Adhesion strength in laminated glazings containing multilayer solar control coatings

We report on the mechanical and optical properties exhibited by a five layer laminated glazing (glass/PVB/PET/PVB/glass) in which a 0.1 mm thick polyethylene-terephthalate (PET) sheet carries a 70–110 nm CuS solar control coatings on either one or both sides of it and laminated with 0.38 mm clear polyvinyl-butyral (PVB) sheets in an autoclave at 135°C for 30 min under a pressure, 13 kg/cm2. The CuS coating was obtained by chemical deposition at 28°C during 1 h (70 nm) or 2 h (110 nm). The optical transmittance (T) of these laminated glazing is less than 1% in the ultraviolet region; 17–32% in the visible region, and 4–12% in the infrared region, depending on the CuS film thickness and whether the PET sheet is coated on one or both sides. The specular reflectance (R) of the glazing in the visible region is similar to that of a monolithic glass: about 10%, but in the infrared it increases toward 20%. The mechanical properties were evaluated through a compressive test giving interfacial adhesive strength of the laminated: 1.5–2 MPa for PET with a single side CuS coating and 3.4 MPa for the laminate with a PET coated on both sides.