Modern world is exposed to various environmental concerns which are closely related to human health condition. Since the automatization, world became vulnerable to the noise and the waste amounts generated. World Health Organization report states, due to noise, Western Europe each year loses approximately 1 million of healthy life years. However, noise is not the only concern. Tyres, since they were banned from the landfills, became enormous problem in a modern society. Approximately 2.6 million tonnes of tyres are generated each year in Europe, out of which 320 000 tonnes of Recycled Tyre Textile Fibre (RTTF) waste. Practically, rubber granules and metals extracted from tyre can be reused, however reusing RTTF is a challenge. The main focus is on the possibility of reuse of RTTF in buildings for acoustical comfort improvement. The determination of sound absorption is implemented by experimental research, based on ISO 10534 standard, involving five types of sound absorbing materials. It was concluded that RTTF has a great potential in use for sound absorption structures and can be an alternative substitute to non-renewable and non-recyclable materials.

In recent years, the recycling of waste materials has become significant due to the movement of the European Union toward the Green Deal and the low impact on the environment. The paper studies the possibility of Waste Tyre Textile Fibre (WTTF) for sound absorption applications. WTTF is the material generated during the end-of-life tyre recycling process, which is separated from rubber and metal parts. In this study, three different types of WTTF samples were tested in which they consist of different levels of rubber impurities. In the first case, rubber particles make up to 10 % of total mass of WTTF (WTTF10), second – 54 % (WTTF54), and third – 70 % (WTTF70). The sound absorption tests were performed using the impedance tube using a two microphone technique, under the ISO 10534-2 standard. The results showed that increasing the level of rubber particles reduces the sound absorption performance of the WTTF. It was noticed that sound absorption of the sample WTTF10 reached 0.67 at low frequencies (500 Hz), while WTTF54 reached 0.31 and WTTF70 reached 0.21. It was concluded that WTTF10 samples had on average a 61 % higher sound absorption capacity compared to the other samples. The aim of the study was to determine the rubber particles impurities in WTTF dependence on sound absorption ability of the material.

Perdirbant padangas, gumos granulės ir metalo pluoštas sėkmingai naudojami pakartotinai, tačiau padangų tekstilės pluošto (PTP) atliekos yra gana didelė problema. Mokslininkai vykdo tyrimus, bandydami šias padangų tekstilės pluošto atliekas, naudoti šiluminei izoliacijai, nes čia matomas didelis jų potencialas. Kadangi šiluminė izoliacija turi artimą ryšį su garso sugertimi, manoma, kad PTP sėkmingai tiktų panaudoti ir triukšmui patalpose mažinti. Tyrimo metodas remiasi ISO 10534-2 standartu, kuriuo būtų nustatytas medžiagos garso sugerties koeficientas α naudojant impedanso vamzdį. Tyrimo metu gauti rezultatai parodė, kad PTP atliekos turi geras garso sugerties savybes, garso sugerties koeficientas, esant žemiems dažniams 250–500 Hz, buvo 0,06–0,52, o esant aukštesniems dažniams – 1000–1600 Hz, sugerties koeficientas varijavo tarp 0,44–0,94. Šios medžiagos naudojimas būtų puiki alternatyva šiuo metu naudojamoms tradicinėms mineralinėms pluoštinėms medžiagoms.

Since society is moving towards sustainable development, interest in secondary use of waste has recently become significant. This paper investigates a process to develop an acoustic material, using two types of waste. Composite acoustic panels were developed using waste tyre textile fibres (WTTF) and paper sludge (PS), and polyvinyl acetate (PVA) were used as a binder. Non-acoustic (bulk density, airflow resistivity) and acoustic (sound absorption coefficient, sound transmission loss) parameters were studied. Composite acoustic panels with different proportions of WTTF/PS/PVA (sixteen samples) were subjected to testing for the sound absorption coefficient according to ISO 10534-2 and sound transmission loss according to ASTM E2611. The density of all samples varied between 155.2 and 709.9 kg/m3, the thickness between 14.4 and 20.5 mm, and the airflow resistivity between 29.5 and 101.5 kPa∙s/m2. The results reveal that the proportion of various waste materials in mixtures can improve the acoustic performance of panels. The combination that gives the highest αavg. with a value of 0.50 was experimentally found to be 70% WTTF mixed with 15% PVA and 15% H2O. The average sound absorption coefficient with a value of 0.46 was also found to be 25% WTTF mixed with 25% PS and 25% PVA and 25% H2O. In sound transmission loss, the most effective was 50% PS and the 50% PVA composite, the TLeq was 28.3 dB, while the composites together with 30% WTTF, 20% PS and 25% PVA, and 25% H2O showed 18.9 dB loss. The results obtained using WTTF and/or PS wastes are attractive and show great and promising development potential.

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