Corrosivity Test Methods for Polymeric Materials. Part 2- CNET Test Method

Abstract

This is the second in a series of papers to investigate smoke corro sivity test methods published by the Polyolefins Fire Performance Council, a unit of The Society of the Plastics Industry, Inc. In the first paper, 24 polymeric materials were evaluated for smoke corrosion using the ASTM E05.21.70 pro posed method for measuring the corrosive effect of smoke from the burning or thermal decomposition of materials and products with a radiant combus tion/exposure apparatus. This paper presents results on the same 24 materials evaluated with the CNET corrosivity test method under consideration by ISO TC61/SC4/WG2 and IEC TC89/WG3. These commercially available polymeric materials cover a broad range of compositions used for wire and cable insula tion and jacketing. The samples were decomposed in the CNET apparatus which contained a printed copper circuit board as the corrosion target. The target was held at a lower temperature than the chamber to facilitate the condensation of the com bustion gases. After exposure to the condensed combustion gases for one hour, the resistance change of the target was measured and the Corrosivity Factor "COR" was calculated for each material. These results are discussed and com pared with the results of the ASTM E05.21.70 method. To complete the review of corrosion test methods, studies are under way to evaluate the DIN 57 472 Acid Gas test method and the cone calorimeter corro sivity test method under review by the ASTM D09.21.04 using the same 24 materials.