Large part injection mold apparatus and process

Patent metadata

Field	Value
Publication number	US-11865755-B2
Application number	US-202217964151-A
Country	US
Kind code	B2
Filing date	Oct 12, 2022
Priority date	Nov 14, 2016
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

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.

First claim

What is claimed is:

1. An injection molding system for performing an injection cycle comprising:
a heated manifold arranged to distribute an injection fluid to two or more nozzles, each nozzle having an associated gate mated with a mold cavity, each nozzle further having an associated valve pin controllably axially drivable upstream and downstream by an actuator associated with each valve pin between a gate closed position at which flow of the injection fluid is stopped and one or more axial positions upstream of the gate closed position at which flow of the injection fluid through the gate into the mold cavity is enabled; and
a controller arranged to execute instructions that instruct the actuators associated with each valve pin to:
begin the injection cycle with the valve pins associated with the two or more nozzles in a gate closed position;
select a first one of the two or more nozzles and controllably drive its associated valve pin from the gate closed position upstream to one or more first axial upstream positions at which a tip end of the valve pin associated with the first one of the two or more nozzles restricts flow of the injection fluid through a first gate associated with the first one of the two or more nozzles to a selected rate of flow that is less than or reduced relative to a maximum rate of flow;
hold the valve pin associated with the first one of the two or more nozzles in the one or more first axial upstream positions such that injection fluid flows through the first gate downstream through the cavity a preselected distance, wherein the first gate is located at a first position entering the mold cavity;
controllably drive the valve pin associated with the other of the two or more nozzles upon downstream flow of the injection fluid through the cavity the preselected distance to a selected second axial upstream position of the gated closed position such that injection fluid flows through a second gate associated with the other of the two or more nozzles downstream through the cavity, wherein the second gate is located at a second position entering the cavity downstream of the first position; and
hold the valve pin associated with the first one of the two or more nozzles in the one or more first axial upstream positions for a duration at least until the cavity is filled.

2. The injection molding system of claim 1 wherein the instructions include instructions that instruct the valve pin associated with the first one of the two or more nozzles to be held or controllably driven in or to the reduced flow axial upstream positions for a duration at least until the cavity is filled and packed.

3. The injection molding system of claim 1 wherein the selected first axial upstream position is a reduced flow position wherein the tip end of the valve pin associated with the first one of the two or more nozzles restricts flow of the injection fluid through the gate associated with the first one of the two or more nozzles to a selected rate of flow that is less than the maximum rate of flow.

4. The injection molding system of claim 1 wherein the instructions include instructions that instruct the valve pin associated with the first one of the two or more nozzles to be held or controllably driven in or to another axial upstream position that is a fully open position wherein injection fluid flows at the maximum rate of flow through the gate associated with the first one of the nozzles.

5. The injection molding system of claim 1 wherein the preselected distance of flow of the injection fluid is a selected distance downstream of the second position of the second gate associated with the other of the two or more nozzles.

6. The injection molding system of claim 1 wherein the instructions include instructions that instruct the actuators to hold or controllably drive the valve pin associated with the other of the two or more nozzles in or to one or more reduced flow axial upstream positions wherein a tip end of the valve pin associated with the other of the two or more nozzles restricts flow of the injection fluid through the gate associated with the other of the two or more nozzles to a selected rate of flow that is less than or reduced relative to the maximum rate of flow for a duration at least until the cavity is filled.

7. The injection molding system of claim 1 wherein the valve pin associated with the other of the two or more nozzles is held or controllably driven in or to the reduced flow axial upstream position for a duration at least until the cavity is filled and packed.

8. The injection molding system of claim 1 wherein the selected second axial upstream position is a reduced flow position wherein a tip end of the valve pin associated with the other of the two or more nozzles restricts flow of the injection fluid through the gate associated with the other of the two or more nozzles to a selected rate of flow that is less than the maximum rate of flow.

9. The injection molding system of claim 1 wherein the instructions include instructions that instruct the actuators to hold or controllably drive the valve pin associated with the other of the two or more nozzles in or to one or more second axial upstream positions that are a fully open position wherein injection fluid flows at the maximum rate of flow through the gate associated with the other of the two or more nozzles.

10. The injection molding system of claim 1 wherein the apparatus includes an injection fluid property detector that detects, at a downstream detection time, a select property of a flow front of the fluid material flowing downstream at a trigger position within the cavity disposed between the first gate and at least one selected downstream gate,
the controller receiving a property signal from the injection fluid property detector indicative of the downstream detection time and including instructions that instruct the actuator of the nozzle associated with the at least one selected downstream gate to withdraw the valve pin from the gate closed position at a predetermined target time determined by the downstream detection time.

11. The injection molding system of claim 10 including a position sensor that detects, at an actual open gate time, withdrawal of the valve pin from the at least one selected downstream gate,
the controller receiving a signal from the position sensor and including instructions that determine an adjusted instruction time, for use on a subsequent injection cycle, wherein the instructions decrease a time of instruction to the valve pin to open on a subsequent injection cycle by an adjustment time equal to any delay in time between the predetermined target time and the actual open gate time.

12. An injection molding system for performing an injection cycle comprising:
a heated manifold arranged to distribute an injection fluid to two or more nozzles, each nozzle having an associated gate mated with a mold cavity, each nozzle further having an associated valve pin controllably axially drivable upstream and downstream by an actuator associated with each valve pin between a gate closed position at which flow of the injection fluid is stopped and one or more axial positions upstream of the gate closed position at which flow of the injection fluid through the gate into the mold cavity is enabled; and
a controller arranged to execute instructions that instruct the actuators associated with each valve pin to:
begin the injection cycle with the valve pins associated with the two or more nozzles in a gate closed position;
select a first one of the two or more nozzles and controllably drive its associated valve pin from the gate closed position upstream to one or more first axial upstream p

Assignees

• Synventive Molding Solutions Inc

Inventors

• Henderson William
• Feng Ling
• Dovey Andrew

Classifications

• B29C45/7613 Primary

  the termination of flow of material into the mould · CPC title

• B29C45/22

  Multiple nozzle systems · CPC title

• B29C45/231

  Needle valve systems therefor · CPC title

• B29C45/77

  of velocity or pressure of moulding material · CPC title

• B29C2045/279

  Controlling the flow of material of two or more nozzles or gates to a single mould cavity · CPC title