An injection molding apparatus includes a mixing section having a hollow cylinder and a stirring member disposed in the cylinder, the mixing section generating a mixed material by using the stirring member to mix a first liquid and a second liquid that flow through the cylinder, the first liquid containing a thermoset material and the second liquid containing a polymerization initiator for initiating a polymerization reaction of the thermoset material, an injection section having a nozzle and being configured to inject the mixed material from the nozzle toward a cavity defined by a fixed molding die and a movable molding die, and a detection section configured to detect a state in the cylinder.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

An injection molding apparatus (5), comprising: a first fluid drive cylinder (940c, 941c, 942c), a second fluid drive cylinder (940ac, 941ac, 942ac) interconnected to a valve pin (1040, 1041, 1042), wherein the first fluid drive cylinder (940c, 941c, 942c) and the second fluid drive cylinder (940ac, 941ac, 942ac) are interconnected in an arrangement wherein reciprocating movement of a piston (940p, 941p, 942p) of the first cylinder drives concomitant back and forth movement of a piston (940ap, 941ap, 942ap) of the second cylinder and concomitant back and forth movement of the valve pin (1040, 1041, 1042); an electrically powered actuator (940, 941, 942) adapted to drive the piston of the first cylinder reciprocally according to a drive program such that the valve pin (1040, 1041, 1042) is driven between gate closed and gate open positions and selected positions therebetween.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

An injection molding machine and a viscosity measurement method of the disclosure are provided with an injection cylinder to which a viscosity measurement unit is attachable and detachable and a control device. When setting an inner diameter of the injection cylinder or an outer diameter of the injection shaft as D. For a capillary installed to the viscosity measurement unit, a capillary inner diameter is set as d. By respectively using three or more values .sub.k of the shear rate, k being a natural number, the control device is configured to calculate injection velocities V.sub.k based on Formula (1) and automatically sets a value of the injection velocity V.sub.k within a predetermined range, among the calculated injection velocities, as an injection velocity at a time of viscosity measurement.

[00001]$\left[\mathrm{Formula}\left(1\right)\right]$$\begin{array}{cc}{V}_k=\frac{d^3}{8D^2}{}_k& \left(1\right)\end{array}$

An injection apparatus (100) for injecting molten plastic, in particular PET, into a mold for molding bottle preforms; the injection apparatus (100) comprisinga first injector (1) and a second injector (2) adapted to receive molten plastic and inject it into the mold alternately to each other; a conduit (8) adapted to carry molten plastic from a plasticization apparatus (102) towards the first injector (1) and towards the second injector (2); a third injector (3) provided with a piston (32), the third injector (3) being connected to the conduit (8) so as to receive molten plastic from the conduit (8) and then inject it into the conduit (8); actuation means (34) adapted to cause the piston (32) of the third injector (3) to move forward to inject the molten plastic into the conduit (8); wherein said actuation means (34) are adapted to control the backward movement of the piston (32) of the third injector (3) while it receives the molten plastic from the conduit (8).

An injection molding machine and a viscosity measurement method of the disclosure are provided with an injection cylinder to which a viscosity measurement unit is attachable and detachable and a control device. When setting an inner diameter of the injection cylinder or an outer diameter of the injection shaft as D. For a capillary installed to the viscosity measurement unit, a capillary inner diameter is set as d. By respectively using three or more values .sub.k of the shear rate, k being a natural number, the control device is configured to calculate injection velocities V.sub.k based on Formula (1) and automatically sets a value of the injection velocity V.sub.k within a predetermined range, among the calculated injection velocities, as an injection velocity at a time of viscosity measurement. $\left[\mathrm{Formula}\left(1\right)\right]$$\begin{array}{cc}{V}_k=\frac{d^3}{8D^2}{}_k& \left(1\right)\end{array}$