PACKAGE BOX

PURPOSE:To prevent a package box from deterioration in strength at the ruled lines even after repetitive use and enable repeating its use many times and over a long period of time by providing in the material metallic or nonmetallic cores across the ruled lines which demarcate the flaps of a package. CONSTITUTION:Ruled lines 21, 22 are provided at the parts from which flaps 4, 5, 7 extend and at the parts where side boards 6, 6 meet a top board 2 and a bottom board 3 respectively. By bending the material along these ruled lines a package 1 is formed. Metallic or nonmetallic cores 23, 24 which are capable of plastic deformation are embedded in the material for the package in such a manner as to have the cores across the ruled lines 21, 22 in the pattern of intersection. The flaps when bent are bent together with the cores and, when spread, both the flaps and cores are spread. Therefore, after removal of the contents of the package, the cores can be stretched out completely when the material for the package is flattened out under a roller press, etc.; the cores redress the tendencies to bending which remain at the ruled parts and make the material maintain its strength at the ruled lines.