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US 2019/0366607 A1Published application
Method for simultaneous closed loop control of gas assist and gas counter pressure in an injection molding process relative to plastic melt pressure and plastic melt flow position
AssigneeImflux Inc.
InventorsWilliam Francis Lawless, III, H. Kenneth Hanson, III, Gene Michael Altonen, Chow-Chi Huang
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Abstract
A controller for an injection molding system is in communication with a melt flow control unit, a gas assist control unit, and a gas counter pressure control unit. The controller can effect real-time adjustments to gas assist pressure and/or gas counter pressure as a function of melt pressure or flow front position.
Claims20
A method for controlling an injection molding filling cycle, comprising:
- injecting a molten thermoplastic material into a mold cavity;
- injecting a first gas at an initial pressure into a portion of the mold cavity downstream of a flow front of the injected thermoplastic material;
- injecting a second gas at an initial pressure into a portion of the mold cavity upstream of the flow front of injected thermoplastic material;
- determining a melt pressure of the injected molten thermoplastic material;
- determining a flow front position of the injected molten thermoplastic material;
- changing the pressure of the first gas at least in part based on at least one of (i) the determined melt pressure of the injected molten thermoplastic material, or (ii) the determined flow front position of the injected molten thermoplastic material;
- and
- changing the pressure of the second gas at least in part based on at least one of (i) the determined melt pressure of the injected molten thermoplastic material, or (ii) the determined flow front position of the injected molten thermoplastic material.
5 more elements
A control system configured to automatically adjust operation of an injection molding apparatus, the control system comprising:
- a melt pressure sensing device;
- a melt flow front position sensing device;
- a gas assist control unit;
- and
- a gas counter-pressure control unit,
- the control system being adapted to:
- cause the injection molding apparatus to inject a molten thermoplastic material into a mold cavity;
- determine a melt pressure of the injected molten thermoplastic material using the melt pressure sensing device;
- determine a flow front position of the injected molten thermoplastic material using the melt flow front position sensing device;
- use the gas assist control unit to change a gas assist pressure at least in part based on the determined melt pressure or the determined flow front position;
- and
- use the gas counter-pressure control unit to change a gas counter-pressure at least in part based on the determined melt pressure or the determined flow front position.
9 more elements
Dependencies are inferred from the claim text.