1 . A preparation method of a sound-absorbing piece, comprising:
preparing perforated sound-absorbing cotton matched with a preset cavity in shape; mixing sound-absorbing material powder with a solvent and a template agent to prepare a sound-absorbing slurry; impregnating the perforated sound-absorbing cotton with the sound-absorbing slurry for a preset period; and drying the perforated sound-absorbing cotton impregnated with the sound-absorbing slurry to remove a liquid in the perforated sound-absorbing cotton.
2 . The preparation method according to claim 1 , wherein the perforated sound-absorbing cotton is made from polyurethane or melamine.
3 . The preparation method according to claim 1 , wherein equal-proportional compression is performed on the perforated sound-absorbing cotton to ensure that the perforated sound-absorbing cotton is matched with the preset cavity in size.
4 . The preparation method according to claim 1 , wherein cells with apertures of less than 0.5 mm account for more than 85% of all cells in the perforated sound-absorbing cotton.
5 . The preparation method according to claim 1 , wherein the sound-absorbing material powder is zeolite powder or white carbon black.
6 . The preparation method according to claim 1 , wherein the template agent accounts for 1-35% of the sound-absorbing slurry by mass.
7 . The preparation method according to claim 1 , wherein the sound-absorbing slurry is doped with a binding agent, and the binding agent is inorganic silica sol or fibrous resin and accounts for 1-35% of the sound-absorbing slurry by mass.
8 . The preparation method according to claim 1 , wherein a drying temperature range is 40-150° C., and a drying atmosphere comprises nitrogen.
9 . The preparation method according to claim 1 , wherein after the drying, the perforated sound-absorbing cotton is roasted, the roasting temperature range is 120-420° C., the heating rate of the roasting is 10-80° C./h, and the roasting time is 0.5-96 h.
10 . A sound-absorbing piece, wherein the sound-absorbing piece is provided with perforated sound-absorbing cotton into which sound-absorbing material powder is adhered, the perforated sound-absorbing cotton is made from polyurethane or melamine, cells with apertures of less than 0.5 mm account for more than 85% of all cells in the perforated sound-absorbing cotton, and the sound-absorbing material powder at least comprises zeolite powder or white carbon black.