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How to Measure the Particle Size of Carbon Black

Posted by Sonoco Conitex Team on December 12,2022

When you’re purchasing, storing, and transporting carbon black particles, the last thing you want to do is lose them. However, that’s precisely what can happen due to the structure of many baffle bags and the minuscule size of carbon black particles. Today, we’re looking at how to measure the particle size of carbon black and how you can avoid losing particles.

How to Measure Carbon Black Particles

Carbon black has many different applications. Therefore, it’s important to know the structure, porosity, physical form, and particle size as these factors determine the performance of a product. For example, carbon black is often used as a strengthening filler in rubber, impacting its flexibility, longevity, and electrical conductivity, among other properties. 

For specialty carbon blacks, the particle size significantly impacts rubber and color properties.

  • Specialty carbon blacks: Small particle diameters result in greater tints in color or a greater surface area, which is associated with better weatherability, higher conductivity, and greater viscosity.
  • Rubber properties: Finer carbon black particles lead to greater reinforcement and improved tensile strength. Particle size ranges from 8-100 nanometers. 

Carbon black particles are extremely small, so distinguishing individual particles from a large group can be difficult with the naked eye. For example, a standard sheet of paper is 100,000 nanometers thick, whereas carbon black particles are a fraction of that, typically less than  100 nanometers.

Common measurement methods include:

  • Laser diffraction: A laser creates a beam of light that is scattered by the particles. The particle size is calculated by evaluating the angle of scattering. 
  • Dynamic light scattering: Carbon black particles are placed in a liquid suspension. A light source scatters light off the particles in the suspension, and then the size is calculated by evaluating the intensity and angle of the scattered light. 

How to Store and Transport Carbon Black

The size of carbon black particles means they require special consideration when storing and transporting. A black baffle-style bulk bag is often used to store and transport carbon black. However, minuscule holes in the seams where these bags are sewn can often result in product leakage. 

Sonoco offers a new BulkSak bag specially desinged for carbon black. As the only U.S. supplier of this proprietary design, the bags are enhanced to reduce product leakage while keeping the price lower than the typical baffle bag. The sturdy baffle design is capable of maintaining structural integrity up to 90+ inches in height! The bag is created using a specific stitching process with fewer seams, to provide fewer shifting points. The seams are also overlapped to further prevent product leakage. 

Although seams are an important consideration in the durability of your carbon black bag, you also want to pay special attention to the lift loops. A benefit of a corner lift loop, as offered with our new carbon black bag, is the material’s handling memory, allowing the loop’s fabric shape to be retained for easy forklift pickup . This minimizes the labor needed to hold the loop in place for forklift tine placement. Therefore, a single forklift driver can pick up the bag without the need for a second worker’s assistance. 

Sonoco’s BulkSak Bags are a Durable Solution for Carbon Black

Carbon black particles are so minuscule that they can’t be measured with the naked eye. This means the particles can easily slip through the seams of black baffle bags that are commonly used for carbon black. That’s why partnering with an innovative organization that focuses on sustainability and durability is vital.

At Sonoco, we’re committed to your success. When you need a durable solution for carbon black and other sustainable, high-performing products, our team of representatives will be there to answer your questions and help you find the perfect solution for your needs. Reach out to us today for pricing and more information!

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Tags: Flexible Packaging, BulkSak®, bulk bags

Sonoco Conitex Team

Sonoco Conitex Team