A mold for reducing a molding cycle time and a cost, the mold including a first cavity and a second cavity includes a hot runner that is a flow path to inject a resin injected from an injection unit into the first cavity and the second cavity, and a switching valve configured to divide the flow path into a first flow path connected to the first cavity and a second flow path connected to the second cavity. The injection unit is connected to the first flow path. A pressurizing mechanism is connected to the second flow path.

A mold device where a pressurized fluid is injected into a clearance between a resin injected into a cavity and a cavity wall surface, the mold device including: a shaft body provided on at least one of a first mold and a second mold, the first mold and the second mold forming a molding space, the shaft body ejecting a molded article molded from the resin injected into the molding space; a ring-shaped elastic member for supporting and sealing the shaft body, an opening of a groove formed in the ring-shaped elastic member along a circumferential direction of the ring-shaped elastic member being oriented toward the molding space, a load being applied on the ring-shaped elastic member to improve adhesion to the shaft body; and an injection portion provided on at least one of the first mold and the second mold for injecting the pressurized fluid into the molding space.

A mold device where a pressurized fluid is injected into a clearance between a resin injected into a cavity and a cavity wall surface, the mold device including: a shaft body provided on at least one of a first mold and a second mold, the first mold and the second mold forming a molding space, the shaft body ejecting a molded article molded from the resin injected into the molding space; a ring-shaped elastic member for supporting and sealing the shaft body, an opening of a groove formed in the ring-shaped elastic member along a circumferential direction of the ring-shaped elastic member being oriented toward the molding space, a load being applied on the ring-shaped elastic member to improve adhesion to the shaft body; and an injection portion provided on at least one of the first mold and the second mold for injecting the pressurized fluid into the molding space.

The present invention relates to a thermoplastic resin substrate for a curved mirror and a method for preparing the same, and a curved mirror and a head-up display comprising the thermoplastic resin substrate. The preparation method comprises the following steps: A) heating up a mold of an injection molding machine to a temperature in a range of 130-190° C. and closing the mold, B) injecting a molten thermoplastic resin into the cavity of the mold cavity, C) applying a pressure of 300-700 bar to the cavity for a period of 5 or more seconds, D) stopping applying pressure and cooling the mold to a temperature in a range of 60-100° C. within 10-50 seconds, and E) opening the mold and taking out the molded thermoplastic resin substrate, wherein a gap of 0.3-1 mm is left between the parting surfaces of the cavity of the mold prior to applying the pressure to the cavity. The thermoplastic resin substrate according to the present invention features a large size, high dimensional stability, and low surface roughness. It can be used for future augmented reality head-up displays to realize large-area, long-distance projection and high-precision imaging, thereby satisfying the requirements for driving safety and comfort of future automobiles.

[Problem] The present invention relates to a manufacturing method for obtaining a molded article having an expanded layer in the molded article, wherein an expanding agent and device used to manufacture a resin having expansion properties, and a means for increasing expansion ratio are provided.

[Solution] In the present invention, an expanding agent placed in a heating cylinder of a molding machine is configured as a liquid, the volume of the expanding agent is controlled, and the expanding agent is injected into a molten resin in the heating cylinder of the molding machine. The volume of the injected expanding agent can thereby be accurately measured each time. When a low-boiling liquid such as water, an alcohol, or an ether is used as the injected expanding agent, all of the liquid is vaporized by the temperature of the heating cylinder of the molding machine, and no residue thereof is therefore left in the molded article. When sodium bicarbonate water is used as the injected expanding agent, solvent water vaporizes and water vapor also becomes expandable gas, which is less expensive than using sodium bicarbonate as the expanding agent for a master batch using the resin that is to be molded.

[Problem] The present invention relates to a manufacturing method for obtaining a molded article having an expanded layer in the molded article, wherein an expanding agent and device used to manufacture a resin having expansion properties, and a means for increasing expansion ratio are provided.

[Solution] In the present invention, an expanding agent placed in a heating cylinder of a molding machine is configured as a liquid, the volume of the expanding agent is controlled, and the expanding agent is injected into a molten resin in the heating cylinder of the molding machine. The volume of the injected expanding agent can thereby be accurately measured each time. When a low-boiling liquid such as water, an alcohol, or an ether is used as the injected expanding agent, all of the liquid is vaporized by the temperature of the heating cylinder of the molding machine, and no residue thereof is therefore left in the molded article. When sodium bicarbonate water is used as the injected expanding agent, solvent water vaporizes and water vapor also becomes expandable gas, which is less expensive than using sodium bicarbonate as the expanding agent for a master batch using the resin that is to be molded.

An extruder has a barrel extending from a feed inlet end to an extruder outlet end. The barrel has an inner surface, an outer surface, and a wall thickness between the inner and outer surfaces. The extruder also has at least one heating member positioned provided on the barrel; a screw drive motor drivingly connected to a rotatably mounted screw positioned within the barrel, whereby the screw is rotatable at various revolutions per minute (RPM); and a controller is operably connected to the screw drive motor to adjust the RPM of the screw based upon a temperature of material passing through and/or being extruded from the barrel. Methods for operating an extruder filling a mold are also provided.

An extruder has a barrel extending from a feed inlet end to an extruder outlet end. The barrel has an inner surface, an outer surface, and a wall thickness between the inner and outer surfaces. The extruder also has at least one heating member positioned provided on the barrel; a screw drive motor drivingly connected to a rotatably mounted screw positioned within the barrel, whereby the screw is rotatable at various revolutions per minute (RPM); and a controller is operably connected to the screw drive motor to adjust the RPM of the screw based upon a temperature of material passing through and/or being extruded from the barrel. Methods for operating an extruder filling a mold are also provided.

Two molded articles having a cylindrical two-piece split shape is formed by forming two primary cavities in a desired shape with molds assembled together and injecting a molten primary resin into the two primary cavities. An assist material is injected into a secondary cavity into which a molten secondary resin is injected in a state where the two molded articles are located opposed to each other via a space therebetween and internally fitted into one secondary cavity formed by the molds that are assembled together by shifting the positions. A flange portion having any desired shape is disposed on an outer circumferential surface of a resin pipe in a two-layer structure in which an inner surface layer formed of the cured secondary resin is integrated with an outer surface layer formed of the two molded articles. Thus, a portion having any desired shape is easily manufactured on the resin pipe.

Two molded articles having a cylindrical two-piece split shape is formed by forming two primary cavities in a desired shape with molds assembled together and injecting a molten primary resin into the two primary cavities. An assist material is injected into a secondary cavity into which a molten secondary resin is injected in a state where the two molded articles are located opposed to each other via a space therebetween and internally fitted into one secondary cavity formed by the molds that are assembled together by shifting the positions. A flange portion having any desired shape is disposed on an outer circumferential surface of a resin pipe in a two-layer structure in which an inner surface layer formed of the cured secondary resin is integrated with an outer surface layer formed of the two molded articles. Thus, a portion having any desired shape is easily manufactured on the resin pipe.