Accelerated and outdoor/natural exposure testing of coatings

Abstract

This article reviews the current state of the art of weathering test design. It describes the primary environmental and procedural variables involved in the design of a weathering test. The relationship between the environmental variables and the current techniques available to accelerate the degradation process either outdoors or in the laboratory is discussed. Primary environmental variables include light, heat and moisture; procedural variables include exposure cycle, exposure time and test initiation. Both laboratory accelerated and outdoor weathering procedures are addressed in the paper. Each of the variables is briefly examined and examples of practical solutions given. The most commonly used exposure racks, boxes and cabinets as well as laboratory accelerated testing devices and instrumentation for monitoring and reporting climatological data are described.