Influence of the number of carded non-woven layers on mechanical and acoustic performance

Abstract

Acoustic absorption consists basically of the transformation of mechanical energy into thermal energy, carried out through the interaction of the fibers with the sound wave through the breaking of such waves and their meeting with the surface of the fibers. Among the various materials that may be employed to this end, the use of non-woven fabrics has stood out. This study aimed to evaluate the influence of the number of carded non-woven web layers on the mechanical and sound absorption capacity. For this purpose, three groups of non-woven fabrics were produced with different numbers of web layers (24, 40, and 58 layers) of equal thickness and density, composed of a mixture of polyester fibers. Standard test procedures were used to measure the physical properties of the non-woven fabrics, the linear density of the fibers used as raw material, the tensile strength, and air permeability and to assess the sound absorption capacity. In addition, to identify a balance point between sound absorption and equipment productivity, the relationship between the acoustic performance of the non-woven fabrics produced and their production speed was evaluated. The greater the number of web layers is, the higher the absorption coefficient of the non-woven. However, the variation was not significant when the various sound absorption frequencies were observed. In this regard, developing a non-woven fabric with fewer layers was more productive and cost-effective without losing technical performance.