Heat-generating tooling systems and methods

Patent metadata

Field	Value
Publication number	US-2021001519-A1
Application number	US-201916459505-A
Country	US
Kind code	A1
Filing date	Jul 1, 2019
Priority date	Jul 1, 2019
Publication date	Jan 7, 2021
Grant date	—

Abstract

Methods of manufacturing composite workpieces that include positioning a heat-generating element proximate to an uncured composite workpiece, triggering the heat-generating element to produce an exothermic chemical reaction or exothermic physical reaction so that the temperature of the uncured composite workpiece is raised to a predetermined first temperature, and curing the composite workpiece while it is at a temperature that is at least the predetermined first temperature.

First claim

What is claimed is:

1 . A method of manufacturing a composite workpiece, comprising:
positioning a heat-generating element proximate to an uncured composite workpiece, the heat-generating element capable of undergoing an exothermic chemical reaction when activated or capable of undergoing an exothermic physical reaction when triggered; triggering the heat-generating element to produce the exothermic chemical reaction or exothermic physical reaction so that a temperature of the uncured composite workpiece is raised to at least a predetermined first temperature; and curing the composite workpiece while the composite workpiece is at a temperature that is at least the predetermined first temperature.

2 . The method of claim 1 , further comprising applying pressure to the uncured composite workpiece while it is curing.

3 . The method of claim 2 , wherein positioning the heat-generating element proximate to the uncured composite workpiece includes positioning a mixture of the heat-generating element and a thermally-expanding element proximate to the uncured composite workpiece;
triggering the heat-generating element includes triggering the thermally-expanding element to undergo a volumetric expansion; and applying pressure to the uncured composite workpiece while it is curing includes constraining a volume around the uncured composite workpiece so that triggering the thermally-expanding element applies at least a predetermined pressure to the uncured composite workpiece during curing.

4 . The method of claim 3 , wherein the thermally-expanding element includes a plurality of expandable pellets configured to expand collectively to produce the predetermined pressure against a surface of the uncured composite workpiece when heated to the predetermined first temperature.

5 . The method of claim 3 , wherein the heat-generating element and the thermally-expanding element are combined in a plurality of heat-generating pellets and expandable pellets that are configured to expand collectively to produce the predetermined pressure against a surface of the uncured composite workpiece when heated by triggering the heat-generating element.

6 . The method of claim 1 , wherein positioning the heat-generating element proximate to the uncured composite workpiece includes positioning a heat-generating element configured to undergo an exothermic physical reaction that is an exothermic change of state; and triggering the heat-generating element includes triggering the exothermic change of state.

7 . The method of claim 1 , wherein positioning the heat-generating element proximate to the uncured composite workpiece includes positioning a heat-generating element configured to undergo an exothermic chemical reaction; and triggering the heat-generating element includes triggering the exothermic chemical reaction.

8 . The method of claim 1 , wherein positioning the heat-generating element proximate to the uncured composite workpiece includes positioning a mixture of the heat-generating element and a heating mediation agent proximate to the uncured composite workpiece.

9 . The method of claim 8 , wherein the heating mediation agent is selected to be capable of undergoing an endothermic physical reaction, or capable of undergoing an endothermic chemical reaction, so that the heating mediation agent decreases a maximum temperature reached proximate the composite workpiece after triggering the heat-generating element.

10 . The method of claim 1 , further comprising removing the heat-generating element after the composite workpiece is cured.

11 . The method of claim 10 , wherein removing the heat-generating element includes cooling the heat-generating element to a second temperature lower than the predetermined first temperature, or allowing the heat-generating element to cool to a second temperature lower than the predetermined first temperature.

12 . The method of claim 1 , further comprising applying a removable barrier film to an outer surface of the uncured composite workpiece before positioning the heat-generating element proximate to the uncured composite workpiece.

13 . The method of claim 1 , wherein the heat-generating element has the form of a plurality of pellets.

14 . The method of claim 13 , wherein the plurality of pellets forming the heat-generating element is not substantially sintered after the heat-generating element is triggered.

15 . The method of claim 13 , wherein the plurality of pellets are contained within one or more flexible bags, and positioning the heat-generating element proximate to the uncured composite workpiece includes positioning the one or more flexible bags proximate to the uncured composite workpiece.

16 . The method of claim 15 , wherein the one or more flexible bags optionally further include a pelletized heating mediation agent and/or a pelletized thermally-expanding element; and positioning the heat-generating element proximate to the uncured composite workpiece includes placing one or more such flexible bags proximate to the uncured composite workpiece.

17 . A cured composite workpiece prepared according to the method of claim 1 .

18 . A method of manufacturing a composite aircraft component, comprising:
positioning a heat-generating element proximate to an uncured composite aircraft component, the heat-generating element capable of undergoing an exothermic chemical reaction when activated or capable of undergoing an exothermic physical reaction when triggered; and triggering the heat-generating element to produce the exothermic chemical reaction or exothermic physical reaction so that a temperature of the uncured composite aircraft component is raised to at least a predetermined first temperature at which the uncured composite aircraft component will be cured.

19 . The method of claim 18 , further comprising positioning a thermally-expanding element proximate to the uncured composite aircraft component so that triggering the heat-generating element additionally triggers the thermally-expanding element to undergo a volumetric expansion and apply pressure to the uncured composite aircraft component while it is curing.

20 . The method of claim 18 , wherein the heat-generating element is pelletized, and positioning the heat-generating element proximate to the uncured composite aircraft component includes placing one or more flexible bags containing the pelletized heat-generating element proximate to the uncured composite aircraft component.

21 . The method of claim 20 , the one or more flexible bags further include a pelletized heating mediation agent and/or a pelletized thermally-expanding element.

22 . A cured composite aircraft component prepared according to the method of claim 18 .

Assignees

• Boeing Co

Inventors

• Wang Xiaoxi
• Georgeson Gary Ernest
• Santiago Jonathan A

Classifications

• B29C44/1271

  the preformed parts being partially covered · CPC title

• B29C61/04

  Thermal expansion · CPC title

• B29C43/52

  Heating or cooling · CPC title

• B29C43/3642

  Bags, bleeder sheets or cauls for isostatic pressing · CPC title

• B29C2043/561

  under vacuum conditions · CPC title