scholarly journals Sound-Absorption Properties of Materials Made of Esparto Grass Fibers

2020 ◽  
Vol 12 (14) ◽  
pp. 5533 ◽  
Author(s):  
Jorge P. Arenas ◽  
Romina del Rey ◽  
Jesús Alba ◽  
Roberto Oltra
Keyword(s):  
Sound Absorption ◽  
Natural Fibers ◽  
Normal Incidence ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
Absorption Performance ◽  
Sustainable Materials ◽  
Reasonable Prediction ◽  
Best Fit

Research on sound-absorbing materials made of natural fibers is an emerging area in sustainable materials. In this communication, the use of raw esparto grass as an environmentally friendly sound-absorbing material is explored. Measurements of the normal-incidence sound-absorption coefficient and airflow resistivity of three different types of esparto from different countries are presented. In addition, the best-fit coefficients for reasonable prediction of the sound-absorption performance by means of simple empirical formulae are reported. These formulae require only knowledge of the airflow resistivity of the fibrous material. The results presented in this paper are an addition to the characterization of available natural fibers to be used as alternatives to synthetic ones in the manufacturing of sound-absorbing materials.

scholarly journals Improvement of the sound absorption performance of jute felt-based sound absorbers using micro-perforated panels

2017 ◽  
Vol 36 (4) ◽  
pp. 376-398 ◽  
Author(s):  
Pritesh V Bansod ◽  
T Sai Teja ◽  
Amiya R Mohanty
Keyword(s):  
Transfer Matrix Method ◽  
Sound Absorption ◽  
Low Cost ◽  
Control Engineering ◽  
Natural Materials ◽  
Sound Absorber ◽  
Absorbing Materials ◽  
Different Types ◽  
Absorbing Material ◽  
Absorption Performance

In industrial and architectural applications, noise can be controlled using sound-absorbing materials. Natural materials are now gaining importance in the noise control engineering as they have advantages like low cost, eco-friendly, easy to produce, etc. Jute is one of such natural materials, which can be used as a sound-absorbing material. Micro-perforated panels along with three different types of jute felts are used in a multilayer sound absorber configuration to improve its sound absorption. The sound absorption performance of these multilayer sound absorbers is evaluated by using the transfer matrix method and experimental method. Dependence of sound absorption performance on the placement of micro-perforated panels in a multilayer sound absorber is also studied. It is observed that the sound absorption performance depends on the position of micro-perforated panels in a multilayer sound absorber.

Investigation of a Compound Perforated Panel Absorber With Backing Cavities Partially Filled With Polymer Materials

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
C. Q. Wang ◽  
Y. S. Choy
Keyword(s):  
Sound Absorption ◽  
Normal Incidence ◽  
Polyester Fiber ◽  
Polymer Materials ◽  
Element Simulation ◽  
Parallel Arrangement ◽  
Cavity Configuration ◽  
Absorption Performance ◽  
Good Agreement ◽  
Panel Absorber

The paper concerns the sound absorption performance of a compound absorber which consists of a parallel arrangement of multiple perforated panel absorbers of different backing cavity depths partially filled with poroelastic polymer materials. Three polymer materials are considered: expandable polystyrene (EPS) foam, polymethacrylimide (PMI) foam, and polyester fiber. The normal incidence sound absorption coefficients of the compound panel absorber are tested experimentally. Results show that the former two foams can achieve similar absorption performance to the rigid cavity configuration, while the resonances shift to lower frequencies due to the changes of effective cavity depths. It is also found that the additional attenuation by polymer foams may improve sound absorption, but the effect is marginal. For polyester fiber, results show that it performs more like a single perforated panel absorber. Finite element simulation of the compound panel absorber is also discussed, and good agreement is observed between simulated and experimental results.

scholarly journals A Preliminary Study on Acoustical Performance of Oil Palm Mesocarp Natural Fiber

2015 ◽  
Vol 773-774 ◽  
pp. 247-252 ◽  
Author(s):  
Hanif Abdul Latif ◽  
Musli Nizam Yahya ◽  
Mohamed Najib Rafiq ◽  
Mathan Sambu ◽  
Mohd Imran Ghazali ◽  
...  
Keyword(s):  
Oil Palm ◽  
Sound Absorption ◽  
Natural Fiber ◽  
Standard Test ◽  
Air Gap ◽  
Test Method ◽  
Synthetic Materials ◽  
Absorbing Material ◽  
Absorption Performance ◽  
Impedance Tube Method

As the population increases, the demand of a comfortable environmental such as sound pollution is getting higher. Sound pollutions also have become worsen and creating concerns for many peoples. Due to this problem, synthetic materials as acoustic absorbers still applied as commonly acoustical panels and this material may hazardous to human health and contribute significantly a pollution to the environments. However, researchers have interested in conducting their research on natural fiber to be an alternative sound absorber. This study investigated the potential of oil palm Mesocarp fiber for sound absorbing material. The Mesocarp fibers were mixed with polyurethane (PU) as binder with ratio of 70:30. The thickness was varied in 10mm, 20mm, 30mm, and 40mm. This study also investigated the air gap of 5mm and 10mm in the sound absorption performance. Impedance Tube Method was used to measure sound absorption coefficient (a). The measurement was done on accordance with ASTM E1050-98, which is the standard test method for impedance and absorption of acoustical materials using a tube. The results showed that the optimum value for Mesocarp fiber is 0.93. The optimum value obtained at 5000 Hz. The influence of air gap increases the sound absorption especially from 250 Hz to 4000 Hz. These results indicate that fiber from Mesocarp is promising to be used sound absorbing material.

Modelling the Effect of Flexural Vibration on Sound Absorption of a Micro-Perforated Panel Using Wave Propagation Method

2013 ◽  
Vol 471 ◽  
pp. 255-260
Author(s):  
Azma Putra ◽  
Muhammad Sajidin Py ◽  
Norliana Salleh
Keyword(s):  
Wave Propagation ◽  
Sound Absorption ◽  
Flexural Vibration ◽  
Rigid Wall ◽  
Flexural Wave ◽  
Wave Propagation Method ◽  
Rigid Condition ◽  
Absorbing Material ◽  
Absorption Performance ◽  
Propagation Technique

Micro-perforated panel (MPP) is well known as the alternative green sound absorbing material replacing the synthetic porous absorber. Several works have been established which model the sound absorption performance of the MPP with various arrangements. However, most existing models are for MPP with rigid condition and rarely discuss the effect of vibration due to the impinging sound. In this paper, a simple approach using wave propagation technique is proposed to take into account the effect of flexural wave in the MPP on its sound absorption. The model begins with an MPP coupled with a solid panel separated by an air gap. The impedance of the back solid panel can then be adjusted to a very large value to simulate a rigid wall.

scholarly journals The influence of the distribution of sound absorbing materials on the estimation of reverberation time in rooms

2018 ◽  
Vol 49 ◽  
pp. 00078
Author(s):  
Marcelina Olechowska ◽  
Artur Nowoświat ◽  
Jan Ślusarek ◽  
Mateusz Latawiec
Keyword(s):  
Absorption Coefficient ◽  
Acoustic Field ◽  
Sound Absorption ◽  
Sound Field ◽  
Reverberation Time ◽  
Type D ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
Different Dimensions ◽  
Materials Used

Reverberation time in rooms depends on many factors, e.g. cubature, surface of envelopes, sound absorption coefficient of materials used for the construction of the envelopes, geometry of rooms or the distribution of sound absorbing materials. The arrangement of sound absorbing materials in rooms has an impact on the dispersion of acoustic field, yet theoretical calculation models do not take into account this impact. According to these models, regardless of the arrangement of sound absorbing materials, the reverberation time in a room will remain unchanged. The present paper investigates the above problem by means of computer simulations. For the needs of the simulation, three rooms with different dimensions were adopted, i.e. type 'p' - a cuboidal room with a square base, type 'd' - a cuboidal room (with one side of the 'p' room lengthened), type 'w' - a cuboidal room (with the height of the room lengthened 'p'). During the simulation, the way of acoustic field dispersion was being changed and its influence on the reverberation time in the rooms was being determined. The authors investigated two situations. The first one involved a non-dampened room, in which the sound absorbing material was being arranged differently. The second one involved a welldampened room, and the dispersion of sound field was analyzed depending on the location of the reflecting material.

scholarly journals Effect of the Pore Shape and Size of 3D-Printed Open-Porous ABS Materials on Sound Absorption Performance

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4474
Author(s):  
Katarina Monkova ◽  
Martin Vasina ◽  
Peter Pavol Monka ◽  
Drazan Kozak ◽  
Jan Vanca
Keyword(s):  
Sound Absorption ◽  
Negative Impact ◽  
Excitation Frequency ◽  
Volume Ratio ◽  
Acrylonitrile Butadiene Styrene ◽  
Normal Incidence ◽  
Absorption Properties ◽  
Absorption Performance ◽  
3D Printed ◽  
Material Volume

Noise has a negative impact on our environment and human health. For this reason, it is necessary to eliminate excessive noise levels. This paper is focused on the study of the sound absorption properties of materials with open-porous structures, which were made of acrylonitrile butadiene styrene (ABS) material using additive technology. Four types of structures (Cartesian, Octagonal, Rhomboid, and Starlit) were evaluated in this work, and every structure was prepared in three different volume ratios of the porosity and three different thicknesses. The sound absorption properties of the investigated ABS specimens were examined utilizing the normal incidence sound absorption and noise reduction coefficients, which were experimentally determined by the transfer function method using a two-microphone acoustic impedance tube. This work deals with various factors that influence the sound absorption performance of four different types of investigated ABS material’s structures. It was found, in this study, that the sound absorption performance of the investigated ABS specimens is strongly affected by different factors, specifically by the structure geometry, material volume ratio, excitation frequency of an acoustic wave, material’s thickness, and air space size behind the tested sound-absorbing materials.

scholarly journals Sound absorption characteristics of KGM-based aerogel

2020 ◽  
Vol 15 (3) ◽  
pp. 450-457
Author(s):  
Yixin Wang ◽  
Fei Xiang ◽  
Wei Wang ◽  
Weiling Wang ◽  
Yuehong Su ◽  
...  
Keyword(s):  
Pore Structure ◽  
Sound Absorption ◽  
Freeze Drying ◽  
Drying Method ◽  
Absorption Potential ◽  
Absorption Performance ◽  
Property Characterization ◽  
High Sound ◽  
Absorption Characteristics

Abstract This study presents the preparation and property characterization of biomass aerogels as sound absorption materials. Biomasses were chosen to prepare aerogels through the freeze-drying method. Results indicated that four components may have different effects on the aerogel pore structure, and the aerogel formula was thus optimized to reach the best sound absorption. Within the experimental range, biomass aerogel with the optimized formula had an average sound efficiency 0.352, density 0.047 g/cm3 and porosity 94.46 ± 0.04%. It shows better sound absorption performance than traditional sound absorption cotton. These results demonstrate the high sound absorption potential of biomass aerogels for building applications.

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