Architectural glass light in industrial factories. Annealed glass is glass without internal stresses caused by heat treatment, i.e., rapid cooling, or by toughening or heat strengthening. Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Float glass is annealed during the process of manufacture. However, most toughened glass is made from float glass that has been specially heat-treated. Annealed glass breaks into large, jagged shards that can cause serious injury and is considered a hazard in architectural applications. Building codes in many parts of the world restrict the use of annealed glass
Laminated glass The PVB or the EVA are sandwiched by the glass, which is either passed through a series of rollers, or vacuum bagging systems, and ovens, or autoclaves, to expel any air pockets. Then it is heated to form the initial melting. These constructions are then heated under pressure in an autoclave or oven, to achieve the final bounded product (fully crosslinked in the case of the thermoset EVA). The tint at the top of some car windshields is in the PVB. Also, colored PET films can be combined with the thermoset EVA material, during the laminating process, in order to