Fonte: Ain Online (07/07/2015)
When the forecast calls for high summer temperatures it is tempting to keep the inside of your aircraft cabin as cool as possible. But Glenn Heil, director of aftermarket sales for an aerospace company, cautions against using materials not designed for aircraft because they might cause a bigger headache than they’re worth.
According to Heil, most of the windows manufactured for pressurized aircraft are constructed from a material known as stretched acrylic. Part of the manufacturing process includes heating the acrylic material to a pliable melting temperature of more than 230 degrees and pulling it in all directions (stretched) to about three times its original size. The acrylic is then cooled, machined and polished to correct optical standards. The process greatly increases strength and rigidity, making the material ideal for aircraft windows. However, once installed if it gets too hot it will try to shrink back to its original shape.
“To avoid mistakes like this we would like to point out some things to avoid using on your aircraft windows. While it might seem like a great idea at first, automotive window tint was not designed for aircraft windows; it could cause your windows to absorb excessive heat to the point of shrinking back to its original size. If the window is clamped in it could fall out of the aircraft. Some windows are fastened in and when the material starts to shrink all it can do is tear. Another problem with automotive window tint is that it is designed to be applied over glass; the adhesive that is used on the tint could have an adverse effect on the acrylic, leading to premature failure,” Heil said.