Abstract: An apparatus is disclosed for electromagnetically and thermally treating polymeric materials, including PAN and other carbon fiber precursors at large scale at atmospheric pressure, while measuring the temperature in the closed environment of the process chamber. The apparatus is designed for continuous processing, and to be compatible with other stages of existing carbon fiber production lines. It provides direct electromagnetic coupling to the fiber tow(s) in the near-field region of one or more microwave waveguide launchers and also provides direct radiative or IR heating from susceptor plates located on the opposite side of the tow from the waveguide opening for processing a band of multiple tows of fiber. It produces low-temperature-carbonized (LTC) fiber with shorter residence time and higher density compared to the conventional process. Its design is inherently scalable to larger production. A related method is also disclosed.

Abstract: An apparatus and method for the low temperature carbonization of a continuous tow of polymeric material fiber, such as PAN or other carbon fiber precursor materials at atmospheric pressure in an inert gas (usually nitrogen or argon) is disclosed. A pair of antennas are arranged within an electromagnetic cavity and face each other in an edgewise fashion for direct electromagnetic heating of the fiber tow as it passes between them. Supplemental background heating increases the dielectric loss of the fiber tow in order to improve absorption of electromagnetic energy and prevent arcing. The invention produces a higher density low temperature carbonized fiber in a shorter residence time compared to conventional low temperature carbonization.