2021, July 22nd @ 9.30 AM CDT in USA (16:30 CET in Europe)
In the powder handling process, it is important to control the particle size distribution. Especially for dry process, because of the stickiness or agglomeration of powder, it becomes more difficult to sieve or classify powder with finer particle size distribution. In the past, it is said that sieve is commonly used for above 50 microns’ cut and air classifier is used for below 50 microns’ cut point. Due to precise particle size control requirement, sieve is used for down to 10 micron range cut point recently.
Sieve is generally used to remove oversize above certain particle size using sieve opening. If powder is spherical, sieving performance is very precise. However, agglomerated particles could be collected in oversize even if the primary particles are finer than opening. On the other hand, air classifier can classify powder down to micron order range. However, small percentage of coarse particles can be collected in fine side, even if this is not shown in particle size distribution data (measured by laser type device).
Using new classification and sieving technology, I discuss the improvement of the classification and sieving performance. This discussion includes representing air classifier’s principle, mesh technologies and other topics. Powder to be discussed in this paper is metal powder, fibrous material, etc.
Dr. Carl K. Ishito is an Engineering Doctor with more than 40 years of professional experience in chemical engineering (powder technology – sieving, air classification and pulverizing), food safety consulting, plant engineering and sales of equipment.
He graduated from Tokyo University, Engineering bachelor degree in Powder Technology with a final paper about “Basic study on dispersion of fine powder”
After a few years of international professional experience in the food industry, he Graduated from Okayama University, as Engineering doctor degree in Powder Technology. The topic of his Doctor paper: “Study on Grinding and Classifying Technologies of The Latest Ultra Fine Powder Materials”
Before establishing AAAmachine, Inc. in Chicago, IL and AAAmachine Japan, Inc. in Tokyo in 2007, He had worked almost 30 years in different firms of Nisshin Group, both in Japan and USA going from positions in the Technical Research Center of Nisshin Flour Milling or the Technological Development Division of Nisshin Engineering Inc. (where he reached to the title of Deputy Division Manager) to engineering roles on the construction management of a pasta factory
or a chemical plant (glass powder, metal powder, soy sauce plant, etc.).
Most lately, he has made global trade of powder technology equipment and has been directly involved in the Engineering for a wheat gluten sieving plant in Japan.