Resin-soluble veils for composite article fabrication and methods of manufacturing the same

Abstract

Embodiments of the invention are directed to resin-soluble thermoplastic veils for use in liquid resin infusion processes, methods of manufacturing resin-soluble thermoplastic veils for use in liquid resin infusion processes, and methods of manufacturing composite articles using resin-soluble thermoplastic veils for use in liquid resin infusion applications. The resin-soluble thermoplastic veils according to embodiments of the invention and of which function as a toughening agent in composites having the veil incorporated therein have improved characteristics including, but not limited to, increased uniformity and decreased thickness relative to prior art veils. These characteristics translate into improvements in the processing of a composite article including, but not limited to, a substantial or complete elimination in premature dissolution of the veil during cure. The resultant composite article also realizes improvements including, but not limited to, distribution evenness of the toughening agent throughout the composite.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Patent Application No. 61 / 418,473 filed Dec. 1, 2010, the disclosure of which is incorporated by reference in its entirety.FIELD OF INVENTION[0002]Methods of manufacturing resin-soluble veils for composite article manufacturing.BACKGROUND OF INVENTION[0003]Liquid resin infusion (LRI) is a process used to manufacture fiber-reinforced composite articles and components for use in a range of different industries including the aerospace, transport, electronics, building and leisure industries. The general concept in LRI technology involves infusing resin into a fiber reinforcement, fabric or a pre-shaped fibrous reinforcement (“preform”) by placing the material or preform into a mold (two-component mold or single-sided mold) and then injecting resin under high pressure (or ambient pressure) into the mold cavity or vacuum bag sealed single-sided mold. The resin infuses into the material or ...

AI Technical Summary

Benefits of technology

[0070]Non-woven engineered veils manufactured according to embodiments of the invention as previously described resulted in numerous advantages relative to conventional veils. For example, it was observed that controlled veil fiber diameter and distribution, achieved through process optimization, provided at least the following benefits: a shorter resin injection cure cycle of thermoplastic veils manufactured according to embodiments of the invention relative to yarn-based thermoplastic material; a controlled dissolution process (i.e., premature dissolution is eliminated through a careful fiber diameter selection in a range of 10 to 16 microns and resin injection temperature of 60 to 75° C.); a greater FAW uniformity of the veil translating into improved composite article characteristics and performance through a more uniform dissolution of the fibers and therefore diffusion of the toughening agent.

Problems solved by technology

Since most resin infusion systems are inherently brittle, the viscosity levels necessary to achieve the injection process preclude the use of toughening agents.

Addition of such tougheners to LRI systems generally results in an unacceptable increase in the viscosity of the resin and / or reduction in resistance of the cured material to solvents.

These limitations render the addition of tougheners conventionally added in prepregs generally unsuitable in LRI applications.

Prior art resin-soluble thermoplastic veils are known to suffer from various shortcomings including bulkiness, low strength, uneven fabric areal weight (FAW) and premature dissolution.

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