Method for indicating a specific processing stage or property of a surface-treated metal sheet, comprises applying a protective plastic film marked with coded perforations while the surface treating material is still hot

摘要

Method for indicating a specific processing stage or property of a surface-treated metal sheet (1) comprises applying a protective plastic film (2) while the surface treating material is still hot. The film is marked with coded perforations (8) which fuse together when applied, producing markings which can be optically detected. An Independent claim is also included for a surface-treated metal sheet with the coded plastic film coating.