# US 10,307,951 B2 · Injection molding flow control apparatus and method

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- Number: US 10,307,951 B2
- Document ID: US10307951B2
- Status: Granted
- Kind: B2
- Application number: 15/432,175
- Filed: 2017-02-14
- Published: 2017-06-01
- Granted: 2019-06-04
- Earliest claimed: 2010-11-23
- Assignees: Synventive Molding Solutions, Inc.
- Applicants: Synventive Molding Solutions, Inc.
- Inventors: Sergio Ribeiro de Oliveira Antunes; Lin Yang; Vito Galati; Hans-Joerg Schreyer
- Web page: https://patentgrep.com/patent/US10307951B2

## CPC

- B29C 45/7613: {the termination of flow of material into the mould}
- B29C 45/03: Injection moulding apparatus (transfer moulding B29C45/02)
- B29C 45/2703: {Means for controlling the runner flow, e.g. runner switches, adjustable runners or gates}
- B29C 45/2708: {Gates (B29C45/2703 takes precedence)}
- B29C 45/2806: {consisting of needle valve systems (B29C45/2896 takes precedence)}
- B29C 45/76: Measuring, controlling or regulating {(measuring in general G01; controlling or regulating in general G05)}
- B29C 45/77: of velocity or pressure of moulding material
- B29C 45/80: of relative position of mould parts
- G05B 15/02: electric
- G05D 7/0635: {by action on throttling means (G05D7/0688, G05D7/0694 take precedence)}
- B29C 45/281: {Drive means therefor}
- B29C 2045/1792: {Machine parts driven by an electric motor, e.g. electric servomotor}
- B29C 2045/2712: {Serial gates for moulding articles in successively filled serial mould cavities}
- B29C 2045/2824: {Needle valves driven by an electric motor}
- B29C 2045/2865: {having position detecting means}
- B29C 2045/2872: {with at least three positions, e.g. two different open positions to control the melt flow}
- B29C 2945/76006: Pressure
- B29C 2945/76076: duration
- B29C 2945/76083: Position
- B29C 2945/76277: nozzles
- B29C 2945/7628: manifolds
- B29C 2945/76381: Injection
- B29C 2945/76545: Flow rate
- B29C 2945/76568: Position
- B29C 2945/76598: linear movement
- B29C 2945/76755: nozzles
- B29C 2945/76859: Injection
- B29C 2945/76933: The operating conditions are corrected immediately, during the same phase or cycle
- B29C 2945/76936: The operating conditions are corrected in the next phase or cycle
- B29C 2945/76939: Using stored or historical data sets
- B29C 2945/76993: Remote, e.g. LAN, wireless LAN
- B29K 2105/0067: {Melt}
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

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.

## Claims

### Claim 1

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin obstructs or closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the pin through the gate, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate that restricts flow of the injection fluid along at least a portion of the length of the drive path extending between the first closed position and the intermediate position, and,
controllably operating the actuator to drive the valve pin 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, and,
controllably operating the actuator to drive the valve pin at an upstream velocity of travel that is reduced relative to a high velocity during the course of the injection cycle.

### Claim 2 (depends on 1)

The method of claim 1 further comprising controllably operating the actuator to drive the valve pin downstream beginning from the full open position to the selected intermediate position, holding the valve pin in the selected intermediate position for the selected period of time, and subsequently driving the valve pin downstream from the intermediate position to the first closed position.

### Claim 3 (depends on 2)

The method of claim 2 further comprising controllably operating the actuator to drive the valve pin downstream beginning from the full open position at a high rate of downstream travel, subsequently driving the valve pin downstream at one or more intermediate rates of downstream travel to the selected intermediate position, subsequently holding the valve pin in the selected intermediate position for the selected period of time and subsequently driving the valve pin downstream from the selected intermediate position to the first closed position.

### Claim 4 (depends on 1)

The method of claim 1 further comprising controllably operating the actuator to drive the valve pin upstream beginning from the first closed position where the tip end of the valve pin obstructs or closes the gate to the selected intermediate position, holding the valve pin in the selected intermediate position for the selected period of time.

### Claim 5 (depends on 4)

The method of claim 4 further comprising controllably operating the actuator to drive the valve pin upstream beginning from the first closed position at a reduced rate of upstream travel, subsequently holding the valve pin in the selected intermediate position and subsequently driving the valve pin upstream from the intermediate position to the full open position at a high rate of upstream travel greater than the reduced rate of upstream travel.

### Claim 6 (depends on 1)

The method of claim 1 wherein the actuator comprises an electrically powered motor or electric motor.

### Claim 7 (depends on 1)

The method of claim 1 wherein the selected intermediate position in which the valve pin is disposed or held is a position at which pressure of the injection fluid is a pack pressure.

### Claim 8

An injection molding apparatus comprising a manifold that receives an injection fluid from an injection molding machine, the manifold distributing the injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel,
wherein the valve pin is interconnected to an actuator in an arrangement wherein the actuator is adapted to drive the valve pin upstream and downstream along the axis and to drive the tip end of the valve pin upstream and downstream 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 where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate that restricts flow of the injection fluid along at least a portion of the length of the drive path extending between the first closed position and the intermediate position,
the apparatus including a controller that contains instructions that instruct the actuator to controllably drive the valve pin 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, and to controllably operate the actuator to drive the valve pin at an upstream velocity of travel that is reduced relative to a high velocity.

### Claim 9 (depends on 8)

The apparatus of claim 8 wherein the controller includes instructions that instruct the actuator to drive the valve pin downstream beginning from the full open position to the selected intermediate position, to hold the valve pin in the selected intermediate position for the selected period of time, and to subsequently drive the valve pin downstream from the intermediate position to the first closed position.

### Claim 10 (depends on 9)

The apparatus of claim 9 wherein the controller includes instructions that instruct the actuator to drive the valve pin downstream beginning from the full open position at a high rate of downstream travel, to subsequently drive the valve pin downstream at one or more of the intermediate rates of downstream travel the selected intermediate position, to subsequently hold the valve pin in the selected intermediate position for the selected period of time and to subsequently drive the valve pin downstream from the selected intermediate position to the first closed position.

### Claim 11 (depends on 8)

The apparatus of claim 8 wherein the controller includes instructions that instruct the actuator to controllably drive the valve pin upstream beginning from a position where the tip end of the valve pin closes the gate to the selected intermediate position, to hold the valve pin in the selected intermediate position for the selected period of time, and to subsequently drive the valve pin upstream from the intermediate position to the full open position.

### Claim 12 (depends on 11)

The apparatus of claim 11 wherein the controller includes instructions that instruct the actuator to drive the valve pin upstream beginning from the first closed position at a reduced rate of upstream travel, to subsequently hold the valve pin in the selected intermediate position for the selected period of time and to subsequently drive the valve pin upstream from the intermediate position to the full open position at a high rate of upstream travel greater than the reduced rate of upstream travel.

### Claim 13 (depends on 8)

The apparatus of claim 8 wherein the actuator comprises an electrically powered motor or electric motor.

### Claim 14

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin obstructs or closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate that restricts flow of the injection fluid along at least a portion of the length of the drive path extending between the first closed position and the intermediate position, and,
controllably operating the actuator to drive the valve pin upstream beginning from the first position where the tip end of the valve pin obstructs or closes the gate at a reduced rate of upstream travel relative to a selected high rate of upstream travel and subsequently holding the valve pin in the selected intermediate position for a selected period of time.

### Claim 15 (depends on 14)

The method of claim 14 further comprising subsequently driving the valve pin upstream from the selected intermediate position to the full open position at the selected high rate of upstream travel.

### Claim 16 (depends on 14)

The method of claim 14 further comprising controllably operating the actuator to drive the valve pin downstream beginning from the full open position at a selected high rate of downstream travel, subsequently driving the valve pin downstream at one or more intermediate rates of downstream travel that are less than the selected high rate of downstream travel.

### Claim 17 (depends on 14)

The method of claim 14 wherein the high rate of upstream travel is a maximum rate of upstream travel.

### Claim 18 (depends on 14)

The method of claim 14 wherein the actuator comprises an electrically powered motor or electric motor.

### Claim 19 (depends on 14)

The method of claim 14 wherein the selected intermediate position in which the valve pin is disposed or held is a position at which pressure of the injection fluid is a pack pressure.

### Claim 20

An injection molding apparatus comprising a manifold that receives an injection fluid from an injection molding machine, the manifold distributing the injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel,
wherein the valve pin is interconnected to an actuator in an arrangement wherein the actuator is adapted to drive the valve pin upstream and downstream along the axis and to drive the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin obstructs or closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate that restricts flow of the injection fluid along at least a portion of the length of the drive path extending between the first closed position and the one or more intermediate positions,
the apparatus including a controller that contains instructions that instruct the actuator to controllably drive the valve pin upstream beginning from the first closed position where the tip end of the valve pin obstructs or closes the gate at a reduced rate of upstream travel relative to a high rate of upstream travel to a selected intermediate position and to hold the valve pin in the selected intermediate position for a selected period of time.

### Claim 21

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis,
driving the actuator to drive the tip end of the valve pin upstream beginning from a first closed position where the tip end of the valve pin obstructs or closes the gate to prevent the injection fluid from flowing into the cavity, subsequently driving the actuator to drive the tip end of the valve pin to a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum pressure, and,
controllably operating the actuator to drive the valve pin to be disposed or held in a selected intermediate position for a selected period of time during the course of an injection cycle such that the pressure of the injection fluid is held at a selected reduced pressure relative to the maximum pressure for the selected period of time,
wherein, in the intermediate position, the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate that restricts flow of the injection fluid along at least a portion of the length of the drive path extending between the first closed position and the intermediate position such that the injection fluid flows through the gate at a reduced pressure relative to the maximum pressure.

### Claim 22

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream 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 and a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum pressure,
wherein pressure of the injection fluid associated with the nozzle varies between zero at the beginning of the injection cycle when the valve pin is in the first closed position and the maximum pressure, the position of the valve pin between the first closed position and the full open position being controllably variable to vary the pressure of the injection fluid,
the method further comprising controllably operating the actuator to drive the valve pin to be disposed or held in a position intermediate the closed position and the full open position for a selected period of time during the course of an injection cycle where the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate such that the pressure of the injection fluid is held at a selected reduced pressure relative to the maximum pressure.

### Claim 23 (depends on 22)

The method of claim 22 wherein the actuator comprises an electrically powered motor or electric motor.

### Claim 24 (depends on 22)

The method of claim 22 wherein the actuator is controllably driven to drive the valve pin upstream beginning from the first closed position where the tip end of the valve pin obstructs or closes the gate.

### Claim 25

An injection molding apparatus for performing an injection cycle comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
the valve pin being drivably interconnected to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream 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 and a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum pressure,
wherein pressure of the injection fluid associated with the nozzle varies between zero at the beginning of the injection cycle when the valve pin is in the first closed position and the maximum pressure, the position of the valve pin between the first closed position and the full open position being controllably variable to vary the pressure of the injection fluid,
a controller including a set of instructions that instruct the actuator to controllably drive the valve pin to be disposed or held in a position intermediate the closed position and the full open position wherein the tip end of the valve pin forms a gap between outer surfaces of the tip end of the valve pin and inner surfaces of the gate for a selected period of time during the course of an injection cycle such that the pressure of the injection fluid is held at a selected reduced pressure relative to the maximum pressure for the selected period of time.

### Claim 26 (depends on 25)

The apparatus of claim 25 wherein the actuator comprises an electrically powered motor or electric motor.

### Claim 27 (depends on 25)

The apparatus of claim 25 wherein the actuator is controllably driven to drive the valve pin upstream beginning from the first closed position where the tip end of the valve pin obstructs or closes the gate.

### Claim 28

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin obstructs or closes the gate to prevent the injection fluid from flowing into the cavity, a fill or injection pressure position where the injection fluid material flows through the gate at a selected high pressure and one or more pack pressure positions between the first closed position and the fill or injection pressure position wherein a gap is formed between outer surfaces of the tip end of the valve pin and inner surfaces of the gate restricting flow through the gate such that pressure of the injection fluid associated with the nozzle in the pack pressure position is greater than a zero pressure when the valve pin is in the first closed position and less than a selected high pressure when the valve pin is in the fill or injection pressure position, the position of the valve pin between the first closed position and the fill or injection pressure position being controllably variable to vary the pressure of the injection fluid,
the method further comprising controllably operating the actuator to drive the valve pin during the course of an injection cycle to first move from the first closed position to the fill or injection pressure position, to subsequently move from the fill or injection pressure position to be disposed and maintained in a pack pressure position for a selected period of time and to subsequently move from the pack pressure position to the first closed position.

### Claim 29 (depends on 28)

The method of claim 28 wherein the valve pin is controllably movable between the first closed position and fill or injection pressure position at one or more selectively variable velocities.

### Claim 30 (depends on 28)

The method of claim 28 wherein the actuator is conrollably driven to drive the tip end of the valve pin upstream beginning from the first position where the tip end of the valve pin obstructs or closes the gate.

### Claim 31 (depends on 28)

The method of claim 28 wherein the valve pin is controllably movable between the pack pressure position and the first closed position at one or more selectively variable velocities.

### Claim 32

An injection molding apparatus for performing an injection molding cycle comprising an injection molding machine that injects an injection fluid to a manifold, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
an actuator drivably interconnected to a valve pin in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream 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 fill or injection pressure position where the injection fluid material flows through the gate at a selected high pressure and one or more pack pressure positions between the first closed position and the fill or injection pressure position wherein a gap is formed between outer surfaces of the tip end of the valve pin and inner surfaces of the gate such that pressure of the injection fluid associated with the nozzle in the pack pressure position is greater than a zero pressure when the valve pin is in the first closed position and less than a selected high pressure when the valve pin is in the fill or injection pressure position, the position of the valve pin between the first closed position and the fill or injection pressure position being controllably variable to vary the pressure of the injection fluid,
a controller including instructions that controllably operate the actuator to drive the valve pin during the course of an injection cycle to first move from the first closed position to the fill or injection pressure position, to subsequently move from the fill or injection pressure position to be disposed and maintained in a pack pressure position for a selected period of time and to subsequently move from the pack pressure position to the first closed position.

### Claim 33 (depends on 32)

The apparatus of claim 32 wherein the controller includes instructions that controllably move the valve pin between the first closed position and fill or injection pressure position at one or more selectively variable velocities.

### Claim 34 (depends on 32)

The apparatus of claim 32 wherein the controller includes instructions that controllably move the valve pin between the fill or injection pressure position and the pack pressure position at one or more selectively variable velocities.

### Claim 35 (depends on 32)

The apparatus of claim 32 wherein the controller includes instructions that controllably drive the actuator to drive the tip end of the valve pin upstream beginning from the first position where the tip end of the valve pin obstructs or closes the gate.

### Claim 36 (depends on 32)

The apparatus of claim 32 wherein the controller includes instructions that controllably move the valve pin from the first closed position to be disposed and maintained in the fill or injection pressure position for a selected period of time.

### Claim 37

A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
drivably interconnecting the valve pin to an actuator in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream 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 and one or more pack pressure positions wherein a gap is formed between outer surfaces of the tip end of the valve pin and inner surfaces of the gate such that pressure of the injection fluid associated with the nozzle in the pack pressure position is greater than a zero pressure when the valve pin is in the first closed position,
the method further comprising controllably operating the actuator to drive the valve pin during the course of an injection cycle to first move from the first closed position to be disposed and maintained in a pack pressure position for a selected period of time and to subsequently move from the pack pressure position to the first closed position.

### Claim 38 (depends on 37)

The method of claim 37 wherein the valve pin is controllably movable between the first closed position and the pack pressure position at one or more selectively variable velocities.

### Claim 39 (depends on 37)

The method of claim 37 wherein the actuator is conrollably driven to drive the tip end of the valve pin upstream beginning from the first position where the tip end of the valve pin obstructs or closes the gate.

### Claim 40

An injection molding apparatus for performing an injection molding cycle comprising an injection molding machine that injects an injection fluid to a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel of a nozzle that delivers the injection fluid under an pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel,
the apparatus comprising:
an actuator drivably interconnected to a valve pin in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream 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 and one or more pack pressure positions wherein a gap is formed between outer surfaces of the tip end of the valve pin and inner surfaces of the gate such that pressure of the injection fluid associated with the nozzle in the pack pressure position is greater than a zero pressure when the valve pin is in the first closed position,
a controller that includes instructions that controllably operate the actuator to drive the valve pin during the course of an injection cycle to first move the valve pin from the first closed position to be disposed and maintained in a pack pressure position for a selected period of time and to subsequently move from the pack pressure position to the first closed position.

### Claim 41 (depends on 40)

The apparatus of claim 40 wherein the controller includes instructions that controllably move the valve pin between the first closed position and the pack pressure position at one or more selectively variable velocities.

### Claim 42 (depends on 40)

The apparatus of claim 40 wherein the controller includes instructions that controllably drive the actuator to drive the tip end of the valve pin upstream beginning from the first position where the tip end of the valve pin obstructs or closes the gate.