ASTM D4572-89(2005)

1.1 This test method covers the evaluation of the particle size distribution of the coarse fraction of sulfur. It is limited to the measurement of those particles greater than 45 m (No. 325 sieve).

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 and health practices and determine the applicability of regulatory limitations prior to use.

This test method is used to evaluate sulfur for suitability as a rubber vulcanizing agent. Sulfur particles must be significantly small enough to dissolve in rubber during cure and produce a uniform network of cross-links. This test method is used as a quality control method to ensure that no excessively large sulfur particles are present and to see if the product follows a typical pattern of size distribution.

This procedure is necessary when problems of the sulfur caking occur with the use of the dry sieving procedure for particle size.