US20090121375A1 - Method for multilayer molding of thermoplastic resins and multilayer molding apparatus - Google Patents

Method for multilayer molding of thermoplastic resins and multilayer molding apparatus Download PDF

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Publication number
US20090121375A1
US20090121375A1 US11/990,780 US99078006A US2009121375A1 US 20090121375 A1 US20090121375 A1 US 20090121375A1 US 99078006 A US99078006 A US 99078006A US 2009121375 A1 US2009121375 A1 US 2009121375A1
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molding
multilayer
injection
mold
thermoplastic resins
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US11/990,780
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English (en)
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Akio Okamoto
Kazuaki Miyamoto
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Ube Machinery Corp Ltd
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Ube Machinery Corp Ltd
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Assigned to UBE MACHINERY CORPORATION, LTD. reassignment UBE MACHINERY CORPORATION, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MIYAMOTO, KAZUAKI, OKAMOTO, AKIO
Publication of US20090121375A1 publication Critical patent/US20090121375A1/en
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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
    • B29C45/16—Making multilayered or multicoloured articles
    • 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
    • B29C44/0461—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 having different chemical compositions in different places, e.g. having different concentrations of foaming agent, feeding one composition after the other
    • 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
    • B29C44/08—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 using several expanding or moulding steps
    • B29C44/083—Increasing the size of the cavity after a first part has foamed, e.g. substituting one mould part with another
    • B29C44/086—Increasing the size of the cavity after a first part has foamed, e.g. substituting one mould part with another and feeding more material into the enlarged cavity
    • 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
    • B29C45/26—Moulds
    • 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
    • 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
    • B29C45/70—Means for plasticising or homogenising the moulding material or forcing it into the mould, combined with mould opening, closing or clamping devices

Definitions

  • the present invention relates to a multilayer-molding method of molding thermoplastic resins and a multilayer-molding apparatus for performing the multilayer-molding method.
  • Multilayer-molded products of thermoplastic resins that contain a foam layer and a non-foamed layer have been used in various fields for a long time.
  • the foam layer in a multilayer-molded product is light in weight and has excellent heat-insulating properties, sound-absorbing properties, and texture, because of bubbles inside the resin.
  • the non-foamed layer in a multilayer-molded product can provide rigidity and excellent appearance.
  • resins used in products have been foamed to reduce the amount of resin for the purpose of weight reduction. Combined with the cost reduction resulting from the weight reduction, multilayer-molded products that contain a foam layer have found wider applications.
  • a foam layer in a multilayer-molded product is manufactured by physical foaming or chemical foaming according to the type of a foaming agent to be mixed with a resin.
  • the physical foaming utilizes an inert gas, such as nitrogen or carbon dioxide, or a volatile substance, such as a hydrocarbon or a fluorocarbon, as a physical foaming agent.
  • the chemical foaming utilizes an organic foaming agent, such as an azo compound or a nitroso compound, or an inorganic foaming agent, such as sodium bicarbonate, as a chemical foaming agent.
  • a multilayer-molding method includes injecting a molten resin that contains a foaming agent and a resin material into a mold cavity, injecting a molten resin that contains a resin material and no foaming agent into the mold cavity, and foaming a resin mixed with the foaming agent.
  • a multilayer-molded product thus manufactured includes a foam layer that contains bubbles having a diameter of about 80 to 300 ⁇ m and a non-foamed layer.
  • Patent Document 1 discloses a method for forming a foam-molded product having bubbles therein, in which an olefin resin mixed with a chemical foaming agent or a physical foaming agent is foamed by a short-shot method.
  • a molten resin that contains a resin material mixed with an inert gas, such as a nitrogen gas, a volatile substance, such as a hydrocarbon or a fluorocarbon, or a chemical foaming agent is fed to the accumulator with an extruder.
  • the molten resin fed to the accumulator is injected into the mold and is foamed, thus yielding a foam-molded product that contains bubbles therein.
  • Patent Document 2 discloses a method for manufacturing a foam-molded product using a physical foaming agent, in which air, another gas, or a volatile substance is fed under pressure from an extruder hopper simultaneously with resin-material feed. The melting of the resin material and the inclusion and dispersion of bubbles are performed with a screw extruder. According to the method disclosed in Patent Document 2, a molded product of a sponge-like substance that contains closed cells can be manufactured by using a polyethylene resin and air having a pressure in the range of about 0.69 to 0.78 MPa.
  • Patent Document 3 discloses a method for remarkably increasing the bubble density (the number of bubbles per unit volume) by using carbon dioxide, an inert gas, in a supercritical state as a foaming gas, as compared with bubbles formed in a molded product using a conventional chemical foaming agent or a conventional physical foaming agent.
  • a molding apparatus is provided with a system composed of a booster and a feeder of a supercritical fluid and a gas cylinder.
  • Carbon dioxide in a supercritical state is injected and dissolved into a molten resin via a cylinder of the molding apparatus.
  • the molten resin that contains dissolved carbon dioxide is injected into a mold, and is foamed, thus yielding a resin-molded product that contains ultrafine pores, called microcells, having a size less than 1 ⁇ m therein.
  • Non-patent Document 1 SEIKEI KAKOU, 2001, No. 2, Vol. 13
  • the means requires a generator and a feeder of the supercritical fluid. Since these apparatuses treat a high-pressure gas, the apparatuses are under a legal restriction, which complicates the installation and the operation of the apparatuses.
  • the means requires a complicated mechanism for sealing a foaming gas injected into a cylinder of an injection-molding machine. This increases the cost of the injection-molding machine.
  • an increase in sealing performance against a foaming gas reduces the plasticizing capacity and therefore the productivity.
  • a foaming gas is generally injected at a controlled flow rate, which requires a complicated controlling mechanism.
  • thermoplastic resins in which the means generates no hazardous decomposition product, releases neither environmental pollutants nor environmental destruction substances in the air, does not require a generator or a feeder of a supercritical fluid under a legal restriction, which complicates the installation and the operation of the apparatuses, and can produce a multilayer-molded product that contains a foam layer having a desired bubble density or a desired bubble size.
  • the present invention provides a multilayer-molding method of molding thermoplastic resins, which includes the use of: a plurality of injection-molding machines that plasticize and inject a plurality of types of thermoplastic resins as a molding material; a mold that has a cavity as a molding space to be filled with the thermoplastic resins injected by the plurality of injection-molding machines; and a clamping apparatus that can clamp the mold and open or close the mold to increase or decrease the volume of the cavity, the method including the steps of: mixing at least one thermoplastic resin selected from the plurality of types of thermoplastic resins with a foaming gas; injecting the plurality of types of thermoplastic resins into the mold cavity such that the thermoplastic resins are layered in the mold cavity; and then after increasing the volume of the mold cavity, foaming the at least one thermoplastic resin mixed with the foaming gas, wherein the foaming gas is supplied at a pressure of 0.1 MPa or more but less than 1.0 MPa to at least one injection-molding machine selected
  • the pressure of the foaming gas supplied to the injection-molding machine is more preferably in the range of 0.5 MPa or more but less than 1.0 MPa.
  • the foaming gas for use in the formation of a foam layer is generally supplied to a predetermined portion in the injection-molding machine at a pressure in the range of 0.1 MPa or more but less than 1.0 MPa.
  • the pressure in this range allows for a simple sealing mechanism in the injection-molding machine, thus ensuring a plasticizing capacity of at least a desired level.
  • the sealing performance of the injection-molding machine is ensured by reducing a screw-flight clearance at a boundary between a first stage and a second stage.
  • too narrow a screw-flight clearance prevents a molten resin from passing through the clearance, resulting in a decreased plasticizing capacity.
  • the pressure range as described above allows for a relatively large screw-flight clearance, satisfying both the plasticizing capacity and the sealing performance. Furthermore, in the pressure range as described above, the emission of the foaming gas from the front-end of a resin can be reduced to an appropriate level during filling injection. Thus, a multilayer-molded product can have a desired appearance. Furthermore, when the injection rate of the foaming gas is regulated by pressure control, the saturating amount of dissolved gas most suitable for a resin used can be obtained independently of the molding conditions.
  • the gas-injection rate is determined by the difference in pressure between the decompression zone (gas injection position) of the two-stage screw and the injected gas. Furthermore, the amount of nitrogen gas dissolved in polystyrene (200° C.) is in the range of 0.4 mol/kg (1 MPa) to 0.6 mol/kg (10 MPa) and does not vary significantly with pressure (see Non-patent Document 1). Thus, the amount of foaming gas required for foaming can be supplied sufficiently at the pressure range of 0.1 MPa or more but less than 1.0 MPa described above. The injection of the foaming gas at the above-mentioned pressure range can therefore achieve sufficient foaming, without having a substantial influence on the product characteristics.
  • the pressure of the foaming gas supplied to the injection-molding machine is set to be less than 1.0 MPa for the following reasons. While a multilayer-molded product having a desired bubble density or a desired bubble size can sometimes be produced at 1.0 MPa, occasionally, foaming cells become coarse, and the expansion ratio varies greatly at different portions of the multilayer-molded product. In addition, the multilayer-molded product may have a defective appearance due to swirl marks.
  • the foaming gas is supplied to the injection-molding machine at a pressure of 0.1 MPa or more but less than 1.0 MPa, in terms of the foaming status, the appearance, and the flexibility of a multilayer-molded product, the pressure is more preferably in the range of 0.2 MPa to 0.99 MPa and still more preferably in the range of 0.5 MPa to 0.9 MPa.
  • the foaming gas is supplied to a hopper for feeding a thermoplastic resin or into a molten resin in a plasticizing cylinder of the injection-molding machine as described below. This ensures sufficient dispersion and mixing of the foaming gas or the bubble-nucleating agent in a molten resin.
  • the foaming gas and the bubble-nucleating agent can be dispersed and mixed in a molten resin. More preferably, the screw has a highly dispersive screw head to improve the dispersibility of the foaming gas and the bubble-nucleating agent in a molten resin.
  • the bubble-nucleating agent is premixed with the foaming gas to be supplied into the injection-molding machine, thereby allowing the thermoplastic resin injected into a mold cavity to contain the bubble-nucleating agent.
  • the bubble-nucleating agent is premixed with the thermoplastic resin serving as a molding material, thereby allowing the thermoplastic resin injected into the mold cavity to contain the bubble-nucleating agent.
  • the bubble-nucleating agent is one or a mixture of at least two selected from the group consisting of iron oxides, calcium silicate, zinc stearate, magnesium stearate, organic acids (citric acid, tartaric acid, etc.), aluminum silicate, glass fiber, and talc.
  • the foaming gas is supplied to the injection-molding machine under controlled pressure.
  • the foaming gas is supplied to a hopper of the injection-molding machine, the hopper serving as a charge port of a thermoplastic resin to be plasticized, or into a plasticized thermoplastic resin in a plasticizing cylinder of the injection-molding machine.
  • the foaming gas is one inorganic gas or a mixture of at least two inorganic gases selected from the group consisting of air, carbon dioxide, and nitrogen.
  • the foaming gas for use in multilayer molding involving a foam layer include carbon dioxide, a nitrogen gas, and air, or mixtures thereof. Air or carbon dioxide is preferred in terms of the characteristics of a multilayer-molded product.
  • the foaming gas must be selected in consideration of the oxidation resistance of a resin.
  • a gas other than air is preferably used for resins having a group susceptible to oxidation. Air is suitably used for resins having high resistance to oxidation, such as polypropylene, also in terms of availability.
  • bubble-nucleating agent examples include fine powders of inorganic substances, such as iron oxides, calcium silicate, aluminum silicate, glass fiber, talc, and sodium hydrogencarbonate (sodium bicarbonate); metallic salts of organic acids, such as zinc stearate and magnesium stearate; and organic acids, such as citric acid and tartaric acid.
  • inorganic substances such as iron oxides, calcium silicate, aluminum silicate, glass fiber, talc, and sodium hydrogencarbonate (sodium bicarbonate); metallic salts of organic acids, such as zinc stearate and magnesium stearate; and organic acids, such as citric acid and tartaric acid.
  • metallic salts of organic acids such as zinc stearate and magnesium stearate
  • organic acids such as citric acid and tartaric acid.
  • a metallic salt and an organic acid may be used in combination.
  • thermoplastic resin for use in a multilayer-molding method of molding thermoplastic resins according to the present invention examples include styrene-based resins, such as polystyrene, AS resins, and ABS resins; olefin resins, such as polyethylene and polypropylene; and so-called engineering resins, including polyester resins, such as polyethylene terephthalate and polybutylene terephthalate, polyamides, polyacetals, polycarbonates, and modified polyphenylene ethers, and olefinic thermoplastic elastomers. These resins may be used in combination according to the application.
  • styrene-based resins such as polystyrene, AS resins, and ABS resins
  • olefin resins such as polyethylene and polypropylene
  • engineering resins including polyester resins, such as polyethylene terephthalate and polybutylene terephthalate, polyamides, polyacetals, polycarbonates, and modified polyphenylene
  • thermoplastic resins may be used in combination with additive agents, such as a plasticizer, a mold-release agent, an antistatic agent, and a flame retardant; various fillers for improving physical properties, such as glass fiber and carbon fiber; and coloring agents, dyes, and the like.
  • additive agents such as a plasticizer, a mold-release agent, an antistatic agent, and a flame retardant
  • various fillers for improving physical properties such as glass fiber and carbon fiber
  • coloring agents, dyes, and the like such as a plasticizer, a mold-release agent, an antistatic agent, and a flame retardant.
  • the present invention also provides an automotive interior multilayer-molded product manufactured by any of the above-mentioned multilayer-molding methods of thermoplastic resins.
  • the present invention also provides a multilayer-molding apparatus for manufacturing a multilayer-molded product that contains a multilayer of a plurality of types of thermoplastic resins, one layer of which is foamed and composed of at least one thermoplastic resin selected from the plurality of types of thermoplastic resins.
  • the multilayer-molding apparatus includes a plurality of injection-molding machines that plasticize and inject the plurality of types of thermoplastic resins as a molding material, a mold that has a cavity as a molding space to be filled with the thermoplastic resins injected by the plurality of injection-molding machines, a clamping apparatus that can clamp the mold and open or close the mold to increase or decrease the volume of the cavity, and a unit for supplying a foaming gas and a unit for supplying a bubble-nucleating agent each for use in the foaming.
  • a multilayer-molding method of molding thermoplastic resins includes the steps of mixing at least one thermoplastic resin selected from a plurality of types of thermoplastic resins with a bubble-nucleating agent and a foaming gas, and injecting the plurality of types of thermoplastic resins into a mold cavity such that the thermoplastic resins are layered in the mold cavity.
  • the foaming gas is supplied at a pressure of 0.1 MPa or more but less than 1.0 MPa to at least one injection-molding machine selected from a plurality of injection-molding machines.
  • thermoplastic resins that contains a foam layer having a desired bubble size and a bubble density and being free from hazardous decomposition product residues can be manufactured without using an environmentally hazardous foaming agent and a generator and a feeder of a supercritical fluid.
  • the supply pressure of the foaming gas in the range of 0.1 MPa or more but less than 1.0 MPa can simplify the mechanism for sealing the foaming gas that is supplied to a cylinder of the injection-molding machine. This prevents a reduction in plasticizing capacity.
  • the sealing performance is ensured by reducing a screw-flight clearance at a boundary between a first stage and a second stage. The screw-flight clearance must be reduced with an increase in pressure of the foaming gas. This reduces the plasticizing capacity.
  • a multilayer-molding method of molding thermoplastic resins according to the present invention can avoid such a problem.
  • the foaming gas is supplied to the injection-molding machine at a pressure in the range of 0.1 MPa or more but less than 1.0 MPa, unlike conventional methods using a foaming gas in a supercritical state, a generator and a feeder of a supercritical fluid are unnecessary. Furthermore, since the supply pressure of the foaming gas is in the range of 0.1 MPa or more but less than 1.0 MPa, the emission of the foaming gas from the front-end of a flowing molten resin during injection filling is smaller than that at a pressure of 1.0 MPa or more. Thus, a multilayer-molded product (final product) has better appearance.
  • the reason that the supply pressure of the foaming gas is set to be 0.1 MPa or more is that a desired bubble density or a desired bubble size cannot be achieved at 0.1 MPa or less.
  • the reason that the supply pressure of the foaming gas is set to be less than 1.0 MPa is that the bubbles become coarse at 1.0 MPa or more, the foam layer (molded product) has a defective appearance due to swirl marks, and the multilayer-molded product has different expansion ratios at different portions, because the pressure applied to the front-end of the flowing molten resin in the injection-molding machine is greatly different from the pressure applied to the resin in the mold during injection filling.
  • the foaming gas is supplied to the injection-molding machine at a pressure of 0.5 MPa or more but less than 1.0 MPa under controlled pressure.
  • This can provide a multilayer-molded product that contains a foam layer having a denser surface and a desired bubble density or a desired bubble size.
  • the foaming gas is supplied to a hopper of the injection-molding machine or into a molten thermoplastic resin in a cylinder. This ensures sufficient dispersion and mixing of the foaming gas or the bubble-nucleating agent in the molten resin, which forms a foam layer. More preferably, the screw has a highly dispersive screw head to improve the dispersibility of the foaming gas and the bubble-nucleating agent in the molten resin.
  • the foaming gas is supplied under controlled pressure.
  • the saturating amount of dissolved foaming gas most suitable for a thermoplastic resin used can consistently be obtained independently of the molding conditions.
  • the amount of supplied foaming gas is determined by the difference in pressure between the decompression zone (injection position of the foaming gas) and the supplied foaming gas.
  • the amount of nitrogen gas dissolved in a polystyrene resin is in the range of 0.4 mol/kg (1 MPa) to 0.6 mol/kg (10 MPa) at 200° C.
  • the amount of foaming gas required for foaming can be supplied sufficiently at a pressure in the range of 0.1 MPa or more but less than 1.0 MPa. Furthermore, a pressure in the range of 0.1 MPa or more but less than 1.0 MPa should not have a significant on the multilayer-molded product (final product).
  • FIG. 1 is a general schematic view of a multilayer-molding apparatus according to an embodiment of the present invention.
  • FIGS. 2( a ) to ( f ) are process drawings of a multilayer-molding method of molding thermoplastic resins according to an embodiment of the present invention.
  • FIGS. 3( a ) to ( e ) are process drawings of a multilayer-molding method of molding thermoplastic resins according to another embodiment of the present invention.
  • FIG. 1 illustrates a multilayer-molding apparatus according to an embodiment of the present invention and is a general schematic view of a horizontal clamping injection-molding machine.
  • an injection-molding machine 80 is composed of a mold 10 , a clamping apparatus 20 , two injection-molding machines 30 and 130 , means 40 for supplying a foaming gas, and a controller 70 .
  • the mold 10 is composed of a stationary mold 3 , which is attached to a stationary platen 1 , and a movable mold 4 , which is attached to a movable platen 2 .
  • the stationary mold 3 and the movable mold 4 have a semi-positive structure, and are fitted together at a fitting part.
  • a face of the stationary mold 3 that forms a cavity 11 (cavity-forming face) and a face of the movable mold 4 that forms the cavity 11 (cavity-forming face) jointly form the cavity 11 of the mold 10 .
  • the fitting part of the semi-positive structure is located all around the cavity 11 of the mold 10 .
  • the fitting part has such a structure that a resin in the cavity 11 of the mold 10 does not leak out of the mold 10 even when the volume of the cavity 11 in the mold 10 is increased after injection filling.
  • the clamping apparatus 20 includes a mold-clamping cylinder 22 that opens and closes the mold 10 , and is designed such that the movable mold 4 can move forward and backward along tie bars (not shown) relative to the stationary mold 3 .
  • the mold is not limited to the mold having the semi-positive structure, in which a resin in the cavity does not leak out during a predetermined stroke.
  • Other molds such as a flash mold, may be used, provided that they are applicable to the foam molding.
  • an injection-molding machine equipped with a toggle type mold-clamping system, an electric servomotor type injection-molding machine, or a vertical clamping injection-molding machine may be used in place of the horizontal clamping injection-molding machine equipped with a straight hydraulic mold-clamping system.
  • Two injection-molding machines 30 and 130 illustrated in FIG. 1 include cylinders 31 and 131 , screws 32 and 132 , which are disposed within the cylinders 31 and 131 and have flights, and hoppers 35 and 135 , through which molding materials are supplied to the cylinders 31 and 131 , and are provided with screw-traveling means 33 and 133 , which move the screws 32 and 132 forward and backward, and screw-rotating means 34 and 134 , which rotate the screws 32 and 132 .
  • Heaters (not shown) are mounted on the periphery of the cylinders 31 and 131 .
  • the injection-molding machine 130 is designed such that a foaming gas is supplied from the means 40 for supplying a foaming gas to the hopper 135 (opening of the hopper) or into a molten resin in the cylinder 131 .
  • the injection-molding machine 30 is designed such that the screw-rotating means 34 rotates the screw 32 to feed molding material pellets from the hopper 35 into the cylinder 31 .
  • the molding material pellets fed are heated by the heater (not shown) mounted on the cylinder 31 , and are kneaded and compressed as the screw 32 rotates.
  • the resulting molten material is transferred in front of the screw 32 .
  • the molten resin transferred in front of the screw 32 is injected into the mold through a nozzle 36 disposed at the tip of the cylinder 31 as the screw-traveling means 33 moves the screw 32 forward.
  • the foaming gas is supplied into a molten resin. While molding material pellets fed are kneaded and compressed, the foaming gas and the bubble-nucleating agent are mixed and dispersed in a molten material. The resulting molten material is transferred in front of the screw 132 .
  • the molten resin that contains the foaming gas and the bubble-nucleating agent dispersed therein and is transferred in front of the screw 132 is injected into the mold through a nozzle 136 disposed at the tip of the cylinder 131 as the screw-traveling means 133 moves the screw 132 forward.
  • the bubble-nucleating agent is supplied in an appropriate amount from a unit for supplying a bubble-nucleating agent described below, according to predetermined molding conditions.
  • the screw-traveling means 33 and 133 of the injection-molding machines 30 and 130 are oil-hydraulic cylinders, and the screw-rotating means 34 and 134 are oil-hydraulic motors in this embodiment, the screw-traveling means or the screw-rotating means may utilize an electric servomotor.
  • an injection-molding machine including a single inline screw, which performs both plasticization and injection as in the injection-molding machines 30 and 130 , a screw-preplastication type injection-molding machine, which performs plasticization and injection separately, may be used.
  • a single-stage screw may be used, for example, when the foaming gas is supplied to the hopper.
  • the means 40 for supplying a foaming gas includes an air source 41 , a carbon dioxide source 42 , and a unit 43 for supplying a foaming gas.
  • the air source 41 and the carbon dioxide source 42 are coupled through a supply passage.
  • the means 40 for supplying a foaming gas is provided with a foaming-gas-supply passage connected to gas-supply ports disposed at the cylinder 131 and at the hopper 135 of the injection-molding machine 130 .
  • the means 40 for supplying a foaming gas supplies a foaming gas to the injection-molding machine 130 according to the instruction issued by the controller 70 .
  • units 61 and 62 for supplying a bubble-nucleating agent are disposed in the vicinity of ends of supply passages that connect the unit 43 for supplying a foaming gas with the injection-molding machine 130 .
  • the units 61 and 62 supply a bubble-nucleating agent to a foaming gas.
  • the bubble-nucleating agent may be added to a thermoplastic resin by previously dry-blending a powdered bubble-nucleating agent with a molding material, by the addition of a masterbatch of the bubble-nucleating agent to a molding material, or by premixing the bubble-nucleating agent with a molding material during the production of the molding material.
  • the controller 70 illustrated in FIG. 1 is composed of a first injection controller 171 and a second injection controller 71 , which control the plasticization of a molding material, the supply of a foaming gas and a bubble-nucleating agent, and the injection of a molten resin into the mold, a clamping controller 72 , which control the opening and closing of the mold 10 and the mold-clamping force, and timers.
  • the clamping controller 72 includes a unit for setting the position to which the movable platen 2 travels and the speed of the traveling to provide a desired volume of the cavity 11 at the beginning of a foaming process for forming a foam layer of a multilayer-molded product.
  • the clamping controller 72 can maintain the position of the movable platen 2 until the end of the foaming process.
  • the foaming process includes the steps of detecting the completion of filling of the cavity 11 in the mold 10 with a resin to reduce the mold-clamping force, and increasing the volume of the cavity 11 in the mold 10 .
  • a skin layer and bubble nuclei are formed during the step of reducing the mold-clamping force.
  • a higher reduction rate of the mold-clamping force results in a larger number of bubble nuclei.
  • the rate of increasing the volume of the cavity 11 in the mold 10 depends on the elongational viscosity of a molding resin, and is desirably low for low elongational viscosity, and high for high elongational viscosity.
  • a multilayer-molding method of molding thermoplastic resins according to the present invention includes a step of injecting a molten resin that contains a foaming agent into a mold cavity and then increasing the volume of the mold cavity to foam the resin.
  • the multilayer-molding method is suitable to manufacture a multilayer-molded product of thermoplastic resins that contains a foam layer and a non-foamed layer.
  • FIG. 2 which includes (a) to (f), is a schematic process drawing illustrating the mold 10 and two injection-molding machines 30 and 130 illustrated in FIG. 1 , and illustrates a multilayer-molding method of molding thermoplastic resins according to an embodiment of the present invention.
  • FIG. 3 which includes (a) to (e), is a schematic process drawing only illustrating a mold 100 and two injection-molding machines 30 and 130 , and illustrates a multilayer-molding method of molding thermoplastic resins according to another embodiment of the present invention.
  • the mold 100 illustrated in FIG. 3 is the same as the mold 10 illustrated in FIGS.
  • a mixing portion 150 in which a resin containing a foaming gas and a bubble-nucleating agent injected from the injection-molding machine 130 , before entering into the cavity 11 , flows into a resin that contains no foaming gas and no bubble-nucleating agent injected from the injection-molding machine 30 .
  • a pressure oil is fed to a piston head side of the mold-clamping cylinder 22 illustrated in FIG. 1 to move a piston rod forward, thereby moving the movable platen 2 toward the stationary platen 1 to close the mold 10 .
  • the mold-clamping force is desirably the smallest force that can prevent the mold 10 from opening owing to the filling pressure during resin filling, in view of energy consumption and the life of the molding apparatus.
  • a resin that contains no foaming gas and no bubble-nucleating agent (molding material) and then a resin that contains a foaming gas and a bubble-nucleating agent (molding material) are injected into the cavity 11 of the mold 10 according to predetermined values of the injection volume, the injection pressure, and the injection speed.
  • a pressure oil is fed to the screw-rotating means 34 to rotate the screw 32 .
  • the molding material fed from the hopper 35 is heated by the heater (not shown) mounted on the cylinder 31 , and is kneaded and compressed as the screw 32 rotates.
  • the resulting molten material is transferred in front of the screw 32 .
  • a pressure oil is fed to the screw-traveling means 33 to move the screw 32 forward, allowing a (molten) resin 124 (containing no foaming gas and no bubble-nucleating agent) transferred in front of the screw to be injected into the cavity 11 of the mold 10 (see FIG. 2( a )).
  • the volume of the cavity 11 in the mold 10 is then maintained and cooled for a predetermined cooling time to form (solidify) a non-foamed layer 121 (see FIG. 2( b )).
  • the pressure of a pressure oil applied to a piston head side of the mold-clamping cylinder 22 is lowered to reduce the mold-clamping force.
  • the pressure oil is fed to the piston rod side to move the piston rod backward.
  • This moves the movable platen 2 away from the stationary platen and opens the mold 10 , thus increasing the volume of the cavity 11 (see FIG. 2( c )).
  • the volume of the cavity 11 in the mold 10 is increased according to the setpoints of a unit for setting the position to which the movable platen 2 travels and the speed of the traveling, disposed in the clamping controller 72 .
  • the movable platen 2 stops and stays at a predetermined position.
  • a pressure oil is then fed to the screw-rotating means 134 to rotate the screw 132 .
  • the molding material fed from the hopper 135 is heated by the heater (not shown) mounted on the cylinder 131 , and is kneaded and compressed as the screw 132 rotates.
  • the foaming gas and the bubble-nucleating agent are mixed and dispersed in a molten material.
  • the molten material is transferred in front of the screw 132 .
  • the (molten) resin 125 that contains the foaming gas and the bubble-nucleating agent dispersed therein and that is transferred in front of the screw is injected between the non-foamed layer 121 previously formed and the movable platen 2 in the cavity 11 of the mold 10 (see FIG. 2( d )).
  • the pressure of a pressure oil applied to a piston head side of the mold-clamping cylinder 22 is lowered to reduce the mold-clamping force.
  • the pressure oil is then fed to the piston rod side of the mold-clamping cylinder 22 to move the piston rod backward.
  • the volume of the cavity 11 in the mold 10 is increased according to the setpoints of a unit for setting the position to which the movable platen 2 travels and the speed of the traveling, disposed in the clamping controller 72 .
  • the movable platen 2 stops at a predetermined position, and maintains the position so as not to be forced back by the resin-expansion pressure in the mold 10 .
  • the volume of the cavity 11 in the mold 10 is controlled to increase the volume of the cavity 11 in the mold 10 , the resin pressure in the cavity 11 of the mold 10 starts to decrease.
  • foaming starts within the resin 125 that contains the foaming gas and the bubble-nucleating agent.
  • the volume of the cavity 11 in the mold 10 is then maintained and cooled for a predetermined cooling time to form (solidify) a foam layer 122 (see FIG. 2( f )), thus producing a multilayer-molded product.
  • a pressure oil is fed to a piston head side of the mold-clamping cylinder 22 illustrated in FIG. 1 to move a piston rod forward, thereby moving the movable platen 2 toward the stationary platen 1 to close the mold 100 (in place of the mold 10 in FIG. 1 ).
  • the mold-clamping force is desirably the smallest force that can prevent the mold 100 from opening owing to the filling pressure during resin filling, in view of energy consumption and the life of the molding apparatus.
  • a resin that contains no foaming gas and no bubble-nucleating agent is injected into the cavity 11 of the mold 100 , during which a resin containing a foaming gas and a bubble-nucleating agent is also injected.
  • a pressure oil is fed to the screw-rotating means 34 to rotate the screw 32 .
  • the molding material fed from the hopper 35 is heated by the heater (not shown) mounted on the cylinder 31 , and is kneaded and compressed as the screw 32 rotates.
  • the resulting molten material is transferred in front of the screw 32 .
  • a pressure oil is fed to the screw-traveling means 33 to move the screw 32 forward, allowing a (molten) resin 124 (containing no foaming gas and no bubble-nucleating agent) transferred in front of the screw to be injected into the cavity 11 of the mold 100 (see FIG. 3( a )).
  • the mixing portion 150 switches the flow pass.
  • a pressure oil is then fed to the screw-rotating means 134 to rotate the screw 132 .
  • the molding material fed from the hopper 135 is heated by the heater (not shown) mounted on the cylinder 131 , and is kneaded and compressed as the screw 132 rotates.
  • the foaming gas and the bubble-nucleating agent are mixed and dispersed in a molten material.
  • the molten material is transferred in front of the screw 132 .
  • the (molten) resin 125 that contains the foaming gas and the bubble-nucleating agent dispersed therein and that is transferred in front of the screw is injected inside the previously charged molten resin 124 that contains no foaming gas and no bubble-nucleating agent (see FIG. 3( b )).
  • the mixing portion 150 changes the flow pass so that the remaining resin 124 is charged (see FIG. 3( d )). This prevents the resin 124 and the resin 125 to be mixed with each other in the next molding. While the injection volumes of the resins 124 and 125 are appropriately selected, it is important to prevent the resin 125 from being exposed at the surface of the resin 124 . After the molten resins 124 and 125 are completely charged, the pressure of a pressure oil applied to a piston head side of the mold-clamping cylinder 22 is lowered to reduce the mold-clamping force.
  • the pressure oil is then fed to the piston rod side of the mold-clamping cylinder 22 to move the piston rod backward.
  • the volume of the cavity 11 in the mold 100 is increased according to the setpoints of a unit for setting the position to which the movable platen 2 travels and the speed of the traveling, disposed in the clamping controller 72 .
  • the movable platen 2 stops at a predetermined position, and maintains the position so as not to be forced back by the resin-expansion pressure in the mold 100 .
  • the resin pressure in the cavity 11 of the mold 100 starts to decrease.
  • foaming starts within the resin 125 containing the foaming gas and the bubble-nucleating agent, which is enclosed with the resin 124 that contains no foaming gas and no bubble-nucleating agent.
  • the volume of the cavity 11 in the mold 100 is then maintained and cooled for a predetermined cooling time to form (solidify) a non-foamed layer 221 and a foam layer 222 (see FIG. 3( e )), thus producing a multilayer-molded product.
  • a two-layer molded product (multilayer-molded product) composed of one foam layer and one non-foamed layer was manufactured by the multilayer-molding method (foaming gas mixing method) illustrated in FIG. 2 using a horizontal toggle injection-molding machine (Ube Machinery Corporation, Ltd., UBE-MD350 injection-molding machine) as an injection-molding machine.
  • a horizontal toggle injection-molding machine Ube Machinery Corporation, Ltd., UBE-MD350 injection-molding machine
  • PP polypropylene resin
  • MFR automotive interior grade
  • TPO olefin thermoplastic elastomer
  • a mixture of sodium bicarbonate and citric acid was used as a bubble-nucleating agent and was premixed with the resin materials.
  • Carbon dioxide was used as a foaming gas, and was supplied into a molten resin in a cylinder at a pressure of 0.9 MPa.
  • a two-stage screw having a mixing head at the tip was used as a screw.
  • a gas-seal portion was adjusted according to the pressure of the foaming gas.
  • the two-layer molded product was a 350 ⁇ 220 mm automotive interior component (glove compartment door).
  • the molding conditions were a resin temperature of 200° C. and a mold temperature of 30° C.
  • the foaming status, the appearance, and the flexibility of the molded product were evaluated by visual inspection. Table 1 shows the results.
  • a two-layer molded product was manufactured as in Example 1, except that the foaming gas, the supply pressure of the foaming gas, and the thicknesses of the foam layer before and after foaming were changed.
  • the foaming status, the appearance, and the flexibility of the molded product were evaluated by visual inspection.
  • Table 1 shows the results, together with the foaming gas, the supply pressure, and the thicknesses of the foam layer before and after foaming.
  • a two-layer molded product was manufactured as in Example 1, except that no foaming gas was used, the foam layer was formed using sodium bicarbonate (inorganic chemical foaming agent), and the thicknesses of the foam layer before and after foaming were changed.
  • the foaming status, the appearance, and the flexibility of the molded product were evaluated by visual inspection. Table 1 shows the results.
  • a multilayer-molding method of molding thermoplastic resins and a multilayer-molding apparatus according to the present invention can be utilized as means for manufacturing any multilayer-molded product.
  • a multilayer-molding method of molding thermoplastic resins and a multilayer-molding apparatus according to the present invention can suitably be utilized as means for manufacturing products that require both high appearance quality and rigidity, for example, two-wheeled vehicle parts, automobile parts, household electrical appliances, and home equipment parts.
US11/990,780 2005-08-25 2006-08-23 Method for multilayer molding of thermoplastic resins and multilayer molding apparatus Abandoned US20090121375A1 (en)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011009745A1 (de) * 2009-07-21 2011-01-27 Kraussmaffei Technologies Gmbh Verfahren zur herstellung eines kunststoff-formteils mit einem geschäumten kern und einer ungeschäumten hülle
WO2012140474A1 (en) * 2011-04-13 2012-10-18 Partes S.R.L. Process to mould objects with a dust material
TWI413195B (zh) * 2011-01-20 2013-10-21 Walton Advanced Eng Inc 減少模封膠體內氣泡之壓縮模封方法與裝置
US20140077406A1 (en) * 2011-05-20 2014-03-20 Ube Machinery Corporation, Ltd. Injection molding method
CN107438506A (zh) * 2015-04-03 2017-12-05 全耐塑料高级创新研究公司 制造包括抗摇晃装置的由塑料材料制成的储箱的方法
US10137620B2 (en) * 2012-12-25 2018-11-27 Ube Machinery Corporation, Ltd. Method of manufacturing sandwich molded product, injection molding machine, and sandwich molded product
CN112776246A (zh) * 2019-11-11 2021-05-11 株式会社沙迪克 注射装置以及注射装置的气体溶解方法
EP4079486A1 (en) * 2021-04-20 2022-10-26 Metsä Spring Oy Method for forming a molded fiber product and a molded fiber product
CN115302661A (zh) * 2022-10-12 2022-11-08 四川航天拓达玄武岩纤维开发有限公司 一种玄武岩纤维增强型树脂基复合材料贮存设备及方法

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8308470B2 (en) * 2005-11-04 2012-11-13 University Of Southern California Extrusion of cementitious material with different curing rates
US8323793B2 (en) * 2007-05-17 2012-12-04 Tellus Technology, Inc. Pelletization of pyrolyzed rubber products
JP5259986B2 (ja) * 2007-05-25 2013-08-07 ソ・エッフェ・テル、テクノポリメリ、ソシエタ、ア、レスポンサビリタ、リミタータ 完全に再利用可能な多層物を製造するための射出成形方法
JP5349027B2 (ja) * 2008-12-03 2013-11-20 カルソニックカンセイ株式会社 二層発泡成形方法および装置
KR101304889B1 (ko) * 2011-04-22 2013-09-06 한일이화주식회사 자동차 내장재의 사출 성형 장치 및 그의 성형 방법
JP2015033849A (ja) * 2013-07-08 2015-02-19 積水テクノ成型株式会社 熱可塑性樹脂発泡成形体及びその製造方法
CN104275767A (zh) * 2013-07-12 2015-01-14 宁波大学 一种超临界流体输送装置
AT520140B1 (de) * 2016-03-03 2021-04-15 Niigon Machines Ltd Spritzgussmaschine mit zweiter Einspritzeinheit
US10870226B2 (en) * 2019-03-27 2020-12-22 Omachron Intellectual Property Inc. Apparatus and methods using multiple extruders
CN110982110B (zh) * 2019-12-23 2022-07-26 苏州申赛新材料有限公司 一种发泡制品的制备工艺及发泡制品
KR102482139B1 (ko) * 2020-10-16 2022-12-29 케이탑아이앤씨 주식회사 반도체 칩 픽업 장치 및 반도체 칩 픽업 장치의 하부 픽업부 제조 방법
KR102408586B1 (ko) * 2021-08-23 2022-06-16 광성기업 주식회사 금형 장치 및 사출 금형 방법

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5098274A (en) * 1989-01-25 1992-03-24 Continental Pet Technologies, Inc. Apparatus for injection molding of multilayer preforms
US5334356A (en) * 1991-04-05 1994-08-02 Massachusetts Institute Of Technology Supermicrocellular foamed materials
US5576080A (en) * 1993-12-20 1996-11-19 Sumitomo Chemical Company, Limited Polyethylenic foaming compositions and molded foams
US5702810A (en) * 1992-03-10 1997-12-30 Mitsubishi Chemical Corporation Cushioning composite molded article and a process for production thereof
US5922363A (en) * 1997-04-07 1999-07-13 Dtl Technology Limited Partnership Molding multi-layered articles using coinjection techniques
US6146577A (en) * 1997-05-21 2000-11-14 Asahi Kasei Kogyo Kabushiki Kaisha Method for injection molding of thermoplastic resins
US6325956B2 (en) * 1997-08-27 2001-12-04 The Dow Chemical Company Crosslinking of polymers and foams thereof
US20020036366A1 (en) * 1997-09-25 2002-03-28 Katsuya Maruyama Injection molding apparatus for molding multi-layered article and method of injection-molding multi-layered article
US6382946B1 (en) * 1998-04-01 2002-05-07 Dtl Technology Limited Partnership Molding multi-layered articles using coinjection techniques
US20030011090A1 (en) * 2000-05-31 2003-01-16 Hiroshi Yamaki Injection molding method
US20050006805A1 (en) * 2000-06-22 2005-01-13 Mitsui Chemicals, Inc. Composition for injection foaming
US20050245625A1 (en) * 2002-07-01 2005-11-03 Hirotaka Miyazaki Foamed injection molded item and method of foam injection molding

Family Cites Families (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3391423A (en) * 1964-08-07 1968-07-09 Osborn Mfg Co Apparatus for making abrasive articles
JPS439913Y1 (ja) 1965-05-29 1968-04-30
US3909169A (en) * 1972-01-20 1975-09-30 Ici Ltd Injection moulding apparatus
JPS5127266B2 (ja) 1972-07-01 1976-08-11
CH566207A5 (ja) * 1972-12-07 1975-09-15 Siemag Siegener Masch Bau
US4096218A (en) * 1973-07-19 1978-06-20 Asahi-Dow Limited Method of producing foamed thermoplastic resin articles having smooth and glossy surfaces free from swirl marks and hair cracks
US4017225A (en) * 1973-09-19 1977-04-12 Societa Internazionale Per Lo Sfruttamento Di Brevetti S.A. Apparatus for the production of synthetic-resin bodies having core and skin of different density
US4067673A (en) * 1975-09-02 1978-01-10 Ex-Cell-O Corporation Apparatus for injection foam molding
DE2612812C3 (de) * 1976-03-25 1983-05-26 Bayer Ag, 5090 Leverkusen Mischkopf zum Vermischen mindestens zweier bei ihrer Reaktion Schaumstoff bildender Komponenten
US4206165A (en) * 1976-03-26 1980-06-03 Tri-Seal International, Inc. Method of co-extrusion with foam core
US4164523A (en) * 1976-09-09 1979-08-14 Robert Hanning Method of injection-molding and cooling of shaped synthetic-resin bodies
US4124308A (en) * 1977-06-21 1978-11-07 Beloit Corporation Sequential co-injection unit adapted for structural foam molding
US4133858A (en) * 1977-12-14 1979-01-09 Usm Corporation Injection foam molding process
US4783292A (en) * 1987-06-15 1988-11-08 Rogers Roy K Method of injection molding a foamed plastic article using a relatively light gas as a blowing agent
WO1989000489A1 (en) * 1987-07-21 1989-01-26 Sumitomo Heavy Industries, Ltd. Injection molding method
JPH0323741A (ja) 1989-06-20 1991-01-31 Fujitsu Ltd 非同期伝送の調歩同期方式
JP3023741B2 (ja) 1992-03-10 2000-03-21 旭化成工業株式会社 クッション性複合成形品及び製造方法
US6403014B1 (en) * 1992-03-23 2002-06-11 Incoe Corporation Method for fluid compression of injection molded plastic material
US5344596A (en) * 1992-03-23 1994-09-06 Icp Systems, Inc. Method for fluid compression of injection molded plastic material
US5628944A (en) * 1992-10-30 1997-05-13 Toyoda Gosei Co., Ltd. Method and apparatus for molding two-color polyurethane parts by RIM
JP3358277B2 (ja) * 1994-03-28 2002-12-16 住友化学工業株式会社 多層成形体の製造方法
US5716560A (en) * 1995-09-14 1998-02-10 Icp Systems, Inc. Gas assisted injection molding combining internal and external gas pressures
EP0765722A1 (en) * 1995-09-28 1997-04-02 Siebolt Hettinga Method for controlling skin thickness of plastic article made with controlled density
US5997781A (en) * 1996-04-04 1999-12-07 Mitsui Chemicals, Inc. Injection-expansion molded, thermoplastic resin product and production process thereof
JP4144916B2 (ja) * 1996-04-04 2008-09-03 三井化学株式会社 熱可塑性樹脂発泡射出成形体およびその製造方法
ES2225692T3 (es) 1997-01-16 2005-03-16 Trexel, Inc. Moldeo por inyeccion de material microcelular.
US6884823B1 (en) * 1997-01-16 2005-04-26 Trexel, Inc. Injection molding of polymeric material
TW438658B (en) 1997-05-07 2001-06-07 Idemitsu Petrochemical Co Method of obtaining a gas-introduced fiber-reinforced resin injection molding and molding obtained by the same
JPH1177711A (ja) * 1997-09-01 1999-03-23 Sumitomo Chem Co Ltd 積層体の製造方法
MY118653A (en) * 1998-07-16 2004-12-31 Mitsui Chemicals Inc Addition method of supercritical carbon dioxide, and production process of expanded thermoplastic resin product by making use of the addition method.
US6322347B1 (en) * 1999-04-02 2001-11-27 Trexel, Inc. Methods for manufacturing foam material including systems with pressure restriction element
JP4233240B2 (ja) * 2000-06-22 2009-03-04 三井化学株式会社 射出発泡成形方法、並びにそれに適した射出成形機および樹脂組成物
US6602063B1 (en) * 2000-07-21 2003-08-05 Trexel, Inc. Discontinuous blowing agent delivery system and method
US6616434B1 (en) * 2000-08-10 2003-09-09 Trexel, Inc. Blowing agent metering system
US6790020B2 (en) * 2000-12-12 2004-09-14 Sumitomo Chemical Company, Limited System for producing foamed article, a molten resin preparing apparatus and a molding apparatus for use in foamed article production system
JP4551003B2 (ja) * 2001-01-05 2010-09-22 積水化学工業株式会社 熱可塑性エラストマー発泡体の製造方法および熱可塑性エラストマー発泡体
JP2002307473A (ja) * 2001-04-09 2002-10-23 Grand Polymer Co Ltd 発泡成形体の製造方法
US20030003291A1 (en) * 2001-07-02 2003-01-02 Shah Suresh D. Foamed thermoplastic resin having fiber reinforcing and apparatuses for making
US6997690B2 (en) * 2001-08-08 2006-02-14 Masco Corporation Flushless mold valve assembly
JP4244809B2 (ja) 2002-02-28 2009-03-25 宇部興産機械株式会社 発泡射出成形方法
JP2004034381A (ja) * 2002-07-01 2004-02-05 Asahi Kasei Chemicals Corp 偏肉成形品の発泡射出成形法
JP2004066501A (ja) * 2002-08-02 2004-03-04 Japan Steel Works Ltd:The 厚肉発泡サンドイッチ成形品の成形方法および厚肉発泡サンドイッチ成形品
JP3951910B2 (ja) * 2002-12-20 2007-08-01 宇部興産機械株式会社 多層射出成形装置の制御方法
JP2005074794A (ja) 2003-08-29 2005-03-24 Mitsui Chemicals Inc 熱可塑性樹脂組成物発泡成形体の成形装置

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5098274A (en) * 1989-01-25 1992-03-24 Continental Pet Technologies, Inc. Apparatus for injection molding of multilayer preforms
US5334356A (en) * 1991-04-05 1994-08-02 Massachusetts Institute Of Technology Supermicrocellular foamed materials
US5702810A (en) * 1992-03-10 1997-12-30 Mitsubishi Chemical Corporation Cushioning composite molded article and a process for production thereof
US5576080A (en) * 1993-12-20 1996-11-19 Sumitomo Chemical Company, Limited Polyethylenic foaming compositions and molded foams
US5922363A (en) * 1997-04-07 1999-07-13 Dtl Technology Limited Partnership Molding multi-layered articles using coinjection techniques
US6146577A (en) * 1997-05-21 2000-11-14 Asahi Kasei Kogyo Kabushiki Kaisha Method for injection molding of thermoplastic resins
US6325956B2 (en) * 1997-08-27 2001-12-04 The Dow Chemical Company Crosslinking of polymers and foams thereof
US20020036366A1 (en) * 1997-09-25 2002-03-28 Katsuya Maruyama Injection molding apparatus for molding multi-layered article and method of injection-molding multi-layered article
US6382946B1 (en) * 1998-04-01 2002-05-07 Dtl Technology Limited Partnership Molding multi-layered articles using coinjection techniques
US20030011090A1 (en) * 2000-05-31 2003-01-16 Hiroshi Yamaki Injection molding method
US20050006805A1 (en) * 2000-06-22 2005-01-13 Mitsui Chemicals, Inc. Composition for injection foaming
US20050245625A1 (en) * 2002-07-01 2005-11-03 Hirotaka Miyazaki Foamed injection molded item and method of foam injection molding

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Dennis Rodrigue and Ryan Gosselin; Blowing Agents and Foaming Processes 2003; May 2003; Rapra Technology Ltd; Fifth International Conference; Page 169 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011009745A1 (de) * 2009-07-21 2011-01-27 Kraussmaffei Technologies Gmbh Verfahren zur herstellung eines kunststoff-formteils mit einem geschäumten kern und einer ungeschäumten hülle
TWI413195B (zh) * 2011-01-20 2013-10-21 Walton Advanced Eng Inc 減少模封膠體內氣泡之壓縮模封方法與裝置
WO2012140474A1 (en) * 2011-04-13 2012-10-18 Partes S.R.L. Process to mould objects with a dust material
US10040225B2 (en) 2011-05-20 2018-08-07 Ube Machinery Corporation, Ltd. Injection molding method
US9636852B2 (en) * 2011-05-20 2017-05-02 Ube Machinery Corporation, Ltd. Injection molding method
US20140077406A1 (en) * 2011-05-20 2014-03-20 Ube Machinery Corporation, Ltd. Injection molding method
US10137620B2 (en) * 2012-12-25 2018-11-27 Ube Machinery Corporation, Ltd. Method of manufacturing sandwich molded product, injection molding machine, and sandwich molded product
CN107438506A (zh) * 2015-04-03 2017-12-05 全耐塑料高级创新研究公司 制造包括抗摇晃装置的由塑料材料制成的储箱的方法
EP3277474B1 (fr) * 2015-04-03 2020-07-15 Plastic Omnium Advanced Innovation and Research Procede de fabrication d'un reservoir en matiere plastique avec dispositif anti-ballottement
US11155008B2 (en) 2015-04-03 2021-10-26 Plastic Omnium Advanced Innovation And Research Method for the production of a plastic tank comprising an anti-slosh device
CN112776246A (zh) * 2019-11-11 2021-05-11 株式会社沙迪克 注射装置以及注射装置的气体溶解方法
EP4079486A1 (en) * 2021-04-20 2022-10-26 Metsä Spring Oy Method for forming a molded fiber product and a molded fiber product
WO2022223880A1 (en) * 2021-04-20 2022-10-27 Metsä Spring Oy Method for forming a molded fiber product and a molded fiber product
CN115302661A (zh) * 2022-10-12 2022-11-08 四川航天拓达玄武岩纤维开发有限公司 一种玄武岩纤维增强型树脂基复合材料贮存设备及方法

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US8262378B2 (en) 2012-09-11
CA2618877A1 (en) 2007-03-01
WO2007023860A1 (ja) 2007-03-01
JP4839728B2 (ja) 2011-12-21
KR20080046174A (ko) 2008-05-26
US20100015268A1 (en) 2010-01-21
KR101275053B1 (ko) 2013-06-17
JP2007055121A (ja) 2007-03-08

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