Why is damping sheet not used for trunk sound insulation?
1 Answers
The reason damping sheet is not used for trunk sound insulation is that it has limited effectiveness against airborne noise. Damping sheets are primarily used in areas with thin metal panels and noticeable vibrations, such as doors, engine hoods, and trunks. It's important to note that covering the entire interior with damping sheets, while improving sound insulation, can make low-frequency noise more uncomfortable. Damping sheets are typically made of butyl rubber, a sticky, sheet-like material similar to chewing gum that can be directly adhered to metal panels. They also feature an aluminum skin for constrained layer damping to enhance effectiveness. Damping sheets effectively suppress metal vibrations, increase rigidity, and reduce noise at its source. Sound insulation foam is a low-density, soft, sponge-like material with numerous pores that block sound transmission through air, thereby reducing interior noise. It works by interrupting the noise transmission path. Acoustic foam, similar to sound insulation foam but more porous, absorbs airborne noise by allowing sound waves to vibrate within its pores, converting the energy into heat and dissipating the noise. The key difference is that sound insulation foam reflects noise, while acoustic foam does not. Generally, sound insulation foam performs better in noise reduction. Reasons why sound insulation foam is better than damping sheets for trunk sound insulation: Sound insulation foam not only reduces noise but also provides thermal insulation; it decreases surface heat in the trunk, prevents fogging in rainy weather, and offers some protection against scratches.
