Polyvinyl Butyral (PVB) Interlayer
Polyvinyl butyral (PVB) interlayer is a transparent polymer film bonded between two sheets of glass to form laminated automotive glazing.
What it does
The interlayer helps hold broken glass fragments together instead of letting the pane separate immediately. Its formulation can also add sound damping or solar-energy control while remaining optically clear. Pilkington — Automotive glass lamination Eastman Saflex — PVB interlayers for automotive glass
In an EV specification, “PVB interlayer” identifies the material inside a laminated pane, not the outer glass itself. Basic PVB should not be treated as proof of acoustic or solar-control performance: those functions require a suitable interlayer formulation and complete glazing design.
The material may be used in windshields and laminated side glazing. Which panes receive it, and which added functions they provide, depends on the vehicle and glazing package.
For the deeper explanation of laminated construction, solar control, acoustic performance, and integration trade-offs, see Solar-Control and Acoustic Automotive Glazing.