Process for rapid annealing of refractory fiber bodies and laminated

Abstract

A process for the rapid annealing of refractory fiber is disclosed. Air at a temperature of 750.degree. F. (400.degree. C.) to 1400.degree. F. (760.degree. C.) is passed through a refractory fiber body for a period of 5 to 200 seconds while the body is held securely in place for dimensional integrity. Apparatus for performing the process of this invention comprises an annealing unit containing opposed foraminous platens and means for passing hot air through the platens and through the fiber body retained between the platens or opposed foraminous belts and adjacent conduits and means for passing the hot annealing air through the conduits and belts and through the fiber body retained between the belts. The process and apparatus may be used to produce fiber bodies of a single material or laminated bodies of a plurality of interlocked layers, which may be of different fiber materials. The resultant products have excellent dimensional integrity, especially of the critical thickness dimension, and the process operates much more economically and thermally more efficiently than prior art tunnel oven processes.