A method, apparatus and press for the injection moulding of plastic material by a plurality of injectors connected to a distributor and provided with respective obturators movable between a closing condition and an opening condition in a controlled fashion. The injection pressure in the distributor is maintained substantially constant by an actuator which actuates a screw of the injection press, from a start of a filling step up to an end of a packing step of the plastic material into a cavity of a mould. A moulding cycle is entirely controlled by each injector, by managing the position/velocity/acceleration of the respective obturator, without affecting the other injectors.

A method, apparatus and press for the injection moulding of plastic material by a plurality of injectors connected to a distributor and provided with respective obturators movable between a closing condition and an opening condition in a controlled fashion. The injection pressure in the distributor is maintained substantially constant by an actuator which actuates a screw of the injection press, from a start of a filling step up to an end of a packing step of the plastic material into a cavity of a mould. A moulding cycle is entirely controlled by each injector, by managing the position/velocity/acceleration of the respective obturator, without affecting the other injectors.

A shut-off nozzle includes a nozzle body portion, a needle valve, and a needle driving mechanism including a cylinder mechanism and a spring holder. The nozzle body portion includes a valve housing and the valve housing has a needle hole, into which a rear end portion of the needle valve is insertable, and a spring holder hole. The spring holder is inserted in the spring holder hole in a direction orthogonal to the axial direction in a state in which slide in the axial direction is allowed, and both ends of the spring holder are fixed to the cylinder mechanism. A central portion of the spring holder presses the rear end portion of the needle valve. Enlargement portions are formed in both side surfaces of the valve housing continuous with the spring holder hole.

An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.

An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.

An injection molding apparatus comprising: a pneumatically driven actuator, the piston forming first and second drive chambers, a source of pressurized gas that generates gas flow to the drive chambers, a gas metering mechanism, a controller including programmable instructions that: automatically controllably positions the gas metering mechanism such that the piston or valve pin is disposed or held in one or more selected intermediate positions for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.

An injection molding apparatus comprising: a pneumatically driven actuator, the piston forming first and second drive chambers, a source of pressurized gas that generates gas flow to the drive chambers, a gas metering mechanism, a controller including programmable instructions that: automatically controllably positions the gas metering mechanism such that the piston or valve pin is disposed or held in one or more selected intermediate positions for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.

An injection molding apparatus comprising: a pneumatically driven actuator having a piston mounted within a fluid sealed chamber for slidable axial movement along or against an interior surface of the fluid sealed chamber via a non-elastomeric engagement or with a non-elastomeric material disposed between the piston and the interior surface of the fluid sealed chamber, the piston forming first and second drive chambers within the fluid sealed chamber, each drive chamber having respective fluid flow ports, a source of pressurized gas that generates gas flow at a selected maximum pressure or flow rate, a gas metering mechanism, a controller interconnected to the gas metering mechanism, the controller controllably moving the gas metering mechanism to selectable positions that correspond to reduced pressures or reduced flow rates during the course of pin travel from the fully downstream gate closed position to the fully upstream gate open position.

An injection molding apparatus comprising: a pneumatically driven actuator having a piston mounted within a fluid sealed chamber for slidable axial movement along or against an interior surface of the fluid sealed chamber via a non-elastomeric engagement or with a non-elastomeric material disposed between the piston and the interior surface of the fluid sealed chamber, the piston forming first and second drive chambers within the fluid sealed chamber, each drive chamber having respective fluid flow ports, a source of pressurized gas that generates gas flow at a selected maximum pressure or flow rate, a gas metering mechanism, a controller interconnected to the gas metering mechanism, the controller controllably moving the gas metering mechanism to selectable positions that correspond to reduced pressures or reduced flow rates during the course of pin travel from the fully downstream gate closed position to the fully upstream gate open position.

The present disclosure provides a molding machine and a method of molding a part. The molding machine may include multiple molding systems (e.g., extruders) for pumping molten material into one or more mold cavities. The multiple molding systems may pump the same material or different materials into the one or more mold cavities. The multiple molding systems may be individually and/or collectively controlled. A method of molding a part may include pumping material into one or more mold cavities via multiple molding systems, ceasing pumping material into the one or more mold cavities when one or more pressures associated with the multiple molding systems are achieved, and releasing a molded part from the one or more mold cavities after the one or more pressures are achieved.