METHOD OF MANUFACTURE OF A NOISE ABSORBING MATERIAL Russian patent published in 2021 - IPC B32B5/00 

FIELD: insulating materials.

SUBSTANCE: invention relates to a method of manufacture of a noise absorbing material. The method of manufacture of a noise absorbing material containing a non-woven, e.g., porous of fibrous base, consists of the base being submerged into an inorganic compound solution, first into 10 to 21.5% wt. solution of a first salt selected from CuSO₄, CaCl₂, BaCl₂, SrCl₂, AlCl₃, Na₂SiO₃, then a 7.5 to 15.5% wt. solution of a second salt is introduced, the salt selected from NaHCO₃, Na₂CO₃, KH₂PO₄, in an amount between equimolar and 2 to 3% excess from stoichiometry, and allow to stand for 1 to 2 hours. Then the produced material is taken out of the solution, rinsed with distilled water and dried.

EFFECT: invention allows producing a noise absorbing material with high efficiency, especially within the range of low acoustic frequencies between 125 and 1000 Hz.

2 cl, 3 dwg, 1 tbl