Evaluation of Sieve Analysis Methods for the Determination of Fiber Content in Samples of Rubber Powder

Abstract

The objective of this article is to study the validity of the test methods that are currently used to determine the fiber content in samples of rubber powder made from end-of-life tires: CEN/TS 14 243, ASTM D 5603-01, and XP T 47–758. For this purpose, rubber powder samples contaminated with one weight percent (wt%) of fiber were prepared and submitted to sieve analyses, with the weight of the sample and sieving time as the variable parameters. The materials used were rubber powder without fibers and polyester fibers from recycled waste tires, both generated during the shredding of the tires. It has been observed that the procedure of determining fiber content based on sieving and extraction of fabric balls does not manage to recover more than 41.00% of the fibers contained in the samples. This research demonstrates that even with different sample weights and sieving times, is not possible to recover 100% of the fiber with which the rubber sample was contaminated. This seems to indicate that it is necessary to develop a methodology that differs from the current practice of sieving and extracting fabric balls to correctly determine the fiber content in a sample of rubber powder.