UV Transmittance
Laminated glass can be designed to control glare, reduce solar energy transmission, and screen out approximately 99% of the invisible ultra-violet (UV) rays that occur below 380 nanometers. However, ultra-violet radiation also occurs above 380 nanometers in the visible spectrum. Laminated glass allows 30% UV to be transmitted at wave lengths above 380 nanometers.
Furnishings, fabrics, and all materials will experience some degree of fading from exposure to UV radiation. However, visible light, oxygen, moisture, heat and air pollution are also contributors to fading occurring. While all causes of fading cannot be eliminated, steps can be taken to minimize their effect. Laminated glass fabrications consisting of PVB interlayer and clear with tinted or reflective glass plies, can offer substantially improved protection against UV radiation.

Sound Reduction

Architects have succeeded in designing windows which let in natural light, but help is needed in preventing the unwanted sound from entering the buildings. Laminated glass is highly effective in reducing sound transmission. The acoustical performance of laminated glass is the result of the shear damping characteristics of the plastic interlayer.
Since sounds are actually a combination of acoustical energy at different frequencies, effective sound control requires that the sound level be reduced across a wide range of frequencies. Truck traffic is typical of a low-frequency noise source; speech and typewriters of a middle frequency; and jet aircraft and industrial equipment of a higher frequency. Different laminated glass combinations are more effective in reducing noise when tailored to the noise source.
Determining sound transmission class - The American Society for Testing and Materials (ASTM) has developed a sound transmission class, or STC rating, in which a single number rating is used for describing the sound isolation performance of a glass material. This number rating is derived from individual transmission losses at specified test frequencies (ASTM E-90; ASTM E-413). The higher the STC values, the greater the noise reduction.

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© 1999 Dave Olmstead
G.L. Specialist PGT Industries