Harper International is a leader in thermal processing solutions for advanced materials and work from research scale to the stage of commercialization on full production line operations. Harper’s focus is processing materials in high temperature and non-ambient atmospheres. AZoMaterials spoke to Bill Stry Ph.D., Senior Process Technology Engineer at Harper International, about the how carbon fiber oxidation processing works, the industrial applications, and what makes Harper’s oxidation oven technology unique.
Can you give a brief overview of your company and the work you do?
Harper International supplies thermal processing solutions to a wide range of material processing companies and organizations. At our Buffalo, NY location with our decades of experience, we have commissioned thousands of systems with ovens, furnaces and associated atmosphere and material handling equipment. We specialize in custom designs, typically with a high degree of temperature and atmosphere control.
Could you explain how carbon fiber oxidation processing works?
The polyacrylonitrile precursor must be stabilized before the high temperature heat treatment that actually converts it to carbon fiber. The precursor is heated in air to between 200ºC and 300ºC for about 1 hour. Because of the temperature range, and especially because the process is exothermic, the heating is done with forced convection ovens. Convection allows both efficient heating of material as it enters the oven and removal of exothermic heat where the chemical reactions are most active.