Injection Molding Feedstock Delivery System

Patent metadata

Field	Value
Publication number	US-2021237149-A1
Application number	US-202117154370-A
Country	US
Kind code	A1
Filing date	Jan 21, 2021
Priority date	Jan 31, 2020
Publication date	Aug 5, 2021
Grant date	—

Abstract

A feedstock delivery system for injection molding includes a vessel unit that includes a vessel with an internal volume and an inlet for receipt of a feedstock. First and second dispensing units are alternatively connectable to the vessel unit and each include first and second ends, first and second valves, and a buffer chamber. The first end is connectable to the dispensing unit such that the buffer chamber is in communication with the internal volume of the vessel. The second end is connectable to an injection mold and defines an outlet of the feedstock delivery system. The outlet is in communication with the buffer chamber, and the buffer chamber is positioned between the first and second valves. The buffer chamber of the first dispensing unit defines a first chamber volume, and the buffer chamber of the second dispensing unit defines a second chamber volume greater than the first chamber volume.

First claim

1 . A feedstock delivery system for injection molding, comprising:
a vessel unit having a vessel defining an internal volume thereof and an inlet opening in communication with the internal volume, the inlet opening defining an inlet of the feedstock delivery system for receipt of feedstock into the internal volume; a dispensing unit having a first end, a second end, and a first conduit disposed therebetween, the first end being connected to the vessel unit such that the first conduit is in communication with the internal volume of the vessel, the second end being configured to connect to an injection mold and having an outlet opening defining an outlet of the feedstock delivery system; and a fluid jacket enclosing at least a portion of the vessel and at least a portion of the first conduit of the dispensing unit such that heated fluid flowing through the fluid jacket transforms the feedstock into a feedstock slurry and maintains the feedstock slurry at a constant temperature as it is dispensed from the internal volume of the vessel unit and out through the outlet opening of the dispensing unit via at least the first conduit.

2 . The feedstock delivery device of claim 1 , wherein the vessel unit includes an outlet opening and a valve positioned at the outlet opening of the vessel, the valve being configured to regulate a flow of the feedstock slurry from the internal volume of the vessel to the dispensing unit.

3 . The feedstock delivery system of claim 2 , wherein the valve has a head configured to move from a first position in which it obstructs the outlet opening of the vessel to a second position in which the outlet opening of the vessel is unobstructed by the head allowing feedstock slurry to flow therethrough, the head being configured to move linearly from the first position to the second position.

4 . The feedstock delivery system of claim 3 , wherein the vessel unit includes a vessel unit conduit extending from the outlet opening of the vessel to the first end of the dispensing unit, the vessel unit conduit being enclosed by the fluid jacket.

5 . The feedstock delivery system of claim 3 , further comprising an air compressor connected to the vessel and in communication with the internal volume thereof such that compressed air from the air compressor imposes a pressure on the feedstock slurry to dispense the feedstock slurry from the internal volume of the vessel to the dispensing unit when the valve is in the second position.

6 . The feedstock delivery system of claim 1 , further comprising a variable speed agitator disposed within the vessel for agitating feedstock slurry contained therein.

7 . The feedstock delivery system of claim 1 , wherein the first conduit extends from the first end to the second end of the dispensing unit.

8 . The feedstock delivery system of claim 1 , wherein the dispensing unit includes a second conduit, a buffer chamber, and a piston within the buffer chamber, the buffer chamber being in communication with the first and second conduits and disposed therebetween.

9 . The feedstock delivery system of claim 8 , wherein the dispensing unit includes first and second valves, the first valve being arranged on the first conduit to regulate flow of the feedstock slurry between the first conduit and buffer chamber, the second valve being arranged on the second conduit to regulate flow of the feedstock slurry between the buffer chamber and second conduit, the second conduit defining the outlet opening of the feedstock delivery system.

10 . The feedstock delivery system of claim 1 , further comprising a fluid circulator module in communication with the fluid jacket and configured to heat a fluid and circulate the fluid through the fluid jacket.

11 . The feedstock delivery system of claim 10 , wherein the fluid jacket includes a first fluid jacket at least partially enclosing the vessel of the vessel unit and a second fluid jacket at least partially enclosing the first conduit of the dispensing unit, the first and second fluid jackets being separate from each other such that fluid flowing through the first fluid jacket is isolated from fluid flowing through the second fluid jacket.

12 . A feedstock delivery system for injection molding, comprising:
a vessel unit having a vessel defining an internal volume thereof and an inlet opening in communication with the internal volume for receipt of feedstock into the internal volume; and first and second dispensing units being alternatively connectable to the vessel unit and each having first and second ends, first and second valves, and a buffer chamber, the first end being connectable to the dispensing unit such that the buffer chamber is in communication with the internal volume of the vessel, the second end being connectable to an injection mold and defining an outlet of the feedstock delivery system, the outlet being in communication with the buffer chamber, and the buffer chamber being positioned between the first and second valves, wherein the buffer chamber of the first dispensing unit defines a first chamber volume and the buffer chamber of the second dispensing unit defines a second chamber volume greater than the first chamber volume.

13 . The feedstock delivery system of claim 12 , wherein the first dispensing unit includes a first fluid jacket enclosing the buffer chamber thereof and the second dispensing unit includes a second fluid jacket enclosing the buffer chamber thereof.

14 . The feedstock delivery system of claim 13 , wherein the vessel unit includes a third fluid jacket enclosing the vessel.

15 . The feedstock delivery system of claim 12 , wherein the first and second dispensing units each include a piston disposed within their respective buffer chambers.

16 . The feedstock delivery system of claim 12 , further comprising a third dispensing unit having a first end, a second end, and a conduit extending uninterrupted from the first end to the second end thereof, the first end being connectable to the vessel unit and the second end defining an outlet of the feedstock delivery system when the third dispensing unit is connected to the vessel unit.

17 . The feedstock delivery system of claim 1 , wherein the first and second valves each include a ball and a spring, the spring of the second valve having a greater spring stiffness than the spring of the first valve.

18 . The feedstock delivery system of claim 17 , wherein the first and second valves are axially arranged in a direction of a feedstock slurry flow such that the balls of the first and second valves travel linearly in a direction with the feedstock slurry flow.

19 . A method of metal injection molding, comprising:
mixing a feedstock including metal powder and a binder, the binder being in a solid state; placing the feedstock in a vessel of a vessel unit; circulating heated fluid through a jacket disposed around the vessel to transform the binder to a liquid state and to form a feedstock slurry; dispensing a shot of the feedstock slurry into an injection mold; and forming a green-part via the injection mold.

20 . The method of claim 19 , wherein the shot of the feedstock slurry has a volume less than a total volume of feedstock slurry within the vessel.

Assignees

• Howmedica Osteonics Corp

Inventors

• Julien Benoit
• Mourski Alexei
• Ste-Marie Michael

Classifications

• B29C45/53

  using injection ram or piston · CPC title

• B29C45/18

  Feeding the material into the injection moulding apparatus {, i.e. feeding the non-plastified material into the injection unit} · CPC title

• B01F23/711

  Heating materials, e.g. melting · CPC title

• B01F35/7543

  using pneumatic pressure, overpressure or gas pressure in a closed receptacle or circuit system · CPC title

• B01F33/5024

  the vehicle being moved by human force · CPC title