Three-dimensional printing system

Patent metadata

Field	Value
Publication number	US-2020147881-A1
Application number	US-201916676940-A
Country	US
Kind code	A1
Filing date	Nov 7, 2019
Priority date	Nov 9, 2018
Publication date	May 14, 2020
Grant date	—

Abstract

A vat polymerization apparatus configured with a resin circulatory system that includes pumps arranged to extract used photo-curing resin from a tank and refresh or replace it with new resin, another fluid, or a combination of new resin and the fluid. Resin flow is regulated using a plurality of valves which are opened and closed to achieve a desired circulation process. Additional aspects of the apparatus include a membrane assembly in which a radiation-transparent flexible membrane is supported in a frame that stretches the membrane. A lip of the frame is secured to a bottom rim of the tank; thus, when the membrane assembly is in place it forms a bottom of the tank. A tension adjustment mechanism may be employed to adjust the tension of the membrane within the frame. The frame may be aligned with the tank with the aid of magnetized alignment aids distributed about the frame.

First claim

What is claimed is:

1 . An apparatus, comprising:
a tank configured to contain a resin, the tank including an entrance port and an exit port; and a resin circulatory system comprising:
a first pump configured to extract the resin from the tank through the exit port of the tank, and flow the resin towards a branch point,
the branch point fluidly coupled to the first pump, a first valve and a second valve;
the first valve regulating a flow of the resin from the first branch point to an inlet of a first reservoir;
the second valve regulating a flow of the resin from the first branch point to a first confluence point;
a third valve regulating a flow of the resin from an outlet of the first reservoir to a second confluence point;
a fourth valve regulating a flow of the resin from the first confluence point to the second confluence point;
a second reservoir configured to supply a fluid to the first confluence point, wherein the fluid comprises at least one of fresh resin or an additive; and
a second pump configured to extract the resin, the fluid or a combination of the resin and the fluid from the second confluence point and flow the resin, the fluid or the combination of the resin and the fluid into the tank via the entrance port of the tank.

2 . A method to operate an apparatus comprising a tank configured to contain a resin, the tank including an entrance port and an exit port; and a resin circulatory system comprising (i) a first pump configured to extract the resin from the tank through the exit port of the tank, and flow the resin towards a branch point, (ii) the branch point fluidly coupled to the first pump, a first valve and a second valve, (iii) the first valve regulating a flow of the resin from the first branch point to an inlet of a first reservoir, (iv) the second valve regulating a flow of the resin from the first branch point to a first confluence point, (v) a third valve regulating a flow of the resin from an outlet of the first reservoir to a second confluence point, (vi) a fourth valve regulating a flow of the resin from the first confluence point to the second confluence point, (vii) a second reservoir configured to supply a fluid to the first confluence point, wherein the fluid comprises at least one of fresh resin or an additive, and (viii) a second pump configured to extract the resin, the fluid or a combination of the resin and the fluid from the second confluence point and flow the resin, the fluid or the combination of the resin and the fluid towards the entrance port of the tank, the method comprising:
during a first time period, opening the first and third valves, and closing the second and fourth valves so as to flow resin from the tank through the first reservoir and back into the tank; and during a second time period, closing the first and third valves, and opening the second and fourth valves so as to flow resin from the tank to the first confluence point attached to the second reservoir, and flow the combination of the resin and the fluid into the tank.

3 . A membrane assembly for a three-dimensional printing system, comprising:
a radiation-transparent flexible membrane; and a frame affixed to a perimeter of the radiation-transparent flexible membrane and configured to stretch the radiation-transparent flexible membrane along a first plane, wherein the frame comprises a lip extending perpendicular to the first plane, the lip configured to be secured to a bottom rim of a tank sidewall, wherein the membrane assembly, when secured to the bottom of the tank sidewall, forms a bottom of a tank configured to contain a photo-curing liquid resin.

4 . The membrane assembly of claim 3 , further comprising:
a tension adjustment mechanism coupled to the radiation-transparent flexible membrane and configured to adjust a tension of the radiation-transparent flexible membrane.

5 . The membrane assembly of claim 3 , further comprising:
a tension sensor affixed to a surface of the radiation-transparent flexible membrane and configured to measure a tension of the radiation-transparent flexible membrane.

6 . The membrane assembly of claim 5 , wherein the tension sensor comprises a strain gauge affixed to the surface of the radiation-transparent flexible membrane.

7 . The membrane assembly of claim 3 , further comprising:
a tension sensor embedded within the radiation-transparent flexible membrane and configured to measure a tension of the radiation-transparent flexible membrane.

8 . The membrane assembly of claim 7 , wherein the tension sensor comprises a conductive strip embedded within the radiation-transparent flexible membrane.

9 . A tank assembly, comprising:
a tank sidewall, wherein a bottom rim of the tank sidewall comprises a groove; a tension sensor coupled to the tank sidewall; a radiation-transparent flexible membrane; and a frame secured to a perimeter of the radiation-transparent flexible membrane, wherein the frame comprises a lip that engages with the groove of the bottom rim of the tank sidewall, wherein the tension sensor is configured to detect a movement of the radiation-transparent flexible membrane upon a loss of tension of the radiation-transparent flexible membrane.

10 . An apparatus, comprising:
a glass frame assembly comprising a first frame and a glass plate, wherein the first frame is configured to hold the glass plate, the first frame including a first plurality of through holes and a first plurality of magnetized portions distributed about a surface of the first frame; and a liquid crystal display (LCD) assembly comprising a second frame and an LCD, wherein the second frame is configured to hold the LCD, the second frame including a second plurality of through holes and a second plurality of magnetized portions distributed about a surface of the second frame, wherein (i) a pattern in which the first plurality of through holes are distributed about the surface of the first frame is a mirror image of a pattern in which the second plurality of through holes are distributed about the surface of the second frame, (ii) a pattern in which the first plurality of magnetized portions are distributed about the surface of the first frame is a mirror image of a pattern in which the second plurality of magnetized portions are distributed about the surface of the second frame, and (iii) each one of the first plurality of magnetized portions is attracted to a corresponding one of the second plurality of magnetized portions such that when the first frame is disposed in a proximity of the second frame, (I) the surface of the first frame automatically contacts the surface of the second frame, and (II) each one of the first plurality of through holes automatically aligns with a corresponding one of the second plurality of through holes.

11 . The apparatus of claim 10 , further comprising:
a gasket disposed within or near a boundary region between the surface of the first frame and the surface of the second frame, the gasket configured to prevent resin from contacting the region between the glass plate and the LCD.

12 . A three-dimensional (3D) printing system, comprising:
a tank assembly comprising:
a tank sidewall, wherein a bottom rim of the tank sidewall comprises a groove;
a radiation-transparent flexible membrane; and
a first frame secured to a perimeter of the radiation-transparent flexible membrane, wherein the first frame comprises a lip that engages with the groove of the bottom rim of the tank sidewall; and
a lighting assembly comprising:
a glass plate secured within a second frame; and
a liquid crystal display (LCD) secured within a third frame, wherein the second frame is secured to the th

Assignees

• Nexa3D Inc

Inventors

• Medalsy Izhar
• Tringali Luciano
• Barker Nathan
• Barker Steve

Classifications

• B29C64/277

  using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] · CPC title

• B29C64/307 Primary

  Handling of material to be used in additive manufacturing · CPC title

• B29C64/35

  Cleaning · CPC title

• B29C64/245

  Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) · CPC title

• B29C64/129

  characterised by the energy source therefor, e.g. by global irradiation combined with a mask · CPC title