UPSTREAM NOZZLE SENSOR FOR INJECTION MOLDING APPARATUS AND METHODS OF USE

• US 20180003575A1
• Filed: 06/07/2017
• Published: 01/04/2018
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: Imflux Inc. (The Procter & Gamble Company)
• Original Assignee: Imflux Inc. (The Procter & Gamble Company)
• Inventors: Pollard, Rick Alan, Allen, Bryan Keith, Huang, Chow-Chi, Altonen, Gene Michael
• Granted Patent: US 10,107,697 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 2945/7619 barrel
• CPC Class Codes: B29C 2945/76381 Injection
• CPC Class Codes: B29C 2945/76481 Strain gauges
• CPC Class Codes: B29C 2945/76498 Pressure
• CPC Class Codes: B29C 2945/76545 Flow rate
• CPC Class Codes: B29C 2945/76658 Injection unit
• CPC Class Codes: B29C 2945/76859 Injection
• CPC Class Codes: B29C 45/1603 Multi-way nozzles specially adapted therefor
• CPC Class Codes: B29C 45/2708 Gates B29C45/2703 takes precedence
• CPC Class Codes: B29C 45/30 Flow control means disposed within the sprue channel, e.g. "torpedo" construction
• CPC Class Codes: B29C 45/77 of velocity or pressure of moulding material
• CPC Class Codes: G01L 1/04 by measuring elastic deformation of gauges, e.g. of springs
• CPC Class Codes: G01L 1/2218 the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means

Abstract

A strain gauge nozzle adapter that may be placed between a barrel end cap and a nozzle body of an injection molding system, the strain gauge nozzle adapter having a strain gauge pin that measures strain within the strain gauge nozzle adapter for use in approximating conditions within an injection molding system, such as pressure or the location of a melt flow front. The strain gauge nozzle adapter may include a plurality of strain gauge pins. An alternative material insert in the strain gauge nozzle adapter may surround a strain gauge pin to amplify meaningful measurements obtained by the strain gauge pin so that noise measurements do not compromise the accuracy of approximation of conditions within a mold.

Claims

1. An external sensor nozzle adapter for an injection molding system comprising:

a melt flow inlet attachable to a barrel end cap;

a melt flow outlet attachable to a nozzle body;

a melt flow conduit extending between the melt flow inlet and the melt flow outlet, the melt flow conduit having an internal melt flow conduit wall and an external melt flow conduit wall;

an aperture for an external sensor on the external melt flow conduit wall, the aperture having a bottom that is at least a minimum distance from the internal melt flow conduit wall; and

an external sensor in the aperture.

2. The external sensor nozzle adapter of claim 1, wherein the external sensor is a strain gauge pin.

3. The external sensor nozzle adapter of claim 1, wherein the minimum distance is at least 0.5 mm.

4. The external sensor nozzle adapter of claim 1, wherein the external sensor nozzle adapter includes an alternative material insert surrounding the aperture, the alternative material insert made from a material that amplifies the strain experienced by the external sensor nozzle adapter.

5. The external sensor nozzle adapter of claim 4, wherein the alternative material insert has a lower flex modulus than the surrounding external sensor nozzle adapter.

6. The external sensor nozzle adapter of claim 5, wherein the alternative material insert is made of brass and the minimum distance is at least 0.5 mm.

7. The external sensor nozzle adapter of claim 6, wherein the alternative material insert is made of aluminum and the minimum distance is at least 0.5 mm.

8. The external sensor nozzle adapter of claim 1, wherein the external sensor nozzle adapter has a plurality of apertures and each of the plurality of apertures has an external sensor in it.

9. The external sensor nozzle adapter of claim 8, wherein the plurality of apertures are located in the same circumferential plane of the external sensor nozzle adapter.

10. An injection molding apparatus, comprising:

a mold comprising one or more mold cavities;

a ram arranged to form a shot of molten thermoplastic material;

a strain gauge nozzle adapter including a strain gauge pin attached between the ram and a nozzle arranged to inject the shot of molten thermoplastic material into the mold cavities;

a controller communicatively connected to the ram and nozzle and the strain gauge pin; and

a virtual cavity sensor, implemented as a set of instructions that are stored on a non-transitory machine-readable medium, to determine at least one of an approximate pressure or melt flow front location using an output of the strain gauge pin, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

11. The injection molding apparatus of claim 10, wherein the strain gauge nozzle adapter includes an aperture for the strain gauge pin.

12. The injection molding apparatus of claim 11, wherein the strain gauge nozzle adapter includes an alternative material insert surrounding the aperture, the alternative material insert made from a material that amplifies the strain experienced by the strain gauge nozzle adapter.

13. The injection molding apparatus of claim 11, wherein the alternative material insert has a lower flex modulus than the surrounding external sensor nozzle adapter.

14. The injection molding apparatus of claim 13, wherein the alternative material insert is one of aluminum and brass.

15. The injection molding apparatus of claim 12, wherein the aperture has a bottom and the strain gauge nozzle adapter has a melt flow conduit having an internal melt flow conduit wall, and wherein the distance between the bottom of the aperture and an internal melt flow conduit wall is a minimum distance necessary to prevent cracking or leakage.

16. The injection molding apparatus of claim 15, wherein the minimum distance is at least 0.5 mm.

17. The injection molding apparatus of claim 11, wherein the strain gauge nozzle adapter has a plurality of apertures and each of the plurality of apertures has an external sensor in it, and wherein the controller determines at least one of an approximate pressure or melt flow front location using an output of each external sensor, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

18. The injection molding apparatus of claim 17, wherein the plurality of apertures are located in the same circumferential plane of the strain gauge nozzle adapter.

19. The injection molding apparatus of claim 11, further comprising a secondary sensor, and wherein the controller determines at least one of an approximate pressure or melt flow front location using an output of the strain gauge pin and the secondary sensor, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

20. A method of injection molding, comprising:

measuring, using a strain gauge pin, the change in strain in a strain gauge nozzle adapter;

approximating at least one of a pressure or a melt flow front location within the mold cavity based on the change in strain;

comparing the approximated pressure or melt flow front location to a trigger point; and

,

if the approximated pressure or melt flow front location equals or exceeds the trigger point, activating a virtual cavity sensor, wherein upon activation, the virtual cavity sensor causes a controller to perform an action.

21. The method of injection molding of claim 20, and amplifying a change in an alternative material insert of the strain gauge nozzle adapter.

22. The method of injection molding of claim 20, wherein measuring the change in strain in a strain gauge nozzle adapter includes using a plurality of strain gauge pins.

23. The method of injection molding of claim 20, wherein measuring the change in strain in a strain gauge nozzle adapter includes using a secondary sensor.

24. An injection molding apparatus, comprising:

a mold comprising one or more mold cavities;

a ram arranged to form a shot of molten thermoplastic material;

a strain gauge feed system adapter including a strain gauge pin attached between the nozzle and the mold;

a controller communicatively connected to the ram and nozzle and the strain gauge pin; and

a virtual cavity sensor, implemented as a set of instructions that are stored on a non-transitory machine-readable medium, to determine at least one of an approximate pressure or melt flow front location using an output of the strain gauge pin, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

25. The injection molding apparatus of claim 24, wherein the strain gauge feed system adapter includes an aperture for the strain gauge pin.

26. The injection molding apparatus of claim 25, wherein the strain gauge feed system adapter includes an alternative material insert surrounding the aperture, the alternative material insert made from a material that amplifies the strain experienced by the strain gauge feed system adapter.

27. The injection molding apparatus of claim 26, wherein the alternative material insert has a lower flex modulus than the surrounding strain gauge feed system adapter.

28. The injection molding apparatus of claim 26, wherein the alternative material insert is one of aluminum and brass.

29. The injection molding apparatus of claim 25, wherein the aperture has a bottom and the strain gauge feed system adapter has a melt flow conduit having an internal melt flow conduit wall, and wherein the distance between the bottom of the aperture and an internal melt flow conduit wall is a minimum distance necessary to prevent cracking or leakage.

30. The injection molding apparatus of claim 29, wherein the minimum distance is at least 0.5 mm.

31. The injection molding apparatus of claim 24, wherein the strain gauge feed system adapter has a plurality of apertures and each of the plurality of apertures has a strain gauge in it, and wherein the controller determines at least one of an approximate pressure or melt flow front location using an output of each strain gauge, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

32. The injection molding apparatus of claim 31, wherein the plurality of apertures are located in the same circumferential plane of the strain gauge feed system adapter.

33. The injection molding apparatus of claim 24, further comprising a secondary sensor, and wherein the controller determines at least one of an approximate pressure or melt flow front location using an output of the strain gauge pin and the secondary sensor, wherein the injection molding apparatus adjusts an operation of the ram in view of the determined approximate pressure or melt flow front location.

34. A method of injection molding, comprising:

measuring, using a strain gauge pin, the change in strain in a strain gauge feed system adapter;

approximating at least one of a pressure or a melt flow front location within the mold cavity based on the change in strain;

comparing the approximated pressure or melt flow front location to a trigger point; and

,

if the approximated pressure or melt flow front location equals or exceeds the trigger point, activating a virtual cavity sensor, wherein upon activation, the virtual cavity sensor causes a controller to perform an action.

35. The method of injection molding of claim 34, and amplifying a change in an alternative material insert of the strain gauge feed system adapter.

36. The method of injection molding of claim 34, wherein measuring the change in strain in a strain gauge feed system adapter includes using a plurality of strain gauge pins.

37. The method of injection molding of claim 34, wherein measuring the change in strain in a strain gauge feed system adapter includes using a secondary sensor.