Laminated Glass is a widely used safety and security glass manufactured by sandwiching two or more layers of glass using a PVB (Polyvinyl Butyral) adhesive under heat and pressure. A mechanical and chemical bond is created between the PVB layer and the laminated glass .The PVB layer tends to hold the glass together even after it has cracked hence it has a wide application as a security glass. On physical impact it does not shatter like ordinary glass but it cracks like a spider web and the glass holds on without injuring anyone.
When the number of layers of glass increases the multilayered laminated glass becomes very strong. Such a method is used to create bullet proof glass. The individual pieces of glass could be annealed glass, heat strengthened glass or tempered glass.
The major use of PVB glass is in the automobile industry for the wind screens and building facades. It is also used in glass ceilings , skylights , glass roofs. The PVB layer could be colored resulting in a tint in the glass or acoustic PVB could become an intermediate layer of the glass resulting in acoustically treated glass.