Rising Carbon Fiber Prices Raise Sourcing Costs for Advanced Composites
Global price increases of 10 to 20 percent on carbon fiber composites force buyers to renegotiate aerospace and wind contracts.
Carbon Fiber Prepreg
Composite Structure
Industrial composite manufacturing relies on semi-finished reinforcement materials that are pre-impregnated with a controlled amount of uncured thermosetting resin. This class of material, known as carbon fiber prepreg, eliminates the need for manual resin application during the layup process. The reinforcement consists of woven fabrics or unidirectional fibers that are held together by the tacky resin matrix.
Thermal Curing
Chemical consolidation of the resin occurs under specific temperature and pressure regimes. When carbon fiber prepreg is placed into an autoclave or heated mold, the applied heat reduces resin viscosity before initiating the cross-linking polymerization. This thermal transformation solidifies the structure into its final rigid form.
Applying vacuum pressure during this phase extracts entrapped air and volatile compounds, reducing the void content of the laminate.
Storage Requirement
Sub-ambient temperature preservation prevents premature curing and extends the workability of the reactive resin system. Since carbon fiber prepreg contains an active catalyst, storing the material at standard room temperatures initiates slow polymer cross-linking that degrades the handling characteristics. Facilities store these rolls in sealed moisture-proof bags at temperatures below minus eighteen degrees Celsius.
Before layup begins, the material must warm slowly to ambient conditions to prevent water vapor from condensing on the reactive surface. Condensation during thaw represents a primary source of internal voiding and subsequent interlaminar shear failure.