THE USE OF EXPERIMENTAL-DESIGN TECHNIQUES TO MEET REFLECTED COLOR TARGETS IN PYROLYTIC LOW EMISSIVITY COATINGS

Low emissivity coatings are common in architectural applications and t he marketplace dictates an increasingly complex set of process and opt ical requirements. The coatings must reflect infrared light, and, simu ltaneously, must have little or no visible reflected color. The first step in commercializing a new coated product is to develop a theoretic al thin film stack that meets the target optical requirements while in corporating real-world materials and production requirements. The expe rimental design process requires a definition of the input or control factors (determined by the process and economics) and a clearly define d target response (determined by the marketplace). In the application of experimental design to thin film modeling, the control factors are the refractive indices and thicknesses of the various coating layers. The target responses are gross properties of the coated glass product, such as its reflected color and emissivity. The infinite combination of layer thicknesses and refractive indices are represented by a simpl e empirical model that quantifies the responses with minimal test case s or experiments. The models can then be used to find a workable solut ion for the design problem and provide insight into the macroscopic be havior of the color as a function of the film stack structure. Publish ed by Elsevier Science S.A.