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JP-7855409-B2 - injection molding machine

JP7855409B2JP 7855409 B2JP7855409 B2JP 7855409B2JP-7855409-B2

Inventors

  • 中井戸 宙
  • 岡坂 周
  • 飯島 透

Assignees

  • 住友ベークライト株式会社
  • 日精樹脂工業株式会社

Dates

Publication Date
20260508
Application Date
20220606

Claims (7)

  1. An injection molding machine for a thermosetting resin composition, comprising a heating cylinder having a heater , a nozzle provided at the tip of the heating cylinder, and a screw provided inside the heating cylinder so as to be able to move back and forth, The nozzle has a temperature adjustment unit provided in the nozzle for adjusting the temperature of the nozzle, An injection molding machine in which, when d1 is the distance from the temperature control unit to the resin flow path in the nozzle, and d2 is the distance from the heater in the heating cylinder to the resin flow path in the resin mixing unit of the heating cylinder, d1 < d2, and the depth and pitch of the screw groove are constant over the entire effective length of the screw .
  2. The injection molding machine according to claim 1, wherein the temperature control unit has a flow path for circulating a heat transfer medium, and the temperature of the nozzle is adjusted by circulating the heat transfer medium.
  3. The injection molding machine according to claim 1 or 2, wherein the ratio L/D of the effective screw length L to the screw diameter D of the screw is 12.5 or more and 17.5 or less.
  4. The injection molding machine according to claim 1 or 2, wherein the screw advances in the direction of the nozzle, causing the thermosetting resin composition in the heating cylinder to be injected from the nozzle into the mold.
  5. The injection molding machine according to claim 1 or 2, wherein the temperature of the thermosetting resin composition injected from the nozzle is adjusted to 80°C or higher and 130°C or lower.
  6. The injection molding machine according to claim 1 or 2, wherein the injection molding machine is a single-screw extruder.
  7. The injection molding machine according to claim 1 or 2, wherein the temperature adjustment unit is attached so as to wrap around the outer surface of the nozzle .

Description

This invention relates to an injection molding machine for thermosetting resin compositions. In injection molding of thermosetting resins, controlling the amount of heat applied to maintain the thermosetting resin's temperature within an appropriate range is crucial for producing molded products of proper quality. Specifically, it is necessary to ensure the thermosetting resin has a viscosity that allows for easy flow and a temperature that inhibits curing. For example, an injection molding machine for thermosetting resins is disclosed, comprising: a heating cylinder with first and second flow channels arranged sequentially from the nozzle side; a first switching device that switches the flow of each medium so that one of a high-temperature medium, a medium, or a low-temperature medium flows through the first flow channel; a temperature controller for the high-temperature medium; and a control device (see, for example, Patent Document 1). Japanese Patent Publication No. 2022-56150 This is a cross-sectional view showing the schematic configuration of an injection molding machine according to an embodiment.This is a front view of an injection molding machine according to an embodiment.This is a cross-sectional view of a heating cylinder according to an embodiment.This is an enlarged view of region A1 in Figure 1 according to the embodiment.This is an enlarged view of region A2 in Figure 3 according to the embodiment.This is a diagram showing a screw according to an embodiment.This figure illustrates a comparative example molded product and an example molded product related to an embodiment of the embodiment.This figure shows the evaluation results of molded product stability (30 continuous shots) according to an embodiment of the model.This figure shows the evaluation results of the molding stability after holding for 3 minutes, according to an example of the embodiment.This figure shows the evaluation results of a stability comparison between a large molding machine and a 100t molding machine according to an embodiment of the model.This figure shows the evaluation results of spiral flow according to an embodiment of the model. <Overview> The injection molding machine 1 of this embodiment will be described with reference to Figures 1 to 6. Figure 1 is a cross-sectional view showing the schematic configuration of the injection molding machine 1, and is the cross-sectional view taken along the line X1-X1 in Figure 2. Figure 2 is a front view of the injection molding machine 1, taken along the line X in Figure 1. Figure 3 is a cross-sectional view of the injection molding machine 1, with the screw 50, hopper 80, and mold 90 removed from Figure 1. Figure 4 is an enlarged view of area A1 in Figure 1, showing an enlarged view of the tip side of the nozzle 20. Figure 5 is an enlarged view of area A2 in Figure 3, showing an enlarged view of the tip side of the nozzle 20 with the screw 50 removed. Figure 6 is a side view of the screw 50. The injection molding machine 1 is for thermosetting resin compositions and comprises a heating cylinder 10, a nozzle 20 provided at the tip of the heating cylinder 10, and a screw 50 provided inside the heating cylinder 10 so as to be able to move back and forth. The machine also includes a nozzle temperature adjustment unit 40 provided on the nozzle 20 for adjusting the temperature of the nozzle 20. This configuration allows for appropriate temperature control of the thermosetting resin composition not only in the heating cylinder 10 but also up to the tip of the nozzle 20, suppressing variations during molding and achieving stable molding. Further details are provided below. <Injection molding machine 1 overview> The injection molding machine 1 injects molten thermosetting resin composition into a mold 90 to manufacture a resin molded product. The injection molding machine 1 includes a heating cylinder 10, a nozzle 20, a heating cylinder heater 30, a nozzle temperature adjustment unit 40, and a screw 50. In this embodiment, a single-screw extruder is exemplified as the injection molding machine 1, and a straight-type, full-flight screw is exemplified as the screw 50. However, other configurations may be applied as long as they do not depart from the spirit of the present invention. In addition to the above configuration, the injection molding machine 1 may also have other configurations not shown, such as a control device for controlling the injection molding machine 1, a drive device for the screw 50, a pressure sensor, a metering device, etc. <Heating cylinder 10> The heating cylinder 10 is a cylindrical member that is elongated from left to right in the diagram. Inside the heating cylinder 10, there is a resin mixing section 13 (resin path) through which the screw 50 is inserted. A nozzle 20 is provided at the tip of the heating cylinder 10 (the left end in the diagram). A hopper 80 (see Figure 1) is attached to a resin supply port 25, which is an opening located at the upper re