•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com

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Sieve Analysis Dry - SADR

This test procedure was employed in the Foresight Ceramic Database and now is available for those having an account at Insight-Live.com. Accumulating test data using the variables defined in these procedures enables us to create tools that enable you to compare the physical properties of materials and recipes.

Notes

A set of numbers representing the percentage of dry material particles retained on each sieve in a stack of interlocked sieves with successively finer openings. The stack of sieves is vibrated in a shaker until all material has filtered down through. The test should specify maximum water content of powder, shaking time, settings for shaker (if appropriate), and what sieve series was used (i.e. US Standard, Tyler). Should also specify whether numbers refer to % on the sieve or % passing the sieve.

For a more detailed test see SIEV. It is our opinion that a water washing test is more effective and accurate.

Variables

VAL - Value (V)

Large particle grogs are difficult to produce

Large particle grogs are difficult to produce

These particles are from a grog that has been milled and separated into its constituent sizes in the lab. As you can see it has a wide range of particle sizes, from 48 to finer than 200 mesh. When fired ceramic (like bricks) is ground the finer sizes often predominate. Because the coarser grades have a lower yield they can be much more expensive and harder to get. But they are the most effective in reducing the drying shrinkage and fired stability of structural and sculptural bodies.

This is what labs use to measure particle size

This is what labs use to measure particle size

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 screen sizes for testing particle size is very wide. The top screen has an opening of 56 mm (that size and smaller pieces can fall through). The bottom sieve has an opening of 0.1 mm, the wires are almost too small to see. Coarser and finer sieves are available. You can buy these on ebay for a lot less than new ones, just search for tyler sieves. Keep in mind that the finer sieves (especially 325) are fragile and easily ripped. We use a series that bottoms out at 200.

Out Bound Links

In Bound Links

  • (Articles) 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) P325 - % Passing 325 Mesh Wet
  • (Tests) AVPS - Average Particle Size (Microns)
  • (Tests) HEGF - Hegman Fineness
  • (Glossary) Splitting

    Refers to a phenomenon where a plastic clay develops cracks and splits open to relieve the self-support stresses it is subjected to. The process often occurs over a period of minutes. This typically happens on the bellies of thrown vases, rims of overhung bowls, on applied handles. This phenomenon i...

  • (Glossary) Particle Size Distribution

    When minerals and mixtures of minerals are ground into a powder a particle size distribution is produced, that is, populations of particles of various sizes. The relative sizes of these populations can be measured to rationalize the behavior of the powder in the ceramic process. Wide distribution...


By Tony Hansen




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