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.

A nonreturn valve includes two half-shells, arranged in a portion of the screw with a reduced screw diameter. One or more channels for the melt to flow through from the screw into the space in front of the screw is/are provided in each of the half-shells, the channels lie substantially parallel to the longitudinal axis of the nonreturn valve or of the screw. In each of the channels are a ball and, following the ball in the direction of flow of the melt, a pin arranged substantially transversely to the direction of flow of the melt. In the direction of flow of the melt, the channels have a first channel portion, with a channel diameter less than the diameter of the ball, and a second channel portion, with a channel diameter greater than the diameter of the ball, the ball and the pin are arranged in the second channel portion.

A nonreturn valve includes two half-shells, arranged in a portion of the screw with a reduced screw diameter. One or more channels for the melt to flow through from the screw into the space in front of the screw is/are provided in each of the half-shells, the channels lie substantially parallel to the longitudinal axis of the nonreturn valve or of the screw. In each of the channels are a ball and, following the ball in the direction of flow of the melt, a pin arranged substantially transversely to the direction of flow of the melt. In the direction of flow of the melt, the channels have a first channel portion, with a channel diameter less than the diameter of the ball, and a second channel portion, with a channel diameter greater than the diameter of the ball, the ball and the pin are arranged in the second channel portion.

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.

Plasticizing unit for a molding machine with an injection cylinder and an axially movable plasticizing screw arranged in the injection cylinder, wherein a filter device for filtering plasticized material, in particular plasticized plastic, is provided, which is or can be arranged axially movable in the injection cylinder.

A method of determining melt flow front travel in a molding apparatus includes setting a sensor threshold, receiving a sensor amount as an output from a sensor monitoring a nozzle of the molding apparatus, and determining that the sensor amount exceeds the sensor threshold. The method further includes receiving a screw location, calculating a travel distance of the screw from the screw location, and calculating melt flow front travel based on the travel distance of the screw. The method further includes receiving, via an interface, an operator generated value for the desired melt flow front travel to be reached, and sending, via an interface, an analog or digital output after the operator generated value has been reached. A method of detecting a leaking condition of a check valve is also included.

An injection moulding machine for producing fibre-reinforced plastic mouldings, having a closing unit and an injection unit, wherein the injection unit has a cylinder and a screw that can be rotated and displaced in the longitudinal direction in the cylinder, the screw having a backflow stop. In the cylinder, filling openings are provided for feeding in a plastic material to be melted and fibre material. To reduce fibre breakage and ensure good mixing, according to the invention a mixing part is provided downstream and/or upstream of the backflow stop, the mixing part being connected to the screw in a rotationally fixed manner for conjoint rotation therewith and having a cylindrical main body with drop-shaped mixing elements arranged thereon.

An injection moulding machine for producing fibre-reinforced plastic mouldings, having a closing unit and an injection unit, wherein the injection unit has a cylinder and a screw that can be rotated and displaced in the longitudinal direction in the cylinder, the screw having a backflow stop. In the cylinder, filling openings are provided for feeding in a plastic material to be melted and fibre material. To reduce fibre breakage and ensure good mixing, according to the invention a mixing part is provided downstream and/or upstream of the backflow stop, the mixing part being connected to the screw in a rotationally fixed manner for conjoint rotation therewith and having a cylindrical main body with drop-shaped mixing elements arranged thereon.

A supercritical fluid microcellular injection molding method includes the following steps. Preheating: the feed pipe is preheated to a hot melt temperature of polymer. Feeding: the polymer is poured into the hopper and enters the feed pipe. A metering screw is rotatably received in the feed pipe for forwardly pushing the hot molten polymer when being rotated. Injecting SCF: the SCF is injected into the feed pipe and mixed with the hot molten polymer into a homogeneous monophasic fluid. Quantitative discharge and depressurization: the monophasic fluid flows across a first gear pump and a second gear pump mounted on the front end of the feed pipe. Discharging and molding: the monophasic fluid actuated by the first gear pump and the second gear pump is injected and molded by the die head fixed to the discharge end of the second gear pump.