CARBONX™ PEI+CF, MADE USING ULTEM™ PEICarbonX CF PEI 3D Printing Filament We manufacture CarbonX Carbon Fiber Reinforced PEI (Polyether Imide) using a custom formulated compound made from ULTEM PEI resin and high modulus carbon fiber. PEI is an amorphous, high performance polymer that offers excellent mechanical, thermal, and chemical resistance properties. Our PEI based filaments offer the ability to create parts with excellent properties at elevated temperatures due to a high glass