To understand how to calculate the density of any substance, we must first state its formula:
Density = Mass / Volume
When we talk about the density of carbon black, we talk about its mass per unit volume. However, carbon black density varies according to its type or structure.
Two relevant densities are bulk or apparent density for powdered carbon black and true density for solid carbon black.
Calculating Carbon Black Density
The density is usually calculated using methods like Helium Pycnometry or X-ray Diffraction. To start, decide whether you want its true density in its solid material form or bulk or apparent density in its powdered form.
Carbon black is highly porous so its bulk density is lower than its true density. The density you should calculate depends on what you want to use it for and in what form. Different applications include rubber reinforcement, pigments, and conductivity.
Apparent Or Bulk Density Of Fine Powdered Carbon Black
Carbon black bulk density depends on the mass of the powder and the volume of the container occupied. It lies somewhere between 80 and 190 kg/㎡.
Granulated carbon black has a higher density range of 300 to 500 kg/㎡.
The density can vary based on structure, particle size, and how it’s measured.
True Density
The true density of solid carbon black is approximately 1800 to 2000 kg/m³ or 1.8 to 2.0 g/cm³. Unless otherwise stated, we always refer to true density when referring to this characteristic property.
True density is much higher than apparent density.
Why Is It Important To Measure Carbon Black Density?
Carbon black’s density affects performance, processing, and final product quality.
In the rubber and tire industry, density changes its reinforcing abilities. Low-density carbon black, for instance, has a low, loose, and randomly oriented structure.
Its high surface area helps reinforce materials like plastics and makes them wear-resistant. Rubbers, electrical insulation, auto parts, and footwear use low-density carbon black.
High-density carbon black has a high plate-like structure with superb colorant and light absorption properties. It’s used in paints, coatings, printing inks, conductive materials, and plastics.
Carbon Black Is Highly Popular In The Industry
Carbon black is used in many industrial applications. It acts as a reinforcing, coloring, protecting, and conducting agent in different products. Here are a few reasons why it’s desired and approved:
- It reinforces rubber, making it wear-resistant and durable, when manufacturing industrial products such as tires.
- It’s a coloring agent that provides a deep black color to paints, inks, coatings, and plastics.
- Its electrical conductivity and antistatic properties make it ideal for manufacturing conductive coatings, cables, and electronics such as lithium-ion batteries.
- It’s a great UV radiation absorber preventing material degradation and enhancing Lifespans of products such as coatings and plastic pipes.
- Carbon black is now being recycled from used tires for a more sustainable industry, reducing carbon dioxide emissions.
- Its high porosity increases its surface area which enhances conductivity and viscosity.
What Is Carbon Black And What Does It Look Like?
Carbon black is a fine black powder of small spherical particles made of mostly disorganized carbon atoms and typically 10 to a few 100 nm wide. The size of the particles affects properties such as dispersibility and the degree of blackness.
Oxygen-containing groups such as carboxyl and hydroxyl can be found on its surface affecting polarity. For instance, an oxidized carbon black mixes well in water-based products such as paints to increase wetting, dispersion, and electrical resistivity.
Unoxidized carbon black is hydrophobic and more suited to oil-based products like rubber.
Challenges Associated With Handling Carbon Black
Carbon Black comes with two main challenges that need to be addressed.
The first is that it’s made using hydrocarbons such as oil. This makes it unsustainable because its production is harmful to the environment.
The second is that since it’s a fine powder, it can irritate the lungs, airways, nose, throat, and eyes. People who work daily with carbon black must follow safety precautions to stay healthy. These include:
- Ensuring proper ventilation of the space they work in.
- Making sure the powder is handled properly so the particles don’t fly here and there.
- Storing it away from potential heat sources because of chances of ignition and explosion.
- Making sure employees wash their hands and face after handling carbon black.
- Ensuring cafeterias or eating spots are built away from work sites so food and drinks don’t get contaminated.
- Ensuring all employees wear protective gadgets such as clothes, masks, and goggles so they don’t inhale the particles.
We at CFI Carbon Products don’t use carbon black because it has certain negative consequences despite its many uses and facilities. Instead, we’ve transitioned to Austin Black 325, a better product and a cheaper alternative with the same benefits but less far-reaching consequences.
If you want to know more about our products and how we do things differently, chat with us!
