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Customers buy high-density
sound-absorbing cotton, how to detect the density of sound-absorbing
cotton density
refers to the unit volume weight of material, a general formula
expression for kg/m3 (how many kilograms per
cubic meter). You can test it at random a piece of sound-absorbing
cotton, their weigh (how many kilograms), and
then calculate the volume of a piece of sound-absorbing cotton (cubic
meters). Finally, the weight divided by the
volume of the material density 1, with the increase in thickness, the
low frequency sound absorption coefficient
significantly increased, but the high frequency (high frequency
absorption is always larger). 2, the thickness of
the same, bulk density increases, the low frequency sound absorption
coefficient also increases; but when bulk
density increases to a certain degree, the material becomes dense, the
flow resistance is greater than the best
flow resistance, sound absorption coefficient instead drops. The
thickness of more than 5cm of the bulk density
of 16Kg/m3 day order sound-absorbing cotton, the low frequency of 125Hz
is about 0.2, in the high frequency
(>500Hz) absorption coefficient is close to 1. When the thickness of the
5cm continues to increase, the low
frequency sound absorption coefficient gradually increased, when the
thickness is more than 1m, the low frequency
125Hz sound absorption coefficient will also be close to 1. When the
thickness, bulk density, low frequency sound
absorption coefficient of sound-absorbing cotton will also continue to
improve, when the bulk density near
110kg/m3 absorption performance reached the maximum thickness of 50mm,
frequency of 125Hz is close to 0.6-0.7.
When bulk density exceeds 120kg/m3, the sound absorption performance
decreases, because the material becomes
denser, the high frequency sound absorption performance is greatly
affected, and the sound absorption performance
decreases a lot when bulk density exceeds 300kg/m3.
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