Print head nozzle for use with additive manufacturing system
A nozzle for printing three-dimensional parts with an additive manufacturing system, the nozzle comprising a nozzle body having an inlet end and a tip end offset longitudinally from the inlet end, a tip pipe for extruding a flowable material, an inner ring extending circumferentially around the tip pipe at the outlet end, an outer ring extending circumferentially around the inner ring, at least one annular recessed groove located circumferentially between the inner ring and the outer ring.
1. A nozzle for use with a print head in an extrusion-based additive manufacturing system, the nozzle comprising: an inlet end configured to be secured to a flow channel of the print head; a tip end offset longitudinally from the inlet end; a tip pipe extending longitudinally at least part way between the inlet end to the tip end; the tip end comprising: an outlet port of the tip pipe configured to extrude molten material from the print head, the outlet port having a first diameter; an inner ring having a second diameter that is larger than the first diameter, wherein the inner ring is substantially concentric and co-planar with the outlet port, wherein the first diameter and the second diameter define a substantially planar surface therebetween; an outer ring comprising a knife edge having a third diameter at the knife edge that is larger than the second diameter, wherein the outer ring is substantially concentric and co-planar with the inner ring; and at least one annular recessed groove having an opening located between the inner ring and the outer ring, wherein the nozzle is configured to produce smooth extruded roads of material having a first width and a second width, wherein the first width is substantially that of the second diameter and the second width is substantially that of the third diameter, wherein the at least one annular recessed groove is configured to accept a flowable material extruded from the outlet port such that at least a portion of the extruded flowable material is accepted by the at least one annular recessed groove such that the extruded flowable material contacts and is guided by the outer ring to form the road of material and the second width.
2. The nozzle of claim 1 , wherein the second diameter ranges from about 500 micrometers to about 1,300 micrometers.
3. The nozzle of claim 1 , wherein the third diameter ranges from about 1,500 micrometers to about 2,500 micrometers.
4. The nozzle of claim 1 , wherein the outer ring is configured to be removably coupled to the tip end.
5. The nozzle of claim 1 , wherein the tip pipe has a longitudinal length and the first diameter, and wherein a ratio of the longitudinal length to the first diameter of the tip pipe ranges from about 1:2 to about 5:1.
6. A print head for use in an extrusion-based additive manufacturing system, the print head comprising: a flow channel having an inlet end and an outlet end, the inlet end of the flow channel being configured to receive a consumable material; a heating element for heating the consumable material in the flow channel to a temperature at which the consumable material is flowable; and a nozzle comprising: an inlet end coupled to or integrally formed with the outlet end of the flow channel; a tip end offset longitudinally from the inlet end of the nozzle; a tip pipe having an exit port proximate the tip end, the exit port having a first diameter and being configured to extrude the flowable consumable material received from the flow channel; an inner ring substantially concentric with the exit port at the tip end of the nozzle, the inner ring having a second diameter that is larger than the first diameter, wherein the first and second diameters define a substantially planar surface therebetween; an outer ring spaced from and substantially coplanar and concentric with the inner ring, wherein the outer ring comprises a knife edge having a third diameter at the knife edge that is larger than the second diameter; and at least one annular recessed groove located between the inner ring and the outer ring, wherein the nozzle is configured to produce smooth extruded roads of material having a first width and a second width, wherein the first width is substantially that of the second diameter and the second width is substantially that of the third diameter, wherein the at least one annular recessed groove is configured to accept a portion of the flowable consumable material extruded from the exit port when a flow rate of the flowable material creates a back pressure between the nozzle and a previously accepted layer of a 3D part such that the portion of the extruded flowable consumable material is accepted by the at least one annular recessed groove and wherein the extruded flowable material contacts the outer ring and is guided by the outer ring to form the road having substantially the third diameter.
7. The print head of claim 6 , wherein the second diameter ranges from about 500 micrometers to about 1,300 micrometers.
8. The print head of claim 6 , wherein the third diameter ranges from about 1,500 micrometers to about 2,500 micrometers.
9. The print head of claim 6 , wherein the at least one annular recessed groove has a radial width between the inner ring and the outer ring of at least about 760 micrometers.
10. A nozzle for use with a print head in an extrusion-based additive manufacturing system, the nozzle comprising: a main body having a first end and a second end; a flow channel through the main body from the first end to the second end wherein the flow channel at the second end defines an extrusion port configured to extrude a molten material, wherein the extrusion port has a first diameter; an inner ring at the second end, the inner ring having a second diameter being larger than the first diameter, the inner ring being substantially co-planar and concentric with the extrusion port; an outer ring at the second end, the outer ring being substantially co-planar and concentric with the inner ring, wherein the outer ring comprises a knife edge having a third diameter at the knife edge that is larger than the second diameter; and a first annular recess within the second end of the main body and having an opening located in the second end, wherein the first annular recess is concentric with the extrusion port, wherein the first annular recess is positioned between the inner ring and the outer ring, wherein the nozzle is configured to produce smooth extruded roads of material having a first width and a second width, wherein the first width is substantially that of the second diameter and the second width is substantially that of the third diameter, and wherein the first annular recess is configured to accept a portion of the molten material extruded from the extrusion port when a flow rate of the flowable material creates a back pressure between the nozzle and a previously accepted layer of a 3D part such that the portion of the extruded molten material is accepted by the first annular recess and wherein the extruded flowable material contacts and is guided by the outer ring to form the road of material having substantially the width of the third diameter.
11. The nozzle of claim 10 and wherein the second end of the nozzle comprises a substantially flat surface between the extrusion port and the first annular recess.