What is the difference between thermal black and carbon black?

What is the Difference Between Thermal Black and Carbon Black?

Thermal black and carbon black are both types of carbon blacks, which are produced from the incomplete combustion of petroleum oils and other fossil fuels. Carbon black is utilized extensively in various industries, including tire, ink, and plastics, due to its unique properties of high tinting strength, conductivity, and abrasion resistance. However, thermal and carbon blacks have some fundamental differences that impact their applications, properties, and costs.

Thermal black is created through the controlled decomposition of natural gas or oil-derived hydrocarbons in an oxygen-free environment. This process, which takes place in specialized ovens called thermal reactors, produces a fine sooty powder that can be easily dispersed in liquid or solid media. The resulting thermal black has a high surface area, low density, and low structure, meaning that it is highly porous and irregular in shape with minimal particle-to-particle interactions. As a result, thermal black imparts a deep black color with excellent hiding power but relatively low tinting strength. Moreover, thermal black has lower electrical conductivity, thermal conductivity, and surface activity than carbon black, making it less suitable for certain applications such as conductive coatings, rubber reinforcement, and battery electrodes.

On the other hand, carbon black is generated by the incomplete combustion of heavy petroleum products, coal tar, or natural gas in large furnaces called reactors. This process creates a dense and spherical powder that is composed of many small primary particles fused together. Carbon black has a high structure, meaning that its particle shape and size distribution are more uniform, and its surface area is lower than that of thermal black. Consequently, carbon black exhibits strong tinting strength due to its ability to absorb light and scatter it effectively. Carbon black also possesses high electrical conductivity, thermal conductivity, and surface activity, which make it a valuable component in conductive polymers, inkjet inks, and rubber products.

In summary, thermal black and carbon black differ in their production methods, particle morphology, surface area, tinting strength, conductivity, and structure. While thermal black is advantageous for applications that require a deep black color and low activity, carbon black excels in applications that demand high reinforcement, conductivity, and pigmenting capabilities. The cost of thermal black is often lower than that of carbon black due to its simpler manufacturing process and lower purity, although some high-performance thermal blacks can be more expensive than certain carbon blacks. Understanding the differences between thermal black and carbon black can help buyers and manufacturers select the best option for their needs.