A method of making a composite article of a graphite-filled polymer mixture that
is robust during high shear mixing and compounding, and that exhibits relatively
low electrical resistivity after molding. The mixture is formed by shear mixing
a liquid polymeric material, graphitized carbon fibers having diameters of less
than one micrometer, and glass fibers longer than the carbon fibers. The carbon
and glass fibers constitute up to about 25 volume percent and up to about 50 weight
percent, respectively, of the mixture, though the addition of as little as about
1 weight percent of the glass fibers has been shown to dramatically reduce resistivity.
The mixture is then introduced into a mold so that the glass fibers are substantially
oriented parallel to the direction of flow. Due at least in part to the glass fibers
being larger than the carbon fibers, the carbon fibers are substantially aligned
with the glass fibers and preferentially segregate to regions of the polymeric
matrix near interfaces between the polymeric matrix and the glass fibers.
