Carbon black is broadly grouped into three types: reinforcing (also known as hard or tread blacks), semi-reinforcing (also known as soft or carcass blacks), and specialty blacks. Reinforcing grades are valued for their abrasion resistance and elasticity and are used in applications calling for good durability such as tyre treads, sidewalls, engine mounts, conveyor belts, and marine bumpers, among numerous other products. Semi-reinforcing grades are used in items requiring flexibility and elasticity, such as tyre sidewalls, hoses, belts, seals, and innerliners/inner tubes. Specialty blacks are used as black pigments and performance fillers in products such as plastic film and pipe, printing inks, inkjet toners, and paints and coatings. Specific grades of carbon black are categorized according to standards developed by ASTM International (a global standards development organization). Under the ASTM classifications, rubber grades of carbon black are designated by the letter N (for normal curing) and a three-digit designation that indicates the grade properties. Major reinforcing grades of carbon black are N110, N234, N326, and N330, while major semi-reinforcing grades are N550, N650, N660, and N772.
Independent Industry Standards
The rCB industry is working to establish official standards to differentiate between carbon char and recovered carbon black. In particular, ASTM International recently adopted new terminology for section D3053 – 15 “Standard Terminology Relating to Carbon Black” that differentiates between “carbon char” and “recovered carbon black.” According to the standards, recovered carbon black “has semi-reinforcing properties in the range of N600 to N700 series CB, and is typically pelletized.”
In January 2017, the ASTM International Board of Directors approved the launch of a new technical committee dedicated to developing standards for recovered carbon black, which is called Committee D36 on Recovered Carbon Black (rCB). The committee was formed from members of the organization’s existing Committee on Carbon Black (D24), who saw a need to create a distinct group to establish standards for recovered carbon black. Pyrolyx personnel are key members of this Committee.
Pyrolyx’s recovered Carbon Black meets the highest quality standards. Pyrolyx is the only ISO 9001:2008 (quality management systems) and ISO 14001:2004 (environmental management systems) certified recovered Carbon Black manufacturer.. All grades of Pyrolyx recovered Carbon Black conform to EU 10/2011 food contact regulations.