11
- 239000002826 coolant Substances 0.000 claims description 11
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- 239000001569 carbon dioxide Substances 0.000 claims description 8
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 7
- 239000011261 inert gas Substances 0.000 claims description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052786 argon Inorganic materials 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000006260 foam Substances 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 239000011148 porous material Substances 0.000 description 17
- 238000000465 moulding Methods 0.000 description 16
- 238000002347 injection Methods 0.000 description 15
- 239000007924 injection Substances 0.000 description 15
- 239000007769 metal material Substances 0.000 description 12
- 238000012545 processing Methods 0.000 description 11
- 230000009467 reduction Effects 0.000 description 10
- 230000035699 permeability Effects 0.000 description 9
- 239000000843 powder Substances 0.000 description 8
- 238000001746 injection moulding Methods 0.000 description 7
- 238000000053 physical method Methods 0.000 description 6
- 238000009413 insulation Methods 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 4
- 150000002484 inorganic compounds Chemical class 0.000 description 4
- 229910010272 inorganic material Inorganic materials 0.000 description 4
- 238000012546 transfer Methods 0.000 description 4
- 238000000149 argon plasma sintering Methods 0.000 description 3
- 230000005587 bubbling Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004512 die casting Methods 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 230000003042 antagnostic effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000004088 foaming agent Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000002087 whitening effect Effects 0.000 description 2
- 238000010146 3D printing Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- -1 and thus Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000010137 moulding (plastic) Methods 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
- B29C44/04—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles consisting of at least two parts of chemically or physically different materials, e.g. having different densities
- B29C44/0415—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles consisting of at least two parts of chemically or physically different materials, e.g. having different densities by regulating the pressure of the material during or after filling of the mould, e.g. by local venting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/34—Auxiliary operations
- B29C44/58—Moulds
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Molding Of Porous Articles (AREA)
Abstract
The invention provides a foam molding system, a mold, a material feeder, and a foam molding method. The foam molding system (100) includes: a mold device (50), a material feeder (30), and a counter pressure supply device (60), the mold device (50) including: an inner mold (51) of gas-permeable metal or gas-permeable ceramic; and an outer mold (52) made of a non-air-permeable metal covering the inner mold (51), the inner mold (51) and the outer mold (52) being formed in an embedded structure or an integrated structure, the material feeder (30) filling a cavity (501) of the inner mold (51) with a resin containing a foaming component; and a counter pressure supply device (60) for supplying a fluid having a counter pressure into the cavity (501) through the inner mold (51) when the cavity (501) is filled with the resin. According to the present invention, a molded article of a desired bubble can be obtained.
Description
Technical Field
The invention relates to a foam molding system, a mold, a material feeder, and a foam molding method.
Background
Injection molding is one method of plastic processing. In addition to general plastic molding, foam molding is also used, and a porous plastic is obtained by molding a foamable plastic by utilizing the characteristics of a foam material such as light weight and heat insulation. Further, as a method of processing a metal product, there is metal die casting, which is a manufacturing technique combining injection molding (plastic injection molding) and metal powder metallurgy.
Japanese patent No. 6316866 discloses a metal die casting method in which a metal powder can be uniformly distributed in a material by increasing the density of a green body by supplying a back pressure gas having a specific pressure into a cavity of a die to contact the green body during die casting of the metal, thereby becoming tough when the metal material is pushed and injected.
In injection foam molding, which is one of foam molding, when a plastic solution containing a foaming agent is injected into a mold, the injection pressure may be reduced even in a closed mold depending on the shape of a cavity, and the plastic solution may be injected while foaming is performed. Therefore, the bubbles in the prefoamed part become large, and the bubbles inside the molded article cannot be controlled to a desired size.
Therefore, as disclosed in japanese patent No. 6316866, a pressure drop during injection can be suppressed by supplying back pressure gas into the cavity. However, since a part of the cavity is blocked by the injected plastic solution, a sufficient back pressure cannot be maintained, and thus, the size of the bubbles inside the molded article cannot be controlled to a desired size. It is more difficult to control the size of the bubbles if the shape of the cavity is more complex.
Disclosure of Invention
The present invention has been made in view of the above circumstances, and an object thereof is to provide a foam molding system, a mold, a material feeder, and a foam molding method that can obtain desired bubbles.
The present invention provides a foam molding system, including: a mold device, a material feeder, and a counter pressure supply device, the mold device comprising: an inner mold of gas permeable metal or gas permeable ceramic; and an outer mold made of a non-gas-permeable metal covering the inner mold, the inner mold and the outer mold being formed in an embedded structure or an integrated structure, the material supplier filling a resin containing a foaming component into a cavity of the inner mold, and the opposing pressure supplier supplying a fluid having an opposing pressure into the cavity through the inner mold when the resin is filled into the cavity.
The present invention also provides a mold for foam molding, comprising: the mold comprises an inner side mold made of air-permeable metal or air-permeable ceramic and an outer side mold made of non-air-permeable metal and covering the inner side mold, wherein the inner side mold and the outer side mold form an embedded structure or an integrated structure.
The present invention also provides a material feeder for foam forming, wherein a resin containing a foaming component is filled into a cavity of an inner mold of a permeable metal or a permeable ceramic covered with an outer mold of a non-permeable metal in a state where a fluid having a counter pressure is supplied into the cavity, and a molded article is taken out in a state where an air pressure in the cavity is reduced to an atmospheric pressure.
The present invention also provides a foam molding method in which a fluid having a pressure resistance is supplied into a cavity of an inner mold of a gas-permeable metal or a gas-permeable ceramic covered with an outer mold of a gas-impermeable metal, and a resin containing a foaming component is filled into the cavity in a state where the fluid is supplied into the cavity through the inner mold.
According to the present invention, desired bubbles can be obtained.
Drawings
Fig. 1 is a schematic diagram showing an example of the structure of a foam molding system according to the present embodiment;
fig. 2 is a schematic view showing a 1 st example of front main members of the mold apparatus of the present embodiment;
fig. 3 is a schematic view showing a 1 st example of a side main member of the mold apparatus of the present embodiment;
fig. 4 is a schematic view showing an example of the structure of the inner mold of the present embodiment;
FIG. 5 is a time chart showing a 1 st example of the operation of the foam molding system according to the present embodiment;
FIG. 6 is a schematic view showing an example of a state of bubble generation/growth when a mold as a comparative example is used;
FIG. 7 is a schematic view showing an example of a state of bubble generation/growth when the mold of the present embodiment is used;
fig. 8 is a schematic view showing a 2 nd example of front main members of the mold apparatus of the present embodiment;
fig. 9 is a time chart showing a 2 nd example of the operation of the foam molding system according to the present embodiment;
fig. 10 is a flowchart showing an example of the operation procedure of the foam molding system according to the present embodiment.
Detailed Description
The invention is explained below with reference to the figures of the corresponding embodiments. Fig. 1 is a schematic diagram showing an example of the structure of a foam molding system 100 according to the present embodiment. Foam molding system 100, comprising: a mold device 50, a molding machine 30 as a material feeder, a counter pressure supply device 60, and the like. In addition, the foam molding system 100 further includes: a high-temperature thermostat 10, a low-temperature thermostat 20, a supercritical device 40, and a control device 70.
A mold apparatus 50, comprising: an inner mold 51 of gas-permeable metal or gas-permeable ceramic, and an outer mold 52 made of gas-impermeable metal covering the inner mold 51, and the like. The gas-permeable metal is a metal material (including porous metal) having numerous fine pores, and has gas permeability. The gas-permeable metal is not limited to a metal material provided with fine pores in advance, and may be formed with fine pores by machining. The average diameter (for example, several tens μm) and porosity of the pores can be appropriately set. The inner mold 51 is not limited to a gas-permeable metal, and may be a sintered body (molded body) obtained by sintering an inorganic compound such as a gas-permeable ceramic by a heat treatment. When the inner mold 51 is made of a gas-permeable metal, a gas-permeable ceramic may be coated on the surface of the gas-permeable metal. In the following embodiments, an example in which a gas-permeable metal is used for the inner mold 51 will be described. The inner mold 51 and the outer mold 52 may be formed in an embedded structure or an integrated structure. The inner mold 51 and the outer mold 52 are collectively referred to as a mold. The inner mold 51 can be made of metal powder by laser sintering using, for example, a metal 3D printer to form a porous mold having air permeability. The inner mold 51 may be formed by processing a gas-permeable metal material. Details of the mold are described later.
The molding machine 30 can fill the cavity 501 of the inner mold 51 with a resin containing a foaming component (e.g., a foaming agent). A method of foam molding comprising: physical methods of generating bubbles by dissolved gas, and chemical methods of generating bubbles by thermally decomposing or chemically reacting dispersed foaming components. The foaming method of the present embodiment may include both a physical method and a chemical method, but the following description will be given by taking a physical method (supercritical foaming) as an example.
The supercritical fluid sent from the critical foaming unit 41 is adjusted to a pressure state corresponding to the pressure in the cylinder 33 of the molding machine 30, and then injected into the molding machine 30 for a certain period of time. The cylinder 33 and the screw 31 disperse the supercritical fluid into the molten resin as fine droplets, and the single-phase dissolved substance is formed by the subsequent mixing. The sprue bush 32 provided at the tip of the nozzle may be made of ceramic or the like, and the temperature of the nozzle and the temperature of the mold may be separated (insulated).
The physical method (physical foaming) is a method in which a supercritical fluid is dissolved in a resin under high pressure and the solubility is reduced by reducing the pressure, thereby generating and growing many bubbles. The bubbles stop growing when the resin in the mold is cooled and solidified, for example. The supercritical fluid is an object (fluid) in which two properties of liquid and gas coexist. Thus, a molded article having fine (for example, bubbles having a diameter of several μm or less) bubbles can be obtained. Hereinafter, an example in which the supercritical fluid is a gas will be described, but the supercritical fluid is not limited to a gas, and may be a liquid.
The confronting pressure supply device 60 includes: an air pump 61, an accumulator 62, and a gas compressor (not shown). The storage tank 62 contains any one of air, nitrogen gas, carbon dioxide gas, and inert gas including argon gas. When a liquid is used as the supercritical fluid, water, alcohol, or the like may be used. The use of inert gas prevents oxidation of the shaped part. A pipe 64 is connected between the pressure resisting device 60 and the mold (specifically, the inner mold 51). The pipe 64 is provided with a switching valve 63 and a pressure sensor 65.
When the cavity 501 is filled with a resin (single-phase dissolved material), the opposing pressure supply device 60 supplies a gas having an opposing pressure (may also be referred to as "back pressure gas") into the cavity 501 through the pipe 64 and the inner mold 51. The cavity 501 is filled with resin and then depressurized to control foaming. The opposing pressure may be, for example, a pressure close to the critical pressure of the supercritical fluid (either above or below the critical pressure), or may be a pressure lower than the injection pressure. The gas having the counter pressure supplied from the counter pressure supply device 60 is supplied into the cavity 501 in a planar form through the numerous pores of the inner mold 51 of a gas-permeable metal (e.g., a porous metal).
In this way, even if the cavity 501 is divided into a plurality of closed spaces by the injected resin, the gas from the numerous gas holes of the inner mold 51 is supplied in a planar form in each closed space, so that the pressure in each closed space can be maintained at the opposing pressure, and the pressure in the cavity can be controlled to an appropriate value. Therefore, the bubbles in the preceding bubbling portion can be suppressed from becoming large, and the size of the bubbles tends to be uniform. Further, the growth of bubbles is stopped after the resin is solidified with cooling. As such, a molded article having bubbles of a desired size can be obtained by controlling the pressure in the cavity.
The branched medium supply pipe 13 and the branched medium return pipe 23 are connected to the male side and the female side of the outer mold 52, respectively. The medium delivery pipes 12 are further branched in the middle, one of the branched medium delivery pipes 13 is connected to the high-temperature control device 10 through an electromagnetic valve 11, and the other branched medium delivery pipe 13 is connected to the low-temperature control device 20 through an electromagnetic valve 21. Similarly, the return medium pipes 23 are further branched halfway, one of the branched return medium pipes 23 is connected to the high-temperature control device 10 via the electromagnetic valve 12, and the other of the branched return medium pipes 23 is connected to the low-temperature control device 20 via the electromagnetic valve 22. The mold is provided with a temperature sensor 53 and a pressure sensor 54.
The control device 70 is a device for controlling the operation of the foam molding system 100, and includes: a temperature acquisition unit 71, a pressure acquisition unit 72, a valve opening/closing control unit 73, a molding machine control unit 74, a counter pressure control unit 75, and a supercritical control unit 76. Further, the control device 70 may be constituted by a plurality of separate devices. In fig. 1, the lines indicated by the two-dot chain lines are part of the communication lines (control lines) with the control device.
The temperature acquisition unit 71 can acquire temperature data detected by the temperature sensor 53.
The pressure acquisition unit 73 can acquire pressure data detected by the pressure sensors 44, 65, and 54.
The valve opening/closing control section 73 can control opening and closing of the electromagnetic valves 11, 12, 21, 22, 43 and the switching valve (three-way switching valve) 63.
The molding machine control section 74 can control the operation of the molding machine 30 in each of the mold clamping process, the injection molding process, the pressure maintaining/cooling process, the metering process, the mold opening process, and the take-out process.
The opposing pressure control section 75 functions as an opposing pressure control device and can control the operation of the opposing pressure supply device 60. Specifically, the opposing pressure control unit 75 may apply a specific pressure before filling the molten resin, and may decrease (reduce) the pressure of the gas supplied into the cavity 501 from before and after the completion of filling to a specific time point in the pressure holding/cooling process. The opposing pressure control unit 75 may decrease (reduce) the pressure of the gas supplied into the cavity 501 at a specific time node when the molten resin is cooled and solidified in the pressure holding/cooling step after the completion of filling of the molten resin. By applying a counter pressure into the mould cavity 501, a uniform bubble or a bubble of a desired size can be obtained.
The supercritical control section 76 can control the operation of the supercritical device 40.
The molds (the inner mold 51 and the outer mold 52) of the present embodiment will be described in detail below.
Fig. 2 is a schematic view showing a 1 st example of front main members of a mold apparatus 50 according to the present embodiment, and fig. 3 is a schematic view showing a 1 st example of side main members of the mold apparatus 50 according to the present embodiment. In addition, in fig. 3, the gasket indicated by reference numeral 55 and the heat insulating member indicated by reference numeral 56 are omitted for ease of understanding. The inner mold 51 has a female-side inner mold 51a and a male-side inner mold 51b, and in a mold closed state (mold clamped state), a cavity 501 is formed as a space into which molten resin is filled (injected). The female-side inner mold 51a may be referred to as a cavity, but in the present description, the cavity 501 is described as a space into which a resin is filled (injected). In fig. 2, the shape of the cavity 501 is shown by a rectangle shown by a broken line for convenience of understanding, but in practice, the flow path into which the molten resin flows, such as a product portion, a channel, a runner, and a gate, has a complicated shape corresponding to the shape of the molded article. The molten resin may be injected at a specific position in the cavity 501, and the injection direction may be set to a direction perpendicular to the sheet of fig. 2.
As described above, the inner mold 51 is made of a gas-permeable metal. Specifically, all or part of the inner mold 51 may be made of a gas-permeable metal. For example, when the cavity 501 of the inner mold 51 has a complicated shape, since there is a possibility that a large number of closed spaces are formed when molten resin is injected, the entire inner mold 51 can be made of a gas-permeable metal, and thus, gas having a pressure resistance can be supplied in a planar form to all the closed spaces. The planar form referred to herein means that it is not limited to being air-permeable in a dot form by air-permeable pins. In the case where the cavity 501 has a relatively simple shape, it is considered that the closed space formed by the injected molten resin is small, and therefore, a part of the inner mold 51 may be made of a gas-permeable metal in accordance with the position of the closed space.
The outer mold 52 has a female-side outer mold 52a and a male-side outer mold 52b, and is formed in a shape completely covering the inner mold 51 in a mold closed state (mold clamping state). A gasket 55 is provided around the inner mold 51 of the outer mold 52. Further, a heat insulating member 56 is provided to cover the outer mold 52.
The mold device 50 has a fluid pipe 511 for supplying the gas supplied from the opposing pressure supply device 60. The fluid pipe 511 is connected to the pipe 64 through a nozzle. The fluid pipe 511 is formed in the outer mold 52 and communicates with the inner mold 51. Thus, the gas having the opposing pressure is supplied to the inner mold 51 through the pipe 64 and the fluid pipe 511, and is supplied into the cavity 501 in a planar form through the numerous air holes of the inner mold 51.
The die apparatus 50 includes a medium pipe 521 into which a heating medium from the high-temperature thermostat 10 and a cooling medium from the low-temperature thermostat 20 flow. The die device 50 has a medium pipe 521 through which the heating medium and the cooling medium flow out. The medium pipe 521 is connected to the medium pipe 13 through a nozzle. The medium pipe 521 is connected to the medium return pipe 23 through a nozzle. The medium pipe 521 is formed in the outer mold 52. By forming the medium pipe 521 in the outer mold 52 made of a non-air-permeable metal covering the inner mold 51 made of an air-permeable metal, it is possible to prevent the heating medium and the cooling medium from flowing into numerous pores, and to adjust the temperature of the mold similarly even in the mold having the inner mold 51 made of an air-permeable metal.
Fig. 4 is a schematic diagram showing an example of the structure of the inner mold 51 according to the present embodiment. The outline of the female-side inner mold 51a of the inner molds 51 is shown in fig. 4. For convenience of explanation, the position of the fluid pipe 511 in the female-side inner mold 51a is easily understood by dividing the mold into 3 parts for illustration. As shown in fig. 4, the fluid pipe 511 may be disposed around the cavity 501 of the female-side inner mold 51 a. Although not shown in the drawings, a fluid pipe 511 facing the cavity 501 may be similarly disposed in the male inner mold 51 b.
Since the fluid pipe 511 is disposed around the cavity 501 of the inner mold 51, the gas having the opposing pressure is supplied to the periphery of the cavity 501 through the fluid pipe 511, and is supplied in a planar form from there into the cavity 501 through the numerous air holes of the inner mold 51, so that the gas having the opposing pressure can be reliably supplied to the cavity 501. However, the fluid pipe 511 shown in fig. 4 is not an essential component of the present invention.
The operation of the foam molding system 100 according to the present embodiment will be described in detail below.
Fig. 5 is a time chart showing a 1 st example of the operation of the foam molding system 100 according to the present embodiment. The operation of the foam molding system 100 will be described in terms of the steps of mold closing, injection molding, pressure holding/cooling, metering, mold opening, and removal.
In the mold clamping process, after the mold is closed, the high-temperature thermostat 10 Opens (ON) the valves (electromagnetic valves 11 and 12), and the mold is heated to a set temperature and the set temperature is maintained. The temperature of the mold is controlled by a high-temperature control device 10 and a low-temperature control device 20. By subjecting the mold to a high temperature at the time of injection, the generation of a skin layer can be delayed, so that reproducibility can be improved and a foamable state can be maintained. Then, the mold is cooled to solidify the resin in the mold, so that foaming can be stopped. By coating the ceramic, the time for heat insulation during injection can be ensured, the generation of a skin layer can be reduced, and the transfer performance can be improved, and the foaming molding can be performed by using 1 low-temperature adjustment device 20. The ceramic coating may be over the entire surface of the mold cavity 501 or a portion thereof. After a predetermined time has elapsed from the start node of the mold clamping process, the opposing pressure supply device 60 connects (ON) the opposing pressure supply device 60 to the cavity 501 by a switching valve (switching valve 63), and the opposing pressure supply device 60 is connected to the pipe 64, so that the gas having the opposing pressure is supplied into the cavity 501. Thus, the cavity 501 is maintained against pressure. The countermeasure pressure may be lower than the injection pressure, and may be a pressure near the critical pressure (for example, may be equal to or higher than the critical pressure, or may be equal to or lower than the critical pressure). In addition, the opposing pressure may be set to a pressure capable of controlling the formation of a uniform foamed state. Further, in the process from the Opening (ON) of the switching valve 63 to the closing (OFF) of the cavity 501, the opposing pressure may be kept constant, the pressure may be gradually decreased, or the pressure may be gradually increased. Alternatively, the pressure increase and pressure decrease may be repeated against the pressure.
In the injection molding process, the molten resin is filled (injected) from the molding machine 30 into the cavity 501. Even if the molten resin injected into the cavity 501 is separated into a plurality of closed spaces, the gas having the opposing pressure is supplied in a planar form from the numerous pores of the inner mold 51 in each closed space, and therefore the pressure in each closed space in the cavity 501 can be maintained at the opposing pressure and can be controlled to an appropriate state. This can suppress the enlargement of the bubbles in the previously foamed portion, and can make the sizes of the bubbles uniform.
In the pressure holding/cooling step, the high-temperature thermostat 10 is closed by the valves (electromagnetic valves 11 and 12), and the low-temperature thermostat 20 is opened by the valves (electromagnetic valves 21 and 22). In the pressure holding/cooling step, the mold is cooled while the pressure in the cavity 501 is maintained.
In addition, the measurement step performed at a specific time node of the pressure maintaining/cooling step is performed for the next injection. Specifically, the molten resin and the supercritical fluid are measured. In addition, the molten resin in which the supercritical fluid is dispersed is stirred to form a single-phase dissolved substance.
During the period from the start node t1 of the pressure holding/cooling process to the time node t2 after a lapse of a predetermined time, the switching valve (solenoid valve 63) for the opposing pressure supply device 60 is switched to pressure reduction (OFF). In this way, the pressure in the cavity 501 is reduced (decompressed) from the opposing pressure to the atmospheric pressure. As the molten resin cools and solidifies. Thus, the growth of bubbles is stopped.
In the mold opening process, the mold is opened and the gas injector is activated (ON). Specifically, the antagonistic pressure control section 75 controls the supply of the gas of a specific pressure by the antagonistic pressure supply device 60. In fig. 5, the activation of the opposing pressure supply device 60 is not illustrated. The specific pressure may be set to a level at which the molded article cured in the mold can be removed from the mold. Therefore, the ejector pin for removing the molded article from the mold is not required, and deformation of the molded article by the ejector pin, a mark (whitening of the surface of the molded article) by the ejector pin, or the like can be prevented.
In the removing step, it is confirmed that the molded article is removed from the mold, and thereafter, the steps after the mold closing step are repeated again.
The generation and growth of bubbles in the molded article will be described below.
Fig. 6 is a schematic view showing an example of a state of bubble generation/growth when the mold as a comparative example is used. The mold 150 as a comparative example was made of a non-gas-permeable metal. In the left drawing of fig. 6, the back pressure gas is supplied to the cavity 501 in a state where the mold 150 is closed (the back pressure gas is supplied in a direction indicated by an arrow marked B). The molten resin injected from the molding machine is injected from a nozzle of the molding machine toward the sprue as indicated by an arrow a.
In fig. 2 from the left in fig. 6, molten resin S is injected into cavity 1501, and cavity 1501 has two spaces 1502 and 1503 created by molten resin S (in the example in fig. 6, two spaces, a closed space 1503 on the upper side of molten resin S and a closed space 1502 on the lower side of molten resin S are shown for convenience of explanation). In the occlusion space 1502, since the back pressure gas is supplied, the pressure in the space 1502 is maintained at a desired value. On the other hand, in the closed space 1503, since the back pressure gas is not supplied, the pressure is decreased.
In fig. 3 from the left in fig. 6, a large number of bubbles are generated and grown due to the pressure drop in the molten resin S that has moved to the upper portion of the closed space 1503 where the pressure drops. The size of the generated bubbles gradually increases as the flow progresses, and the size of the bubbles exceeds the required size. On the other hand, the molten resin S1 in the lower part maintains the back pressure, and therefore, the bubbles are formed into a desired size.
As shown in the right drawing of fig. 6, in the comparative example, the molded article had both a portion (shown by reference numeral S1) where the bubbles were formed to a desired size and a portion (shown by reference numeral S2) where the sizes of the bubbles were formed to be larger than desired and uneven. The portion having a good foaming state in which the pressure is controlled and the portion having a poor foaming state in which the pressure is not controlled are present together as a whole, and the quality is poor. The present embodiment can solve such a problem.
Fig. 7 is a schematic view showing an example of a state of bubble generation/growth when the mold of the present embodiment is used. In the left drawing of fig. 7, a gas having a counter pressure is supplied into the cavity 501 (the gas is supplied in the direction indicated by the arrow marked B) in a state where the molds (the outer mold 52 and the inner mold 51) are closed. Since the inner mold 51 has numerous air holes formed therein, a gas against pressure is supplied in a planar manner into the cavity 501 from the surface of the inner mold 51 surrounding the cavity 501 (indicated by a broken-line arrow in the figure for convenience of description). The molten resin injected from the molding machine 30 is injected from a nozzle of the molding machine 30 toward the sprue as indicated by an arrow a.
In fig. 2 from the left in fig. 7, the molten resin S is injected into the cavity 501, and the cavity 501 generates two spaces by the molten resin (in the example of fig. 7, a closed space located above the molten resin S and a closed space located below the molten resin S are illustrated for convenience of explanation). In both of these spaces, since the gas having the opposing pressure is supplied from the numerous gas holes of the inner mold 51, the pressure in each space is maintained at the opposing pressure.
In fig. 3 from the left of fig. 7, the molten resin S1 heading toward the upper closed space and the lower closed space is maintained at the resist pressure, and therefore, the bubbles are formed in the desired size. That is, a large number of bubbles are not generated and grown due to the pressure reduction, and the size of the generated bubbles is not enlarged as the flow proceeds.
As shown in fig. 7, in the present embodiment, even if the cavity is divided into a plurality of closed spaces by the injected molten resin, since the gas is supplied to each closed space from the numerous gas holes of the inner mold 51, the pressure of each closed space can be maintained at the opposing pressure, and the pressure can be controlled to an appropriate state, whereby the size of the bubbles can be made uniform. Further, when the cavity is filled with a resin containing a foaming component, a molded article having cells of a desired size can be obtained by controlling the rate and value of pressure reduction.
Fig. 8 is a schematic view showing a 2 nd example of the front main member of the mold apparatus of the present embodiment. The structure of the example of fig. 8 is different from that of the example of fig. 2 in that the inner mold 51 is divided into a plurality of (3 in the example of fig. 8) blocks. As shown in fig. 8, the inner mold 51 includes: a plurality of inner mold blocks 515, 516, 517 of gas permeable metal separated by walls 571, 572 of gas impermeable metal. The inner mold blocks 515, 516, 517 of the gas-permeable metal can be used to manufacture a porous mold having gas permeability by controlling the bonding state of the metal powder when the metal powder is sintered by laser using, for example, a metal 3D printer to manufacture a mold. When the inner mold blocks 515, 516, 517 are made of a gas-permeable metal, a gas-permeable ceramic may be coated on the surface of the gas-permeable metal.
The plurality of inner mold blocks 515, 516, 517 are connected to fluid pipes 511a, 511b, 511c, respectively. The pipes 64a, 64b, and 64c to which the 3 counter pressure supply devices 60 are connected to the fluid pipes 511a, 511b, and 511c through nozzles, respectively. That is, the plurality of inner mold blocks 515, 516, 517 are supplied with the gas having the resist pressure from the 3 pieces of the resist pressure supply devices 60, respectively.
Therefore, for example, the time node of the pressure reduction can be changed for each cavity 501 of the plurality of inner mold blocks 515, 516, 517 by filling the molten resin to match the specific time node of the cooling solidification. In this way, the air bubbles in the molded product in each cavity 501 of the inner mold blocks 515, 516, 517 can be formed to a desired size. That is, the state of the bubbles at a specific position of the molded article can be formed to be a desired state thereof.
Therefore, the temperature of the mold can be adjusted for each of the plurality of inner mold blocks 515, 516, 517, and, for example, even when the shape of the cavity is a complicated shape, the entire mold can be adjusted to an optimum temperature.
Fig. 9 is a time chart showing a 2 nd example of the operation of the foam molding system 100 according to the present embodiment. Example 2 shown in fig. 9 is a configuration using example 2 of fig. 8. The difference from the 1 st example schedule illustrated in fig. 5 is that: there are 3 temperature adjusting devices 10 and 20 for high temperature and 3 temperature adjusting devices 20 for low temperature, respectively, 3 backpressure supply devices 60, and the stop time nodes (OFF time nodes, in the example of fig. 9, time nodes t21, t22, t23) of the 3 backpressure supply devices 60 can be set appropriately.
That is, the backpressure control unit 75 can control the pressures of the gases supplied from the 3 backpressure supply devices 60. Specifically, the pressure-resistant controller 75 may perform pressure reduction at time nodes (time nodes t21, t22, and t23 in the example of fig. 9) required for the molten resin in the inner mold blocks 515, 516, and 517 to be cooled and solidified, respectively, in the pressure reduction/cooling step. Accordingly, bubbles having a desired size can be obtained in each of the plurality of inner mold blocks 515, 516, 517, and the state of the bubbles at a specific position of the molded article can be set to a desired state.
Fig. 10 is a flowchart showing an example of the operation procedure of the foam molding system 100 according to the present embodiment. For convenience of description, the control device 70 will be described as an operation subject. The controller 70 starts the high-temperature thermostat 10 in the mold closed state (S11). The control device 70 activates the opposing pressure supply device 60 to supply the gas having the opposing pressure into the cavity 501 of the inner mold 51 (S12).
The controller 70 fills (injects) the molten resin containing the foaming component into the cavity 501 of the inner mold 51 (S13). The controller 70 stops the high temperature thermostat 10 at a time node at which the pressure maintaining/cooling process starts, and starts the low temperature thermostat 20 (S14).
The control device 70 stops the opposing pressure supply device 60 at a time node when a required time elapses from the start of the pressure holding/cooling process until the molten resin is cooled and solidified (S15).
The controller 70 performs a metering process at a specific time node of the pressure holding/cooling process (S16), operates the gas injector in the mold opening process (S17), and takes out the molded article from the mold (S18). The controller 70 determines whether or not the operation processing is completed (S19), and if the processing is not completed (determination of S19 is NO), the operation processing after step S11 is repeated, and if the processing is completed (determination of S19 is YES), the operation processing is ended.
The foam molding system of the present embodiment includes: a die device, a material feeder, and a counter pressure feeding device; the mold apparatus, comprising: the mold comprises an inner side mold made of air-permeable metal or air-permeable ceramic and an outer side mold made of non-air-permeable metal and covering the inner side mold; the inner side mold and the outer side mold form an embedded structure or an integrated structure; the material feeder fills a resin containing a foaming component into the cavity of the inner mold; the opposing pressure supply means supplies a fluid having an opposing pressure into the cavity through the inner mold when filling the resin into the cavity.
In the foam molding method of the present embodiment, a fluid against pressure is supplied into a cavity of an inner mold of a gas-permeable metal or a gas-permeable ceramic covered with an outer mold of a gas-impermeable metal, and a resin containing a foaming component is filled into the cavity in a state where the fluid is supplied into the cavity through the inner mold.
Foam-forming molding system comprising: a mold device, a material feeder, and a counter pressure feeding device. The material feeder may be, for example, an injection molding machine.
A mold apparatus, comprising: an inner mold of gas-permeable metal or gas-permeable ceramic, and an outer mold made of gas-impermeable metal covering the inner mold 1, and the like. The gas-permeable metal is a metal material (including porous metal) having numerous fine pores, and has gas permeability. The gas-permeable metal is not limited to a metal material provided with fine pores in advance, and may be formed with fine pores by machining. The average diameter (for example, several tens μm) and porosity of the pores can be appropriately set. The inner mold is not limited to a gas-permeable metal, and may be a sintered body (molded body) obtained by sintering an inorganic compound such as a gas-permeable ceramic by a heat treatment. The inner mold and the outer mold are collectively referred to as a mold. The inner mold may be a porous mold having air permeability, which is made by laser sintering metal powder using, for example, a metal 3D printer. The inner mold 51 may be formed by processing a gas-permeable metal material.
And a material supplier for filling the cavity of the inner mold with resin containing foaming components. A method of foam molding comprising: physical methods of generating bubbles by dissolved gas, and chemical methods of generating bubbles by thermally decomposing or chemically reacting dispersed foaming components. The physical method (physical foaming) is a method in which a liquefied gas or a supercritical fluid is dissolved in a resin under high pressure, and the solubility is reduced by reducing the pressure or heating to generate bubbles. The supercritical fluid is an object (fluid) in which two properties of liquid and gas coexist. As the supercritical fluid, for example, nitrogen gas, carbon dioxide, or the like can be used, and fine (for example, bubbles having a diameter of several μm or less) bubbles can be obtained.
And a counter pressure supply device for supplying gas with counter pressure into the cavity through the inner mold when the cavity is filled with resin, and for reducing the pressure after the cavity is filled with resin to control foaming. The opposing pressure may be, for example, a pressure close to the critical pressure of the supercritical fluid (may be equal to or higher than the critical pressure), or may be a pressure lower than the injection pressure. The gas having the counter pressure supplied from the counter pressure supply means is supplied in a planar form into the cavity through the numerous pores of the inner mold of the gas-permeable metal (for example, porous metal).
Therefore, even if the cavity is divided into a plurality of closed spaces by the injected resin, the gas from the numerous gas holes of the inner mold is supplied in a planar form in each closed space, and therefore the pressure in each closed space can be maintained at the opposing pressure, and the pressure can be controlled to an appropriate value. Therefore, the bubbles in the preceding bubbling portion can be suppressed from becoming large, and the size of the bubbles tends to be uniform.
In the foam molding system according to the present embodiment, all or part of the inner mold is made of a gas-permeable metal or a gas-permeable ceramic.
And the whole or part of the inner mold is made of air-permeable metal or air-permeable ceramic. For example, when the cavity of the inner mold has a complicated shape, there is a possibility that a large amount of closed space is formed when molten resin is injected, and therefore the entire inner mold can be made of air-permeable metal or air-permeable ceramic. In addition, when the cavity has a relatively simple shape, it is considered that the closed space formed by the injected molten resin is small, and therefore, a part of the inner mold can be made to be air-permeable metal or air-permeable ceramic in accordance with the position where the closed space is formed.
In the foam molding system according to the present embodiment, the surface of the air-permeable metal of the inner mold is coated with air-permeable ceramics.
The inner mold is coated with a gas-permeable ceramic on the surface of the gas-permeable metal. By coating the permeable ceramic, the time for heat insulation during injection can be ensured, the generation of a skin layer can be reduced, and the transfer performance can be improved.
In the foam molding system of the present embodiment, the mold device has a fluid pipe for supplying the fluid supplied from the opposing pressure supply device; the fluid pipe is formed in the outer mold and communicates with the inner mold.
And a mold device having a fluid pipe for supplying a fluid from the opposing pressure supply device, the fluid pipe being formed in the outer mold and communicating with the inner mold. Therefore, the fluid having the opposing pressure is supplied to the inner mold through the fluid pipe, and is supplied into the cavity through the numerous air holes of the inner mold.
In the foam molding system according to the present embodiment, the fluid pipe is disposed around the cavity of the inner mold.
The fluid pipe is disposed around the cavity of the inner mold. Since the fluid piping is arranged around the cavity of the inner mold, the fluid having the opposing pressure is supplied to the periphery of the cavity through the fluid piping, and from there to the cavity through the numerous air holes of the inner mold, so that the gas having the opposing pressure can be reliably supplied to the cavity.
In the foam molding system of the present embodiment, the mold device includes a medium pipe through which a heating medium and/or a cooling medium flows; the medium pipe is formed in the outer mold.
The mold device has a medium pipe through which a heating medium and/or a cooling medium flows, and the medium pipe is formed in the outer mold. Since the medium pipe is formed on the air-permeable nonmetal outer mold covering the air-permeable metal or ceramic inner mold, the heating medium and the cooling medium can be prevented from flowing into the numerous pores, and the temperature of the mold can be adjusted even in the mold having the air-permeable metal or ceramic inner mold.
The foam molding system of the present embodiment, the inside mold having a plurality of inside mold blocks of gas-permeable metal or gas-permeable ceramic partitioned by walls made of non-gas-permeable metal; the inner mold blocks and the outer mold form an embedded structure or an integrated structure; each of the plurality of inner mold blocks is connected to a fluid pipe for supplying the fluid supplied from the opposing pressure supply device.
The inner mold has a plurality of inner mold blocks of gas permeable metal or gas permeable ceramic separated by walls made of non-gas permeable metal. The plurality of inner mold blocks of the gas-permeable metal may be manufactured by sintering metal powder by laser using, for example, a metal 3D printer. The inner mold may be made of a gas-permeable metal material.
Each of the plurality of inner mold blocks is communicated with a fluid pipe for supplying fluid from the backpressure supply device. Therefore, for example, the time node of the pressure reduction can be changed for each cavity of the inner mold blocks in accordance with a specific time node of cooling and solidification. In this way, the air bubbles in the molded product in each cavity 501 of the inner mold blocks can be formed to a desired size. That is, the state of the bubbles at a specific position of the molded article can be formed to be a desired state thereof.
In the foam molding system according to the present embodiment, the surfaces of the air-permeable metal of the plurality of inner mold blocks are coated with air-permeable ceramics.
The surfaces of the gas-permeable metal of the plurality of inner mold blocks are coated with gas-permeable ceramics. By coating the permeable ceramic, the time for heat insulation during injection can be ensured, the generation of a skin layer can be reduced, and the transfer performance can be improved.
In the foam molding system according to the present embodiment, a medium pipe through which a heating medium and/or a cooling medium flows is formed in each outer mold covering each inner mold block of the plurality of inner mold blocks.
A medium pipe through which a heating and/or cooling medium flows is formed in an outer mold covering the plurality of inner mold blocks. Therefore, the temperature of the mold can be adjusted for each of the plurality of inner mold blocks, and for example, even when the shape of the cavity is a complicated shape, the entire mold can be adjusted to an optimum temperature.
The foam molding system of the present embodiment further includes: a counter pressure control device that controls a pressure of the fluid supplied from the counter pressure device; the opposing pressure control device performs decompression at a necessary timing in the pressure maintaining/cooling process.
Including a counter pressure control device that controls the pressure from the fluid supplied by the counter pressure device. The opposing pressure control device performs decompression at a necessary timing in the pressure holding/cooling process. For example, the pressure may be reduced to atmospheric pressure. Since the growth of bubbles can be stopped by reducing the pressure, the pressure can be reduced at a necessary timing to obtain bubbles having a desired size.
The foam molding system of the present embodiment further includes: a counter pressure control device that controls a pressure of the fluid supplied from the counter pressure device; the opposing pressure control device performs decompression at a necessary timing for each of the plurality of inner mold blocks in the decompression/cooling process.
Including a counter pressure control device that controls the pressure from the fluid supplied by the counter pressure device. The opposing pressure control device performs pressure reduction at a timing necessary for cooling and solidifying the molten resin in each of the plurality of inner mold blocks in the pressure holding/cooling process. For example, the pressure may be reduced to atmospheric pressure. Therefore, the plurality of inner mold blocks can each obtain a bubble of a desired size, and can be decompressed as necessary to obtain a bubble of a desired size, so that the state of the bubble at a specific position of the molded article can be brought to a desired state.
In the foam molding system according to the present embodiment, the opposing pressure control device controls the fluid supplied from the opposing pressure supply device to be supplied at a specific pressure in the mold opening step.
And a counter pressure control device for controlling the fluid supplied from the counter pressure supply device to be supplied at a specific pressure in the mold opening process. The specific pressure may be set to a level at which the molded article cured in the mold can be removed from the mold. Therefore, the ejector pin for removing the molded article from the mold is not required, and deformation of the molded article by the ejector pin, a mark (whitening of the surface of the molded article) by the ejector pin, or the like can be prevented.
In the foam molding system of the present embodiment, the opposing pressure supply means supplies at least one fluid of air, nitrogen, carbon dioxide, and an inert gas including argon, or water and a liquid containing alcohol.
The overpressure resistant supply device supplies at least one fluid of air, nitrogen, carbon dioxide and inert gas containing argon, or water and liquid containing alcohol. The use of inert gas prevents oxidation of the shaped part.
The mold of the present embodiment is a mold suitable for foam molding, and includes an inner mold made of a gas-permeable metal or a gas-permeable ceramic, and an outer mold made of a gas-impermeable metal covering the inner mold; the inner mold and the outer mold are formed into an embedded structure or an integrated structure.
The mould is suitable for foaming forming and comprises an inner side mould made of air-permeable metal or air-permeable ceramic and an outer side mould made of non-air-permeable metal and covering the inner side mould. The gas-permeable metal is a metal material (including porous metal) having numerous fine pores, and has gas permeability. The gas-permeable metal is not limited to a metal material provided with fine pores in advance, and may be formed with fine pores by machining. The average diameter (for example, several tens μm) and porosity of the pores can be appropriately set. The inner mold is not limited to a gas-permeable metal, and may be a sintered body (molded body) obtained by sintering an inorganic compound such as a gas-permeable ceramic by a heat treatment. The inner mold and the outer mold are collectively referred to as a mold. The inner mold may be a porous mold having air permeability, which is made by laser sintering metal powder using, for example, a metal 3D printer. The inner mold may be formed by processing a metal material having gas permeability. The inner mold 51 is not limited to a gas-permeable metal, and may be a sintered body (molded body) obtained by baking an inorganic compound such as a gas-permeable ceramic by a heat treatment. The inner mold and the outer mold are called a set mold. The inner mold can be manufactured by, for example, 3D printing of metal and sintering metal powder into porous metal having gas permeability by laser. The inner mold 51 may be formed by processing a gas-permeable metal material. Therefore, the inside of the cavity can be communicated through the numerous air holes of the inner mold around the cavity.
In the mold of the present embodiment, the surface of the gas-permeable metal is coated with a gas-permeable ceramic.
The inner mold is coated with a gas-permeable ceramic on the surface of the gas-permeable metal. By coating the permeable ceramic, the time for heat insulation during injection can be ensured, the generation of a skin layer can be reduced, and the transfer performance can be improved.
A mold according to the present embodiment, in which a fluid pipe for supplying the fluid supplied from the opposing pressure supply device is formed in the outer mold; the fluid piping is communicated with the inner mold.
A fluid pipe for supplying a fluid from the opposing pressure supply device is formed on the outer mold; the inner mold communicates with the fluid piping. Therefore, the fluid having the opposing pressure is supplied to the inner mold through the fluid pipe, and is supplied into the cavity through the numerous air holes of the inner mold.
The mold of the present embodiment, the inside mold having a plurality of inside mold blocks of gas-permeable metal or gas-permeable ceramic partitioned by walls made of non-gas-permeable metal; the inner mold blocks and the outer mold form an embedded structure or an integrated structure; each of the plurality of inner mold blocks is connected to a fluid pipe for supplying the fluid supplied from the opposing pressure supply device.
The inner mold has a plurality of inner mold blocks of gas permeable metal or gas permeable ceramic separated by walls made of non-gas permeable metal; each of the plurality of inner mold blocks is connected to a fluid pipe for supplying the fluid supplied from the opposing pressure supply device. Therefore, for example, the pressure reduction time node can be changed to match the specific time node at which each of the plurality of inner mold blocks is cooled and solidified by filling the molten resin into each cavity. Therefore, the bubbles of the molded article in each cavity of the inner mold blocks can be formed to have a desired size, respectively. I.e. the state of the air bubbles at a specific position of the shaped part can be brought to its desired state.
The material feeder of the present embodiment is a material feeder suitable for foam forming, which fills a resin containing a foaming component into a cavity of an inner mold of air-permeable metal or air-permeable ceramic covered with an outer mold of air-impermeable metal with a fluid having a counter pressure; the molded article is taken out in a state where the pressure in the cavity is reduced to atmospheric pressure.
And a material feeder which fills a resin containing a foaming component into a cavity of an inner mold of air-permeable metal or air-permeable ceramic covered by an outer mold of air-impermeable metal in a state of supplying a fluid having a counter pressure into the cavity, and takes out a molded article in a state of reducing the pressure in the cavity to atmospheric pressure.
Even if the cavity is divided into a plurality of closed spaces by the injected resin, the pressure in each closed space can be maintained at the opposing pressure and the pressure in the cavity can be controlled to an appropriate value because the gas is supplied from the numerous gas holes of the inner mold in each closed space. Therefore, the bubbles in the preceding bubbling portion can be suppressed from becoming large, and the size of the bubbles tends to be uniform. Further, bubbles of a desired size can be controlled according to the timing of the pressure reduction.
In the foam molding method of the present embodiment, at least one of the decompression rate and the decompression value is controlled when the cavity is filled with the resin containing the foaming component.
In the case where the resin containing the foaming component is filled into the cavity, at least one of the decompression rate or the decompression value is controlled, so that a molded article having cells of a desired size can be obtained.
As described above, in the present embodiment, the size of the bubbles in a specific portion of the molded article can be formed to a desired size. In general, the larger bubble size portion can soften the hardened resin and the smaller bubble size portion can harden the resin, so that varying the hardness of each portion throughout the molded article can achieve the desired product.
In the above embodiment, both the female-side inner mold and the male-side inner mold are made of a gas-permeable metal, but the present invention is not limited to this, and only either the female-side inner mold (also referred to as a cavity) or the male-side inner mold (also referred to as a core) may be made of a gas-permeable metal, and the other may be made of a non-gas-permeable metal.
At least some of the above embodiments may be arbitrarily combined.
Claims (20)
1. A foam molding system comprising: a mold device, a material feeder, and a counter pressure supply device, the mold device comprising: an inner mold of gas permeable metal or gas permeable ceramic; and
an outer mold made of a non-gas-permeable metal covering the inner mold,
the inner mold and the outer mold are formed into an embedded structure or an integrated structure,
the material feeder fills a resin containing a foaming component into the cavity of the inner mold,
the opposing pressure supply means supplies a fluid having an opposing pressure into the cavity through the inner mold when filling the resin into the cavity.
2. The foam molding system according to claim 1,
and all or part of the inner side die is made of air-permeable metal or air-permeable ceramic.
3. Foam molding system according to claim 1 or 2,
and the surface of the gas-permeable metal of the inner mold is coated with gas-permeable ceramics.
4. Foam molding system according to claim 1 or 2,
the die device has a fluid pipe for supplying the fluid supplied from the backpressure supply device,
the fluid pipe is formed in the outer mold and communicates with the inner mold.
5. The foam molding system according to claim 4,
the fluid pipe is disposed around the cavity of the inner mold.
6. The foam molding system according to claim 4,
the mold device has a medium pipe for flowing a heating medium and/or a cooling medium,
the medium pipe is formed in the outer mold.
7. The foam molding system according to claim 4,
the inner mold having a plurality of inner mold blocks of gas permeable metal or gas permeable ceramic separated by walls of gas impermeable metal,
the inner mold blocks and the outer mold are formed into an embedded structure or an integrated structure,
each of the plurality of inner mold blocks is connected to a fluid pipe for supplying the fluid supplied from the opposing pressure supply device.
8. The foam molding system according to claim 7,
the surfaces of the gas-permeable metal of the plurality of inner mold blocks are coated with gas-permeable ceramics.
9. The foam molding system according to claim 7,
a medium pipe through which a heating medium and/or a cooling medium flows is formed in each outer die covering each inner die of the plurality of inner dies.
10. The foam molding system of claim 4, further comprising:
a counter pressure control device that controls a pressure of the fluid supplied from the counter pressure device,
the opposing pressure control device performs decompression at a necessary timing in the pressure maintaining/cooling process.
11. The foam molding system of claim 7, further comprising:
a counter pressure control device that controls a pressure of the fluid supplied from the counter pressure device,
the opposing pressure control device performs decompression at a necessary timing for each of the plurality of inner mold blocks in the decompression/cooling process.
12. The foam molding system according to claim 10,
the opposing pressure control device controls the fluid supplied from the opposing pressure supply device to be supplied at a specific pressure in the mold opening process.
13. Foam molding system according to claim 1 or 2,
the overpressure resistant supply device supplies air, nitrogen, carbon dioxide, and an inert gas including argon, or at least one fluid of water and a liquid containing alcohol.
14. A mold for foam molding, comprising:
an inner mold of gas-permeable metal or gas-permeable ceramic, and
an outer mold made of a non-gas-permeable metal covering the inner mold,
the inner mold and the outer mold are formed into an embedded structure or an integrated structure,
a fluid pipe is disposed in the inner mold.
15. The mold according to claim 14,
and the inner side die is coated with air-permeable ceramics on the surface of the air-permeable metal.
16. The mold according to claim 14 or 15,
a fluid pipe for supplying the fluid supplied from the backpressure supply device is formed on the outer die,
the fluid piping is communicated with the inner mold.
17. The mold according to claim 14,
the inner mold having a plurality of inner mold blocks of gas permeable metal or gas permeable ceramic separated by walls of gas impermeable metal,
the inner mold blocks and the outer mold are formed into an embedded structure or an integrated structure,
each of the plurality of inner mold blocks is connected to a fluid pipe for supplying the fluid supplied from the opposing pressure supply device.
18. A material feeder for foam forming, characterized in that,
filling a resin containing a foaming component into a cavity of an inner mold, which is covered with an outer mold made of a non-gas-permeable metal and has a gas-permeable ceramic and in which a fluid pipe is arranged, with a fluid having a counter pressure being supplied into the cavity,
the molded article is taken out in a state where the pressure in the cavity is reduced to atmospheric pressure.
19. A method for foam molding is characterized in that,
supplying a fluid having a pressure-resistant property to a cavity of an inner mold of a gas-permeable metal or a gas-permeable ceramic covered with an outer mold of a gas-impermeable metal and having a fluid pipe disposed therein,
and filling a resin containing a foaming component into the cavity in a state where the fluid is supplied into the cavity through the inner mold.
20. The foam molding method according to claim 19,
at least one of the decompression rate and the decompression value is controlled when the resin containing the foaming component is filled in the cavity.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018151501A JP6694021B2 (en) | 2018-08-10 | 2018-08-10 | Foam molding system, mold, material feeder and foam molding method |
| JP2018-151501 | 2018-08-10 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109605645A CN109605645A (en) | 2019-04-12 |
| CN109605645B true CN109605645B (en) | 2021-04-09 |
Family
ID=66002427
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811219603.5A Active CN109605645B (en) | 2018-08-10 | 2018-10-19 | Foam molding system, mold, material feeder, and foam molding method |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP6694021B2 (en) |
| CN (1) | CN109605645B (en) |
| TW (1) | TWI716738B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW202027942A (en) * | 2019-01-16 | 2020-08-01 | 中原大學 | Injection molding apparatus and injection molding method |
| CN113710449A (en) * | 2019-04-19 | 2021-11-26 | 铃木康公 | Mold device for resin molded article, molding device, molding system, and method for producing molded article |
| TWI787543B (en) * | 2019-09-05 | 2022-12-21 | 歐特捷實業股份有限公司 | Molding device and molding method |
| TWI782267B (en) * | 2020-04-01 | 2022-11-01 | 瑞皇精密工業股份有限公司 | Improved mold structure |
| TWI746092B (en) * | 2020-07-28 | 2021-11-11 | 萬 道樂 | New injection mold |
| KR102223690B1 (en) * | 2020-08-10 | 2021-03-05 | 오병섭 | Injection system and method for foam resin product |
| US11717996B2 (en) * | 2020-09-25 | 2023-08-08 | King Steel Machinery Co., Ltd. | Molding method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998000287A1 (en) * | 1996-06-28 | 1998-01-08 | Kaneka Corporation | Method of manufacturing skin-carrying internal-mold expansion molded body of synthetic resin and metal mold used for the same method |
| WO2012124476A1 (en) * | 2011-03-11 | 2012-09-20 | Sintokogio, Ltd. | Die-casting die |
| CN106346685A (en) * | 2016-09-28 | 2017-01-25 | 山东大学 | Monolateral cavity freestyle foaming mould |
| CN106626201A (en) * | 2016-09-28 | 2017-05-10 | 山东大学 | Unilateral cavity free foaming method |
| CN207344955U (en) * | 2017-10-31 | 2018-05-11 | 广州捷佛明新材料科技有限公司 | Foaming mould |
| CN108219322A (en) * | 2018-01-10 | 2018-06-29 | 河南工业大学 | Hard PVC structural foam and preparation method thereof and molding die |
| CN108372619A (en) * | 2018-02-10 | 2018-08-07 | 郑州大学 | A kind of preparation process of injection moulding high density microcellular foam material |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3408846B2 (en) * | 1993-08-25 | 2003-05-19 | 鈴木総業株式会社 | Biodegradable resin foam manufacturing equipment |
| JP2002011797A (en) * | 2000-06-28 | 2002-01-15 | Sumitomo Chem Co Ltd | Light-weight molded body of fiber-reinforced thermoplastic resin |
| JP2003320556A (en) * | 2002-05-01 | 2003-11-11 | Asahi Kasei Corp | Surface modifying injection molding method |
| JP4215653B2 (en) * | 2004-01-14 | 2009-01-28 | 株式会社オートネットワーク技術研究所 | Method and apparatus for molding thermoplastic resin molded member into wire harness |
| US20100098929A1 (en) * | 2005-07-11 | 2010-04-22 | John Anthony Dispenza | Impact resistant composite material |
| JP5231820B2 (en) * | 2008-01-22 | 2013-07-10 | 積水化学工業株式会社 | Manufacturing method of foam injection molded product |
| JP5605807B2 (en) * | 2010-08-05 | 2014-10-15 | 積水テクノ成型株式会社 | Molding device for foamed resin moldings |
| TWI508837B (en) * | 2010-08-26 | 2015-11-21 | 私立中原大學 | Mold gas pressure and temperature control device |
| JP2014018965A (en) * | 2012-07-12 | 2014-02-03 | Tosoh Corp | Metal member-polyphenylene sulfide foam member composite and method of manufacturing the same |
| US9963566B2 (en) * | 2013-08-02 | 2018-05-08 | Nike, Inc. | Low density foamed articles and methods for making |
| FR3024675B1 (en) * | 2014-08-06 | 2017-03-31 | Faurecia Automotive Ind | METHOD FOR MANUFACTURING A PIECE OF AUTOMOTIVE EQUIPMENT AND ASSOCIATED PIECE |
| WO2017119228A1 (en) * | 2016-01-06 | 2017-07-13 | 鈴木康公 | Die device, molding apparatus, injection molding system, and molding manufacturing method |
| JP6899639B2 (en) * | 2016-09-30 | 2021-07-07 | 三井化学株式会社 | Metal / resin composite structure and method for manufacturing metal / resin composite structure |
-
2018
- 2018-08-10 JP JP2018151501A patent/JP6694021B2/en active Active
- 2018-09-25 TW TW107133586A patent/TWI716738B/en active
- 2018-10-19 CN CN201811219603.5A patent/CN109605645B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998000287A1 (en) * | 1996-06-28 | 1998-01-08 | Kaneka Corporation | Method of manufacturing skin-carrying internal-mold expansion molded body of synthetic resin and metal mold used for the same method |
| WO2012124476A1 (en) * | 2011-03-11 | 2012-09-20 | Sintokogio, Ltd. | Die-casting die |
| CN106346685A (en) * | 2016-09-28 | 2017-01-25 | 山东大学 | Monolateral cavity freestyle foaming mould |
| CN106626201A (en) * | 2016-09-28 | 2017-05-10 | 山东大学 | Unilateral cavity free foaming method |
| CN207344955U (en) * | 2017-10-31 | 2018-05-11 | 广州捷佛明新材料科技有限公司 | Foaming mould |
| CN108219322A (en) * | 2018-01-10 | 2018-06-29 | 河南工业大学 | Hard PVC structural foam and preparation method thereof and molding die |
| CN108372619A (en) * | 2018-02-10 | 2018-08-07 | 郑州大学 | A kind of preparation process of injection moulding high density microcellular foam material |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6694021B2 (en) | 2020-05-13 |
| TWI716738B (en) | 2021-01-21 |
| CN109605645A (en) | 2019-04-12 |
| JP2020026074A (en) | 2020-02-20 |
| TW202009124A (en) | 2020-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109605645B (en) | Foam molding system, mold, material feeder, and foam molding method | |
| US4824732A (en) | Process and apparatus for injection moulding and mouldings produced thereby | |
| US4164523A (en) | Method of injection-molding and cooling of shaped synthetic-resin bodies | |
| US4685881A (en) | Nozzle assembly for injection molding | |
| US11911936B2 (en) | Single-phase solution molding | |
| JPS6169421A (en) | Molding method of foamed molding | |
| US4435523A (en) | Process for manufacturing articles of foamed thermoplastic material and article produced thereby | |
| JP2010110934A (en) | Molding device and molding method of hollow article | |
| EP1259368B1 (en) | Gas assisted moulding | |
| JP2004167777A (en) | Thermoplastic resin foam and method/device for manufacturing the foam | |
| JP2016175204A (en) | Injection foam molding machine | |
| JP4162662B2 (en) | Injection impregnation foam molding method | |
| JP2003231148A (en) | Molding method for thermoplastic resin foam | |
| JP7194987B2 (en) | Mold control device, mold control unit, mold and mold control method | |
| JP3893538B2 (en) | Molding method of resin foam molding | |
| JP2003334846A (en) | Method for manufacturing foamed thermoplastic resin | |
| CN217704370U (en) | Gas back-pressure micropore foaming injection mold | |
| JP3151769U (en) | Hollow product molding apparatus and hollow product | |
| KR20180034995A (en) | Foam molding apparatus and method for an injection molding | |
| CN216068364U (en) | Device for preparing supercritical foaming material | |
| JP2003191274A (en) | Method for foam molding of thermoplastic resin and foamed molded object | |
| JP4229490B2 (en) | Filling method in foam molding method | |
| JP2022131087A (en) | Injection molding machine and injection foam molding method | |
| JP2009018470A (en) | Method and device for forming resin molded product | |
| JP2024024714A (en) | Hollow casting apparatus and hollow casting method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |