Possesses the rim of four radii of rigidity the paper plate

摘要

PURPOSE: To increase rigidity by circularly punching a pressed paper plate, erecting the first and second rim portions in sequence at the prescribed radii of curvature from a planar bottom section, and forming a rim portion trailing downward on the outermost periphery. ;CONSTITUTION: A pressed paper plate 10 is circularly punched, and a planar circular center 12 is formed at the center section. The periphery 13 of the center 12 is erected upward at the prescribed radius of curvature to form the first rim portion 14A, and a side wall 14 is formed. The side wall 14 is bent to form the second rim portion 14B. The second rim portion 14B is bent downward to form the third rim portion 16A and the fourth rim portion 16B, and a rim 16 is formed. A high-rigidity paper board container is manufactured from a paper board.;COPYRIGHT: (C)1993,JPO