A method of performing an injection cycle having a duration comprising: beginning the injection cycle with the valve pins associated with two or more nozzles in a gate closed position, selecting a first one of the two or more nozzles and controllably driving its associated valve pin from the gate closed position to a selected first axial upstream position, upon downstream flow of the injection fluid through a cavity the preselected distance, controllably driving the valve pin associated with the other of the two or more nozzles to a selected second axial position upstream, holding or controllably driving the valve pin associated with the first one of the two or more nozzles in or to one or more reduced flow axial upstream positions that are partially closed.

A method of performing an injection cycle having a duration comprising: beginning the injection cycle with the valve pins associated with two or more nozzles in a gate closed position, selecting a first one of the two or more nozzles and controllably driving its associated valve pin from the gate closed position to a selected first axial upstream position, upon downstream flow of the injection fluid through a cavity the preselected distance, controllably driving the valve pin associated with the other of the two or more nozzles to a selected second axial position upstream, holding or controllably driving the valve pin associated with the first one of the two or more nozzles in or to one or more reduced flow axial upstream positions that are partially closed.

For processing cost reduction and improvement of efficiency, a no-mold-runner multi-nozzle device, comprising: an injection machine, a multi-nozzle component, a front template, and a no-mold-runner. The multi-nozzle component includes a plurality of nozzles, which is connected to the injection machine. The injection machine is used to inject a mixture of molding material and supercritical fluid into multiple nozzles. The front template is provided with a plurality of first passage holes. The no-mold-runner is provided with a mold cavity and a plurality of second passage holes communicating with the mold cavity. The nozzle correspondingly passes through a plurality of first passage holes and second passage holes and is installed in cooperation. By controlling the opening or closing of the nozzle, the mixed material of the molding material and the supercritical fluid enters the mold cavity or stops entering the mold cavity.

A component for a nozzle for injecting molten plastic into a molding cavity of a container, in particular of a test tube or a bottle preform, the component comprising a first body in which a shutter can slide along an axis; wherein the first body has a wall which extends about said axis; wherein said wall is provided with a first zone adapted to guide the sliding of the shutter along the axis, and a second zone which delimits a first stretch of a channel for the molten plastic; wherein said first body is provided with at least one through hole which crosses said wall, in particular transversely to the axis, which allows the molten plastic to pass through, in particular to enter, said first stretch of the channel.

An injection molding apparatus (10) comprising: one or more valves each comprised of a valve pin (1040, 1041, 1042) adapted to be driven upstream and downstream through a downstream channel (1006) that has a downstream channel portion (1006ds) that has a control surface (1008), the control surface (1008) forming a channel or restriction gap (CG, 1006rg), the valve pin (1041) being controllably drivable upstream and downstream through the channel or restriction gap (CG, 1006rg) at a single selected rate of upstream acceleration up to a selected reduced upstream velocity that is less than a maximum velocity at which the valve pin (1041) is drivable, the size or configuration of the channel or restriction gap (CG, 1006rg) and the single selected rate of upstream acceleration being selected in combination with each other to control flow of injection fluid (18) through the channel gap (CG, 1006rg).

A co-injection nozzle for an injection moulding device for producing multi-layered injection-moulded products. The nozzle includes: a central bore; a valve needle for opening and closing a nozzle opening; an annular inner melt channel for the first melt; an annular central melt channel for a second melt; and an annular outer melt channel for the first melt. The inner, central and outer melt channels are fluidically combined in the region of the nozzle tip to form a concentrically-layered melt stream. The co-injection nozzle has a back-flow barrier, integrated into the central bore, for the second melt, this barrier formed by a cut-out in the valve needle and by a melt channel for the second melt, the channel penetrating the central bore. In the open position of the back-flow barrier, the cut-out is located such that the second melt can flow through the melt channel, whilst flowing in the central bore past the valve needle.

Systems and methods for controlling the closing speed of valve gated nozzles are disclosed. In one embodiment, a hot runner have a valve gated nozzle including a valve stem movable between an open position and a closed position is provided. The valve stem is moved at a first speed for a first portion of valve stem closure and a second speed for a second end portion of the valve stem closure.

Injection unit for injection molding of plastic material including: an injection nozzle; a closure pin; and a guide and cooling assembly, interposed between the back driving plate and the hot distribution plate, in turn comprising: a guide and seal element for guiding the axial motion of the closure pin; a cooling ring; and pressure means configured to press the cooling ring directly and against the back driving plate; wherein the guide and seal element is slidably coupled, at an upper end, with a central hole of the cooling ring, and is fixed integrally, at the other end, to the hot distribution plate; and the cooling ring is able to slide laterally with respect to the back driving plate to recover the differences in thermal expansion between the hot distribution plate and the back driving plate and to transmit heat from the guide and seal element towards the back driving plate.

A method of manufacturing an article using injection molding includes a step of injecting resin from an injection nozzle having a valve pin via a resin flow path in a first mold (metal mold) into a cavity in the first mold, a step of inserting the valve pin into the resin flow path, extracting the valve pin from the resin flow path, starting to increase a distance between the injection nozzle and the first mold after extracting the valve pin, and a third step of, after starting to increase the distance between the injection nozzle and the first mold, injecting resin from the injection nozzle via a resin flow path in a second mold into a cavity in the second mold.

A method for manufacturing an impeller with a number of impeller blades and a cover disc covering the impeller blades. Plastic is injected into an injection mold using a cascade injection molding process to form the impeller. The injection mold has a number of shut-off nozzles to feed the plastic at various joint positions and different opening times. The number of shut-off nozzles is determined as a function of the number of impeller blades.