This document is the TN 4.03 Abrasion Resistance of Polypropylene. Taber abrasion test and abrasion resistance in water flow with results discussed.

With the introduction of ADS High Performance (HP) polypropylene (PP) pipe for the storm drainage and sanitary sewer markets, it is necessary for designers to have confidence in polypropylene’s expected performance in conditions where the effluent may carry debris or abrasive materials.

To address designer’s concerns, a comparative evaluation of whether polypropylene had similar abrasion resistance to high density polyethylene (HDPE) was undertaken. While it was initially hypothesized that polypropylene would have comparable, if not better, abrasion resistance, testing verification is essential. If it could be established that polypropylene and HDPE have similar resistance to abrasion, the more extensive history and test data for HDPE could be applied to polypropylene insofar that polypropylene would behave similarly to HDPE in abrasive environments.

To test this hypothesis, two types of tests were conducted. The first test used Taber® abrading wheels directly on a sample of thermoplastic material. The second test, in order to more closely mimic drainage and sewer conditions, involved placing thermoplastic samples in water flow carrying abrasive sand. Both tests measured the mass loss over time and provide a direct comparison between the two materials.

In April 2009, Polymer Diagnostics, Inc. conducted Taber abrasion testing on polypropylene, HDPE and PVC material samples in accordance with ASTM D3389 in order to determine the material’s mass loss under direct abrasion. Although this test does not simulate pipe carrying effluent, the test still provides a standardized method for comparing the abrasion resistance, or hardness, of different materials. Test setup and results are listed with a table for Taber Abrasion Test Results for Material Mass Loss.

A 2nd test for abrasion resistance in water flow was conducted, photographs of the closed loop test system and plaques in the test system are shown.

Results noted during visual inspections of the samples throughout the test that minor scouring of the samples was occurring. These observations affirmed that the test was successful in creating the desired abrasive conditions for sample analysis. These results favor polypropylene over HDPE for constant flow applications where the effluent carries a high bed load.