| 摘要 |
PURPOSE:To judge easily whether a package is altered or not, by sealing an alteration indicating print, which is discolored by the change of gas concentration, in the package formed with a gas barrier wrapping material. CONSTITUTION:With respect to a package 1, food 3 put on a tray 2 is packed with a flexible gas barrier wrapping material sheet, and air in the package is substituted with nitrogen in the production process. A printed layer of an oxygen detector is provided on the inside face of the sheet so that this printed layer can be seen from the external. Explanations related to color change of the printed layer 5 at a package alteration time are printed near the printed layer 5. If some alteration is given to the package 1, oxygen penetrates the package 1 to discolor the printed layer 5; and therefore, a seller and buyer see the printed layer 5 to judge easily whether the package is altered or not. |
