ASTM D3349-21 PDF

SIGNIFICANCE AND USE 4.1 The absorption coefficient of polyolefin polymer pigmented with carbon black is useful to judge the degree and uniformity of dispersion of the pigment, and the adequacy of the quantitative level of pigment addition. These factors are used to predict the performance of the polymer material in response to prolonged exposure to ultraviolet light as evidenced by minimal changes in specific properties. Note 1: This test method was developed to evaluate ethylene polymer materials pigmented with small particle size carbon blacks suitable for UV protection. It is not known how accurate and reproducible the test would be with larger (35 nm or greater) particle size blacks. However, for larger particle sizes of carbon black, such as furnace black at 275 nm, when there is at least 5 or higher percent of carbon black, the material pigmented as such has suitable UV protection. SCOPE 1.1 This test method measures the amount of light transmitted through a film of carbon black pigmented ethylene polymer. 1.2 After calculation of the amount of light and film thickness, an absorption coefficient is calculated. 1.3 Whenever two sets of values are presented, in different units, the values in the first set are the standard, while those in parentheses are for information only. 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.