What types of sound absorbing materials can be divided into according to the principle of sound absorption?
According to the sound absorption mechanism, sound absorption materials are divided into:
①Porous materials attenuate sound waves from the surface to the interior through many small open channels, they mainly absorb medium and high frequency sound waves, there are various organic or inorganic fiber aggregates, fibers and their products, as well as open-cell foam and expanded perlite products porous structure.
②Flexible materials (such as closed-cell foam, absorb medium frequency), thin film materials (such as plastic film or cloth, canvas, linoleum and artificial leather, absorb low frequency and medium frequency board (such as plywood, hard fiberboard, asbestos cement board, gypsum board) absorbing low frequencies) and perforated plates (made by perforating various sheets or metal plates to absorb intermediate frequencies).
The combination of the above materials can expand the sound absorption range, improve the sound absorption coefficient, stick decorative sound-absorbing panels on the walls or ceilings, install porous materials and perforated panels or membrane-like materials on the walls, and even hang with floating clouds, which can improve Indoor sound quality, noise control. In addition to absorbing air-borne sound, porous materials can attenuate structure-borne sound and vibration caused by air-borne air-borne sound. Filling porous materials into composite structures composed of various plate-like materials can improve sound insulation. , reduce the weight of the structure.
For materials that absorb incident sound energy, sound-absorbing materials are mainly used to control and adjust indoor reverberation time, eliminate echoes, improve indoor listening conditions, reduce noise in noisy places, and improve living and working conditions (see Sound absorption and noise reduction); it is also widely used to reduce noise in ventilation and air conditioning ducts.