On April 25th, 2023, Particle Technology Labs’ Laboratory Division Manager, Jorie Kassel*, attended the International Powder & Bulk Solids Conference & Exhibition where she gave a presentation detailing the many techniques available for particle size and shape characterization available at PTL and how these services can play a role in the processing and manufacturing of powders and bulk solids. The event occurred from April 25th through 27th, 2023, in Rosemont, IL.
The conference, also known as “The Powder Show”**, focuses on connecting executives, engineers, manufacturers, and others involved in the powder and bulk solids handling and dry processing industry. PTL already serves many leaders in these fields; food and beverage, pharmaceutical, agricultural, chemical, and more.
During her presentation, Ms. Kassel provided education regarding particle size and shape techniques, touching on the following:
- Definitions of particle size and shape
- Potential problems in processing/manufacturing and how particle size and shape characterization can help solve them.
- Selecting the correct technique for a specific material with real-world examples and implementation.
- Guides and references in the industry.
Ms. Kassel offered expert knowledge to attendees on both particle ensemble sizing and particle counting techniques. Here is a breakdown of many of the techniques mentioned in Ms. Kassel’s demonstration as well as some of the applications to the powder and bulk solids industries and beyond:
Ensemble Analyzers – Common Techniques and Applications
Ensemble techniques offer a broad range of particle size analysis, and most of the instrumentation available at PTL allows for the analysis of both dry and liquid dispersions. However, these techniques provide lower resolution than particle counting techniques and cannot report number-weighted size distributions.
Analytical Sieving
Considered the backbone of particle size technology, the continuing popularity of sieving stems from the technique’s simple principles and methodology, historical reference, and cost-effectiveness. Examples of materials analyzed by sieving include cement components, soil samples, excipients, grit on sandpaper, and other spherical/irregular materials.
Laser Diffraction
One of the most widely used techniques across varying industries, laser diffraction (also known as static light scattering) measures the intensity of light scattered by particles passing through a laser beam to generate a particle size distribution. Examples of materials analyzed by laser diffraction include inks and coatings, food powders/suspensions, battery components, spray-dried materials, animal feed, and pharmaceuticals.
Dynamic Light Scattering
Similarly to laser diffraction, dynamic light scattering is a popular choice in the business of pharmaceuticals and many other industries. In contrast to other techniques, dynamic light scattering at PTL can measure suspended materials with particles under 1 micrometer (µm) and as small as 1 nanometer (nm) in size. Examples of materials analyzed by dynamic light scattering include CBD oil/emulsions and vaccine suspensions.
Particle Counters – Common Techniques and Applications
Particle counters provide high resolutions along with number and volume-weighted size results. Unlike ensemble techniques, these techniques typically require particles suspended in a liquid and are limited to narrower detection size ranges.
Coulter Technique
The Coulter technique offers true high-resolution, high-speed particle counting and particle size distribution analysis. Along with the particle size of a material, this technique can determine the concentration of particles/mL of a fluid. The Coulter technique is commonly used to analyze: cell-counting, filtration, polymer spheres, and polishing slurries.
Single Particle Optical Sensing (SPOS)
Capable of high-resolution analysis, SPOS (also referred to as light obscuration) can detect small percentages of outliers and measure overall particle size distribution. SPOS is often used to analyze: contamination counting, emulsions, wastewater/filtration, inks, CMP slurries, and APIs.
Nanoparticle Tracking Analysis (NTA)
NTA is one of the first commercially-available technologies allowing high-resolution particle size distribution results on a number-weighted basis and concentration analysis of sub-micron particles. Industry uses for NTA include exosomes, colloids, metals, vaccine development, and protein aggregation studies.
Static Image Analysis
In real-world scenarios, particles are rarely spherical and cannot be described by a single number. Static image analysis is a powerful technique which provides material information beyond the particle size and distribution reported by other techniques. The additional parameters provided by image analysis can provide insight into material properties that affect dissolution, flowability, and processing/material handling concerns.
Trust the Particle Characterization Experts
These techniques and more are available at PTL to serve the powder and bulk solids industry and beyond. Contact us today to speak with our expert staff and begin your journey to a deeper understanding of your materials.
*As one of PTL’s Laboratory Division Managers, Ms. Kassel is responsible for the production operations of the laboratory. Ms. Kassel works closely with clients on particle characterization method projects such as method development, validation, and verification.
**With over 3,000 attendees from 30 countries worldwide, The Powder Show is North America’s largest powder and bulk solid technology event for education and resources for the powder manufacturing community. Leaders, professionals, and suppliers unite to speak on solutions, products, and innovations.
