In-situ desizing for liquid infusion processes

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.

1 . 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 to form a plurality of sized fibers comprising a preform;   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.   
     
     
         2 . The apparatus according to  claim 1 , 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. 
     
     
         3 . The apparatus according to  claim 1 , wherein the infusion liquid is resin. 
     
     
         4 . The apparatus according to  claim 1 , wherein the preform is comprised of a non-pre-impregnated material. 
     
     
         5 . The apparatus 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. 
     
     
         6 . The apparatus according to  claim 5 , wherein the plurality of fibers are comprised of a polyimide-matrix composite material. 
     
     
         7 . The apparatus according to  claim 5 , wherein the low temperature sizing is comprised of a material capable of complete decomposition at temperatures less than 850 degrees Fahrenheit. 
     
     
         8 . The apparatus according to  claim 1 , wherein the mold is heated to the curing temperature for a predetermined period of time to provide a cured preform. 
     
     
         9 . The apparatus according to  claim 1 , wherein the preform is comprised of a non-pre-impregnated material. 
     
     
         10 . The apparatus according to  claim 1 , wherein the preform comprises a three-dimensional dry-shaped preform. 
     
     
         11 . The apparatus according to  claim 10 , wherein the three-dimensional dry-shaped preform is formed by at least one of braiding and weaving. 
     
     
         12 . The apparatus according to  claim 1 , wherein the preform comprises a two-dimensional stack of tackified fabric.