Granted Patent B2

US 12,525,215 · App. 18/004,620 · Granted Jan 13, 2026

Inventors: Akira Ito (Tokyo, JP); Keisuke Sawamoto (Kanagawa-ken, JP)

Assignee: 3M Innovative Properties Company

G10K11/168B29C43/003B29C43/203B29K2105/122B29K2995/0067B29K2995/0097B29L2009/00

Abstract

Claims (16)

1 . A sound absorbing material comprising:

a rising portion rising from a base plane, and an opposing portion in contact with a side of the rising portion opposite to the base plane, wherein

each of the rising portion and the opposing portion includes a core layer and a ventilation resistant layer, and

in at least a part of the opposing portion and the rising portion, a variation in thickness of the ventilation resistant layer is 40% or less of an average value of the thickness of the ventilation resistant layer.

2 . The sound absorbing material according to claim 1 , wherein

in 80% or greater of a region of the sound absorbing material that includes the opposing portion and the rising portion and that includes no edge portions, the variation in the thickness of the ventilation resistant layer is 40% or less of the average value.

3 . The sound absorbing material according to claim 1 , wherein the ventilation resistant layer has a thickness of 1 mm or greater and 6 mm or less.

4 . The sound absorbing material according to claim 1 , wherein the ventilation resistant layer has a ventilation resistance value in a range of a reference value±120 Rayls.

5 . The sound absorbing material according to claim 1 , wherein the ventilation resistant layer has a ventilation resistance value of 300 Rayls or greater and 1100 Rayls or less.

6 . The sound absorbing material according to claim 1 , wherein the ventilation resistant layer is positioned on a side of the component as viewed from the core layer.

7 . The sound absorbing material according to claim 1 , wherein at least one of the ventilation resistant layer and the core layer includes microfibers.

8 . A method of producing a sound absorbing material comprising a core layer and a ventilation resistant layer, the method comprising the steps of:

preparing a material constituting the ventilation resistant layer;

holding, on a first mold, the material constituting the ventilation resistant layer and forming the ventilation resistant layer; and

holding, between the ventilation resistant layer and a second mold, a material constituting the core layer and forming the core layer.

9 . The method of producing the sound absorbing material according to claim 8 , wherein the forming of the ventilation resistant layer comprises adjusting thickness of the ventilation resistant layer using a press or using a calendar roll and the press.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (44)