Characteristics of Automotive Glass
The worlds glazing manufacturers are constantly striving to deliver products that provide the best possible technological solutions to meet automobile manufacturers' and end-users' needs from a comfort, safety and security perspective, whilst at the same time helping the industry to meet its climate commitments.
Safety and Security
Glass plays an important role in a car's ability to offer safety and security to its occupants. The automobile industry is ever increasing its use of laminated glass, which is literally a "sandwich" of two glass sheets with a thin but resilient plastic layer between them. This plastic layer is polyvinyl butyral or PVB. It can be made in two variations, standard and acoustic. Laminated glass can now be found in sidelites and in panoramic roofs on intermediate priced automobiles as well as luxury offerings. The layers are bonded to each other under controlled heat and pressure by using an autoclave.
If the glass suffers an impact, the glass layers may fragment but, depending on the force of the impact, the plastic interlayer will hold. This type of construction is mandated for windscreens and is becoming increasing popular in sidelites for sound attenuation. This safety feature enables the vehicle to absorb some of the energy of the impact and helps to prevent the ejection of the driver and passengers and the penetration of objects in case of an accident. Moreover, after an impact the resulting glass fragments tend to remain attached to the plastic interlayer, reducing the hazards of sharp projectiles during an accident. And the fact that windows made of laminated glass will tend to remain in their frame greatly improves the performance of the side airbags, providing the necessary support during inflation.
The #1, 2, etc. are surface designations. #1 is the outside or class ‘A’ surface, #2 is the surface adhering to the PVB, and same with #3, #4 is the surface inside the cockpit/cabin.
