Zoltek Companies, Inc., through its subsidiaries, develops, manufactures, and markets carbon fibers and technical fibers primarily in the United States, Europe, and Asia. It provides commercial carbon fibers that are used as reinforcement material in composites; and oxidized acrylic fibers and specialty carbon fibers used to manufacture aircraft brake pads, as well as for heat/fire barrier applications. The company sells its carbon fibers under the Panex trade name; and oxidized acrylic fibers under the Pyron trade name. It also provides water treatment and electrical services; and manufactures and markets filament winding and pultrusion equipment for the production of composite parts. The company was founded in 1975 and is based in St. Louis, Missouri.