Nozzle shut off for injection molding system
AssigneeExtrude To Fill, LLC
InventorRichard Ernest Fitzpatrick
Life of this patent
Estimating the term…
Abstract
An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.
Claims34
A method of fabricating a molded part, the method comprising:
- clamping a mold;
- opening a nozzle by separating a tip of an extrusion screw from an opening formed in the nozzle;
- rotating the extrusion screw to pump a molten material into the mold until the mold is filled;
- closing the nozzle by positioning the tip of the extrusion screw in sealed engagement with the nozzle;
- and
- unclamping the mold to release the molded part;
- wherein:
- opening the nozzle comprises rotating the extrusion screw to move the screw tip away from the nozzle;
- and
- closing the nozzle comprises reversing rotation of the extrusion screw to move the screw tip into contact with the nozzle.
A method of fabricating a molded part, the method comprising:
- clamping a mold;
- opening a nozzle by separating a tip of an extrusion screw from an opening formed in the nozzle;
- rotating the extrusion screw to pump a molten material into the mold until the mold is filled;
- closing the nozzle by positioning the tip of the extrusion screw in sealed engagement with the nozzle;
- and
- unclamping the mold to release the molded part;
- wherein:
- opening the nozzle comprises moving a barrel in a first direction relative to an extrusion screw to move a nozzle attached to the barrel away from a tip of the extrusion screw;
- and
- closing the nozzle comprises moving the barrel in a second direction opposite the first direction relative to the extrusion screw to move the nozzle into engagement with the screw tip.
A method of fabricating a plastic component by an apparatus comprising a hopper, an extrusion screw with a screw tip, a nozzle, one or more heaters, and a motor, the method comprising:
- clamping a mold;
- activating the motor to rotate the extrusion screw to move the screw tip away from the nozzle to open the nozzle;
- rotating the extrusion screw to pump a molten material into the mold until the mold is filled;
- reversing rotation of the extrusion screw to move the screw tip to close the nozzle;
- cooling the mold to solidify the molten material in the mold;
- and
- unclamping the mold to release a molded part.
An injection molding apparatus comprising:
- a barrel;
- a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel;
- and
- an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel, the extrusion screw including a screw tip configured to prevent formation of a cold slug in the opening of the nozzle;
- wherein relative axial movement between the barrel and the extrusion screw opens or closes the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle;
- and
- wherein the screw tip comprises:
- a cylindrical tip portion configured to extend to an exterior surface of the nozzle and seal the opening of the nozzle;
- and
- an angled portion extending rearwardly and outwardly from the cylindrical tip portion, the angled portion configured to form a seal with a portion of the nozzle surrounding the opening.
An apparatus comprising:
- an extrusion screw inside a barrel;
- a hopper coupled to the barrel and configured to fill a material into the barrel;
- one or more heaters configured to heat the material inside the barrel;
- a nozzle having a tip portion configured to enclose the screw tip, a barrel connection configured to connect to the barrel, and a middle portion between the tip portion and the barrel connection, the tip portion of the nozzle having an opening for injecting the material;
- and
- a screw tip coupled to the extrusion screw, the screw tip configured to fit inside the tip portion of the nozzle and displace the material from the opening in the tip portion of the nozzle to prevent formation of a cold slug in the opening, the screw tip configured to move along an axial direction to open and close the opening;
- wherein the screw tip comprises:
- a cylindrical tip portion configured to extend to an exterior surface of the tip portion of the nozzle and seal the opening in the tip portion of the nozzle;
- and
- an angled portion extending rearwardly and outwardly from the cylindrical tip portion, the angled portion configured to form a seal with the middle portion of the nozzle.
Dependencies are inferred from the claim text.