Sound Absorption of Hemp Fibers (Cannabis Sativa L.) Based Nonwoven Fabrics and Composites: A Review

Compared to the commonly used synthetic fibrous materials, natural fiber represents an eco-friendly solution in various engineering fields. Noise control is an important application of natural fibers due to the unique acoustic characteristics. Studies on the sound absorption of hemp fibers have attracted more and more attention in recent years. Generally, hemp products for sound absorption mainly including nonwoven fabrics and fiber-reinforced composites. This review has gathered the most recent advances on the acoustics of hemp fibers, and also the sound absorption design principles of hemp-based materials. A detailed information related to the improvement of the sound absorption properties of hemp is given, which mainly including the optimization of manufacturing, materials component, bulk density, morphologies, and structural parameters, etc. Hemp fibers exhibit robust acoustical performance, and the present work is beneficial to the development of sound absorption hemp-based materials.