Methods related to inductive heating in extruders
First Claim
1. A method for heating a feedstock of meltable or flowable material, comprising:
- a) providing a heating body of electrically conductive material, having inlet and outlet orifices connected via a passage or passages or mixing chamber to define a nozzle;
b) said nozzle sandwiched between the two ends of, or inserted through a hole or gap in, a continuous or segmented core of material having high magnetic permeability but low electrical conductivity, forming a complete magnetic loop, said nozzle not oriented substantially in the same plane as said magnetic loop,c) one or more coils of electrically conductive wire passing through the center of said loop and around the outside of said loop, and one or more sources of alternating current connected to said coil or coils, inducing said magnetic flux lines and said eddy currents,d) feeding said feedstock in the form of filament, rod, wire, granules, or liquid stream into said inlet orifice or orifices;
e) said feedstock being heated by contact with said nozzle, andf) extruding said feedstock from said outlet orifice or orifices.
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Accused Products
Abstract
Methods related to inductive heating in extruders. In some embodiments, a method for heating a feedstock or liquid material can include providing a heating body having inlet and outlet orifices connected via a passage or passages or mixing chamber to define a nozzle, and forming a magnetic loop with a coil of conductive wire wound through the center and around the outside of a core of magnetic but electrically non-conductive or low-conductivity material. The method can further include a high-frequency alternating current applied to the coil, producing a magnetic flux locally heating the nozzle. Some embodiments have passive regulation or limiting of nozzle temperature by selection of a core material with an appropriate Curie temperature.
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Citations
20 Claims
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1. A method for heating a feedstock of meltable or flowable material, comprising:
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a) providing a heating body of electrically conductive material, having inlet and outlet orifices connected via a passage or passages or mixing chamber to define a nozzle; b) said nozzle sandwiched between the two ends of, or inserted through a hole or gap in, a continuous or segmented core of material having high magnetic permeability but low electrical conductivity, forming a complete magnetic loop, said nozzle not oriented substantially in the same plane as said magnetic loop, c) one or more coils of electrically conductive wire passing through the center of said loop and around the outside of said loop, and one or more sources of alternating current connected to said coil or coils, inducing said magnetic flux lines and said eddy currents, d) feeding said feedstock in the form of filament, rod, wire, granules, or liquid stream into said inlet orifice or orifices; e) said feedstock being heated by contact with said nozzle, and f) extruding said feedstock from said outlet orifice or orifices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for heating a feedstock of meltable or flowable material for additive manufacturing or 3D printing, comprising:
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a) providing a heating body of electrically conductive material, having inlet and outlet orifices connected via a passage or passages or mixing chamber to define a nozzle; b) said nozzle sandwiched between the two ends of, or inserted through a hole or gap in, a continuous or segmented core of material having high magnetic permeability but low electrical conductivity, forming a complete magnetic loop, said nozzle not oriented substantially in the same plane as said magnetic loop, c) one or more coils of electrically conductive wire passing through the center of said loop and around the outside of said loop, and one or more sources of alternating current connected to said coil or coils, inducing said magnetic flux lines and said eddy currents, d) feeding said feedstock in the form of filament, rod, wire, granules, or liquid stream into said inlet orifice or orifices; e) said feedstock being heated by contact with said nozzle, and f) extruding said feedstock from said outlet orifice or orifices. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for heating a feedstock of meltable or flowable material for adhesive application, comprising:
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a) providing a heating body of electrically conductive material, having inlet and outlet orifices connected via a passage or passages or mixing chamber to define a nozzle; b) said nozzle sandwiched between the two ends of, or inserted through a hole or gap in, a continuous or segmented core of material having high magnetic permeability but low electrical conductivity, forming a complete magnetic loop, said nozzle not oriented substantially in the same plane as said magnetic loop, c) one or more coils of electrically conductive wire passing through the center of said loop and around the outside of said loop, and one or more sources of alternating current connected to said coil or coils, inducing said magnetic flux lines and said eddy currents, d) feeding said feedstock in the form of filament, rod, wire, granules, or liquid stream into said inlet orifice or orifices; e) said feedstock being heated by contact with said nozzle, and f) extruding said feedstock from said outlet orifice or orifices. - View Dependent Claims (18, 19, 20)
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Specification