Sound Absorption Properties of Polyester Fibers Needle-Punched Nonwoven Fabrics

2011 ◽  
Vol 332-334 ◽  
pp. 1300-1303
Author(s):  
Ke Tian Guan ◽  
Xu Pin Zhuang ◽  
Xiao Ning Jiao ◽  
Men Qin Li ◽  
Hong Jun Li ◽  
...  
Keyword(s):  
Surface Structure ◽  
Standing Wave ◽  
Sound Absorption ◽  
Fiber Diameter ◽  
Absorption Property ◽  
Wave Tube ◽  
Absorption Properties ◽  
Nonwoven Fabrics ◽  
Polyester Fibers ◽  
Standing Wave Tube

Polyester fiber needle-punched nonwovens with different structures were manufactured and their sound absorption properties were examined using the standing wave tube method. The results show that the sound absorption property of the nonwovens depends on their thickness, needling intensity, fiber diameter and surface structure.

Fabrication and Sound Absorption Properties of Porous Fe0.2(Co20Ni80)0.8 Alloy Microfibers

2012 ◽  
Vol 538-541 ◽  
pp. 2220-2223
Author(s):  
Xiang Qian Shen ◽  
Hong Bo Liu ◽  
Qing Rong Liang ◽  
Xin Chun Yang
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Transformation Process ◽  
Sound Absorption Coefficient ◽  
Wave Tube ◽  
Absorption Properties ◽  
Thick Sample ◽  
Noise Absorption ◽  
Reduction Coefficient ◽  
Standing Wave Tube

The porous nanocrystalline Fe0.2(Co20Ni80)0.8 alloy microfibers with diameters of 2-4 μm have been prepared by the citrate-gel and phase transformation process. The sound absorption coefficient for microfibers samples is measured by the standing wave tube method and it is is over 0.8 for the 15 mm thick sample at the frequency range of 2300-6000 Hz, which is extended to 600-6300 Hz for the 40 mm thick sample. The band width with the sound absorption coefficient above 0.6 is wider than 4300 Hz for the 15 mm thick sample and 5800 Hz for the 40 mm thick sample. For the 40 mm thick sample, the maximum absorption coefficient, noise absorption coefficient, noise reduction coefficient and half-width of the absorption peak are 0.99, 0.59, 0.64 and 5828 Hz, respectively. These microfibers are promising advanced acoustic absorbers.

scholarly journals Effect of Thickness, Density and Cavity Depth on the Sound Absorption Properties of Wool Boards

2018 ◽  
Vol 18 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Hua Qui ◽  
Yang Enhui
Keyword(s):  
Sound Absorption ◽  
Raw Material ◽  
Wave Tube ◽  
Absorption Coefficients ◽  
Absorption Properties ◽  
Cavity Depth ◽  
Low Frequencies ◽  
High Frequencies ◽  
Standing Wave Tube ◽  
Better Than

Abstract A novel wool absorption board was prepared by using a traditional non-woven technique with coarse wools as the main raw material mixed with heat binding fibers. By using the transfer-function method and standing wave tube method, the sound absorption properties of wool boards in a frequency range of 250-6300 Hz were studied by changing the thickness, density, and cavity depth. Results indicated that wool boards exhibited excellent sound absorption properties, which at high frequencies were better than that at low frequencies. With increasing thickness, the sound absorption coefficients of wool boards increased at low frequencies and fluctuated at high frequencies. However, the sound absorption coefficients changed insignificantly and then improved at high frequencies with increasing density. With increasing cavity depth, the sound absorption coefficients of wool boards increased significantly at low frequencies and decreased slightly at high frequencies.

Investigation on the Sound Absorption Properties of MPA/MR

2009 ◽  
Vol 79-82 ◽  
pp. 2147-2150 ◽  
Author(s):  
Yan Hong Ma ◽  
Jie Hong ◽  
Bin Zhu ◽  
Hong Wang
Keyword(s):  
Sound Absorption ◽  
Sound Propagation ◽  
Propagation Theory ◽  
Wave Tube ◽  
Absorption Properties ◽  
Acoustic Characteristics ◽  
Analogy Method ◽  
Metal Rubber ◽  
Standing Wave Tube ◽  
Application Prospects

This paper introduces a sound absorption structure named as MPA/MR which is a combination of the MPA and Metal Rubber (MR) material. On the basis of Rayleigh model and sound propagation theory in pipe, according to the acoustoelectric analogy method, the theoretical acoustic model of MPA/MR is established, and the formula of absorption coefficient is derived. The multi-function standing wave tube with two microphones was used to obtain acoustic characteristics of MPA/MR experimentally, and the effects of the parameters were analyzed as well. The investigation indicates that MPA/MR can be applied with a broad range of application prospects.

scholarly journals Effect of Bicomponent Fibers on Sound Absorption Properties of Multilayer Nonwovens

2017 ◽  
Vol 12 (4) ◽  
pp. 155892501701200
Author(s):  
Dilan Canan Çelikel ◽  
Osman Babaarslan
Keyword(s):  
Sound Absorption ◽  
Middle Layer ◽  
Absorption Coefficients ◽  
Absorption Properties ◽  
Cross Sectional ◽  
Bicomponent Fibers ◽  
Nonwoven Fabrics ◽  
Polyester Fibers ◽  
Absorption Performance ◽  
Round Cross

In this study sound absorption properties of multilayer nonwovens with bicomponent fibers have been derived compared with homocomponent fibers. Multilayer nonwovens obtained by polyester fibers consisted of three layers. The top and bottom layers were spunbonded nonwoven and middle layer was meltblown nonwoven sandwiched between them. Each layer was produced separately to compose unbonded three-layered nonwoven structures. Four different spunbonded nonwoven fabrics having a basis weight of 40 gsm made from four different polyester cross-sectional fibers (homocomponent round and trilobal, bicomponent round and trilobal). Five different meltblown nonwoven fabrics having five different basis weights ranging 100 gsm to 200 gsm were made from polyester round cross-sectional fibers. Spunbonded/ Meltblown/ Spunbonded (SMS) type unbonded multilayer nonwovens had basis weights ranging 180 gsm to 280 gsm. The effect of basis weight on sound absorption performance of multilayer nonwovens has been evaluated in the study. All results have been analyzed statistically. Results show that three-layered nonwoven structures including bicomponent fibers as outer layers had better sound absorption performance than nonwoven structures including homocomponent fibers. This effect becomes more significant as the basis weight increases, resulting insound absorption coefficients.

Development of a Standing Wave-Tube System for Acoustical Property Measurement of Sound Absorption Materials Used on Vehicles

2011 ◽  
Vol 474-476 ◽  
pp. 1146-1150
Author(s):  
Yan Song Wang ◽  
Jian Peng Zhou ◽  
Yan Feng Xing
Keyword(s):  
Standing Wave ◽  
Sound Absorption ◽  
Ratio Method ◽  
Wave Tube ◽  
Tube System ◽  
Signal Amplifier ◽  
Acoustical Property ◽  
Property Measurement ◽  
Standing Wave Tube ◽  
Materials Used

A standing wave-tube system for acoustical property measurement of vehicle-used sound absorption materials is developed in this paper. Theoretically, the standing wave ratio method and the two-cavity method with two-microphone configurations are combined and applied for calculating some acoustical parameters, such as sound absorption ratio, reflection coefficient, characteristic impedance, propagation constant, of a sample material. Based on the combined method, the standing wave-tube system including two microphones, an A/D board, a signal amplifier, a DSP computer and a set of software is carefully designed and performed. The verification results suggest that the newly designed system is accurate for acoustical property measurement of the materials used on vehicles. It can be directly used for selecting noise-control materials in vehicle acoustical designs.

A New Method to Measure the Absorption Coefficient of the Automotive Driving Room Based on the Sound Pressure Delaying

2011 ◽  
Vol 415-417 ◽  
pp. 1350-1354
Author(s):  
Cong Yun Zhu ◽  
Jian Ru Shi ◽  
Shu Feng Yang
Keyword(s):  
Absorption Coefficient ◽  
Standing Wave ◽  
Sound Pressure ◽  
Measurement Methods ◽  
The Other ◽  
New Method ◽  
Wave Tube ◽  
Absorption Function ◽  
Equal Distance ◽  
Standing Wave Tube

Absorption coefficient is an important parameter of the absorption function of the absorption material. Traditional measurement methods of absorption coefficient are standing wave tube and reverberation which have some shortcomings. In this paper, phase of the sound pressure measured by two equal distance microphones placed in the front of the absorption material is delayed in order to attain the absorption coefficient. At the last, an experiment for one absorption material is carried out, the experiment results compare with the results of the other methods above mentioned that denotes that the theory is correct and practicable.

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