ASTM D3045-2018 pdf free download

ASTM D3045-2018 pdf free download.Standard Practice for Heat Aging of Plastics Without
1. Scope
1.1 This practice is intended to define the exposure condi- tions for evaluating the thermal endurance of plastics when exposed solely to hot air for extended periods oftime. Only the procedure for heat exposure is specified. The effect of elevated temperature on any particular property is determined by selection of the appropriate test method and test specimens for that property. 1.2 This practice can be used as a guide to compare thermal aging characteristics of materials as measured by the change in some property of interest. The property of interest is measured at room temperature. 1.3 This practice recommends procedures for comparing the thermal aging characteristics of materials at a single tempera- ture. Recommended procedures for determining the thermal aging characteristics of a material using a series of elevated temperatures for the purpose of estimating endurance time to a defined property change at a lower temperature are also described; the applicability of the Arrhenius relation for making predictions to other temperatures, is assumed in this case. 1.4 This practice does not predict thermal aging character- istics where interactions between stress, environment, temperature, and time control failure occur. 1.5 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. N OTE 1—This standard and ISO-2578 address the same subject matter but differ in technical content. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 General—The terminology given in Terminology D883 and Terminology E456 is applicable to this practice. Terminol- ogy not in place is defined in 3.2. 3.2 Definitions: 3.2.1 continuous use temperature (CUT)—the temperature in degrees Celsius corresponding to a given thermal endurance time for a given failure criterion (typically 50 % reduction in property), derived from the Arrhenius relation of endurance time and temperature, determined by heat aging at several elevated temperatures. Several CUT values can exist, one for each property, endurance time and endurance criterion. 3.2.1.1 Discussion—In practice, the continuous use tem- perature for a plastic, involves other environmental consider- ations as discussed elsewhere in this standard, than thermal endurance alone. The term, CUT, used here, is intended as an index for thermal endurance alone. The use of this term is found in automotive applications of plastics. The endurance time used for the CUT value reported should be specified as CUT (endurance time). 3.2.2 temperature index (TI), also referred to as thermal index (TI)—the temperature in degrees Celsius corresponding to an endurance time of 20,000 hours for a given failure criterion (typically 50% reduction in property), derived from the Arrhenius relation of endurance time and temperature, usually determined by heat aging at several elevated tempera- tures. 3.2.2.1 Discussion—The TI can thus be seen as a special case ofCUT where the endurance time is fixed at 20,000 hours. A given plastic material and property and its retention criterion may be characterized by several CUT times, for example, CUT (1000 hours), CUT (5000 hours), etc. as needed per require- ments of different applications. Further, several TI values can exist, one for each property and endurance criterion.