A plasticization device that plasticizes a material, includes: a drive motor; a rotor that is to be rotated by the drive motor and has a groove-forming surface in which a curved projection strip portion is formed from a peripheral edge of a circular central portion toward an outer periphery of the rotor; a barrel that faces the groove-forming surface and includes a communication hole at a position facing the central portion of the groove-forming surface; and a heating unit that heats the material supplied between the rotor and the barrel, the rotor includes a protrusion protruding from the central portion toward the communication hole, and
0.28?S2/S1?1.03(1), wherein S1 is an area of the central portion and S2 is a maximum area of a cross section of the protrusion along the groove-forming surface.

A thermosetting composition for injection molding comprising: (A) a compound represented by the following formula (A2) or (A3), and (B) a thermal polymerization initiator; wherein the composition further comprises no (G) titanium oxide or comprises (G) titanium oxide, when the composition comprises the component (G), the content of the component (G) is 5 parts by mass or less, based on a total of 100 parts by mass of components other than the component (B) and the component (C); and the composition comprises no polybutadiene di(meth)acrylate:

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An injection apparatus including a plasticizing unit (2) that plasticizes a raw material resin and an injection unit (3) that injects a plasticized molten resin. The plasticizing unit includes a heating cylinder (20) having a foaming gas injection valve and a screw (21) provided inside the heating cylinder. The rotation and advance and retreat movements of the screw are controlled such that a raw material resin is plasticized by the screw and a foaming gas injected from a foaming gas injection valve is dissolved in the plasticized molten resin. After the screw retreats to a prescribed position according as the molten resin accumulates in the front end side of the heating cylinder by the screw that is rotating, the screw advances with rotating to cause the molten resin which has been accumulated in the front end side of the heating cylinder to be transferred to the injection unit.

An injection apparatus including a plasticizing unit (2) that plasticizes a raw material resin and an injection unit (3) that injects a plasticized molten resin. The plasticizing unit includes a heating cylinder (20) having a foaming gas injection valve and a screw (21) provided inside the heating cylinder. The rotation and advance and retreat movements of the screw are controlled such that a raw material resin is plasticized by the screw and a foaming gas injected from a foaming gas injection valve is dissolved in the plasticized molten resin. After the screw retreats to a prescribed position according as the molten resin accumulates in the front end side of the heating cylinder by the screw that is rotating, the screw advances with rotating to cause the molten resin which has been accumulated in the front end side of the heating cylinder to be transferred to the injection unit.

As an injection screw 2 applies pressure, a holding pressure plunger 22 is moved backward under the pressure of a resin to flow the resin into a holding pressure path 9, and the resin in a resin path 6 is pressurized (primary holding pressure process). A shutoff plunger 12 is closed, and the resin in the resin path 6 and the holding pressure path 9 is pressurized by the holding pressure plunger 22 (secondary holding pressure process). Further, the shutoff plunger 12 is opened, and the holding pressure plunger 22 is moved forward until its tip projects into the resin path 6 to discharge all the resin in the holding pressure path 9 to the resin path 6, whereby the resin beside the injection screw 2 as compared with the shutoff plunger 12 is held with respect to the holding pressure path 9.

As an injection screw 2 applies pressure, a holding pressure plunger 22 is moved backward under the pressure of a resin to flow the resin into a holding pressure path 9, and the resin in a resin path 6 is pressurized (primary holding pressure process). A shutoff plunger 12 is closed, and the resin in the resin path 6 and the holding pressure path 9 is pressurized by the holding pressure plunger 22 (secondary holding pressure process). Further, the shutoff plunger 12 is opened, and the holding pressure plunger 22 is moved forward until its tip projects into the resin path 6 to discharge all the resin in the holding pressure path 9 to the resin path 6, whereby the resin beside the injection screw 2 as compared with the shutoff plunger 12 is held with respect to the holding pressure path 9.

[Problem] To provide an injection apparatus including a flow path switching mechanism that is simple in construction and low in cost.

[Solution] An injection apparatus (1) includes a plasticization device (2) for melting resin, a first and second plunger injection devices (4, 5) for measuring an amount of resin and injecting the resin, an injecting portion (8), and a flow path switching block (7) that connects the plasticization device, the first and second plunger injection devices and the injecting portion together. A first to fourth connecting flow paths (23a, 23b) and a flow path switching valve (21) are provided in the flow path switching block (7). The plasticization device (2), the first plunger injection device (4), the injecting portion (8) and the second plunger injection device (5) are connected to the first to fourth connecting flow paths (23a, 23b), respectively. When the flow path switching valve (21) is switched to a first position, the first and second connecting flow paths (23a, 23b) communicate with each other, and the third and fourth connecting flow paths (23c, 23d) communicate with each other, whereas when the flow path switching valve (21) is switched to a second position, the first and fourth connecting flow paths (23a, 23d) communicate with each other and the first and third connecting flow paths (23b, 23c) communicate with each other.

A plasticizing process in which a molten resin that has been plasticized and dissolved in a foaming gas is sent to the front end side of a heating cylinder (20) by means of a screw (21) that rotates in a heating cylinder (20), and the screw (21) retreats according as the molten resin accumulates in the front end side of the heating cylinder (20); a transfer process in which the screw (21) is advanced with rotating and transfers the molten resin accumulated in the front end side of the heating cylinder (20) from a plasticizing unit (2) to an injection unit (3), and an injection process in which the molten resin is injected from the injection unit (3) are conducted and repeated to produce a foamable injection molded product.

A plasticizing process in which a molten resin that has been plasticized and dissolved in a foaming gas is sent to the front end side of a heating cylinder (20) by means of a screw (21) that rotates in a heating cylinder (20), and the screw (21) retreats according as the molten resin accumulates in the front end side of the heating cylinder (20); a transfer process in which the screw (21) is advanced with rotating and transfers the molten resin accumulated in the front end side of the heating cylinder (20) from a plasticizing unit (2) to an injection unit (3), and an injection process in which the molten resin is injected from the injection unit (3) are conducted and repeated to produce a foamable injection molded product.

Disclosed is a method of adjusting a motion profile of a shooting pot plunger for use in a molding system, the shooting pot plunger slidably movable within a shooting pot cavity, the method comprising: sensing a characteristic at a predetermined location in an injection circuit of the molding system; determining that the sensed characteristic is outside of a threshold range; adjusting the motion profile of the shooting pot plunger to account for determining that the sensed characteristic is outside of the threshold range; and storing the adjusted motion profile in a memory.