System for post-processing orthodontic appliance molds

• US 8,776,391 B1
• Filed: 07/23/2007
• Issued: 07/15/2014
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: Align Technology Incorporated
• Original Assignee: Align Technology Incorporated
• Inventors: Kaza, Srinivas, Phan, Long, Sambu, Shiva P, Tata, Kamesh, Doung, Michael J
• Primary Examiner(s): Rinehart, Kenneth
• Assistant Examiner(s): MCCORMACK, JOHN PATRICK
• Application Number:
  US11/781,809
• Time in Patent Office: 2,549 Days
• Field of Search: 34/58, 343/18, 343/19, 342/01, 342/02, 343/81, 344/06, 344/07, 344/08, 342/75, 34312-317
• US Class Current: 34/317
• CPC Class Codes: A61C 13/00 Dental prostheses; Making same tooth crowns for capping teeth A61C5/70; dental implants A61C8/00
• CPC Class Codes: F26B 5/08 by centrifugal treatment

Abstract

A system and method for post-processing of polymeric items having a liquid component and a predetermined heat deflection temperature is provided. The system includes a washing station to spray water at elevated temperature and pressure on the items while maintaining the temperature of the item below the heat deflection temperature. Then using a water distillation system to separate the water from the water mixed with the liquid polymer component by evaporating the water using heating coils with surface that is not conducive to adhesion of the liquid polymer component and then condense the water vapor into liquid water. The system may further include a spin station to separate the liquid polymer component by spinning the item. The system may further include one or more processing stations to rinse the item, dry the item, cure the item, remove the item from a tray to which the item may be attached and clean trays after removing the item. A conveyor system may be used to automate the post-processing of the items.

Claims

1. A system for removing extraneous liquid polymer from polymeric items having a curable liquid polymer component, the system comprising:

a spin station, comprising;

a spin chamber having a predetermined load side and a predetermined unload side;

a loading mechanism external to the spin chamber at the load side and operable to receive a tray carrying a plurality of polymeric items having extraneous liquid polymer thereon;

a turntable having an axis of rotation and located in the spin chamber so as to receive the tray from the loading mechanism at the load side of the spin chamber and to discharge the tray from the unload side of the spin chamber, the turntable being operable to spin the tray about the axis of rotation so as to remove at least a first quantity of the extraneous liquid polymer from the items by centrifugal force;

a first sensor mechanism operably associated with the turntable so as to determine when the turntable is positioned relative to the load side of the spin chamber for receiving the tray from the loading mechanism;

an unloading mechanism external to the spin chamber at the unload side and operable to receive the tray from the turntable at the unload side of the spin chamber; and

a second sensor mechanism operably associated with the turntable so as to determine when the turntable is positioned relative to the unloading mechanism for delivering the tray to the unloading mechanism;

a washing station located and configured to receive the tray from the spin station and operable to spray water at an elevated temperature and pressure on the items so as to remove a second quantity of the extraneous liquid polymer from the items, thereby producing a mixture of water and liquid polymer; and

a water distillation system arranged to receive at least a portion of the mixture of water and liquid polymer from the washing station, and operable to separate by distillation the water from the liquid polymer in the mixture, wherein the distillation system comprises;

a reaction chamber operable to maintain a vacuum and having a heating coil operable to separate the liquid polymer from the water in the mixture by evaporating the water, wherein the heating coil has a surface that is not conducive to adhesion of the liquid polymer component during the separation; and

a condensation chamber arranged to receive water vapor from the reaction chamber and operable to condense the water vapor into liquid water.

2. The system of claim 1, wherein the spin chamber further comprises a shroud that is movable between an open position and a closed position in which it surrounds the turntable so as to receive the extraneous liquid polymer removed from the items.

3. The system of claim 2, wherein the shroud includes a top and a bottom, and a wall that connects the top and the bottom at inclined angle.

4. The system of claim 3, further comprising a collection bin arranged and configured to receive the extraneous liquid polymer from the shroud.

5. The system of claim 1, wherein the turntable includes a clamp mechanism that is movable between an open position configured to permit placement of the tray on the turntable and removal of the tray therefrom, and a closed position in which the tray is secured to the turntable.

6. The system of claim 1, further comprising a water supply mechanism operable to (a) supply water at an elevated temperature to the washing station;

(b) receive the mixture of water and liquid polymer produced by the washing station; and

(c) supply at least a portion of the mixture of water and liquid polymer to the water distillation system.

7. The system of claim 1, further comprising an air handling system operable to remove air mixed with water particles from the washing station and to separate the water particles from the air mixed with water particles.

8. The system of claim 1, further comprising an isolation station, located and configured to receive the tray from the washing station, and operable to blow air onto the items so as to remove water from the items.

9. The system of claim 8, further comprising a rinsing station, located and configured to receive the tray from the isolation station, and operable to spray water on the items at elevated temperature and pressure, thereby producing a second mixture of water and liquid polymer.

10. The system of claim 9, further comprising a water supply mechanism operable to (a) supply water at an elevated temperature to the rinsing station;

(b) receive the second mixture of water and liquid polymer produced by the rinsing station; and

(c) supply at least a portion of the second mixture of water and liquid polymer to the water distillation system.

11. The system of claim 1, further comprising a drying station operable to receive the tray from the washing station and to remove water from the items on the tray.

12. The system of claim 11, wherein the drying station includes an apparatus that is operable to direct air onto the items.