【国外标准】 Standard Test Method for Wire-Cloth Sieve Analysis of Nonplastic Ceramic Powders

3.1 Sieve analyses are carried out to determine the particle size distribution of powders which, in turn, are used to qualify those materials as to their usefulness in the process under consideration. Since particle size analyses have only relative significance, the results should be considered only where they correlate with process characteristics. The parameter that is being measured in this test is the amount of material that will pass through a cloth having theoretically square openings. It must be remembered that all the holes are not square, nor uniform in size, and the question of whether a given particle will go through is a statistical one. Since each particle size analysis method measures a unique physical parameter, the results from one method may not agree with those from another. Particle size distributions play a role in such properties as bulk density, dustiness, and handling characteristics. Care should be taken, however, when interpretations are made from one or two points (sieves) on the distribution curve.1.1 This test method covers the determination of the particle size distribution of nonplastic ceramic powders such as alumina, silica, feldspar, pyrophyllite, nepheline syenite, talc, titanates, and zircon using wire cloth sieves.1.2 Materials containing a large amount of fines, containing agglomerates, or that are nonfree-flowing, are wet-sieved to remove excessive fines or to disperse agglomerates before performing the test. This technique is not applicable to materials that are, to any degree, water soluble.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units, or are other customary units (in the case of sieve frame diameter and sieve number), that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.