Acoustic Properties of Multi-Layer Wool Nonwoven Structures

ABSTRACT

Wool insulating materials provide good acoustic insulation and are increasingly used for room insulation. These insulating materials are usually produced using nonwoven techniques. The structure and nonwovens parameters affect the acoustic properties of the product. During the investigation, acoustic properties of needle punched and stitch-bonded wool nonwovens were examined. Sound absorption coefficient and noise reduction coefficient for monolayer and multi-layer structures were determined. Relations between acoustic characteristics and nonwoven thickness, surface density, and air permeability were revealed. For the multi-layer structures, an increase of sound absorption with an increase in layer numbers was observed. The increase in sound absorption coefficient was correlated with the decrease in air permeability.

摨要

羊毛绝缘材料提供了良好的隔音效果，并且越来越多地用于室内保温.这些绝缘材料通常是用无纺布技术生产的.结构和非织物参数影响产品的声学性能。在调查过程中，对针刺和缝合羊毛非织物的声学特性进行了研究.确定了单层和多层结构的吸声系数和降噪系数.揭示了声特性与无纺布厚度、表面密度和透气性的关系.对于多层结构，随着层数的增加，吸声量增加.吸声系数的增加与透气性的降低有关.

KEYWORDS:

• Wool
• nonwoven
• needle punching
• stitch bonding
• multi-layered structure
• acoustic properties

关键词:

• 羊毛
• 非织造布
• 打针
• 缝合
• 多层结构
• 声学性能

Additional information

Notes on contributors

Jan Broda

Jan Broda, works as a professor at the faculty of Materials, Civil and Environment Engineering, University of Bielsko-Biala (Poland). He is the Vice Director of the Institute of Textile Engineering and Polymer Materials, University of Bielsko-Biala. He completed his masters's degree in textile engineering (1982). After graduation he started to work at the University of Bielsko-Biala. He obtained a PhD in textile engineering from the Technical University of Lodz (1991). His research interests include the structure and properties of natural and man-made fibres, formation and modification of polypropylene fibres and functionalization of textiles. Professor Broda published over 50 scientific papers on polypropylne and wool fibres. He has lead several national and international research projects. He combines research and teaching on technical textiles, fibres science and high-performance fibres.

Marcin Bączek

Marcin Bączek, works as an adjunct professor at the Faculty of Materials, Civil and Environment Engineering, Unversity of Bielsko-Biala (Poland). He completed his master's degree in technical physics, University of Science and Technology - Krakow (2001). After graduation he started work at the University of Bielsko-Biala, were obtained PhD in textile engineering (2011). His scientific interest concenrns investigations of the internal structure of polymeric materials as well as synthetic and natural fibres using X-ray diffraction methods (WAXS and SAXS). He published several papers on this topic. He is a member of an organizing committee of a periodic International Conference “X-Ray Investigations of Polymer Structure XIPS. He has been a participant of a few scientific projects. He conducts lectures on physics, research methods, acoustioc and noise protection.