Carbon Black

Q: What is the purpose of “good” carbon black in a geomembrane formulation?

A: Carbon black is a powerful black pigment widely used to color plastics. It acts as a UV absorber, protecting plastic from degradation caused by sunlight. This is particularly important for outdoor applications where geosynthetics are exposed to the sun’s harmful UV rays. It can also improve the weather resistance of geosynthetics, helping geosynthetics withstand harsh chemicals and conditions. Carbon black can improve the dispersion of other materials within the polymer matrix and may influence the viscosity of the geosynthetic formulation.

The “good” quality carbon black used in plastics significantly impacts the performance and durability of the final product. Key factors that contribute to the “good” quality of carbon black include particle size, structure, surface area and purity. We generally check the carbon black content (ASTM D4218 or D1603) and carbon black dispersion (ASTM D5596) in polyolefin geomembranes.