Acoustic Panels Made of Paper Sludge and Clay Composites

Astrauskas, Tomas; Januševičius, Tomas; Grubliauskas, Raimondas

doi:10.3390/su13020637

Cited by 18 publications

(18 citation statements)

References 36 publications

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“…9,30,31 The transmission coefficient refers to the energy dissipation through the material when the sound wave arrives, it is expected that a material that is applied as an acoustic barrier has a low amplitude transmission coefficient. 4,12 In Figure 6(c) the materials studied have transmission coefficients that decrease in the order: nopal, nopal composite, bentonite, coconut composite, and coconut. The fibers and the composite with nopal contain mucilage that generates a protective polymeric barrier, which increases the density and decreases the porosity as the fibers adhere (with each other and with the bentonite, respectively) and therefore increase the transmission coefficient.…”

Section: Resultsmentioning

confidence: 99%

“…The main purpose of composites in acoustic insulation applications are acoustic barriers, acoustic panels, and bricks or wall coverings. 4,9,10,12,13…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the waste generated hurts the environment, so many investigations have been carried out to find new materials that have adequate properties to replace them. [4][5][6][7][8] In recent publications, results have been reported on the use of different natural fibers such as coconut, luffa, bamboo, and sugar cane, among others, owing to their low cost, abundance in nature, light materials, Division of Basic Sciences and Engineering, Universidad Autónoma Metropolitana Unidad Azcapotzalco, Ciudad de Mexico, Mexico and natural origin. [4][5][6]9 However, the low thermal stability is a limitation that some of these materials present.…”

Section: Introductionmentioning

confidence: 99%

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Acoustic properties of composites materials based on bentonite and coconut or cactus (nopal) fibers

Martínez

Loera‐Serna

Vázquez-Cerón

2023

Journal of Composite Materials

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Materials made from natural fibers or waste have been studied to acquire a composite with good acoustical isolation properties, commercial materials used in this concern are polyurethane foam, fiberglass, Rockwool, and drywall. This work proposes using waste coconut and cactus ( Opuntia ficus-indica) fibers to synthesize bentonite composites and study their physicochemical and acoustic properties. Physicochemical properties of precursor and composites (75% wt. fiber) were determined by XRD, FTIR, N2 adsorption, optical, and SEM microscopies. The transmission, reflection, and absorption coefficients, 50 to 10,000 Hz, were obtained in an impedance tube and were compared with commercial materials. The composites were subjected to surface humidity and thermal (30, 50, and 70°C) tests to evaluate the stability of acoustic properties. The mechanical properties of the composites are improved with the addition of bentonite, hardness is increased by 6.7% and 0.9%, and the density is decreased by 73.6% and 45.5%, for coconut and nopal, respectively, porosity also changes. We corroborated the significant presence of montmorillonite in bentonite (XRD), while the nopal or coconut fibers are composed of hemicellulose, cellulose, and lignin (FTIR). Also, mucilage was identified in the nopal samples as adherent biopolymer that generates stability either thermally or in wetting conditions. Coconut fiber has a high absorption coefficient (similar to polyurethane), which is reduced with humidity. However, by adding bentonite, the reflection is more elevated, and transmission is lower than commercial materials. The bentonite and nopal (fiber and composite) presented stability in the acoustic coefficients as a function of humidity and temperature.

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Section: Resultsmentioning

confidence: 99%

“…The main purpose of composites in acoustic insulation applications are acoustic barriers, acoustic panels, and bricks or wall coverings. 4,9,10,12,13…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Acoustic properties of composites materials based on bentonite and coconut or cactus (nopal) fibers

Martínez

Loera‐Serna

Vázquez-Cerón

2023

Journal of Composite Materials

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“…Based on the SAC of each material aforementioned, the capability of sound absorption of the WHBC500-PVA composite is little bit better than all the materials mentioned as shown in Table 4. As we can see in 4, SAC of the WHAC500-PVA composite (0.21) is bigger than that of paper sludge-cemented composite, i.e., 0.05 [42], wool and jute each is 0.200 [39][40][41], and polystyrene, i.e., 0.100 [39]. However, the capability of sound absorption of the WHBC500-PVA composite is still lower than the others ones shown in Table 4, for examples such as Micro-perforated panel circle shape-based Jute system (SAC: 0.850), Micro-perforated panel hexagonal shape-based Jute system (SAC: 0.810), Micro-perforated panel spiral shape-based Jute system (SAC: 0.790), and so on.…”

Section: Sound Absorption Analysismentioning

confidence: 86%

Fabrication, Characterization and Application of The Water Hyacinth Biochar- Polyvinyl Alcohol Composite as an Advantageous Sound Absorber Material

Wibawa

Grafiana

Gunawan

2023

Preprint

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The research was aiming to investigate the potency of water hyacinth (WH) biochar as the most advantageous sound absorber composite when it was blended with polyvinyl alcohol (PVA). Analysis and characterization of the produced WH biochar were essentially performed using N2 absorption-desorption, FTIR spectrophotometer, and SEM methods. While the capability of the sound absorber material was technically conducted using a polyvinylchloride (PVC) impedance tube of about 95 cm in length with internal and outer diameters of about 9.5 cm and 9.8 cm respectively. The materials that would be tested for their capability of sound absorber were prepared in a disk-like form with about 9.5 cm in diameter and 0.5 cm in thickness. The sound source was continuously turned on for 2 minutes and transmitted wirelessly through the impedance tube, and the decreasing intensity of the sound was recorded every 5 seconds. The results showed that the sound absorption coefficient (SAC) of the WH biochar-PVA composite was about 6.50% (0.0650) up to 21.03% (0.2103), while the SAC of the Styrofoam was just about 4.37% (0.0437). This research concluded that the WH biochar produced by the thermal energy of 500oC indicated it could be the best sound absorber composite when it was blended with PVA, especially for a low frequency of about 440 Hz.

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“…Tabla 5. Resumen de estudios sobre compósitos utilizados como absorbentes acústicos [13,28,29,30,31,32,33,34,35,36,37,38,39,40,41].…”

Section: Compósitosunclassified

Estudio de compósitos de fibras naturales y arcilla para aplicaciones acústicas

Martínez¹

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During the last decade, actions and studies to counteract the effects of noise have increased through the use of insulating or absorbent materials, and civil regulations based on monitoring in urban areas, since exposure to high levels of sound pressure can cause psychological and physiological health problems such as anxiety, depression, stress, fatigue, cardiac, hearing or cognitive problems, as well as irreversible hearing loss. This work aims to develop and study natural compounds made of clay reinforced with coconut or nopal fibers to analyze their acoustic coefficients and determine their applications as insulation or conditioning material. The composites were obtained incorporating 25, 50 and 75% by weight of each fiber with bentonite clay. The physical and chemical characterization of the composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical microscopy, Fourier transforms infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The properties of hardness and apparent density of the composites were obtained from samples aged three months. Using XRD, the compounds were identified in the bentonite: montmorillonite, quartz and feldspar. The FT-IR allowed the identification of the functional groups of the clay and for the fibers the presence of lignin and hemicellulose was determined. Micrographs show that coconut fiber is more porous than nopal; the size of the nopal fibers was between 71.8 and 219.7 nm (electron microscopy) and that of the coconut fibers was 0.1613 mm (optical microscopy). The apparent density of the composites follows the model of the mixture rule, while the hardness changes very little in the samples prepared with nopal fiber. Through ATG it was found that bentonite improves the thermal stability of the composites. The acoustic absorption, reflection, and transmission coefficients of the materials were determined using the impedance tube method, in the range of 50 to 10,000 Hz. The samples obtained after the synthesis process was weighed and characterized in the impedance tube; For the humidity tests, a drop was placed on the surface of the sample and the characterization process was repeated. These tests were carried out until 4 drops of water were added to each composite. The results showed an increase in the acoustic absorption properties when adding the fibers in the composites, where it was observed that the coconut fiber presented a higher sound absorption than the nopal fiber. The hardness and density of the material are directly related to a reduction in the absorption coefficient, although the tests carried out show that the nopal fibers in the composites do not increase their hardness and their acoustic properties, unlike coconut fibers. The results obtained from the acoustic characterization carried out in the surface humidity test showed that the absorption, reflection and absorption coefficients of the coconut change with increasing humidity in the samples. While, in the case of nopal, due to its composition and hydrophobic properties, there is no significant variation in its acoustic properties. Composites made from coconut fiber have better acoustic absorption and reduction properties, while those made from nopal fiber stand out in terms of sound reflection.

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Acoustic Panels Made of Paper Sludge and Clay Composites

Cited by 18 publications

References 36 publications

Acoustic properties of composites materials based on bentonite and coconut or cactus (nopal) fibers

Acoustic properties of composites materials based on bentonite and coconut or cactus (nopal) fibers

Fabrication, Characterization and Application of The Water Hyacinth Biochar- Polyvinyl Alcohol Composite as an Advantageous Sound Absorber Material

Estudio de compósitos de fibras naturales y arcilla para aplicaciones acústicas

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