Porous materials for sound absorption

Fibrous materials have been widely used in noise reduction due to the porous structures. In this review, available studies regarding the prediction methods of acoustic absorption coefficient are gathered. Empirical model could predict the acoustic absorption coefficient based on facile airflow resistivity, while microstructural model is determined by detailed structural parameters of fibrous materials. Various fibrous materials including inorganic and metallic fibers, synthetic fibers, natural fibers, and nanofibrous membranes for noise reduction are reviewed. Inorganic and metallic fibers have the advantages of corrosion resistance, high temperature resistance and long service life. The tailored cross-sections of synthetic fibers such as circle, hollow and triangle are beneficial to improve acoustic absorption properties. Natural fibrous materials are biodegradable, renewable and eco-friendly. Nanofibrous materials are lightweight and have good potential in low frequency noise reduction. Herein, we summarized the recent advances concerning the acoustic absorption of various fibrous materials.

Acoustic energy absorption properties of fibrous materials: A review

Textile Technology for Soft Robotic and Autonomous Garments

The invention relates to a method of nanofibres production from a polymer solution using electrostatic spinning in an electric field created by a potential difference between a charged electrode and a counter electrode. The polymer solution (2) is for spinning supplied into the electric field using the surface of the rotating charged electrode (30), while on a part of the circumference of the charged electrode (30) near to the counter electrode (40) is a spinning surface created, by which is a high spinning capacity reached. Further the invention relates to a device for carrying out the method, where the charged electrode (30) is pivoted and by its (bottom) part of its circumference it is immersed in the polymer solution (2), while against the free part of the circumference of the charged electrode (30) is positioned the counter electrode (40).

A method of nanofibres production from a polymer solution using electrostatic spinning and a device for carrying out the method

Electrospinning has attracted a worldwide interest as a technique for the production of nanofibrous membranes with diameter ranging 2 nm to several microscales using natural and synthetic polymers. The electrospun nanofibres have advantages such as high surface area, easy surface modification, functionalization of polymeric chains, inexpensive and tunable thermo-mechanical properties. Moreover, electrospinning is one of the simplest techniques for the incorporation of nanofillers into polymeric nanofibres. Herein, we review the preparation and applications of natural and polymer-based nanofibrous membranes. We focus on applications of the electrospun membrane for energy storage, water purification and biomedical. Furthermore, we show surface morphologies of nanofibrous membranes using fast emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy, Brunauer–Emmett–Teller and micrographs.

Electrospinning production of nanofibrous membranes

Socks need to perform better in comfort properties than other garments, as less air circulation occurs in socks in shoes than in garments on other parts of the body. In this paper, we studied the comfort properties of socks made from new fibers, such as modal, micro modal, bamboo, soybean, and chitosan. In order to compare their properties with conventional fibers such as cotton and viscose, these fibers were also included in the study. Water vapor transfer, air permeability, wicking, wetting and heat transfer — properties which are related to comfort — were evaluated. In order to conduct thermal conductivity measurements, a special experimental setup was designed according to the hot plate method (ISO 8302). The results suggested that the fiber type, together with regain and fabric properties such as thickness, appears to affect some comfort-related properties of the fabrics. It is suggested that for certain end uses, various combinations of fiber blends can be used.

A Comparative Study of Some Comfort-related Properties of Socks of Different Fiber Types:

This research, which is divided into two parts, is a comparative study of the physical properties of cotton yarns produced by using new, modified and conventional spinning methods. The first part focuses on the performance of yarns with a final count of Ne 20 produced by conventional and compact spinning methods, whereas the second part focuses on the performance of Ne 30 combed ring, compact and vortex cotton yarns. Effects of the tested properties of the yarns on the performance of fabrics knitted have also been studied. Results showed that the structural differences of each yarn type conferred different tensile, evenness and hairiness values, and the differences in the yarn structure were reflected onto the fabric properties.

Comparison of the Effects of Cotton Yarns Produced by New, Modified and Conventional Spinning Systems on Yarn and Knitted Fabric Performance

This paper investigated wicking properties of cotton-acrylic rotor yarns and knitted fabrics. The effect of yarn wicking on wicking of fabric in both wale and course directions was also discussed. One way ANOVA results of the experimental study suggested that wicking abilities of yarns and fabrics increased with the increase in acrylic content in the blends and with the use of coarse yarns. Besides, yarn wicking had a significant effect on fabric wicking.

A study of wicking properties of cotton-acrylic yarns and knitted fabrics

This paper proposes lightweight textile acoustic structure, wherein electrospun polyacrylonitrile-based nanofibers enhance sound absorption properties with no weight and thickness penalty. Polyacrylonitrile nanofibers with diameter of 110 ± 7 nm were electrospun on spacer-knitted fabrics by varying deposition amount and surface coating arrangement. Proposed novel approach eliminated additional processing steps such as handling and post-lamination and provided easy scalability of nanofibers at macro-scale. The results showed that the sound absorption of nano-enhanced specimens was improved drastically when deposited amount of nanofibers or its effective surface area increased. Sound propagation paths in different configurations were interpreted from sound absorption and air permeability measurements. The sound absorption coefficient values up to 0.7 are achieved in the low and medium frequency ranges with no weight and thickness penalty by tuning deposition amount and surface coating arrangement.

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Nanofiber-enhanced lightweight composite textiles for acoustic applications:

Fibrous textile materials are widely used in acoustic applications. However, the absorption of lower-frequency sound is problematic with fibrous material made up of coarser fibers. For this reason ...

Banu Uygun Nergis

Papers

A Comparative Study of Some Comfort-related Properties of Socks of Different Fiber Types:

Comparison of the Effects of Cotton Yarns Produced by New, Modified and Conventional Spinning Systems on Yarn and Knitted Fabric Performance

A study of wicking properties of cotton-acrylic yarns and knitted fabrics

Nanofiber-enhanced lightweight composite textiles for acoustic applications:

Comparison of resonance frequency of a nanofibrous membrane and a homogeneous membrane structure