Sound and UV protection
Holding glass fragments and shards in place and preventing penetration of missiles and weapons are not the only features of laminated glass. It also can screen out some annoying and harmful waves. Sound exists in the form of a wave. When sound is not pleasant, it is considered noise, and noise can be annoying and harmful. Laminated glass has long been known to have damping qualities that deaden the sound that comes through it.
Recent advances in technologies have brought forth specially designed interlayer configurations that have even more effective damping capabilities. The new acoustical interlayers are multilayered and capable of providing a reduction in the noise transmitted through the glass that cuts the decibel rating in certain frequencies to such an extent that the perceived sound is only half as loud as it actually is transmitted.
The use of a multilayer acoustical interlayer, which consists of a layer of special acoustical PVB interlayer sandwiched between two layers of traditional PVB (figure 1), suppresses the coincident effect of glass, which makes glass transparent to sound, and is ideal for use in exterior laminated glazing to reduce rail, traffic, airplane, construction, speech and other airborne noise. It delivers up to a 10 dB noise reduction (transmission loss) in the critical frequency range of 1000 Hz–5,000 Hz, the range in which most speech is heard and understood, compared to laminated glass made with standard PVB. The EPA’s Office of Noise Abatement and Control notes that, “Noise constitutes a real and present danger to people’s health and can produce serious physical and psychological stress.”
Most laminated glasses also have superb UV screening capabilities as compared to uncoated monolithic glass. Common claims are that these glasses can screen out 99 percent or more of the UV radiation entering a building through a window in the 200–380 nanometer wavelength range. This is the range of UV that can contribute to the fading of furniture and priceless or sentimental artwork. It is also the range of radiation know to cause skin cancer.
Color trends are also significant market drivers for the glazing industry. Custom color interlayer systems in laminated glass can produce a broad spectrum of colors and moods that are unachievable using stock selections of glass. Interlayers can be combined to produce countless transparent, translucent or opaque color options to help create unique tones and intensities with all the proven performance benefits of laminated glass, including safety, security, sound reduction and the structural integrity. Curtain walls, atriums, skylights, partitions and conference rooms are just a few applications where laminated colored glass allows architects and builders to build structures that are expressive and beautiful with distinctive hues from subtle to dramatic.