The sound insulation performance of PP sheets (polypropylene sheets) stems from their material properties and structural design. As a polymer, PP sheets have a moderate density (approximately 0.9-1.0g/cm³) and a dense molecular structure, which enables them to absorb part of the airborne sound (such as speaking voices and equipment operating noise) through vibration damping. If a hollow structure or composite design is adopted (e.g., combined with foam materials or sound insulation cotton), the air layer can be further utilized to block sound wave transmission, enhancing the shielding effect against low-frequency noise (such as mechanical vibration and water flow noise in pipelines). However, the sound insulation capability of pure PP sheets is moderate. They are generally better than ordinary plastic sheets (such as PE sheets) but weaker than professional sound insulation materials (such as gypsum boards and sound insulation panels). Their sound insulation effect improves with increasing sheet thickness; typically, 3-5mm thick PP sheets can reduce medium and high-frequency noise by 10-20 decibels.

The sound insulation applications of PP sheets focus on scenarios where sound insulation requirements are not extreme, but a balance of lightness, corrosion resistance, and ease of processing is needed. In industrial fields, they can be used for equipment protective covers and linings of sound insulation enclosures to reduce the spread of operational noise from devices such as motors and pumps, while withstanding mechanical oil stains and minor corrosion. In construction and decoration, they serve as indoor partitions and pipeline wrapping materials—for example, wrapping drainage pipes in bathrooms and kitchens to reduce water flow impact noise, or being used in the wall interlayers of temporary compartments to help improve space sound insulation. In transportation, they play a role in lightweight and basic sound insulation in interior parts of electric vehicles and ships (such as instrument panel partitions and cabin baffles), working with other sound insulation materials to optimize the overall acoustic environment. In household and office settings, they can be made into simple sound insulation boxes (such as covering small devices like printers and routers) or used as sealing baffles for door and window gaps to reduce the infiltration of external environmental noise.