Modification of continuous carbon fibers during precursor formation for composites having enhanced moldability

Abstract

Methods of producing continuous carbon fibers for composites having enhanced moldability are provided. Discrete regions are introduced into a continuous precursor fiber comprising an acrylic polymer material, such as polyacrylonitrile (PAN), as the precursor fiber is formed. The precursors may be heterogeneous fibers having a second distinct material interspersed in discrete regions with the acrylic polymer material. Alternatively, the precursors may be heterogeneous fibers where laser is applied to the acrylic polymer material in discrete regions to cause localized molecular disruptions. After the continuous precursor fiber is heated for carbonization and / or graphitization, the precursor forms a continuous carbon fiber having a plurality of discrete weak regions. These relatively weak regions provide noncontiguous break points that reduce stiffness and improve moldability for carbon fiber polymeric composites, while retaining high strength levels. Carbon fiber polymeric composites incorporating continuous carbon fibers having the plurality of discrete noncontiguous weak regions are also provided.

Description

technical field [0001] The present disclosure relates to methods of processing and manufacturing continuous carbon fiber precursors that are modified to produce continuous carbon fibers that can enhance the moldability of high strength carbon fiber composite materials. Background technique [0002] Carbon fibers are usually produced by carbonizing or graphitizing fibers of carbon fiber precursor material. For example, traditional carbon fiber precursors may be formed from polyacrylonitrile (PAN) precursors, petroleum pitch precursors, or rayon precursors. Carbon fibers and graphite fibers are manufactured and heat-treated at different temperatures and therefore each have a different carbon content. Generally, carbon fibers are fibers that have at least about 90% carbon (by weight). [0003] Carbon fibers are used as a lightweight reinforcing phase in order to create high-strength lightweight polymer composites. Carbon fibers may be continuous filaments with lengths of tho...

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Problems solved by technology

This inflexibility and rigidity translates into poor moldability, which makes it difficult to form three-dimensional shapes into composites with continuous carbon fibers.

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