PURPOSE: To provide the manufacturing method of acoustic material, in which the deformation, collapse and the like of wood do not develop at the treatment of the wood with low molecular weight phenolic resin.
CONSTITUTION: Acoustic material is produced through an impregnating process, in which wood is impregnated with phenolic resin by immersing the wood in the aqueous solution of low molecular weight phenolic resin having an average molecular weight of 200-500, a first drying process, in which the wood impregnated with the molecular weight phenolic resin is naturally dried, then a second drying process, in which the wood after being naturally dried is dried by forced drafting at 30-60°C, a first curing process for curing the low molecular weight phenolic resin by gradually or stepwise raising the temperature of the wood after being dried by forced drafting from 100°C to 160°C over 1-6 hours and a second curing process, in which further curing of the low molecular weight phenolic resin by maintaining the temperature of the wood within the range of 160±5°C for 30 min-1 hour.
GETSUKOUDOU KK
YANO HIROYUKI