In-situ desizing for liquid infusion processes

Patent metadata

Field	Value
Publication number	US-2016243772-A1
Application number	US-201415027800-A
Country	US
Kind code	A1
Filing date	Oct 20, 2014
Priority date	Nov 6, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

A method of molding a component includes the steps of providing a plurality of fibers, applying the fibers with a low temperature sizing to form a plurality of sized fibers, forming a preform from the plurality of sized fibers, placing the preform in a mold, and de-sizing the preform by heating the mold to an initial temperature that is sufficient to break down the low temperature sizing to a gaseous phase. A molding apparatus is also disclosed.

First claim

1 . A method of molding a component comprising the steps of:
(a) providing a plurality of fibers; (b) applying the fibers with a low temperature sizing to form a plurality of sized fibers; (c) forming a preform from the plurality of sized fibers; (d) placing the preform in a mold; and (e) de-sizing the preform by heating the mold to an initial temperature that is sufficient to break down the low temperature sizing to a gaseous phase.

2 . The method according to claim 1 , wherein the plurality of fibers are high temperature fibers formed from a material that is capable of being processed at a temperature that is 600 degrees Fahrenheit or greater.

3 . The method according to claim 2 , wherein the plurality of fibers are comprised of a polyimide-matrix composite material.

4 . The method according to claim 2 , wherein the low temperature sizing is comprised of a material capable of complete decomposition at temperatures less than 850 degrees Fahrenheit.

5 . The method according to claim 1 , including (f) removing the gaseous phase of the low temperature sizing from the mold via at least one of a vacuum pressure and a positive pressure.

6 . The method according to claim 5 , including (g) heating the mold to an infusion temperature and injecting an infusion liquid to completely infuse the preform with the infusion liquid.

7 . The method according to claim 6 , including (h) heating the mold to a curing temperature for a predetermined period of time to provide a cured preform.

8 . The method according to claim 1 , wherein the preform is comprised of a non-pre-impregnated material.

9 . The method according to claim 1 , wherein the preform comprises a three-dimensional dry-shaped preform.

10 . The method according to claim 10 , wherein the dry-shaped preform is formed by at least one of braiding and weaving.

11 . The method according to claim 1 , wherein the preform comprises a two-dimensional stack of tackified fabric.

12 . A method of molding a component comprising the steps of:
(a) providing a plurality of fibers; (b) applying the fibers with a low temperature sizing to form a plurality of sized fibers; (c) forming a preform from the plurality of sized fibers; (d) placing the preform in a mold; (e) de-sizing the preform by heating the mold to an initial temperature that is sufficient to break down the low temperature sizing to a gaseous phase; (f) removing the gaseous phase of the low temperature sizing from the mold; (g) heating the mold to an infusion temperature and injecting an infusion liquid to infuse the preform; and (h) heating the mold to a curing temperature to form a cured polyimide-matrix composite material.

13 . The method according to claim 12 , wherein step (g) is performed subsequent to step (f).

14 . The method according to claim 12 , wherein the low temperature sizing is comprised of a material capable of complete decomposition at temperatures less than 850 degrees Fahrenheit.

15 . The method according to claim 14 , wherein the infusion liquid is resin.

16 . The method according to claim 14 , wherein step (f) includes removing the gaseous phase with a vacuum pump.

17 . A molding apparatus comprising:
a mold defining an internal cavity; a shaped reinforcement configured to be positioned within the internal cavity, the shaped reinforcement comprised of a plurality of fibers sized with a low temperature sizing; a heat source configured to heat the mold, wherein the preform is de-sized by the heat source heating the mold to an initial temperature that is sufficient to break down the low temperature sizing to a gaseous phase; a vacuum pump configured to remove the gaseous phase of the low temperature sizing material or a pressurized gas flow designed to remove the gaseous phase of the low temperature sizing material; and an injector configured to inject an infusion liquid to infuse a de-sized shaped reinforcement, wherein the heat source heats the mold to an infusion temperature such that the infusion liquid completely wets-out the fibers to provide an infused shaped reinforcement, and wherein the heat source heats the infused shaped reinforcement to a curing temperature.

18 . The apparatus according to claim 17 , wherein the plurality of fibers are high temperature fibers and wherein the low temperature sizing is comprised of a material capable of complete decomposition at temperatures less than 850 degrees Fahrenheit.

19 . The apparatus according to claim 17 , wherein the infusion liquid is resin.

20 . The apparatus according to claim 17 , wherein the preform is comprised of a non-pre-impregnated material.

Assignees

• United Technologies Corp

Inventors

• Riehl John D
• Watson Charles R

Classifications

• B29C33/10

  with incorporated venting means · CPC title

• B29L2009/00

  Layered products · CPC title

• B29B2013/005

  Degassing undesirable residual components, e.g. gases, unreacted monomers, from material to be moulded · CPC title

• B29C70/48 Primary

  and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] {, e.g. by vacuum} · CPC title

• B29B2013/002

  Extracting undesirable residual components, e.g. solvents, unreacted monomers, from material to be moulded · CPC title