Optimal design of acoustic material from tire fluff

Waste tires cause both health and environmental problems and this has forced governments to develop laws for recycling. There are several different recycling processes for end-of-life tires in which steel is recovered and rubber is reused. However, the reuse of other parts of the waste tires is currently not possible. These other parts mainly consist of textiles that are separated from the tire during the recycling process – this material is usually known as ‘fluff’. In this study a procedure for the design of materials with superior acoustic properties using this material was developed. The main component of the acoustic material is textile waste from mechanically fragmented tires obtained through recycling activity. The design process is based on several parameters: acoustic absorption coefficient measurement by the impedance tube method, acoustic modelling, mechanical characterization of the material and, finally, finite element modelling of the end acoustic product. In this work it was also established that the mechanical and acoustic properties need to be opposite to obtain the desired characteristics in the materials under investigation. In order to produce a competitive material formed completely from textile waste from recycled tires, a solution formed by two layers is proposed. This approach was used to provide a self-supporting material with a high acoustic absorption coefficient for use in acoustic ceiling tiles.

► Tire fluff can be used for designing superior acoustic material.
► Low density material from tire fluff gives high acoustic absorption coefficient.
► High density material from tire fluff can be used for increase mechanical strength.
► Multilayer tire fluff combines high acoustic properties with mechanical strength.