查了第一个，不是羽绒的，应该是类似于化纤材料的

By definition, alternative down or faux down is synthetic insulation made from polyester fibers that are arranged in various sizes and shapes to simulate down. However not all down alternatives are created equal and the same holds true for down.

https://www.thermore.com//en/down-alternatives-a-guide-to-insulations/