Centrifugal glass wool internal fibers, also have a large number of tiny pores, are typical porous sound absorbing materials with good sound absorption properties. Centrifugal glass wool can be placed in this space, the reduced reverberation time, the ceiling of the gypsum board, the space absorbent, and the large amount of internal noise that absorbs the acoustic energy. The sound absorbing properties of centrifugal glass wool are not only in the thickness and density of the covering material, structure, and other factors. Building applications requires cost, aesthetics, fire, moisture, dust, aging, and many other issues.
A porous sound absorbing material of centrifugal glass wool which has good acoustic properties. Centrifugal glass wool sound absorption has not been based on rough surfaces, but due to tiny pores and pores that communicate with a large interior and exterior. When sound waves are incident on the glass wool, the centrifugal force of the acoustic waves of the material in the inner bore is caused by the vibration of the air molecules in the gap. Due to the frictional resistance of the air and the friction of the air molecules and the walls of the pores, the clay can be lost during thermal energy conversion.
1 Centrifugal glass wool absorbs high frequency performance in sound. The main factors affecting the performance of centrifugal pump glass wool sound absorption, thickness, density and air flow resistance. The density is the resistance unit thickness ratio of the air flow on both sides of the weight of the material per cubic meter of the air flow and the air flow rate. The effect of air resistance on centrifugal glass wool sound absorption performance is the most important factor, the flow path resistance is too small, the sparse material is easy to pass the air vibration, the acoustic performance is degraded; the flow resistance is too large, the explanatory material compaction is difficult, air Vibration and acoustic performance are also reduced. Centrifugal glass wool, in relation to the sound absorption properties, this is an optimal flow resistance. In technical practice, the determination of the resistance to air flow is difficult, but through the rough estimation and control of thickness and density. As shown in Fig. 1, as the thickness increases, the absorption coefficient and the low frequency of the medium are increased significantly, but the high frequency does not change much (high frequency absorption is large).
2 having the same thickness, an increase in bulk density, also increases the sound absorption coefficient at a low frequency, but if the bulk density is increased to a certain extent, the density of the material lowers the sound resistance coefficient of the flow resistance to the optimum flow resistance. Centrifugal glass wool of more than 5 cm 16 kg/m3, a low frequency of about 125 Hz, and a bulk density at a high frequency (> 500 Hz) absorption coefficient close to 1. When the thickness is continuously increased by 5 cm, the frequency at which the absorption coefficient is low is gradually increased, and the low frequency of 125 Hz when the thickness is greater than 1 m is also close to 1. If the same thickness, the bulk density is increased, and the bulk density at the time when the sound absorbing ability reaches the maximum value at 110 kg/m3 of the low-frequency sound-absorbing centrifugal glass wool is further improved. Near 50mm thick, the frequency close to 125Hz is 0.6~0.7, the density is over 120kg/m3, and the acoustic performance is reduced because the material has a bulk density greater than 300kg/m3 when the high frequency power density of sound absorption is significantly reduced. The sound power is reduced. Building acoustic sound absorbing glass wool has a thickness of 2.5 cm, 5 cm, 10 cm, 16, 24, 32, 48, 80, 96, 112 kg/m3. Usually 5cm thick, 12 48 kg / m3 centrifugal glass wool.