Chang Feng licensing perforated aluminum honeycomb panels with
sound-absorbing function, according to application requirements can
change the perforation rate, the largest perforation rate <30%
of the general choice of aperture ¢2.0, ¢2.5, ¢3.0 specifications,
perforated back panel the same requirements and . Sound-absorbing
paper for the German production, thick 0.2mm, Weight 61g/m2, its
sound-absorbing performance and 40mm thick glass wool centrifugal
close to 32K.