What is graphite electrode bulk density? graphite electrode data sheet

Bulk Density is also called apparent density or volumetric density. It is a characteristic of a volume of divided material such as powders, grains, and granules.
Density can be both an indicator and result of the particle size, strength and porosity inherent in a specific graphite material, because the larger the particle size and more openings filled with air, the lower the density.  
The density of graphite can be adjusted by the raw materials, formulation and manufacturing processes used to create the specific material grade during initial production. The finished graphite material's density may also be increased though the use of additives and impregnations that will fill in the open porosity of the base graphite material.

Porosity is an undesirable phenomenon in electrodes as porosity leads to reduced electrode density, and typically, lower mechanical strength and electrical conductivity.
When graphite flakes have been compressed under a high pressure, each of them will come closer and, consequently, the density of bulk graphite becomes higher. Higher density of bulk graphite leads to higher electrical conductivity because there is greater connectivity for the electrons to move across the graphite particle. In contrast, a lower density of the bulk graphite indicates a high level of voids which strongly reduces electron mobility, thus, resulting in a lower electrical conductivity of the bulk graphite.