Microstructure and performance characteristics of acoustic insulation materials from post-consumer recycled denim fabrics

One of the key issues of the 21(st)century is to reduce the rate of continuously increasing environmental pollution from waste generated by human beings. Use of recycled materials and environmentally friendly approaches to manufacturing can be a good way to deal with these challenges. Similarly, sound pollution has been increasing at an alarming rate due to industrialization and modernization. Use of acoustic insulation materials produced from recycled textile waste can play a vital role in reduction of sound pollution while simultaneously helping reduce municipal solid waste. The goal of this study was to evaluate the recycling of used apparels to produce commercially feasible sustainable products using nonwoven fabrication techniques with a biodegradable thermoplastic binder fiber for possible use as acoustic insulation panels. Recycled denim fibers were used with Sorona (R) or a PLA binder fiber to successfully produce sound insulation with good performance properties. Maximum transmission loss of about 24 dB and transmission coefficient close to zero at around 1000 Hz were observed. The data indicated that there is a direct correlation between loss of sound transmission with increase in thickness, areal density and decrease in air permeability. When compared with commercially available acoustic insulation material (gypsum board), these products had better insulation properties, indicating that recycled textile products can be used to produce such value-added materials, giving them another useful life before safely disposing in composting environments.