|Monthly Tech-Tip |
Also called "Sieve Analysis Water Washed".
A set of numbers representing the percentage of material particles retained on each sieve in a stack of interlocked sieves with successively finer openings. The material is slaked and washed through the stack of sieves. Each percentage value should show the screen size. Use this for presentation on data sheets, use the SIEV test if you are managing the measurement and collection of the actual data.
To measure particle size in a slurry or powder you need sieves. This is the most popular type used in labs. They are made from brass by a company named Tyler. The range of screen sizes for testing particle size is very wide (obvious here: the top screen has an opening of 56 mm, the bottom one 0.1 mm - the wires are almost too small to see). You can buy these on ebay for a lot less than new ones, search for "tyler sieve". The finer sieves (especially 200) are fragile and easily ripped. It is good to have a 50, 100 and 150.
The coarsest screen is at the top, the finest on the bottom. The opening for each is shown on the label. They are chosen such that each successive screen going down has an opening that is about half the area of the one above it. Using this series you can produce a practical measurement of the distribution of particle sizes in ceramic materials and bodies used in traditional ceramics (structural products industries, like brick, measure coarser particles than this, starting at perhaps 10 mesh and ending at 70). The 325 screen on the bottom is only used sometimes, it is difficult to finer-that-325 particles to pass through it because it blinds. It is not possible to shake powder through sieves that are this fine, samples must be washed through. We use the SIEV test to log results.
The Physics of Clay Bodies
Learn to test your clay bodies and recording the results in an organized way and understanding the purpose of each test and how to relate its results to changes that need to be made in process and recipe.
|Tests||% Passing 325 Mesh Wet|
|Tests||Sieve Analysis 35-325 Wet|
Tests conducted to determine particle populations, sizes, shapes, densities, surface areas, etc.
Particle Size Distribution
Knowing the distribution of particle sizes in a ceramic material is often very important in assessing its function and suitability for an application.
Sieves are important in ceramics for removing particulates and agglomerates from glaze, engobe and body slurries.