US 12,447,730 B2
Method of manufacturing soundproof sheet and soundproof sheet
Hideaki Yajima, Nagano (JP); and Yuta Okawa, Nagano (JP)
Assigned to Seiko Epson Corporation, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Aug. 28, 2023, as Appl. No. 18/456,547.
Claims priority of application No. 2022-135664 (JP), filed on Aug. 29, 2022.
Prior Publication US 2024/0066855 A1, Feb. 29, 2024
Int. Cl. B32B 38/08 (2006.01); B32B 5/02 (2006.01); B32B 5/26 (2006.01); B32B 7/027 (2019.01); B32B 37/06 (2006.01); B32B 37/08 (2006.01); B32B 37/10 (2006.01)
CPC B32B 38/08 (2013.01) [B32B 5/02 (2013.01); B32B 5/26 (2013.01); B32B 7/027 (2019.01); B32B 37/06 (2013.01); B32B 37/08 (2013.01); B32B 37/1027 (2013.01); B32B 2250/02 (2013.01); B32B 2250/20 (2013.01); B32B 2260/023 (2013.01); B32B 2260/046 (2013.01); B32B 2262/0284 (2013.01); B32B 2262/062 (2013.01); B32B 2262/12 (2013.01); B32B 2262/16 (2021.05); B32B 2305/07 (2013.01); B32B 2307/102 (2013.01); B32B 2419/00 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of manufacturing a soundproof sheet comprising:
a first accumulating step of producing a first accumulated fiber body in which a plurality of first fibers, which are natural fibers, and a plurality of second fibers including a first core portion and a first coating layer coating the first core portion and having a first melting point are mixed;
a second accumulating step of producing a second accumulated fiber body in which a plurality of first fibers and a plurality of third fibers including a second core portion and a second coating layer coating the second core portion and having a second melting point higher than the first melting point are mixed;
a heating step of stacking and heating the first accumulated fiber body and the second accumulated fiber body to melt the first coating layer and the second coating layer;
a cooling step of cooling the stacked first accumulated fiber body and second accumulated fiber body to a temperature equal to or higher than the first melting point and lower than the second melting point to solidify the second coating layer without solidifying the first coating layer;
a pressurizing step of applying a predetermined compressive force to the stacked first accumulated fiber body and second accumulated fiber body in which the second coating layer is solidified; and
a pressurized cooling step of cooling the first accumulated fiber body and the second accumulated fiber body to a temperature lower than the first melting point to solidify the first coating layer and the second coating layer, while still applying the predetermined compressive force.