Influence of Fibre Diameter on the Wool-Based Felt Properties

Felts are nonwovens formed by fibres with a random orientation. The felting process is a bonding process and usually it includes the steps mechanical agitation, heat, moisture and usually soap. Due to its three-dimensional structure, its applicability has been growing in areas such as musical instruments, industrial sound insulation and fashion. The current work aims to study the influence of the fibre diameter in the wool-based felt performance, mainly in terms of air permeability (AP) and mechanical properties, considering a range of felts prepared with blends of wool fibres with distinct diameters — namely 14, 16 and 18 µm. The felted structures were tested for physical characteristics (thickness, aerial mass), morphologically, AP, and tearing and tensile strength, in a comparative analysis to assess the effect of fibre diameter. The results show that the fibre diameter has implications in the structure of the three-dimensional structure. The obtained results showed that fibres with higher diameters have higher AP values, due to the empty spaces among the fibres.