System and method for roll-to-roll film tensioning for reduced separation force during bottom-up stereolithography

Patent metadata

Field	Value
Publication number	US-11623396-B2
Application number	US-202017028543-A
Country	US
Kind code	B2
Filing date	Sep 22, 2020
Priority date	Sep 22, 2020
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

The present disclosure relates to a tensioning system for use in a stereolithography manufacturing application. The system may have a build plate for supporting a three dimensional part being formed using a photo responsive resin, a base plate and a release element extending over the base plate. The release element is configured to receive a quantity of photo responsive resin for forming a new material layer of the three dimensional part. A pair of tensioning components are secured to opposite ends of the release element, and apply a controlled tension force to the release element during peeling of the release element to reduce a separation force required to separate the release element from the new material layer after the new material layer is cured.

First claim

What is claimed is:

1. A method of controlling tensioning of a release element being used to support a photo responsive resin in a stereolithography manufacturing application, the method including:
arranging a release element over a base plate, the release element for supporting a three dimensional part being formed using a quantity of photo responsive resin;
controlling a pair of tensioning components operatively coupled to the release element, where the tensioning components are disposed in fixed locations relative to the base plate, and on opposite lateral sides of the base plate, to control a tension experienced by the release element as the release element is peeled from a newly formed material layer after the quantity of photo responsive resin being used to form the newly formed material layer has cured; and
controlling a tension applied to the release element using the tensioning components such that a peel angle of the release element is maintained constant while the release element is peeled from the newly formed material layer.

2. A tensioning system for use in a stereolithography manufacturing application, the system including:
a controller;
a build plate for supporting a three dimensional part being formed using a photo responsive resin;
a base plate;
a release element extending over the base plate, the release element configured to receive a quantity of photo responsive resin for forming a new material layer of the three-dimensional part;
a pair of independently rotationally supported tensioning components to which opposite ends of the release element are secured for applying a controlled tension force to the release element;
the pair of tensioning components being arranged at laterally fixed positions relative to the build plate, and on opposing sides of the build plate;
wherein a tension applied to the release element by the tensioning components is controlled to reduce a separation force required to separate the release element from the new material layer after the new material layer is cured, and further such that the controller controls the pair of tensioning components to enable rotation in opposite rotational directions, to controllably unspool the release element to enable a peel angle of the release element to be maintained constant and non-parallel to a surface of the new material layer, while the release element is peeled from the newly formed material layer.

3. The system of claim 2 , wherein the release element comprises a low surface energy release film.

4. The system of claim 3 , wherein the low surface energy release film comprises a polytetrafluoroethylene (PTFE) release film.

5. The system of claim 3 , wherein the low surface energy release film comprises at least one of a fluorinated ethylene propylene (FEP) polytetrafluoroethylene (PTFE) release film, or a PTFE amorphous fluoroplastic film, or a polymethylpentene film.

6. The system of claim 2 , wherein the tensioning components comprise tensioning rollers.

7. The system of claim 3 , wherein each said tensioning roller includes an electric motor for controlling rotational movement of its associated said tensioning roller.

8. The system of claim 7 , further comprising a pair of idler rollers disposed on opposing sides of the base plate, for assisting in supporting the low surface energy release film and helping to control a peel angle of the low surface energy release film while peeling of the low surface energy release film is occurring.

9. The system of claim 7 , wherein each said electric motor comprises an electric stepper motor.

10. The system of claim 9 , further comprising an electronic controller for controlling each of the electric stepper motors.

11. The system of claim 2 , further comprising a UV light source for curing the new material layer of photo responsive resin.

12. The system of claim 2 , further comprising a doctor blade component for assisting in spreading a new quantity of photo responsive resin on the release element to achieve a generally uniform thickness of the new quantity of photo responsive resin.

13. The system of claim 12 , wherein the doctor blade component is arranged in a path of movement of the release element.

14. The system of claim 12 , wherein the doctor blade component is arranged parallel to a path of movement of the release element, and movable laterally along an axis perpendicular to the path of movement.

15. The system of claim 2 , further comprising at least one sensing component for sensing a tension being experienced by the release element while peeling of the release element is occurring.

16. The system of claim 2 , further comprising a lifting mechanism for lifting the build plate to assist in peeling the release element from the newly cured material layer.

17. A tensioning system for use in a stereolithography manufacturing application, the system including:
an electronic controller;
a build plate for supporting a three dimensional part being formed using a photo responsive resin;
a base plate;
a low surface energy release film extending over the base plate, the low surface energy release film configured to receive a quantity of photo responsive resin for forming a new material layer of the three dimensional part;
a pair of independently controllable, rotational tensioning rollers to which opposite ends of the low surface energy release film are secured for applying a controlled tension force to the low surface energy release film;
the pair of tensioning rollers being arranged at laterally fixed positions on opposing sides of the build plate;
a pair of motors for controlling rotational movement of the pair of tensioning rollers in response to signals from the electronic controller;
the electronic controller controlling the motors to vary a tension force applied by the tensioning rollers during fabrication of the new material layer and release of the new material layer from the low surface energy release film; and
wherein a peel angle of the low surface energy release film and a tension applied to the low surface energy release film by the tensioning rollers is controlled by the electronic controller controlling the pair of motors to rotate in opposite directions to enable a controlled unspooling of the release film from the pair of tensioning rollers, to maintain the peel angle the same on both sides of the build plate, non-parallel to a surface of the new material layer, and to reduce a separation force required to separate the low surface energy release film from the new material layer when the new material layer is cured and being removed from the low surface energy release film.

18. The system of claim 17 , further comprising a pair of idler rollers disposed on opposing sides of the base plate, for assisting in supporting the low surface energy release film and helping to control the peel angle of the low surface energy release film while peeling of the low surface energy release film is occurring.

19. The system of claim 17 , wherein the low surface energy release film comprises at least one of:
a polytetrafluoroethylene (PTFE) release film; and
a fluorinated ethylene propylene (FEP) polytetrafluoroethylene (PTFE) release film.

Assignees

• L Livermore Nat Security Llc
• Univ Texas

Inventors

• Duoss Eric B
• Oakdale James
• Rodriguez Nicholas Anthony
• Song Hongtao
• Crawford Richard
• Seepersad Carolyn
• Chen Morgan

Classifications

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/264

  Arrangements for irradiation · CPC title

• B33Y40/00

  Auxiliary operations or equipment, e.g. for material handling · CPC title

• B29C64/232

  for motion along the axis orthogonal to the plane of a layer · CPC title

• B29C64/245 Primary

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