Crimped or spooled polymer fiber in tow format feeds into the pretreatment module and proceeds through the tow band former and moistener prior to heat treatment. The station is designed for multiple tow sizes ranging from 3,000 to 80,000 filaments.
Polymer pellets such as lignin can be fed into an extruder and melted through a combination of heat and pressure.The molten precursor feeds into a metering pump, then through an extrusion die to turn very fine filaments into a continuous web up to 1 foot wide. The melt spinner has bicomponent filament capability upgradable to tricomponent.
Fibers in tow form make multiple passes through four oven zones. Each thermal zone has three distinct flow regimes and is configurable. Thermal Zone 2 is corrosive-proof, which enables it to function as a desulfurization unit. Temperature ranges are 100 to 400°C. A conveyer belt enables processing in tow or web format.
The material makes a single pass through two carbonization furnaces. The low-temperature furnace is rated at l,ooooc and has the added capability to produce nanoporous fibers. Approximately half of the material is vaporized during carbonization, with gases exhausted through a pollution treatment system. Both furnaces are capable of processing in tow or web format.
The remaining mater ial is nearly 100% pure car bon as it enters a surface treatment process that renders it chemically compatible with resin. A thin coat of polymer is applied to the carbon during sizing, which protects the fiber and makes it easier to handle. The carbon fiber is then dried and packaged.
Carbon fiber is a strong, lightweight enabling material for improved performance in many applications. However, use of carbon fiber composites in cost-sensitive, high-volume industrial applications such as automobiles, wind energy, oil and gas, and infrastructure is limited because of today’s relatively high price.
By working closely with industry, the CFTF serves to accelerate the development and deployment of lower-cost carbon fiber materials and processes and create a new generation of strong, lightweight composite materials that will improve America’s competitiveness.