VAPOR-GROWN CARBON-FIBERS - MODELING OF FILAMENT LENGTH DISTRIBUTIONS

A mechanistic model has been used to predict filament length distribut ions for vapor grown carbon fibers during the lengthening stage. Optim al values for the two parameters, alpha and Lt, in this model are obta ined by curve-fitting one set of experimental results, giving excellen t agreement. The model can easily be used to predict length distributi ons for cases where alpha and L vary with time in any prescribed manne r. Results are obtained for the case where alpha undergoes a step incr ease after some time, and it is found that the filament length distrib utions are quite sensitive to the history, alpha(t). In fact, situatio ns can easily be found for which the mean lengths are identical, but t he distributions differ significantly.