Effects of porosity, fiber size, and layering sequence on sound absorption performance of needle‐punched nonwovens

Yılmaz, Nazire Deniz; Banks‐Lee, P.; Powell, Nancy; Michielsen, Stephen

doi:10.1002/app.33312

Cited by 85 publications

(61 citation statements)

References 14 publications

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“…It is clear that the four dispersion powders show the same absorption intensity [Figure (a)] that corresponds to two strong peaks (at 1151and 1210cm −1 ). These peaks could be attributed to the E1 or A2 symmetric stretching vibration of the molecular chains of CF 2 chemical bonds . From the spectra, it is reasonable to conclude that the chemical composition of four PTFE powder samples have no significant difference, implying that virgin dispersion powders do not contain extra chemical reagent.…”

Section: Resultsmentioning

confidence: 86%

A comparative study of characteristics of polytetrafluoroethylene fibers manufactured by various processes

Huang

Jin

2016

J of Applied Polymer Sci

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A series of polytetrafluoroethylene (PTFE) fibers were manufactured by three processing methods including extrusion process, split‐sheet process and split‐film process. The influence of processing methods on fiber properties were systematically studied using four PTFE powders with various molecular weights (3.86 × 107, 4.71 × 107, 4.92 × 107 and 5.11 × 107, respectively). Morphology, crystallinity, tensile behavior and friction properties of PTFE fibers were compared by scanning electron micrograph, X‐ray diffraction pattern, strength‐elongation curves and friction coefficients, respectively. The results showed that the in terms of flat filaments, mechanical properties became weak with the increase of molecular weight of PTFE powders at first, but were improved dramatically with further enhancement of molecular weight. In the case of both round filaments and split‐film fibers, fiber properties were improved with growth of molecular weight. Based on characteristics and friction coefficients, potential applications of three types of PTFE samples were analyzed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43553.

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Section: Resultsmentioning

confidence: 86%

A comparative study of characteristics of polytetrafluoroethylene fibers manufactured by various processes

Huang

Jin

2016

J of Applied Polymer Sci

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“…Additionally, finer fibers could be vibrated easily, causing acoustic energy dissipation. As the material is fibrous, the flow resistivity increased with decreasing fiber . Of course, the relationship between the fiber size and the flow resistivity depends on the fiber type .…”

Section: Resultsmentioning

confidence: 99%

“…The equivalent fiber density (

\bar{ρ}

, Table ) of PWFM was expressed by Eq. :

\bar{ρ} = \frac{ρ_{w} ρ_{p}}{N ρ_{w} + true(1 - N true) ρ_{p}}

…”

Section: Methodsmentioning

confidence: 99%

Analysis of polyester/wood composite fiber needling mat sound absorption performance

Wang

Peng

et al. 2017

Polymer Composites

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The use of natural fibers in the manufacturing of sound absorbing materials has received much attention as a strategy to increase environment‐protection performance. In this study, the sound absorption property of a polyester/wood composite fiber needling mat (PWFM) was investigated by the Delany–Bazley (D‐B) model, phenomenon model (PM), and impedance tube. The applicability of those models and the effects of the parameters of the PWFM on sound absorption were analyzed. The results showed that the PM and D‐B models adequately predicted the sound absorption property of the PWFM. However, the discrepancies between the measurement and theoretical values were larger for lower density PWFWs. The accuracy of wood fiber diameter and the wood fiber morphology were significant determinants of the usability of those models. The sound absorption performance for PWFM increased with increased flow resistivity and density. The wood fiber surface roughness and small cracks played important roles in the improvement of the sound absorption characteristics of the PWFM. POLYM. COMPOS., 39:3823–3830, 2018. © 2017 Society of Plastics Engineers

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“…Hemp fibers that were field retted and processed through BioFibeRefinery™ were purchased from Stemergy (Canada, Ontario). PP and glassfibers were selected due to the fact that these fiber types are commonly used in conventional nonwoven composites as the carrier and reinforcement materials, respectively 13. PLA was selected as a biodegradable alternative carrier fiber.…”

Section: Methodsmentioning

confidence: 99%

Effects of material and treatment parameters on noise‐control performance of compressed three‐layered multifiber needle‐punched nonwovens

Yılmaz

Michielsen

Banks‐Lee

et al. 2011

J of Applied Polymer Sci

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The effects of material and treatment parameters on airflow resistivity and normal-incidence sound absorption coefficient (NAC) of compressed threelayer nonwoven composites have been studied. Material parameters included fiber size and porosity, and treatment factors included applied pressure and duration of compression. Fibers used included poly(lactic acid) (PLA), polypropylene (PP), glassfiber, and hemp. Three-layered nonwoven composites were classified based on material content and fiber blend. LHL and PGP were sandwiched structures consisting of PLA/Hemp/PLA and PP/glassfiber/PP layers, respectively. PGI consisted of three layers of an intimate blend of PP and glassfiber. Statistical models were developed to predict air flow resistivity from material parameters and the change in air flow resistivity from compression parameters. Independent variables in the first model were porosity and fiber size and, in the latter model, were compressibility, pressure, and initial mate-rial parameters. An increase in air flow resistivity was found with increased compression. No significant effect of compression duration was detected. Two additional statistical models were developed for the prediction of sound absorption coefficient based on material and treatment parameters. The independent variables of the first model were air flow resistivity, thickness, and frequency, and those of the second model were compressibility, initial thickness, and initial density of the composite, diameter and density of the fiber, compression pressure, and frequency. A decrease in sound absorption coefficient was detected with increasing compression, while no effect of duration was detected.

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Effects of porosity, fiber size, and layering sequence on sound absorption performance of needle‐punched nonwovens

Cited by 85 publications

References 14 publications

A comparative study of characteristics of polytetrafluoroethylene fibers manufactured by various processes

A comparative study of characteristics of polytetrafluoroethylene fibers manufactured by various processes

Analysis of polyester/wood composite fiber needling mat sound absorption performance

Effects of material and treatment parameters on noise‐control performance of compressed three‐layered multifiber needle‐punched nonwovens

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