An apparatus for controlling the rate of flow of mold material to a mold cavity, the apparatus comprising: an injection molding machine and a manifold; an actuator interconnected to a valve pin having a tip end; a valve system in fluid communication with the actuator to drive the actuator at one or more rates of travel, the valve system having a start position, one or more intermediate drive rate positions and a high drive rate position, the start position holding the valve pin in a gate closed position; a controller that instructs the valve system to move from the start position to the one or more intermediate drive rate positions and to remain in the one or more intermediate drive rate positions for one or more corresponding predetermined amounts of time.

A method is disclosed for micro-molding articles. The method comprises melting and pre-pressurizing thermoplastic material to a first level, within a plasticizing barrel. The melt pressure of the thermoplastic material is manipulated to a second level, within a hot runner. The melt pressure of the thermoplastic material is manipulated to an ultra-cavity packing pressure within a valve gate nozzle.

A method and apparatus for producing hollow articles made of injection moulded plastic material by a mould having a die within which there is inserted a core, and at least one injector including a pin valve displaceable between a closing position and an opening position for injecting the pressurized plastic material into a space comprised between the die and the core. During the injection, any flexural deflection of the core is detected and the pin valve of the or of each injector is displaced in a controlled fashion to adjust a pressure and a flow rate of the injected plastic material, so as to reduce or eliminate such deflection of the core.

A method for injection molding of plastic materials into a cavity of a mold by means of a molding apparatus including at least one injector having a pin valve displaceable between a fully closed position and a maximum opening position, and vice versa, in a controlled fashion in respect of its position and speed. In the opening displacement from the fully closed position to the maximum opening position, the pin valve is initially moved at a first speed and subsequently at a second speed, where the first speed is the highest opening displacement speed of the pin valve.

A method and apparatus for producing hollow articles made of injection moulded plastic material by a mould having a die within which there is inserted a core, and at least one injector including a pin valve displaceable between a closing position and an opening position for injecting the pressurized plastic material into a space comprised between the die and the core. During the injection, any flexural deflection of the core is detected and the pin valve of the or of each injector is displaced in a controlled fashion to adjust a pressure and a flow rate of the injected plastic material, so as to reduce or eliminate such deflection of the core.

In one aspect, a method of coinjection molding a multilayer article having a multi-segment internal layer is disclosed. A surface layer material is injected into a mold cavity from at least one of an inner outlet and an outer outlet of a multi-channel nozzle. An internal layer material is intermittently injected into the mold cavity from an intermediate outlet of the multi-channel nozzle that is between the inner and outer outlets. The intermittent injecting of the internal layer material is controlled, at least in part, by intermittent opening and closing of the intermediate outlet. An apparatus for coinjection molding the multilayer article with the segmented internal layer is also disclosed.

A method for injection molding of plastic material by means of at least one injector whose pin valve can be displaced between a fully closed position and a maximum controlled fashion according to a position and speed of the pin valve. During displacement of the pin valve from the fully closed position to the maximum open position, and/or vice versa, the pin valve is stopped in intermediate positions and the displacement speed thereof is uniform and constant. An initial opening step at maximum speed and one or more steps of inversion of the motion of the pin valve can be provided for.

A system is disclosed for micro-molding articles. The system melts and pre-pressurizes thermoplastic material to a first level, within a plasticizing barrel. The melt pressure of the thermoplastic material is manipulated to a second level, within a hot runner. The melt pressure of the thermoplastic material is manipulated to an ultra-cavity packing pressure within a valve gate nozzle.

An apparatus for controlling the rate of flow of a fluid mold material comprising: a manifold, an actuator interconnected to a valve pin, a position sensor that senses position of the valve pin, a controller that controls movement of the actuator according to instructions that instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities in response to receipt by the controller of a signal from the position sensor that the valve pin is disposed in the one or more intermediate upstream gate open positions.

Injection molding system having a flow control apparatus and method that controls the movement and/or rate of movement of a valve pin over the course of an injection cycle to cause the pin to move to one or select positions and/or to control the rate of movement of the pin over the course of the injection cycle. In one embodiment the method includes steps of: a) first controllably operating the actuator to drive the valve pin upstream beginning from the first closed position (50) to be moved to and held in a first selected position (51) for a first selected period of time during the course of an injection cycle, the first selected position (51) being the full open position; b) second controllably operating the actuator to drive the valve pin, during the injection cycle, downstream beginning from the first selected position (51) to be moved to and held in a second closed position (52) for a second selected period of time; c) third controllably operating the actuator to drive the valve pin, during the injection cycle, upstream beginning from the second closed position (52) to be moved to and held in a second selected position (53) for a third selected period of time, the second selected position being an intermediate position or the full open position; and d) fourth controllably operating the actuator to drive the valve pin, during the injection cycle, downstream beginning from the second selected position (53) to be moved to a third closed position (54).