Method and apparatus for high-temperature post-curing of UV-cured photopolymers

Patent metadata

Field	Value
Publication number	US-10144185-B2
Application number	US-201514676398-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 1, 2015
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

Methods, systems and apparatuses are disclosed for making and post-processing a 3-D printed object for laminate-forming tooling, and components made using post-processed 3-D printed laminate-forming tooling.

First claim

What is claimed is:

1. A method comprising the steps of:
preparing a 3-D printed tool precursor made from a material comprising a polymer and a UV-curable additive;
curing the 3-D printed tool precursor with UV radiation to obtain a 3-D printed UV-cured tool precursor;
exposing the 3-D printed UV-cured tool precursor to a basic solution having a pH of from about 11 to about 14 for a predetermined amount of time; and
exposing the 3-D printed UV-cured tool precursor to a predetermined post-UV-curing regimen, said post-UV-curing regimen maintained at a pressure of 90 psi, and said post-UV-curing regimen comprising progressively increasing a temperature at a ramp rate of 1° F./min. from about room temperature to a predetermined maximum temperature from about 300° F. to about 400° F., with predetermined dwell periods during temperature increases, and progressively decreasing the temperature at a rate of 1° F./min from the predetermined maximum temperature to a temperature of 250° F. followed by a dwell period of 60 mins., followed by a temperature decrease from 250° F. to room temperature to obtain a 3-D printed finished tool for the manufacture of a composite layment.

2. The method of claim 1 , wherein the basic solution comprises sodium hydroxide.

3. The method of claim 1 , further comprising the step of maintaining the 3-D printed UV-cured tool precursor in an inert environment during the post-UV-curing regimen, wherein the inert environment comprises a gas selected from the group consisting of: argon, nitrogen and combinations thereof.

4. The method of claim 1 , wherein, in the step of preparing a 3-D printed tool precursor made from a material comprising a polymer and a UV-curable additive, the polymer comprises photopolymer.

5. The method of claim 3 , wherein the inert environment is maintained at a pressure of at least about 90 psi during the predetermined heating regimen.

6. The method of claim 3 , wherein the inert environment comprises nitrogen.

7. The method of claim 1 , wherein, in the step of exposing the 3-D printed UV-cured tool precursor to a predetermined post-UV-curing regimen, further comprising:
exposing the 3-D printed UV-cured tool precursor to a predetermined post-UV-curing regimen, said subsequent post-UV-curing regimen regimen maintained at a pressure of 90 psi, and said post-UV-curing regimen comprising increasing a temperature at a ramp rate of 1° F./min. from about room temperature to a temperature of 150° F. followed by a dwell period of 30 mins. at 150° F., followed by increasing a temperature at a ramp rate of 1° F./min. heating from 150° F. to 250° F. followed by a dwell period of 60 mins at 250° F., followed by increasing a temperature at a ramp rate of 1° F./min. from 250° F. to 350° F. followed by a dwell period of 120 mins at 350° F., and decreasing the temperature at a rate of 1° F./min. from 350° F. to 250° F. followed by a dwell period of 60 mins., followed by further decreasing the temperature at a rate of about 1° F./min. from 250° F. to room temperature to obtain a 3-D printed finished tool for the manufacture of a composite layment.

8. The method of claim 1 , wherein, in the step exposing the 3-D printed UV-cured tool precursor to a basic solution, the basic solution is maintained at a temperature of from about 120° F. to about 150° F.

9. The method of claim 8 , wherein, after the step of exposing the 3-D printed UV-cured tool precursor to a basic solution, the basic solution maintained at a temperature of from about 120° F. to about 150° F., further comprising the step of:
allowing the basic solution to cool to room temperature.

10. The method of claim 7 , wherein the inert environment comprises nitrogen.

11. The method of claim 7 , wherein, in the step exposing the 3-D printed UV-cured tool precursor to a basic solution, the basic solution is maintained at a temperature of from about 120° F. to about 150° F.

Assignees

• Boeing Co

Inventors

• Stephenson Benjamin J
• Frankenbery Scott K
• Ingram Jr William H
• Hollensteiner William S

Classifications

• B29K2105/243

  Partially cured · CPC title

• B29C2035/0827

  using UV radiation · CPC title

• B29C35/0805

  using electromagnetic radiation · CPC title

• B29C71/02

  Thermal after-treatment {(B29C71/0063 and B29C71/0072 take precedence)} · CPC title

• B29C71/04 Primary

  by wave energy or particle radiation {, e.g. for curing or vulcanising preformed articles (during moulding, e.g. in a mould B29C35/08)} · CPC title