ASTM introduces new rCB standard to support tire circularity

Conshohocken, Pennsylvania – The American Society for Testing and Materials (ASTM) International has introduced a new standard for recovered carbon black (rCB), a move aimed at supporting circularity in the tire industry.

The new standard, D8632, was developed by ASTM’s recovered carbon black committee (D36) and establishes a classification system for rCB, said the organisation 13 Feb.

According to ASTM, the framework is designed to "encourage consideration of the entire life cycle of tires by providing a classification system for rCB."

“Recovered carbon black is a semi-reinforcing filler obtained from post-consumer rubber products such as tires and conveyor belts,” said ASTM member Jorge Lacayo-Pineda.

“Through various thermal decomposition processes, the feedstock is converted into oil, gas, and raw rCB. After subsequent post-processing steps, the final product is rCB.”

According to Lacayo-Pineda, the classification format consists of the letter R, indicating the material is recovered carbon black.

The letter R is then followed by a number that represents the class of toluene transmittance, and a second number representing the class of inorganic content.

Lacayo-Pineda described the classification system as “essential” for defining product categories and facilitating trade between producers and users.

He added that the approach will "promote fair competition" by enabling quality comparisons within specific categories, rather than across all rCB types.

“The new standard will help promote the transition toward a circular economy,” Lacayo-Pineda said.

“Moving to a circular economy requires designing products and systems with resource recovery in mind. End-of-life tires can be transformed into valuable raw materials, and rCB is one such example,” he concluded.