1. Middle- and high- frequency sound-absorbing structure
A.Original brick metope and rendering (or light division wall)
B. Light-steel keel or wooden keel of 50mm or 75mm.
C. Glass wool panels in 50mm or 75mm. (density: 24-32kg/m3)
D. Perforated LCFC (NALC) panels of 5-8mm thick, with fiberglass cloth or yarn free cloth or sound-absorbing paper pasted inside, and coatings or sound transparent cloth on the exterior surface.
Generally, the perforating rate is greater than or equal to 16%. If the perforating rate is from 8 to 12% under middle- or high- frequency conditions, the high- frequency sound-absorbing performance will be influenced. If the perforating rate is between 4 and 6%, the low-frequency sound-absorbing performance is preferable and the middle- or high- frequency ones are of a sort.
2.Wide-frequency sound-absorbing structure
A.Original brick metope and rendering (or light division wall)
B. Light-steel keels or steel & wood assembled keels
C.Cavum in 50mm, 75mm or 100mm.
D. A layer of steel net
E. Thick centrifugal glass wool panels in 50mm or 75mm thick. (density: 24-32kg/m)
F、 Perforated LCFC (NALC) panels in 5-8mm thick, with fiberglass cloth or yarn free cloth or sound-absorbing paper pasted inside, and paint coated on the exterior surface.
When the perforating rate is greater than or equal to 16%, the low-frequency performance will be improved compared to Chart one.
3.Low-frequency sound-absorbing structure
A. Original brick metope and rendering (or light division wall)
B. Light-steel keels or wooden keels.
C. Vacuum in 50mm, 75mm or 100mm long.
D. The inside is covered with a layer of fiberglass cloth or yarn free cloth.
E. Low- perforating rate LCFC (NALC) panels in 5-8mm thick, and 0.5-4% perforating rate.
4.Wide frequency sound-absorbing structure
A.Original brick metope and rendering (or light division wall)
B. Light-steel keels and vacuum in 50mm, 75mm or 100mm long.
C. Perforated LCFC(NALC) panels in 5-8mm thick and 20% perforating rate.
D. Fully covered with burn-resistance and sound-absorbing panels with 25mm or 50mm thick.
5.Low- and middle- frequency sound-absorbing structure
A. Original brick metope and rendering (or light division wall)
B. Keels in 50mm or 75mm thick, centrifugal glass-wool sound-absorbing layer (Density: 32-48kg/m3)
C. Polystyrene film or PVC film
D.Perforated LCFC (NALC) panels in 5-8mm thick and 8-12% perforating rate.
The surface is covered with coatings or sound-transparent cloth.
