Abstract
Various kinds of carbon were used as the surface materials in the manufacture of fire resistive composite boards. The fire resistive boards were tested by an oxygen index method in accordance with the Japanese Industrial Standards (JIS) K 7201, and by a burn-through method. Flammability of the carbon-based boards decreased with an increase in board density. Fire endurance of the carbon-based boards was found to increase in the order of natural amorphous graphite, synthetic graphite, charcoals from bark, sawdust and rice hulls, and natural crystalline graphite. Electric resistivity of these boards increased in the order of natural crystalline graphite, synthetic graphite, natural amorphous graphite, rice hull charcoal, bark charcoal, and sawdust charcoal. Bending strength of the carbon-based boards increased with an increase in density of boards. Reinforcing with glass whiskers did not improve the bending strength of natural crystalline graphite-surfaced composite board.
