Real time weathering as a test for evaluating materials

Abstract

AbstractPerhaps as much as 75% of the material placed on exposure in outdoor test fields or in laboratory accelerated testing devices is on test because of a specification requirement that is a part of the condition of sale. Government standards, automotive manufacturers' specifications, and many architectural guidelines are filled with directives instructing prospective suppliers to expose the candidate material to specific weather durability criteria before they submit their product for consideration or acceptance. Approximately another 15% of the materials on exposure is for product warranty. Results from exposures performed in harsh climatic environments to a known industry standard are used to back up claims of product or material durability. Finally, there is a 10% group using exposure sites and laboratory weathering machines for research and development. An ever‐increasing demand for new and more durable products has made the seemingly simple task of weathering a key part of product development, quality assurance, and warranty. Even with the rapid technological improvements in field exposures, laboratory machines, test methods, and evaluation techniques there is mystery, mistrust, and misunderstanding of the weathering process. This paper discusses the reasons for and choices to be made when considering a program for assessing the ability of materials to resist degradation due to weathering.