SANDWICH PANEL AND ACOUSTIC INSULATION

Acoustic insulation should be used in areas where protection against the harmful effects of noise is required or areas where prevention of noise emissions to the surrounding environment is required. Many countries have their own regulations on noise emissions issued based on the following factors:

  • Environmental exposure to noise from industrial premises
  • Traffic noise exposure in buildings
  • Indoor noise levels in buildings

The required parameters and calculation methods for acoustic insulation between the rooms as well as acoustic insulation of roof and exterior wall cladding can be determined during the design stage. Some portion of the sound wave hitting on a surface is reflected while another portion is absorbed, and the remaining portion is transmitted. The rates of reflection, absorption, and transmission depend on various factors such as the shape of the surface, sound absorbing properties of the materials, and the audio frequency. Sound absorption materials consist of porous, or fiber materials and they are effective in the transformation of some portion of acoustic energy into thermal energy by causing friction losses in the air entering in the pores found in their structures.

Polyurethane (PUR) sandwich panels provide satisfactory levels of acoustic absorption in normal industrial buildings based on the requirements of the building; however, these are not adequate for other locations or offices that are too sensitive to noise whereas additional solutions may be required in such cases.

Example for calculation:

What is the acoustic transmission loss of 70 dB noise of 630 Hz frequency in polyurethane (PUR) sandwich panel? Using the table showing the change of acoustic absorption coefficient based on frequency:

70 dB x 0.49 = 34.3 dB 70 dB – 34.3 dB = 35.7 dB (resulting sound level).