A coating method has a reciprocating rotating step. A wire bar is rotated at a first rotational speed for coating a film on a web. In a process of rotating the wire bar at the first rotational speed, a tangential direction of the wire bar at a connecting area between the wire bar and the web is opposite to a moving direction of the web, and then the wire bar is rotated to restore to an original position at a second rotational speed. Meanwhile, the tangential direction is changed and is same to the moving direction of the web. The second rotational speed is far faster than the first rotational speed. A coating device has a base, the wire bar disposed across the base, and a rotation adjusting module connected to the wire bar for driving the wire bar to rotate reciprocatingly.

A coating method has a reciprocating rotating step. A wire bar is rotated at a first rotational speed for coating a film on a web. In a process of rotating the wire bar at the first rotational speed, a tangential direction of the wire bar at a connecting area between the wire bar and the web is opposite to a moving direction of the web, and then the wire bar is rotated to restore to an original position at a second rotational speed. Meanwhile, the tangential direction is changed and is same to the moving direction of the web. The second rotational speed is far faster than the first rotational speed. A coating device has a base, the wire bar disposed across the base, and a rotation adjusting module connected to the wire bar for driving the wire bar to rotate reciprocatingly.

A method for forming a packaging material. The method can comprise moving a web of material in a downstream direction. The web can comprise fibrous material. The method further can comprise applying a moisturizing liquid to the web to at least partially wet the fibrous material. The applying the moisturizing liquid to the web can comprise receiving the web in a moisturizing station comprising at least, a drive roller and a transfer roller. The receiving the web in the moisturizing station can comprise moving the web between the drive roller and the transfer roller, and the applying the moisturizing liquid to the web can comprise engaging a face of the fibrous material with the moisturizing liquid on the transfer roller. The method further can comprise forming a film on the web, which can comprise applying a film-forming liquid to the web.