Intro:

ASTM International’s Recovered Carbon Black (rCB) committee (D36) is developing a new standard—WK91069, that promises to drastically reduce testing time for key quality metrics, such as ash content. The current method, adapted from ASTM’s conventional carbon black committee, can take up to 18 hours to complete. The proposed method aims to reduce this to a few hours. 

Why the New Standard Matters

• The existing method (from ASTM D24 protocols) is time-intensive, which delays process feedback and increases the risk of off-spec outputs. 
• With the new WK91069 standard, manufacturers can adjust parameters in near real-time, helping to maintain consistent quality and reduce waste or rework. 
• For buyers and end-users, faster testing means more reliable and timely results, making rCB more competitive compared to virgin carbon black. 
• The move also aligns with broader industry pressure for standardization in the rCB space, which has long been hindered by inconsistent testing and a lack of uniform metrics.

ASTM International’s recovered carbon black (rCB) committee (D36) is advancing work on a new standard that could greatly improve production process monitoring and productivity for rCB manufacturers.

The proposed method, known as WK91069, is being developed within the committee’s Recovered Carbon Black Subcommittee (D36.10). According to ASTM member Pieter ter Haar, director of rCB at Circtec, the standard addresses one of the industry’s key challenges: long testing times.

“The method currently used, which has been adopted from ASTM’s carbon black committee (D24), results in a testing time that can take up to 18 hours,” explains Ter Haar. “This is very inconvenient for producers for whom this is an important quality parameter.”

By contrast, the new ASTM test could reduce the time required to only a few hours, enabling producers to adjust processes more quickly and reduce the risk of off-spec material. End-users will also benefit from faster and more accessible results.

Ter Haar noted that ASTM Committee D36 recently released the D8621 Standard Test Method for Recovered Carbon Black – Ash Content and that several other standards are under development to support the tire pyrolysis value chain. These efforts are expected to help further shape the rCB industry by ensuring consistent quality and broader market acceptance.

ASTM encourages participation in its standards development process. More information can be found at JOIN ASTM.

Klean Industries is an international company specializing in end-of-life tire recycling and pyrolysis. For over 20 years, Klean has helped companies grow and build profitable businesses in the end-of-life tire sector. Numerous members of the KleanTeam sit on the ASTM voting committee, contributing and setting the standards of the recovered carbon black industry. 

Learn more:

• Tire Pyrolysis Project
• Pyrolysis Oil Fuel Credits
• Tyre Pyrolysis Guide
• Plastic Pyrolysis Solutions
• Tire Pyrolysis Plant Setup

Raise the Bar on rCB Quality with Klean’s Technical Leadership

Faster Standards. Better Control. One Partner That Helps You Lead.

As new standards, such as ASTM’s WK91069, emerge, staying ahead becomes a competitive advantage. Klean Industries offers deep expertise in rCB, lab integration, process validation, and benchmarking to make sure your production and quality systems are ready.

Klean’s Value in rCB Testing & Quality Strategy:

✅ Lab method validation & standard alignment
✅ Integration of rapid testing into production loops
✅ Quality control & assurance system setup
✅ Comparative performance benchmarking for rCB vs virgin CB
✅ Advisory support from protocol adoption through scaling

With Klean’s domain insight and end-to-end experience, your rCB operations will not only comply, but they’ll also compete.

Ready to accelerate your rCB quality systems?

Talk to a Klean Industries ASTM Materials & Lab Expert » GO.