Fibrous materials are used as sound-absorbing media in noise reduction applications. We know the importance of characterizing, analyzing and even predicting the sound absorption performance of fiber materials for the development of fiber noise reduction systems. Alfa Chemistry provides customers with fiber sound absorption performance analysis and prediction services. Our fiber analysis laboratory has a strong technical infrastructure and a team of well-trained and experienced specialists.
The sound absorption performance of fiber materials benefits from the large number of micropores and gaps inside the material. When the sound wave enters the material, the friction between the fiber and the air and the vibration of the fiber itself will convert the sound energy into heat energy and dissipate it. Alfa Chemistry is committed to assisting customers in researches of sound absorption mechanisms (such as the relationship between noise reduction coefficient and various macro/microstructural parameters), and can combine various empirical models and theoretical models to characterize and predict sound absorption characteristics.
Our team combines rich analysis experience, advanced technology and interdisciplinary expertise to provide customers with comprehensive and systematic fiber sound absorption performance analysis and prediction services, as well as detailed analysis results and reports. Our services include but are not limited to:
The sound absorption coefficient is an important reference index for the sound absorption performance of reactive materials. The sound absorption coefficient is usually measured by impedance tube (also known as standing wave tube) method, including standing wave ratio method and transfer function method. This performance analysis service is suitable for theoretical research on sound absorption, optimization tests of sound-absorbing structures, research and development of new products, and comparison of sound-absorbing properties of materials.
Among them, with the development of digital measurement technology, it is a more convenient and faster method to measure the sound absorption coefficient and acoustic impedance of materials directly in the impedance tube by using the transfer function method. This method can simultaneously measure the material complex reflection coefficient, normal acoustic impedance and sound absorption coefficient at all frequencies within a certain frequency range.
Schematic diagram of measuring sound absorption coefficient by transfer function method [1]
Our sound absorption prediction model is based on Zwikker and Kosten theory. On this basis, we can choose the most suitable empirical model and microstructure model according to different fiber types. Available empirical models include Delany-Bazley, Dunn-Davern, Miki, Garai-Pompoli, Ramis and Yoon models. Available microstructural models include the Johnson-Allard model.
Commonly used standard methods for sound absorption performance analysis and characterization include:
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