US20050285294A1 - Resin molded articles and method of manufacturing the same - Google Patents
Resin molded articles and method of manufacturing the same Download PDFInfo
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- US20050285294A1 US20050285294A1 US11/130,341 US13034105A US2005285294A1 US 20050285294 A1 US20050285294 A1 US 20050285294A1 US 13034105 A US13034105 A US 13034105A US 2005285294 A1 US2005285294 A1 US 2005285294A1
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- Prior art keywords
- cavity
- foaming
- mold
- resin
- injection material
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- 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
- B29C44/0446—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 increasing the density locally by compressing part of the foam while still in the mould
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- 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
- B29C44/3469—Cell or pore nucleation
- B29C44/348—Cell or pore nucleation by regulating the temperature and/or the pressure, e.g. suppression of foaming until the pressure is rapidly decreased
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- 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
- B29C44/586—Moulds with a cavity increasing in size during foaming
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- 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
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/72—Heating or cooling
- B29C45/73—Heating or cooling of the mould
- B29C2045/7343—Heating or cooling of the mould heating or cooling different mould parts at different temperatures
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- 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
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
- B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
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- 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
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
- B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
- B29C45/568—Applying vibrations to the mould parts
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- 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
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/72—Heating or cooling
- B29C45/73—Heating or cooling of the mould
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/1376—Foam or porous material containing
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
- Y10T428/24496—Foamed or cellular component
- Y10T428/24504—Component comprises a polymer [e.g., rubber, etc.]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
- Y10T428/2495—Thickness [relative or absolute]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
- Y10T428/269—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension including synthetic resin or polymer layer or component
Definitions
- the present invention relates to resin molded articles and a method of manufacturing the same. More particularly, the present invention relates to resin molded articles defining voids therein and a method of manufacturing the same.
- the air conditioning case 101 includes a top case 111 , a bottom case 112 , and thermal protection sheets 120 .
- An evaporator 102 is provided in the case 101 .
- the top and bottom cases 111 , 112 are molded articles without having foam structure therein.
- the thermal protection sheets 120 are molded articles having foam structure.
- the thermal protection sheets 120 are arranged at portions where the case 101 makes contact with the evaporator 102 and where condensed water from the evaporator 102 flows to restrict generation of the dew drops and further to restrict the dew drops from falling in a passenger compartment.
- the thermal protection sheet 120 In manufacturing the case 101 , the top case 111 , the bottom case 112 and the thermal protection sheet 120 are separately molded, and then the thermal protection sheets 120 are fixed in the top case 111 and the bottom case 112 . Therefore, a manufacturing process is complicated.
- JP-B2-2625576 U.S. Pat. No. 4,473,665 discloses a method of producing an article having foam structure therein. According to the method, voids are uniformly formed in the article, even at a portion where the foam structure is not required. Therefore, if an air conditioning case is produced by the method, the size of the case is likely to increase to ensure strength of portions where the foam structure is not required.
- the present invention is made in view of the foregoing disadvantages and it is an object of the present invention to provide resin molded articles and a method of manufacturing the same by a simple process and without increasing in size of the articles.
- a first wall defining voids therein and a second wall having an expansion ratio less than that of the first wall are integrally molded.
- resin including a foaming agent is injected into a cavity defined in a mold assembly first and then foamed in the cavity.
- the foaming of the resin is partly promoted by a foam-promoting device provided in the mold assembly, thereby creating expansion ratio difference in the molded article.
- the molding article having expansion ratio difference therein can be produced.
- the foaming is partly promoted by partly expanding the cavity by a movable core.
- a mold wall defining the cavity can be partly vibrated by a vibrator.
- temperature difference can be created in the mold wall by a temperature difference generating means.
- the cavity can be partly narrowed by a movable core so that the expansion ratio of the molded article can be partly reduced at the narrowed part.
- FIG. 1 is a schematic cross-sectional view of an air conditioning case produced by resin molding according to the first embodiment of the present invention
- FIG. 2 is a schematic cross-sectional view of a mold assembly according to the first embodiment of the present invention
- FIG. 3A is a schematic cross-sectional view of the mold assembly for explaining an injecting step of a method of manufacturing a resin molded article according to the first embodiment of the present invention
- FIG. 3B is a schematic cross-sectional view of the mold assembly for explaining a foaming step of the method according to the first embodiment of the present invention
- FIG. 4 is a schematic cross-sectional view of a mold assembly for explaining a manufacturing method according to the second embodiment of the present invention
- FIG. 5 is a schematic cross-sectional view of a mold assembly for explaining a manufacturing method according to the third embodiment of the present invention.
- FIG. 6A is a schematic cross-sectional view of a mold assembly for explaining an injecting step of a manufacturing method according to the fourth embodiment of the present invention.
- FIG. 6B is a schematic cross-sectional view of the mold assembly for explaining a foaming step according to the fourth embodiment of the present invention.
- FIG. 7 is a schematic cross-sectional view of a air conditioning case produced by resin molding according to further another embodiment of the present invention.
- FIG. 8 is a schematic cross-sectional view of an air conditioning case produced by resin molding of a related art.
- FIG. 1 shows a schematic cross-sectional view of the case 1 in which an evaporator 2 is arranged.
- the case 1 includes a first case (top case) 11 and a second case (bottom case) 12 .
- the first case 11 has a contact portion 11 a that makes contact with the evaporator 2 on its inside surface (inside top surface in FIG. 1 ).
- the second case 12 has contact portions 12 a that make contact with the evaporator 2 on ends of its inside surface (inside bottom surface in FIG. 1 ).
- the second case 12 has a drain port 14 in its bottom middle. Condensed water generated on surfaces of the evaporator 2 is discharged from the case 1 through the drain port 14 . Walls 13 between the contact portions 12 a and the drain port 14 are sloped so that the condensed water flows toward the drain port 14 .
- the first case 11 and the second case 12 are made of polypropylene and have foam structure (voids) therein.
- Each of the first and the second cases 11 , 12 has a high foamed portion 21 and a low foamed portion 22 that have different expansion ratios.
- the top wall which forms the contact portion 11 a inside, is formed of the high foamed portion 21 .
- wall of the first case 11 other than the top wall are formed of the low foamed portion 22 .
- the bottom wall which forms the contact portions 12 a , the sloped walls 13 and the drain port 14 , is formed of the high foamed portion 12 .
- the walls other than the bottom wall are formed of the low foamed portion 22 .
- an expansion ratio of the high foamed portion 21 to a part without having foam structure (non-foamed portion) is approximately 4.0.
- an expansion ratio of the low foamed portion 22 to the non-foamed portion is approximately in a range 1.1 to 1.2. Therefore, the first case 11 and the second case 12 are provided by the resin molded products that have thermal insulation at the high foamed portion 21 and reduces weight at low foamed portion 22 while maintaining strength.
- a mold assembly 50 for injection molding includes a fixed mold 51 and a movable mold 52 .
- a mold cavity 54 is formed between the fixed mold 51 and the movable core 52 when the fixed mold 51 is joined with the movable mold 52 .
- the movable mold 52 is provided with a pin 52 at its inner middle portion for forming the drain port 14 . Also, the movable mold 52 includes a movable core 53 that is movably supported in a top and bottom direction in FIG. 2 . The movable core 53 is connected to an actuator 55 that is provided outside of the movable mold 52 as a movable core-driving means. The movable core 53 is moved in the top and bottom direction by operation of the actuator 55 , thereby changing a volume of the cavity 54 .
- a hydraulic actuator having a hydraulic cylinder is used as the actuator 55 .
- a pneumatic actuator and a motor-driven actuator can be used as an example of the actuator 55 .
- the fixed mold 51 and the movable mold 52 are joined as shown in FIG. 3A .
- a molten resin 20 including a foaming agent is injected from a gate (not shown) into the mold cavity 54 .
- polypropylene resin is used as the resin 20 .
- Nitrogen molecules in a supercritical liquid state are contained in the resin 20 as the foaming agent.
- a supercritical liquid is defined as a material maintained under a pressure over a critical pressure and a temperature over a critical temperature. Under that condition, the material is in a supercritical liquid state.
- N 2 (nitrogen) used as the foaming agent is in a supercritical state when maintained under a pressure over 3.4 MPa and a temperature over ⁇ 147 degrees Celsius.
- the supercritical liquid is characterized by acting as gas and liquid. Therefore, supercritical liquid nitrogen is readily diffused and mixed in the polypropylene resin. In the embodiment, supercritical liquid nitrogen of 0.6 percent by weight is included in the resin 20 .
- the movable core 53 is moved in a direction expanding the volume of the cavity 54 (downward in FIG. 3 ), by operation of the actuator 55 .
- a mold temperature is 15 degrees Celsius.
- the movable core 53 is moved approximately two seconds later a completion of the resin injection.
- the supercritical liquid nitrogen in the resin 20 gradually vaporizes immediately after injected in the cavity 54 and forms foam nuclei. As the vaporization of the supercritical liquid nitrogen continues, foam nuclei grow and forms voids, thereby forming foam structure in the resin 20 . At a part where the cavity 54 is expanded by movement of the movable core 53 , forming of the foam nuclei is accelerated or promoted, thereby increasing the expansion ratio.
- the second case 12 in which the high foamed portion 21 and the low foamed portion 22 are integrally molded is produced. Since the expansion ratio of the high foamed portion 21 is approximately 4.0, voids may be communicated therein. However, thin resin layers (skin layers) are formed on the surfaces of the molded product. Therefore, the wall of the second case 12 does not have communication structure allowing communication between the inside surface and the outside surface.
- the step shown in FIG. 3A is referred to as an injecting step and the step shown in FIG. 3B is referred to as a foaming step.
- the above method it is possible to create expansion ratios difference in a single article. Therefore, it is unnecessary to separately mold articles having different expansion ratios and to assemble then together to make the first case 11 and the second case 12 . Accordingly, a manufacturing process is simple. Further, the high foamed portions 21 are formed partly in the first case 11 and the second case 12 , respectively. Therefore, the resin molded article is compact.
- the high foamed portion 21 has a thermal conductivity of 0.5 W/(m ⁇ K) even when the evaporator 2 is arranged in the case 1 . Therefore, dew drops less likely to generate on outer faces of the case 1 .
- the drain port 14 is cooled more than the other portion in the case 1 . Because the drain port 14 is formed of the high foamed portion 21 , it is effective to restrict generation of dew drops.
- the high foamed portion 22 is formed in a manner different from that of the first embodiment.
- the movable mold 52 includes a body portion 61 and an insert portion 62 .
- a vibrator 64 is provided under the insert portion 62 as a vibrating device.
- the insert portion 62 vibrates by operation of the vibrator 64 .
- Gaps 63 are defined partly between the body portion 61 and the insert portion 62 to restrict the body portion. 61 from vibrating due to vibrations of the insert portion 62 .
- the vibrator 64 an ultrasonic vibrator and air vibrator can be used.
- the resin 20 including the foaming agent is injected into the cavity 54 in a manner similar to the first embodiment.
- the vibrator 64 is turned on to vibrate the insert portion 62 .
- a surface 62 a of the insert portion 62 which defines the cavity 64 , vibrates. Therefore, foam nucleation of the resin 20 is promoted at the vibrated portion. As a result, the expansion ratio of the vibrated portion is higher than the other portion.
- the high foamed portion 21 and the low foamed portion 22 are formed integrally in the second case 12 .
- the step of vibrating the insert portion 62 corresponds to the foaming step.
- the manufacturing method is simple. Also, the high foamed portions 21 are formed partly in the first case 11 and the second case 12 . Therefore, it is possible to make the resin molded article compact.
- the high foamed portion 21 is formed in a manner different from that of the first embodiment.
- the movable mold 52 includes the body portion 61 and the insert portion 62 .
- An electric heater 74 is embedded in the insert portion 62 from the bottom.
- the electric heater 74 is a heating device and heats the insert portion 62 when it is electrically conducted.
- the gaps 63 are formed partly between the body portion 61 and the insert portion 62 to prevent the body portion 61 from receiving heat from the insert portion 62 .
- a heat insulation material can be provided between the body portion 61 and the insert portion 62 .
- the electric heater 74 is a temperature difference-generating device to create temperature differences in walls defining the cavity 54 .
- the resin 20 including the foaming agent is injected in the mold cavity 54 in a manner similar to the first embodiment.
- the insert portion 62 has been heated by the electric heater 74 .
- the body portion 61 is maintained at 15 degrees Celsius and the insert portion 62 is heated at 80 degrees Celsius.
- the nucleation is promoted at a part adjacent to the surface 62 a that is approximately 80 degrees Celsius.
- the expansion ratio of the part adjacent to the surface 62 a is higher than that of the other part.
- FIG. 5 illustrates the injecting step and the foaming step of the method.
- the manufacturing process is simple. Also, the high foamed portions 21 are formed partly in the first case 11 and the second case 12 . Therefore, the resin molded article is compact.
- the high foamed portion 21 and the low foamed portion 22 are formed in a manner different from that of the first embodiment.
- the movable mold 52 includes a plurality of movable cores 83 .
- the movable cores 83 are supported slidably in the left and right direction in FIG. 6A .
- the movable cores 83 are respectively connected to actuators 85 that are provided on the outside of the movable mold 52 as a movable core driving means.
- the walls of the movable cores 83 defining the cavity 54 are moved by operation of the actuators 85 so that the volume of the cavity 54 is partly changed.
- the resin 20 including the foaming agent is injected into the cavity 54 in a manner similar to the first embodiment, as shown in FIG. 6A .
- the movable cores 83 are moved by the actuators 85 inwardly, that is, in the direction that the volume of the cavity 54 is reduced.
- the resin 20 is injected into the cavity 54 maintained at the mold temperature of 80 degrees Celsius.
- the movable cores 83 are moved approximately two seconds later the completion of the resin injection.
- the nucleation in the resin 20 is limited and the foams grown therein are compressed. Therefore, the expansion ratio of the compressed part is smaller than the other parts.
- the second case 12 in which the high foamed portion 21 and the low foamed portion 22 are integrally formed can be produced.
- the step shown in FIG. 6A corresponds to the injecting step and the step shown in FIG. 6B corresponds to the foaming step.
- the manufacturing process is simple. Also, the high foamed portions 21 are formed partly in the first case 11 and the second case 12 , respectively. Therefore, it is possible to make the resin molded article compact.
- the foaming agent can be supercritical liquid carbon dioxide.
- the bowing agent is not limited to the supercritical liquid.
- it can be a physical foaming agent that foams by evaporation.
- it can be a chemical foaming agent that foams by cracked gas.
- the high foamed portions 21 and the low foamed portion 22 are integrally molded.
- the case 1 can be a molded article in which a foamed portion 21 a defining voids therein and a non-foamed portion 22 a without defining voids therein are integrally molded, as shown in FIG. 7 .
- the non-foamed portion 22 a is formed by avoiding foam nucleation in a method similar to that of the above-described embodiments.
- the electric heater 74 is used as the heating device.
- another type of heater such as a glow plug, can be used.
- the heater 74 is used as a device to create temperature difference in the mold 50 .
- the temperature difference can be created by other methods. For example, passages through which coolant (e.g. cold water) and heating medium (e.g. hot water) flow can be formed in the mold. By this, the temperature differences can be created on the walls of the mold defining the cavity.
- the resin 20 is not limited to the polypropylene resin. Another resin material can be used to the present invention.
- the movable core 53 , vibrator 64 , electric heater 74 and the movable cores 83 are arranged on a side of the movable mold 52 .
- the arrangements are not limited to the above. Those can be arranged other positions, for example, in the fixed core 51 .
- the devices such as the movable the core 53 , the actuator 55 , the insert portion 62 , the vibrator 64 and the electric heater 74 , are used as foam-promoting devices to create expansion ratio differences in the singe molded article. Those devices can be used in variable combinations.
- the method is explained in a case of molding the air conditioning case as an example.
- the product is not limited to the air conditioning case.
- the method of the present invention can be used to produce molded articles for other purposes.
Abstract
In a method of manufacturing a resin molded article, resin including a foaming agent is injected into a cavity defined in a mold assembly. Then, a movable mold of the mold assembly is moved to partly expand the cavity so that the foaming is promoted at the part where the cavity is expanded. Therefore, a high foamed portion having voids therein and a low foamed portion having an expansion ratio less than that of the high foamed portion are integrally formed in the resin molded article.
Description
- This application is a divisional application of U.S. application Ser. No. 10/437,602 filed May 14, 2003 which is based on Japanese Patent Application No. 2002-141065 filed on May 16, 2002, the disclosure of which is incorporated herein by reference.
- The present invention relates to resin molded articles and a method of manufacturing the same. More particularly, the present invention relates to resin molded articles defining voids therein and a method of manufacturing the same.
- As an example of a resin molded article, there is an air conditioning case of a vehicular air conditioning unit shown in
FIG. 8 . As shown inFIG. 8 , theair conditioning case 101 includes atop case 111, abottom case 112, andthermal protection sheets 120. Anevaporator 102 is provided in thecase 101. The top andbottom cases thermal protection sheets 120 are molded articles having foam structure. - Generally, when heat on an outer periphery of the case is absorbed by the evaporator and the condensed water, dew drops are generated on the outer faces of the case. In the
case 101, thethermal protection sheets 120 are arranged at portions where thecase 101 makes contact with theevaporator 102 and where condensed water from theevaporator 102 flows to restrict generation of the dew drops and further to restrict the dew drops from falling in a passenger compartment. - In manufacturing the
case 101, thetop case 111, thebottom case 112 and thethermal protection sheet 120 are separately molded, and then thethermal protection sheets 120 are fixed in thetop case 111 and thebottom case 112. Therefore, a manufacturing process is complicated. - As another example of the resin molded article, JP-B2-2625576 (U.S. Pat. No. 4,473,665) discloses a method of producing an article having foam structure therein. According to the method, voids are uniformly formed in the article, even at a portion where the foam structure is not required. Therefore, if an air conditioning case is produced by the method, the size of the case is likely to increase to ensure strength of portions where the foam structure is not required.
- The present invention is made in view of the foregoing disadvantages and it is an object of the present invention to provide resin molded articles and a method of manufacturing the same by a simple process and without increasing in size of the articles.
- According to a resin molded article of the present invention, a first wall defining voids therein and a second wall having an expansion ratio less than that of the first wall are integrally molded.
- Accordingly, it is unnecessary to separately mold articles having different expansion ratio and to assemble them together. Therefore, it makes a manufacturing process simple. Since the first wall having the expansion ratio higher than that of the second wall is partly formed in the molded article, the molded article is compact. Also, thermal conductivity difference can be created in the single molded article.
- According to a method of manufacturing a resin molded article of the present invention, resin including a foaming agent is injected into a cavity defined in a mold assembly first and then foamed in the cavity. The foaming of the resin is partly promoted by a foam-promoting device provided in the mold assembly, thereby creating expansion ratio difference in the molded article.
- According to the method, the molding article having expansion ratio difference therein can be produced.
- Preferably, the foaming is partly promoted by partly expanding the cavity by a movable core. Alternatively, a mold wall defining the cavity can be partly vibrated by a vibrator. Further, temperature difference can be created in the mold wall by a temperature difference generating means.
- In place of partly promoting the foaming by the foam-promoting device, the cavity can be partly narrowed by a movable core so that the expansion ratio of the molded article can be partly reduced at the narrowed part.
- Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:
-
FIG. 1 is a schematic cross-sectional view of an air conditioning case produced by resin molding according to the first embodiment of the present invention; -
FIG. 2 is a schematic cross-sectional view of a mold assembly according to the first embodiment of the present invention; -
FIG. 3A is a schematic cross-sectional view of the mold assembly for explaining an injecting step of a method of manufacturing a resin molded article according to the first embodiment of the present invention; -
FIG. 3B is a schematic cross-sectional view of the mold assembly for explaining a foaming step of the method according to the first embodiment of the present invention; -
FIG. 4 is a schematic cross-sectional view of a mold assembly for explaining a manufacturing method according to the second embodiment of the present invention; -
FIG. 5 is a schematic cross-sectional view of a mold assembly for explaining a manufacturing method according to the third embodiment of the present invention; -
FIG. 6A is a schematic cross-sectional view of a mold assembly for explaining an injecting step of a manufacturing method according to the fourth embodiment of the present invention; -
FIG. 6B is a schematic cross-sectional view of the mold assembly for explaining a foaming step according to the fourth embodiment of the present invention; -
FIG. 7 is a schematic cross-sectional view of a air conditioning case produced by resin molding according to further another embodiment of the present invention; and -
FIG. 8 is a schematic cross-sectional view of an air conditioning case produced by resin molding of a related art. - Embodiments of the present invention will be described hereinafter with reference to the drawings.
- A resin molded article of the embodiment forms an
air conditioning case 1, as shown inFIG. 1 .FIG. 1 shows a schematic cross-sectional view of thecase 1 in which anevaporator 2 is arranged. Thecase 1 includes a first case (top case) 11 and a second case (bottom case) 12. Thefirst case 11 has acontact portion 11 a that makes contact with theevaporator 2 on its inside surface (inside top surface inFIG. 1 ). Also, thesecond case 12 has contactportions 12 a that make contact with theevaporator 2 on ends of its inside surface (inside bottom surface inFIG. 1 ). - The
second case 12 has adrain port 14 in its bottom middle. Condensed water generated on surfaces of theevaporator 2 is discharged from thecase 1 through thedrain port 14.Walls 13 between thecontact portions 12 a and thedrain port 14 are sloped so that the condensed water flows toward thedrain port 14. - The
first case 11 and thesecond case 12 are made of polypropylene and have foam structure (voids) therein. Each of the first and thesecond cases foamed portion 21 and a lowfoamed portion 22 that have different expansion ratios. In thefirst case 11, the top wall, which forms thecontact portion 11 a inside, is formed of the highfoamed portion 21. Also, wall of thefirst case 11 other than the top wall are formed of the lowfoamed portion 22. In thesecond case 12, the bottom wall, which forms thecontact portions 12 a, the slopedwalls 13 and thedrain port 14, is formed of the high foamedportion 12. Also, the walls other than the bottom wall are formed of the low foamedportion 22. - In this embodiment, an expansion ratio of the high foamed
portion 21 to a part without having foam structure (non-foamed portion) is approximately 4.0. Also, an expansion ratio of the low foamedportion 22 to the non-foamed portion is approximately in a range 1.1 to 1.2. Therefore, thefirst case 11 and thesecond case 12 are provided by the resin molded products that have thermal insulation at the high foamedportion 21 and reduces weight at low foamedportion 22 while maintaining strength. - Next, a method of manufacturing the
case 1 will be described. Because thefirst case 11 and thesecond case 12 are produced in a similar manner, the method will be described mainly in a case of thesecond case 12. - As shown in
FIG. 2 , amold assembly 50 for injection molding includes a fixedmold 51 and amovable mold 52. Amold cavity 54 is formed between the fixedmold 51 and themovable core 52 when the fixedmold 51 is joined with themovable mold 52. - The
movable mold 52 is provided with apin 52 at its inner middle portion for forming thedrain port 14. Also, themovable mold 52 includes amovable core 53 that is movably supported in a top and bottom direction inFIG. 2 . Themovable core 53 is connected to anactuator 55 that is provided outside of themovable mold 52 as a movable core-driving means. Themovable core 53 is moved in the top and bottom direction by operation of theactuator 55, thereby changing a volume of thecavity 54. - In the embodiment, a hydraulic actuator having a hydraulic cylinder is used as the
actuator 55. Further, as an example of theactuator 55, a pneumatic actuator and a motor-driven actuator can be used. - In molding the
case 12, first, the fixedmold 51 and themovable mold 52 are joined as shown inFIG. 3A . Then, amolten resin 20 including a foaming agent is injected from a gate (not shown) into themold cavity 54. In the embodiment, polypropylene resin is used as theresin 20. Nitrogen molecules in a supercritical liquid state are contained in theresin 20 as the foaming agent. - A supercritical liquid is defined as a material maintained under a pressure over a critical pressure and a temperature over a critical temperature. Under that condition, the material is in a supercritical liquid state. N2 (nitrogen) used as the foaming agent is in a supercritical state when maintained under a pressure over 3.4 MPa and a temperature over −147 degrees Celsius.
- The supercritical liquid is characterized by acting as gas and liquid. Therefore, supercritical liquid nitrogen is readily diffused and mixed in the polypropylene resin. In the embodiment, supercritical liquid nitrogen of 0.6 percent by weight is included in the
resin 20. - After the
resin 20 is injected into themold cavity 54, as shown inFIG. 3B , themovable core 53 is moved in a direction expanding the volume of the cavity 54 (downward inFIG. 3 ), by operation of theactuator 55. In the embodiment, a mold temperature is 15 degrees Celsius. Themovable core 53 is moved approximately two seconds later a completion of the resin injection. - The supercritical liquid nitrogen in the
resin 20 gradually vaporizes immediately after injected in thecavity 54 and forms foam nuclei. As the vaporization of the supercritical liquid nitrogen continues, foam nuclei grow and forms voids, thereby forming foam structure in theresin 20. At a part where thecavity 54 is expanded by movement of themovable core 53, forming of the foam nuclei is accelerated or promoted, thereby increasing the expansion ratio. - In this way, the
second case 12 in which the high foamedportion 21 and the low foamedportion 22 are integrally molded is produced. Since the expansion ratio of the high foamedportion 21 is approximately 4.0, voids may be communicated therein. However, thin resin layers (skin layers) are formed on the surfaces of the molded product. Therefore, the wall of thesecond case 12 does not have communication structure allowing communication between the inside surface and the outside surface. - In the manufacturing method, the step shown in
FIG. 3A is referred to as an injecting step and the step shown inFIG. 3B is referred to as a foaming step. - According to the above method, it is possible to create expansion ratios difference in a single article. Therefore, it is unnecessary to separately mold articles having different expansion ratios and to assemble then together to make the
first case 11 and thesecond case 12. Accordingly, a manufacturing process is simple. Further, the high foamedportions 21 are formed partly in thefirst case 11 and thesecond case 12, respectively. Therefore, the resin molded article is compact. - The high foamed
portion 21 has a thermal conductivity of 0.5 W/(m·K) even when theevaporator 2 is arranged in thecase 1. Therefore, dew drops less likely to generate on outer faces of thecase 1. - Especially, in the
case 1, since the condensed water flows through thedrain port 14, thedrain port 14 is cooled more than the other portion in thecase 1. Because thedrain port 14 is formed of the high foamedportion 21, it is effective to restrict generation of dew drops. - In the second embodiment, the high foamed
portion 22 is formed in a manner different from that of the first embodiment. - As shown in
FIG. 4 , themovable mold 52 includes abody portion 61 and aninsert portion 62. Avibrator 64 is provided under theinsert portion 62 as a vibrating device. Theinsert portion 62 vibrates by operation of thevibrator 64.Gaps 63 are defined partly between thebody portion 61 and theinsert portion 62 to restrict the body portion. 61 from vibrating due to vibrations of theinsert portion 62. As examples of thevibrator 64, an ultrasonic vibrator and air vibrator can be used. - When the
second case 12 is molded, first, theresin 20 including the foaming agent is injected into thecavity 54 in a manner similar to the first embodiment. Then, thevibrator 64 is turned on to vibrate theinsert portion 62. With this, asurface 62 a of theinsert portion 62, which defines thecavity 64, vibrates. Therefore, foam nucleation of theresin 20 is promoted at the vibrated portion. As a result, the expansion ratio of the vibrated portion is higher than the other portion. - In this way, the high foamed
portion 21 and the low foamedportion 22 are formed integrally in thesecond case 12. Here, the step of vibrating theinsert portion 62 corresponds to the foaming step. - Similar to the first embodiment, it is unnecessary to mold articles having different expansion ratio separately and to assemble them to construct the
first case 11 and thesecond case 12. Therefore, the manufacturing method is simple. Also, the high foamedportions 21 are formed partly in thefirst case 11 and thesecond case 12. Therefore, it is possible to make the resin molded article compact. - In the third embodiment, the high foamed
portion 21 is formed in a manner different from that of the first embodiment. - As shown in
FIG. 5 , themovable mold 52 includes thebody portion 61 and theinsert portion 62. Anelectric heater 74 is embedded in theinsert portion 62 from the bottom. Theelectric heater 74 is a heating device and heats theinsert portion 62 when it is electrically conducted. Thegaps 63 are formed partly between thebody portion 61 and theinsert portion 62 to prevent thebody portion 61 from receiving heat from theinsert portion 62. Instead of thegaps 63, a heat insulation material can be provided between thebody portion 61 and theinsert portion 62. - When the
insert portion 62 is heated by operation of theelectric heater 74, thesurface 62 a of theinsert portion 62, which defines thecavity 54, is heated and the temperature of thesurface 62 a is higher than the other surrounding walls. Theelectric heater 74 is a temperature difference-generating device to create temperature differences in walls defining thecavity 54. - In molding the
second case 12, first, theresin 20 including the foaming agent is injected in themold cavity 54 in a manner similar to the first embodiment. At this time, theinsert portion 62 has been heated by theelectric heater 74. In the embodiment, thebody portion 61 is maintained at 15 degrees Celsius and theinsert portion 62 is heated at 80 degrees Celsius. Thus, the nucleation is promoted at a part adjacent to thesurface 62 a that is approximately 80 degrees Celsius. As a result, the expansion ratio of the part adjacent to thesurface 62 a is higher than that of the other part. - In this way, the
second case 12 in which the high foamedportion 21 and the low foamedportion 22 are integrally formed can be produced.FIG. 5 illustrates the injecting step and the foaming step of the method. - Also in this embodiment, it is unnecessary to separately mold the articles having different expansion ratios and to assemble them to construct the
first case 11 and thesecond case 12. Therefore, the manufacturing process is simple. Also, the high foamedportions 21 are formed partly in thefirst case 11 and thesecond case 12. Therefore, the resin molded article is compact. - In the fourth embodiment, the high foamed
portion 21 and the low foamedportion 22 are formed in a manner different from that of the first embodiment. - As shown in
FIG. 6A , themovable mold 52 includes a plurality ofmovable cores 83. Themovable cores 83 are supported slidably in the left and right direction inFIG. 6A . Themovable cores 83 are respectively connected to actuators 85 that are provided on the outside of themovable mold 52 as a movable core driving means. The walls of themovable cores 83 defining thecavity 54 are moved by operation of theactuators 85 so that the volume of thecavity 54 is partly changed. - In molding the
second case 12, first, theresin 20 including the foaming agent is injected into thecavity 54 in a manner similar to the first embodiment, as shown inFIG. 6A . Then, as shown inFIG. 6B , themovable cores 83 are moved by theactuators 85 inwardly, that is, in the direction that the volume of thecavity 54 is reduced. In the embodiment, theresin 20 is injected into thecavity 54 maintained at the mold temperature of 80 degrees Celsius. Themovable cores 83 are moved approximately two seconds later the completion of the resin injection. - At the part where the volume of the
cavity 54 is reduced, the nucleation in theresin 20 is limited and the foams grown therein are compressed. Therefore, the expansion ratio of the compressed part is smaller than the other parts. - In this way, the
second case 12 in which the high foamedportion 21 and the low foamedportion 22 are integrally formed can be produced. In the embodiment, the step shown inFIG. 6A corresponds to the injecting step and the step shown inFIG. 6B corresponds to the foaming step. - Also in this embodiment, it is unnecessary to separately mold parts having different expansion ratios and to assemble the parts to construct the
first case 11 and thesecond case 12. Therefore, the manufacturing process is simple. Also, the high foamedportions 21 are formed partly in thefirst case 11 and thesecond case 12, respectively. Therefore, it is possible to make the resin molded article compact. - As another modification, another supercritical liquid can be used as the foaming agent, in place of the supercritical liquid nitrogen. For example, the foaming agent can be supercritical liquid carbon dioxide. Further, the bowing agent is not limited to the supercritical liquid. For example, it can be a physical foaming agent that foams by evaporation. Also, it can be a chemical foaming agent that foams by cracked gas.
- In the
case 1 described in the above embodiments, the high foamedportions 21 and the low foamedportion 22 are integrally molded. However, thecase 1 can be a molded article in which a foamedportion 21 a defining voids therein and anon-foamed portion 22 a without defining voids therein are integrally molded, as shown inFIG. 7 . Thenon-foamed portion 22 a is formed by avoiding foam nucleation in a method similar to that of the above-described embodiments. - In the third embodiment, the
electric heater 74 is used as the heating device. However, another type of heater, such as a glow plug, can be used. Also, theheater 74 is used as a device to create temperature difference in themold 50. However, the temperature difference can be created by other methods. For example, passages through which coolant (e.g. cold water) and heating medium (e.g. hot water) flow can be formed in the mold. By this, the temperature differences can be created on the walls of the mold defining the cavity. - The
resin 20 is not limited to the polypropylene resin. Another resin material can be used to the present invention. - In the above-described embodiment, the
movable core 53,vibrator 64,electric heater 74 and themovable cores 83, are arranged on a side of themovable mold 52. However, the arrangements are not limited to the above. Those can be arranged other positions, for example, in the fixedcore 51. - Further, the devices, such as the movable the
core 53, theactuator 55, theinsert portion 62, thevibrator 64 and theelectric heater 74, are used as foam-promoting devices to create expansion ratio differences in the singe molded article. Those devices can be used in variable combinations. In the above embodiments, the method is explained in a case of molding the air conditioning case as an example. The product is not limited to the air conditioning case. The method of the present invention can be used to produce molded articles for other purposes. - The present invention should not be limited to the disclosed embodiments, but may be implemented in other ways without departing from the spirit of the invention.
Claims (20)
1. A method of manufacturing a resin molded article comprising:
injecting resin including a foaming agent into a cavity defined in a mold assembly; and
foaming the injected resin in the mold assembly, wherein the foaming of the resin is partly promoted in the cavity by a foam-promoting device provided in the mold assembly, thereby creating expansion ratio difference in the molded article.
2. The method according to claim 1 , wherein the foam-promoting device includes a movable core, wherein the movable core moves to partly expand the cavity after the resin injection, thereby increasing the expansion ratio of the resin at the part where the cavity is expanded.
3. The method according to claim 1 , wherein the foam-promoting device includes a vibrator disposed to partly vibrate a mold wall defining the cavity, wherein the vibrator operates during the foaming, thereby increasing the expansion ratio of the resin at a vibrated part.
4. The method according to claim 1 , wherein the foam-promoting device includes a temperature difference generating means disposed to create temperature difference in a mold wall defining the cavity during the foaming, thereby increasing the expansion ratio at a portion where temperature is higher than the other in the mold wall.
5. The method according to claim 4 , wherein the temperature difference generating means includes a heater disposed to partly heat the mold wall.
6. The method according to claim 1 , wherein the foaming agent includes supercritical liquid nitrogen.
7. The method according to claim 1 , wherein the foaming agent includes supercritical liquid carbon dioxide.
8. A method of manufacturing a resin molded article comprising:
injecting resin including a foaming agent into a cavity defined in a mold assembly; and
foaming the injected resin in the mold assembly, wherein during the foaming the cavity is partly narrowed by a movable core provided in the mold assembly, thereby reducing an expansion ratio of the molded article at a part where the cavity is narrowed.
9. The method according to claim 8 , wherein the foaming agent includes supercritical liquid nitrogen.
10. The method according to claim 8 , wherein the foaming agent includes supercritical liquid carbon dioxide.
11. A method of manufacturing a resin molded article comprising:
preparing injection material including resin and a foaming agent;
defining a cavity in a mold;
injecting the prepared injection material into the cavity so that the cavity is filled with the injection material;
foaming the injection material injected in the cavity by the foaming agent;
while the foaming process, differentiating a foaming ratio of the injection material filled in at least two locations in the cavity; and
opening the mold to eject a molded article which has integrally molded at least two portions having different foaming ratio.
12. The method according to claim 11 , wherein the mold defines a thicker portion and a thinner portion in the cavity, and the differentiating step provides a higher foaming ratio in the injection material filled in the thicker portion.
13. The method according to claim 12 , wherein the differentiating step is performed by adjusting a thickness of the cavity after the cavity is filled with the injection material.
14. The method according to claim 12 , wherein the differentiating step is performed by widening the cavity to define the thicker portion during the foaming step, widening the cavity being capable of increasing the foaming ratio of the injection material filled in the thicker portion.
15. The method according to claim 14 , wherein the widening the cavity is performed after the injecting step and is performed during the foaming step.
16. The method according to claim 12 , wherein the differentiating step including the step of vibrating a portion of the mold defining the thicker portion to increase the foaming ratio of the injection material filled in the thicker portion.
17. The method according to claim 12 , wherein the differentiating step differentiates temperature of portions of the mold such that a portion defining the thicker portion is higher temperature than a portion defining the thinner portion, the higher temperature being capable of increasing the foaming ratio of the injection material filled in the thicker portion.
18. The method according to claim 12 , wherein the differentiating step including the step of heating the portion of the mold defining the thicker portion to increase the foaming ratio of the injection material filled in the thicker portion.
19. The method according to claim 12 , wherein the differentiating step is performed by narrowing the cavity to define the thinner portion during the foaming step, the narrowing the cavity being capable of decreasing the foaming ratio of the injection material filled in the thinner portion.
20. The method according to claim 19 , wherein the narrowing the cavity is performed after the injecting step and is performed during the foaming step.
Priority Applications (1)
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US11/130,341 US20050285294A1 (en) | 2002-05-16 | 2005-05-16 | Resin molded articles and method of manufacturing the same |
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US11/130,341 US20050285294A1 (en) | 2002-05-16 | 2005-05-16 | Resin molded articles and method of manufacturing the same |
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US8574473B2 (en) | 2010-08-05 | 2013-11-05 | Ford Global Technologies, Llc | Foamed resin injection molding method |
US20180339441A1 (en) * | 2017-05-23 | 2018-11-29 | Otrajet Inc. | Processing method for molding foamed polymer |
US11780129B2 (en) | 2020-03-20 | 2023-10-10 | King Steel Machinery Co., Ltd. | Molding method for operating molding device |
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US6545729B1 (en) * | 2000-08-18 | 2003-04-08 | Mitsubishi Digital Electronics America, Inc. | Foam cabinetry for electronic devices |
SE0301075D0 (en) * | 2003-05-08 | 2003-05-08 | Arca Systems Ab | A process for the manufacture of an article made of plastic material |
US20050252127A1 (en) * | 2004-03-31 | 2005-11-17 | Toyoda Gosei Co., Ltd. | Foamed molded product and manufacturing method thereof |
JP4412053B2 (en) * | 2004-05-13 | 2010-02-10 | 豊田合成株式会社 | Manufacturing method of foam molded product |
CN101370637B (en) * | 2006-01-17 | 2012-04-18 | 丰田自动车株式会社 | Mold for molding and method for molding product |
US8151591B2 (en) * | 2007-03-05 | 2012-04-10 | Denso International America, Inc. | Air conditioning case and drain for condensate removal |
JP5132965B2 (en) * | 2007-03-30 | 2013-01-30 | ユニプレス株式会社 | Automotive undercover |
JP5315702B2 (en) * | 2008-01-21 | 2013-10-16 | マツダ株式会社 | Molding method and molding apparatus for foamed resin molded product |
JP2009166458A (en) * | 2008-01-21 | 2009-07-30 | Mazda Motor Corp | Method and apparatus for molding foamed resin molding |
JP2013178034A (en) * | 2012-02-28 | 2013-09-09 | Kyoraku Co Ltd | Foamed duct |
KR101428417B1 (en) | 2013-08-28 | 2014-08-07 | 현대자동차주식회사 | Filling assembly and method for automotive panel space |
CN109385058B (en) * | 2018-09-06 | 2020-08-11 | 广东奔迪新材料科技有限公司 | Method for preparing non-mold three-dimensional structure foaming product by supercritical fluid |
CN112776277B (en) * | 2021-02-04 | 2022-11-25 | 贵州乐嘉文创科技有限公司 | Plastic mold |
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FR2839677A1 (en) | 2003-11-21 |
FR2839677B1 (en) | 2007-11-16 |
US6926940B2 (en) | 2005-08-09 |
JP2003326539A (en) | 2003-11-19 |
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US20030215586A1 (en) | 2003-11-20 |
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