About Rubber Carbon Blacks

Carbon Black has been produced by Orion's predecessors since 1862. It plays a crucial role in the rubber industry. When used in tires Carbon Black ensures a high resistance to abrasion, good road handling and ageing resistance. Carbon Black is also an important ingredient in the production of a multitude of other rubber goods like profiles, hoses and anti-vibration systems.

Carbon Black is nearly pure carbon. Today the most common method for producing Carbon Black is the Furnace Black Process. A liquid hydrocarbon feedstock is injected into a flame, which is generated by the combustion of a gaseous or liquid fuel in combination with preheated air. Under these conditions the feedstock decomposes and Carbon Black particles are formed. After separation of the process gas/Carbon Black mixture in filter systems, the Carbon Black powder is pelletized in order to improve handling properties. Alternative production processes working according to the same physico-chemical principle are the Lamp Black Process and the Degussa Gas Black Process, which provide Carbon Blacks with a unique combination of properties.

Carbon Blacks can be divided into:

  • Hard Blacks (synonyms: tread grades, reinforcing Carbon Black): a type of furnace Carbon Black having an average nitrogen surface area of 70 mn or greater.
  • Soft Blacks (synonyms: carcass grades, semi-reinforcing Carbon Black): a type of furnace Carbon Black having a nitrogen surface area in the range of 21 to 69 mn.
  • Thermal Blacks: produced under controlled conditions by the thermal decomposition of hydrocarbons in the absence of air or flames.
  • Gas Blacks: Degussa process, high reinforcing capability, imparts scorch safety to compounds.
  • Acetylene Blacks: Produced by the thermal exothermic decomposition of acetylene gas leading to pure grades with morphologies exhibiting high conductivity.


Nitrogen surface area (m2/g)


121 - 150


100 - 120


70 - 99


40 - 49


33 - 39


21 - 32


< 10

Major Brands for Rubber Blacks

Most Rubber Carbon Blacks are manufactured to ASTM specifications in a variety of reinforcing and semi-reinforcing grades. They are available in average particle sizes from 20nm (N110) to 280nm (N990) to meet formulation and performance requirements. Under the trademark CORAX® Orion produces a comprehensive range of standard grades of Furnace Blacks in accordance with the requirements of ASTM D 1765.

In addition to ASTM Carbon Blacks, considerable emphasis is placed on the development of new products, also manufactured with the Furnace Black Process. With these products Orion Engineered Carbons responds to the fast growing demand for specialties for high- and ultra-high performance car tires and fuel-efficient truck tires. The ECORAX® grades used in tire treads and bodies provide a significant reduction in rolling resistance and consequently in fuel consumption. CORAX® HP Blacks are Specialty Carbon Blacks designed for excellent dry grip as required in high performance, ultra high performance, racing and motorcycle tires.

For special applications Corax® N 990 is used. This grade's low degree of reinforcement allows particularly high loadings and has excellent processing properties.

The clean PUREX® and SABLE grades are of particular value in the manufacturing of mechanical rubber goods like extruded profiles and seals. These grades show a good processability and contribute to a smooth surface of the final product.

DUREX® 0 is a special type of Carbon Black produced by the Lamp Black Process. It is used in the production of mechanical rubber goods, where it guarantees excellent extrusion properties in terms of dimensional stability, very smooth surface finish and some unique in-rubber properties.

CK 3 is a Gas Black which imparts considerable scorch safety to rubber compounds by delaying the onset of cure. It provides uncured compounds with high green strength and vulcanizates with excellent tensile strength, elongation at break and cut growth resistance during flexing. Application fields are seals, rubber-to-metal bonding compounds, molded goods, unvulcanized sheets and adhesives.

Special conductive Carbon Blacks are offered under the PRINTEX® brand.





CK 3