Patent ID: 11945150
Assignee: EXTRUDE TO FILL, INC.
Field: Other special machines (Mechanical engineering)
Classification: CPC B  G  H  Y | IPC B  G  H

Claim 10:
11. A fill by extrusion molding apparatus comprising:
a barrel defining a nozzle in an end associated with a mold;
a hopper coupled to the barrel and configured to feed a raw material into the barrel;
one or more heaters associated with the barrel positioned apart from the hopper to heat the raw material and transform the raw material into a molten material; and
an extrusion screw received inside the barrel and configured to rotate in a first direction and a second direction relative to the barrel,
wherein:
the extrusion screw is configured to move in an axial direction within and with respect to the barrel between a first position in which the extrusion screw is fixed axially to open the nozzle and where it rotates in the first direction to extrude the molten material into the mold through the nozzle and a second position in which a tip of the extrusion screw is received in the nozzle to seal the nozzle;
the extrusion screw is configured to move in the axial direction from the first position to the second position to seal the nozzle when the mold is filled while rotating the extrusion screw in the second direction to decompress the barrel and to break a non-Newtonian action of the molten material;
the extrusion screw is configured to move in the axial direction from the second position to the first position to open the nozzle while rotating the extrusion screw in the first direction; and
the barrel is configured to operate with an internal pressure in the barrel that ranges the same as and 10% higher than a pressure inside the mold when the molten material is extruded into the mold.