An injection molding device includes a barrel, an injection screw, and an injection driving unit, wherein the injection screw includes a screw body, a screw head coupled to a front end of the screw body, and a check ring coupled to the screw head, the check ring including an accommodation groove that accommodates a portion of the screw head, a front member disposed in front of the screw head accommodated in the accommodation groove, and an accommodation member connected to the front member and surrounding a side surface of the at least a portion of the screw head accommodated in the accommodation groove, and when the injection screw moves forward to supply a molding material in the barrel to a clamping device, as the front member is pushed by the molding material accumulated on a front side of the injection screw, the check ring moves rearward from the screw head.

The present disclosure relates to a screw of an injection molding machine in which a heating cylinder is formed with a first compression section, a starvation section, and a second compression section, and in which an inert gas is to be introduced into the starvation section. At a portion of the screw corresponding to the first compression section, a barrier flight as a double flight including a combination of a main flight and a sub-flight having a lead angle larger than that of the main flight is formed, and a dam flight having a predetermined-width ring shape is formed, downstream of, i.e., in front of the barrier flight. A seal structure to prevent backflow of the resin may be provided between the dam flight and the starvation section.

The present disclosure relates to a screw of an injection molding machine in which a heating cylinder is formed with a first compression section, a starvation section, and a second compression section, and in which an inert gas is to be introduced into the starvation section. At a portion of the screw corresponding to the first compression section, a barrier flight as a double flight including a combination of a main flight and a sub-flight having a lead angle larger than that of the main flight is formed, and a dam flight having a predetermined-width ring shape is formed, downstream of, i.e., in front of the barrier flight. A seal structure to prevent backflow of the resin may be provided between the dam flight and the starvation section.

The present disclosure prevents load from being produced in an injection molding machine. The control device for an injection molding machine according to one embodiment of the present disclosure has a determining part that is configured to determine, based on information detected in accordance with a movement of a measurement motor provided in the injection molding machine, whether or not an operation of removing or attaching a screw that rotates in accordance with the measurement motor has been performed.

An abrasion amount estimation device stores a learning result obtained through supervised learning performed based on a feature amount, which is extracted from a physical amount which is acquired in injection performed by an injection molding machine, and information related to an abrasion amount of a check valve which has been attached to the injection molding machine in the injection. The abrasion amount estimation device estimates an abrasion amount of a check valve which has been attached to the injection molding machine in the injection based on the learning result which is stored and the feature amount which is extracted.

A modular barrel and screw assembly for use in injection molding including a barrel having a barrel body, a separate barrel injection portion and a separate barrel end cap, with the barrel end cap being removably connected to the barrel injection portion and the barrel injection portion being removably connected to the barrel body, and a screw assembly having a screw tip assembly removably connected to a screw portion, wherein an injection chamber having a shot volume is defined by the barrel injection portion, the barrel end cap and the screw tip assembly. The modular barrel and screw assembly enables servicing of the barrel injection portion, barrel end cap and/or screw tip assembly without requiring removal of the barrel body, and enables use of a plurality of alternative corresponding separate barrel injection portions, separate barrel end caps and tip assemblies that provide a plurality of different shot volumes.

A kneading apparatus for a thermoplastic resin, includes: a plasticizing cylinder which has a high pressure kneading zone and a pressure reduction zone; a screw in the plasticizing cylinder; a downstream side seal mechanism which shuts off communication between the high pressure kneading zone and the pressure reduction zone; and a pressure reduction zone pressure adjusting mechanism which is connected to the pressure reduction zone and which controls a pressure of the pressure reduction zone so that the pressure is not less than an atmospheric pressure and the pressure is not more than a maximum pressure of the high pressure kneading zone that is achieved when kneading a molten resin with a pressurized fluid, when the downstream side seal mechanism shuts off the communication between the high pressure kneading zone and the pressure reduction zone.

A kneading apparatus for a thermoplastic resin, includes: a plasticizing cylinder which has a high pressure kneading zone and a pressure reduction zone; a screw in the plasticizing cylinder; a downstream side seal mechanism which shuts off communication between the high pressure kneading zone and the pressure reduction zone; and a pressure reduction zone pressure adjusting mechanism which is connected to the pressure reduction zone and which controls a pressure of the pressure reduction zone so that the pressure is not less than an atmospheric pressure and the pressure is not more than a maximum pressure of the high pressure kneading zone that is achieved when kneading a molten resin with a pressurized fluid, when the downstream side seal mechanism shuts off the communication between the high pressure kneading zone and the pressure reduction zone.

A plasticizing device includes a plasticizing cylinder and a plasticizing screw arranged in the plasticizing cylinder. The plasticizing screw is rotatable about, and linearly movable along, a longitudinal axis. The plasticizing screw comprises a functioning section. A sensor is arranged in or on the plasticizing cylinder, and a distance to the surface of the functioning section of the plasticizing screw can be measured by the sensor. A detecting device can detect a type of the functioning section and/or an operating state of the functioning section, can detect a distance signal progression by a movement of the functioning section relative to the sensor, can compare the detected distance signal progression with a stored distance signal progression, and can issue a signal representing the type of functioning section and/or the operating state of the functioning section depending on a matching of the detected distance signal progression with a stored distance signal progression.

A partial reflux injection function part 5 is provided according to which resin R at the front side of a screw head portion 4s is injected into the metal mold 2 to fill the metal mold 2 with the resin R in synchronization with the refluxing of a predetermined amount of the reflux resin Rm to be used as a part of the resin R to the screw body part 4m side at the rear side of the screw head portion 4s through the inner side of the screw head portion 4s and/or the outer periphery side of the screw head portion 4s. A control function is provided that sequentially performs a plasticization step Wi1 to rotate the screw 4 in the heating cylinder 3 to thereby subject the resin in the heating cylinder 3 to a plasticization processing; an injection step Wi2 to allow, after the completion of the plasticization step Wi1, the screw 4 to move forward to thereby inject, into the metal mold 2, a part of the plasticized resin R accumulated at the front side of the screw head portion 4s of the screw 4 to fill the metal mold 2 with the resin; and a plasticization promotion step Wi3 to allow, after the completion of the injection step Wi2, a part of the remaining part of the accumulated plasticized resin R to be refluxed as the reflux resin Rm to the rear side of the screw head portion 4s.