Influence of coatings on the perception of the anisotropy phenomenon

3 Influence of coatings on the perception of the anisotropy phenomenon Abstract Since the dissertation of Saverio Pasetto (2014) on the appearance of anisotropy in heat treated glass, a lot of e orts have been made to minimize the visibility of anisotropy on façades. On-line measurement equipment has been developed, an o cial standard ASTM C1901-21e2 was published but all of this is related to only the monolithic heat treated glass. However, most heat treated glass is further processed into laminated glass and/or insulating glass units (IGU). One important factor to consider is the influence of the post temperable coatings on the optical retardation and as such on the anisotropy of the finished glass product. The interaction of the inner pane with the outer pane of an IGU is more important when coatings with low outside light reflection and a high light transmission are used. Measurements combined with a survey, where people graded the level of anisotropy, allow us to link the optical properties of a coated glass with the appearance of anisotropy. Further work needs to be done to predict the e ective level of anisotropy of the finished unit based on the optical retardation measured on the single heat treated glass and the type of solar control (reflective) coating used. A technical paper Keywords: 1. Anisotropy 2. Post temperable coatings 3. Optical retardation 4. Light transmission / Outside light reflection Francis Serruys - Saint-Gobain BU Glass Façades