Elements Of Particle Size Analysis Using Test Sieves
Particle size Analysis using test sieves entails the passing of particles through screens (sieves) of ever decreasing size. To effectively conduct sieve testing operations beyond the simplest manual sieve test, several components are needed.
The basic element is the test sieve. Because of its normal construction, the tolerance of the sieve openings from one sieve to another of the same stated size becomes an important detail. ASTMand ISO provide standardsdealing with test sieve construction and acceptable variations of sieve openings. These openings range in size from 5” down to 20µ.
Watch this video to see how some of these sizes compare to every day items.
To facilitate the movement of particles through a group ( known as a stack) of sieves, vertical and horizontal motion is imparted to the test sample, a machine known as a sieve shaker is employed. These shakers have simple mechanisms and are used for common materials. For materials that have problems of agglomeration, other more violent forces are needed such as tapping. When smaller particles, for example in the 20µ. to 50µ micron range, need to be passed through a sieve other techniques are needed. These include vacuum assisted methods and ultra-sonic means.
The final step in particle size analysis using test sieves is the determination of the amount of test material remaining on each sieve in the stack. This is done by weighing each sieve and subtracting the empty sieve weight or by removing the material from each sieve and weighing it. This process has always been tedious. Several schemes are used to speed up this final process. Check out the CSC Solution.
The last step in the process is the cleaning of residue left in the sieves after completing a sieve analysis test. The cleaning procedures span a range from brushing out the mesh to using ultra-sonic cleaners.
We provide products to accomplish each of these tasks. Check out our sieve and sieve shaker offerings, as well as our accessory equipment. To Order on-line and see the full listing of sieve testing equipment Click on the button for the Particle Size Department of our on line store.