STUDIES OF CARBON BLACK: IV. THE CHANNEL PROCESS—THE EFFECT OF DRAFT CONTROL AND CHANNEL HEIGHT ON RUBBER REINFORCEMENT, SORPTION, AND VOLATILE CONTENT

Abstract

In an experimental carbon black plant of the channel type, the effect of channel height, draft control and gas composition on the properties of the carbon has been examined. The channel height was shown to be the most important variable. The rubber reinforcement and the yield of the carbon vary in a similar manner with the channel height at which the carbon was recovered. The sorption of the iodine and methylene blue increased almost logarithmically with the channel height. No direct relation between reinforcement and sorption is possible over the whole range, although the very high sorption obtained at greater channel heights was accompanied by a retarded cure. Sorption was increased by heating the blacks. The volatile content is high at low channel heights, passing through a minimum at the point of optimum yield. This test showed even poorer correlation with rubber reinforcement. Apparent density varied directly with channel height.The effect of draft control upon reinforcement, sorption, and volatile content was indefinite. However, the volatile content seemed to vary directly with the yield. No effects characteristic of the gas composition were found.