The main properties of carbon black:

I2.NO :

 I2.NO measures the amount of iodine which can be adsorbed on the surface of a given mass of carbon black.

The iodine adsorption number is useful in characterizing carbon blacks. It is related to the surface area of carbon blacks.


DBP absorption measures the relative structure of carbon black by determining the amount of DBP a given mass of carbon black can absorb before reaching a specified viscous paste.

The oil absorption number of a carbon black is related to the processing and vulcanizate properties of rubber compounds containing the carbon black.


The heating loss of carbon black is important in determining its moisture content. The heat loss determination is made at 125°C.

Carbon black is hygroscopic. The amount of moisture absorbed is related to the surface area of the black and to the

relative humidity, ambient temperature, and time to which the material is exposed.


Pellet hardness is the force required to crush an individual pellet.

The subsequent level of dispersion obtained in some mixed compounds containing the carbon black may be affected by pellet hardness.


the pellets and pellet fragments that pass through a 125 micron sieve  after being shaken for 5 minutes.

The fines content of carbon black is related to the bulk flowability, dustiness, and, in some instances,the level of dispersion.


The ash content of a carbon black is the amount of non-carbon components present after combustion.

Primary contributants to ash are the manufacturing process water and the catalyst in the feedstock.

Sieve Residue :

Sieve residue refers to non-dispersable contaminants (such as coke, refractory particles, water soluble salts and metal oxides) and is expressed as a percentage of the carbon black by weight.