Used since ancient times, carbon black is one of the most important ingredients in products that you use every day. It is used to give strength to the rubber in tires, but can also act as a UV stabilizer, pigment and an insulating or conductive agent in a number of different ink, plastic, rubber and coating applications. Carbon black is also used in other everyday applications including printing inks, plastics, conveyor belts, hoses and automotive coatings.
Because it is such a versatile material, the carbon black industry has seen an increase in demand. This feature can improve the properties of a wide range of materials and is used various applications.
Properties of Carbon Black
Carbon black has a number of properties that make it an extremely valuable material in various industries and applications such as:
- Particle Size: This fundamental property is measured by electron microscopy and significantly affects color properties for specialty carbon blacks and rubber properties. Smaller particle diameter for specialty carbon blacks results in higher tinting strength and surface area. Finer particles for rubber increase abrasion resistance and reinforcement and improve tensile strength.
- Structure: This measures the three-dimensional fusion of particles of carbon black to form aggregates. Structure refers to the degree of branching and the shape of the aggregates. Highly structured carbon blacks provide greater electrical conductivity, higher viscosity, and make it easier to disperse specialty carbon blacks. Ultimately, its structure level determines its effect on a number of important in-rubber properties.
- Porosity: This fundamental property of carbon black can be controlled when it is being produced. The degree of porosity tends to be higher in conductive specialty carbon blacks. Porosity increase also allows a rubber compounder to increase loading of carbon black while still maintaining gravity that is compound specific. This results in higher compound modulus and electrical conductivity for a fixed loading.
- Surface Chemistry or Surface Activity: This is a function that takes place during the manufacturing process and generally refers to the oxygen-containing groups present on the surface of carbon blacks. Although it is difficult to directly measure for rubber, surface chemistry presents itself through its effects on various properties in rubber, such as modulus, hysteresis, tensile strength and resistance to abrasion. Surface activity effects on cure characteristics will depend significantly on the type of cure system that the manufacturer uses.
- Physical Form: This is an important property when it comes to matching a carbon black to its dispersal equipment. The physical form, which can either be powder or beads, can have an impact on the mixing and handling characteristics. Carbon blacks in powder form are recommended on three-row mills and low-shear dispersers. Carbon blacks in beaded form are recommended for high-energy equipment like ball mills and shot mills. The powdered form offers improved dispersibility while the beaded form provides higher bulk densities and lower bulk handling capabilities and dusting.
Carbon black solutions will always be invaluable in a wide range of industries. This material can be used in many applications as it is a safe, easy-to-use and eco-friendly product. The use of carbon black in the future will be more extensive as more industries will discover its versatility and the countless benefits of using carbon black, no matter what type of products they manufacture.
