A metal sheet for containers includes a metal sheet and a polyester film which is laminated on a surface of the metal sheet to be an inner surface side of containers. The polyester film contains a wax in an amount of 0.010 to 2.000 mass %, and has a dipole-dipole force of 40 mN/m or less.

A film-uncovering and material-feeding mechanism includes a food material box, a film-uncovering assembly, and a connection housing assembly configured to support the food material box and the film-uncovering assembly. The connection housing assembly is provided with a feed port. The food material box includes a box body movably connected to the connection housing assembly and configured to accommodate the food material and a seal film provided between the box body and the connection housing assembly and configured to seal the box body. The seal film is provided with a hitching opening. The film-uncovering assembly includes a film-uncovering rotation shaft and a drive device configured to drive the film-uncovering rotation shaft to rotate. The film-uncovering rotation shaft is provided with a hook configured to be hitched with the hitching opening to uncover the seal film via rotation and to drive the box body to move towards the feed port.

A metal sheet for containers includes a metal sheet and a polyester film which is laminated on a surface of the metal sheet to be an inner surface side of containers. The polyester film contains a wax in an amount of 0.010 to 2.000 mass %, and has a dipole-dipole force of 40 mN/m or less.