Panels of eco-friendly materials for architectural acoustics

2020 ◽  
Vol 54 (25) ◽  
pp. 3743-3753
Author(s):  
J Fontoba-Ferrándiz ◽  
E Juliá-Sanchis ◽  
JE Crespo Amorós ◽  
J Segura Alcaraz ◽  
JM Gadea Borrell ◽  
...  

The objective of this work is to study the acoustic and mechanical properties of environmentally friendly materials manufactured through the process of resin infusion made from different types of fibres: some are biodegradable obtained from renewable resources and others from recycled textile waste. The materials studied are composed of fibres of jute, hemp, coconut, biaxial linen and textile waste. The modulus of elasticity and the airborne sound insulation are determined through dynamic and acoustic tests, respectively. The behaviour of these innovative materials is compared to some traditional materials commonly used in architectural acoustics. The acoustic study of these environmentally friendly materials is carried out considering them as light elements of a single layer for their application to insulation of walls. The results are compared to plasterboards, considered as the most commonly used light material in buildings for airborne sound insulation. In conclusion, these materials are a real and effective alternative to the traditional composites of synthetic matrices and reinforcements of glass fibres and there is a reduction in the production cost compared to the usual porous synthetic media that have expensive production processes.

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1544
Author(s):  
Yi-Jun Guan ◽  
Yong Ge ◽  
Hong-Xiang Sun ◽  
Shou-Qi Yuan ◽  
Xiao-Jun Liu

In this work, a low-frequency, open, sound-insulation barrier, composed of a single layer of periodic subwavelength units (with a thickness of λ/28), is demonstrated both numerically and experimentally. Each unit was constructed using two identical, oppositely oriented Helmholtz resonators, which were composed of a central square cavity surrounded by a coiled channel. In the design of the open barrier, the distance between two adjacent units was twice the width of the unit, showing high-performance ventilation, and low-frequency sound insulation. A minimum transmittance of 0.06 could be observed around 121.5 Hz, which arose from both sound reflections and absorptions, created by the coupling of symmetric and asymmetric eigenmodes of the unit, and the absorbed sound energy propagating into the central cavity was greatly reduced by the viscous loss in the channel. Additionally, by introducing a multilayer open barrier, a broadband sound insulation was obtained, and the fractional bandwidth could reach approximately 0.19 with four layers. Finally, the application of the multilayer open barrier in designing a ventilated room was further discussed, and the results presented an omnidirectional, broadband, sound-insulation effect. The proposed open, sound-insulation barrier with the advantages of ultrathin thickness; omnidirectional, low-frequency sound insulation; broad bandwidth; and high-performance ventilation has great potential in architectural acoustics and noise control.


2018 ◽  
Vol 432 ◽  
pp. 680-698 ◽  
Author(s):  
N.B. Roozen ◽  
Q. Leclère ◽  
D. Urbán ◽  
T. Méndez Echenagucia ◽  
P. Block ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mengwei Xie

More and more designers and companies in the packaging industry begin to pay attention to research on environmentally friendly packaging design. From studying the additional functions of packaging to starting to study the environmentally friendly materials of packaging, as well as the “zero-pollution” packaging advocated today, the traditional form and mode of packaging has changed. This article aims to study the design of the overall packaging box of environmentally friendly packaging materials and discuss its performance. In this paper, the platform construction method and the modulus definition classification method are used to calculate the positive axis stiffness of the single-layer board. The effect of coating process on the wear resistance of paper-based materials was studied, the wear resistance of box board base paper and coated box board under different temperatures and different humidity conditions was compared, and the optimal design variable value range was set. The experimental results show that after the first level of optimization, the overall mass of the structure is reduced from the initial 39.42 kg to 31.18 kg and the optimization efficiency is 20.90%; the maximum relative deformation of the flap structure has increased from 0.143 mm to 0.198 mm, despite having the maximum tension. The opening displacement has increased, but it still meets the sealing deformation requirements. The design and performance discussion of the overall packaging box of environmentally friendly packaging materials have been completed relatively well.


2021 ◽  
Vol 263 (3) ◽  
pp. 3350-3361
Author(s):  
Andreas Fuchs ◽  
Reinhard Wehr ◽  
Marco Conter

In the frame of the SOPRANOISE project (funded by CEDR in the Transnational Road Research Programme 2018) the database of the European noise barrier market developed during the QUIESST project was updated with newly acquired data. This database gives the opportunity for an empirical study on the correlation between the different measurement methods for the acoustic properties of noise barriers (according to the EN 1793 series) to further investigate the interrelationships between these methods by using single-number ratings and third-octave band data. First a correlation of the measurement methods for sound absorption under diffuse field conditions (EN 1793-1) and sound reflection under direct sound field conditions (EN 1793-5) is presented. Secondly, a correlation of the measurement methods for airborne sound insulation under diffuse field conditions (EN 1793-2) and airborne sound insulation under direct sound field conditions (EN 1793-6) is shown. While for airborne sound insulation a distinct correlation is found due to the wide data range, for sound absorption no robust correlation can be found.


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