Injection molding apparatuses and methods wherein a valve pin is controllably driven upstream and downstream along an axis between a first closed position where the tip end of the valve pin obstructs the gate to prevent the injection fluid from flowing into the cavity, a full open position and one or more intermediate positions, wherein the valve pin is drivable to be disposed or held in a selected intermediate position 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.

Mold used to manufacture a gasket member includes a first mold, second mold, and plate-shaped substrate clamped between the first and second molds. The first mold includes circumferential groove that opens to a bottom surface of the first mold and forms a cavity, injection groove that opens to the bottom surface and connects to the cavity at first location of the circumferential groove, injection hole having a lower end opens into the injection groove and upper end extends to top surface of the first mold, exhaust groove that opens to the bottom surface and connect to the cavity at a second location of the circumferential groove, and exhaust hole having lower end connect into the exhaust groove and an upper end extends to the top surface of the first mold. The elastic material is injected and filled into the cavity to form the gasket member.

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 manifold, an actuator having a piston that divides an enclosed actuator housing into upstream and downstream actuator drive chambers, the piston having an internal piston chamber and a piston bore that communicates flow of the drive fluid between one of the upstream or downstream actuator drive chambers and the internal piston chamber, a flow rate controller adapted to enable flow of drive fluid between one of the upstream or downstream actuator drive chambers and a source of drive fluid at a first low rate of flow over a selected first portion of the stroke length of the piston and at a second high rate of flow over a selected second portion of the stroke length of the piston.

An apparatus for controlling the rate of flow to a mold cavity including a controller instructing a valve system to drive an actuator and a valve pin and including instructions that instruct the valve system to drive an actuator and a valve pin and including instructions that instruct the valve system to move from a start position to one or more intermediate drive rate positions and subsequently from the one or more intermediate drive rate positions to a high drive rate position on receipt by the controller of a signal from a position sensor that is indicative of the valve pin having reached a second position.

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 and further drives the valve system to move from the one or more intermediate drive rate positions to the high drive rate position on expiration of the one or more predetermined amounts of time.

An injection molding apparatus including an actuator interconnected to a rod or valve pin having a smooth continuous cylindrical outer surface and one or more discontinuous or relieved or relieved portions formed as discontinuities in the cylindrical outer surface and adapted to be disposed within a fluid flow channel, the one or more discontinuous or relieved portions being configured and arranged along the axial length of the pin or rod such that the flow of injection fluid over or past the one or more discontinuous or relieved portions is modified to flow at substantially different rates or velocities or in substantially different flow patterns relative to rate or velocity or pattern of flow of injection fluid over or past the smooth continuous cylindrical outer surface.

An injection-molding station for the manufacture of multilayer preforms comprises an injection-molding machine (2), at least one multi-component nozzle (3), at least two melt accumulators (4, 5) constructed as cylinder accumulators and connected thereto, at least two plasticizer units (6, 7) for charging them and a control unit (8). The multi-component nozzle has slides (17, 19), which are associated with the melt channels (9, 10) and which are separately activated by the control unit independently of one another in such a way that the respective melt channels have an infinitely variable passage cross section. Proportional actuators (26, 27) that can be activated by the control unit are associated with the pistons (22, 23) of the cylinder accumulators. The control unit comprises a memory unit for coordinated movement or position profiles of the at least two closing slides and the at least two melt-accumulator pistons.

An apparatus for controlling the rate of flow of fluid mold material from an injection molding machine to a mold cavity, the apparatus comprising: a manifold having a fluid delivery channel, an actuator interconnected to a valve pin having a tip end drivable between a first position, a second position upstream and a third position upstream of the second position, the actuator and the valve pin being translationally driven by a valve system adjustable between a start position, a plurality of intermediate drive rate positions and a high drive rate position, a pressure sensor and a controller, the pressure sensor sensing a metered pressure of a drive fluid, the controller instructing the valve system to drive valve pin continuously upstream and including instructions that instruct the valve system to move according to a predetermined profile of metered pressures from the start position to selected intermediate drive rate positions and subsequently to the high drive rate position.

A method and apparatus for performing an injection molding cycle comprising drivably interconnecting a valve pin to an electric motor actuator and controllably operating the electric motor to drive the valve pin at one or more reduced rates of upstream or downstream travel based on either detection of the position of the pin or actuator or on a preselected length of time at which to drive the valve pin.