Powder processors across industries often face the same decision. Should this material be screened or air classified? Both methods separate particles by size, yet they work in very different ways. At Elcan Industries, companies bring us everything from metal powders and oxides to pigments, black mass, and energy materials. After thousands of trials, a clear pattern has emerged for when each technology performs best.
What’s The Difference Between Screening and Air Classification
Screening separates powder through a physical opening and only particles smaller than this opening can pass through. It produces a sharp top cut, high throughput, and a predictable separation. Traditional Air classification separates based on particle size, but uses a spinning classifier wheel and gap in order to make a separation. Some Air Classifiers are able to make a separation using particle density and drag without the spinning wheel like the Elbow Jet.
Here is the part that most powder processors get wrong.
There is a common misconception that screening at or below 20um is not realistically possible with conventional or ultrasonic sieving machines. Screen mesh blinding, low energy, and poor dispersion shut down the process.
The Hi Sifter is the exception. It is the only high-energy screening system that can make true separations down to 10 microns without ultrasonics. This performance is not achievable on standard vibratory or ultrasonic systems, and it is the reason screening is always the right move when using the Hi Sifter at fine sizes.
Once the target cut drops below 10 microns, air classification becomes the preferred tool. Especially if multiple cuts are required.
When is Sieving the Right Choice?
Screening is the preferred method when the material needs a clean cut, maximize yield, and fast throughput. The key point is that this applies only when the screening machine is capable of operating at those sizes, which all but the Hi-Sifter cannot.
For the Hi Sifter, screening is always the correct first step when the goal is a cut size at 10 microns or higher. Situations that point to screening include:
- You need a cut size of 15 microns or higher
- You want tight separations without losing yield.
- You are processing AM powders, metal powders, oxides, battery materials, catalysts, pigments, or engineered carbons.
- You want to actually be able to sieve at the exact size you’re looking for without having to go up in mesh size in order to “cheat the hole”
- You want to maintain PSD shape while removing the coarse fraction.
Where Elcan Industries fits
The Hi Sifter is a high energy screening machine that does not blind and does not rely on balls, sliders or ultrasonics. It is the only screening system currently in the market that performs consistently down to 10 microns without sacrificing yield, throughput or having to “cheat the hole” to make efficient separations. This capability makes it the right move for almost every application within that size range. Other sieving machines cannot hit these cuts, which is why most people when that think of particle size separations, automatically think that they need to “air classify” anything under 74um before they contact Elcan Industries. Once they find out about our Hi-Sifter technology and see that it is possible to sieve down to as fine as 10 and even 5um on a sieving machine their whole perspective on what is possible through sieving changes forever.
So, When is Air Classification the Better Tool?
Air classification is the right approach when the separation requires ultra fine control or needs a bottom cut below what screening can reliably produce. You know you are in air classifier territory when:
• You need to remove fines below 10 microns.
• You need a narrow bottom cut in the 1 to 5 micron range.
• You need to eliminate ultra fine agglomerates.
• You need clean, contamination free separation.
• You need sub micron classification.
Where Elcan Industries fits
The Elbow Jet Air Classifier uses only airflow, with no wheels or metal contact. This design removes the risk of metal wear or contamination and gives precise control over ultra fine separations. It is ideal for carbon powders, metal oxides, battery precursors, pigments, catalysts, and any product with a bottom cut in the ultra fine range.
How Companies Decide the Turning Point
The cut size always dictates the technology.
• If the target cut is 20 microns or above, the Hi Sifter is the correct first step.
• If the target cut is around 10 microns, the Hi Sifter screens first, and the Elbow Jet can tighten the fines afterward if required.
• If the target cut is below 10 to 5 microns, air classification then becomes the starting point.
For many materials, the best route uses both approaches. The Hi Sifter removes the coarse fraction. The Elbow Jet removes ultra fines. Together, they create a narrow and consistent distribution that protects the value of the powder.
Final Thoughts
Screening and air classification play different roles, and each is designed for a specific micron range. With the Hi Sifter, screening is always the right move at 10 microns and above because it is the only screening technology that can operate at these fine levels. When the application demands a separation below 10 microns, air classification takes over. In many cases, using both machines produces the most valuable material.
Elcan Industries offers production scale trials for both technologies at our ISO 9001 certified toll processing facility in Tuckahoe, NY. Companies can test both systems on the same day and walk away with the full process needed for commercial production.
Call today to schedule your trial!
