| 摘要 |
PURPOSE:To prevent the strength of a container at its thin wall part from lowering without impairing its easily-openable property by a method wherein the linear thin wall part is produced by vacuum-forming or air pressure forming plastic sheet, to the specified depth of the thickness of which continuous cut is made by laser machining. CONSTITUTION:A round mirror-shaped rice-cake ('KAGAMI-MOCHI' in Japanese) container 1 has a container body part 3 prepared by forming plastic sheet- like matter into the shape of the round mirror-shaped rice-cake having swollen parts at its middle and near its lower end and a flange 5, at the bottom of which a plastic bottom sheet 4 is sealed by heat sealing, at its lower end part. In the above-mentioned container, linear thin wall part 6 is provided on the outer surface of the container body part 3 and, in addition, a notched part 7 is provided in the flange 5 so as to facilitate the opening of sealing. At the formation of the thin wall part 6, continuous cut is made by laser machining to the depth of 50% or less of the thickness of the plastic sheet so as to be turned into the linear thin wall part, when the sheet is vacuum-formed or air pressure formed in the form of the container main body 3. |
