Method of manufacturing a packaging container

A method of producing a packaging container having a peelable seal which comprises steps of:

• a. supplying bottom members, each made of foamed plastic sheet material and having a plurality of rectangular-shaped bottom sections series-connected at predetermined intervals, out of a stocker one by one to a conveyer;
• b. placing contents in content-receiving recesses provided in said bottom sections of each of said supplied bottom member;
• c. placing top members made of non-foamed plastic sheet material and having a plurality of rectangular-shaped top sections, corresponding to said plurality of rectangular-shaped bottom sections, series-connected at predetermined intervals, on said bottom members, respectively;
• d. heat-sealing peripheral portions along the elongated sides of said bottom sections and top sections except for a substantially middle portion thereof with a predetermined width between adjacent assemblies of said bottom sections and top sections by abutting a heated sealing member against said peripheral portions;
• e. cutting said middle portion between adjacent assemblies of said bottom section and top section by a cutting member thereby obtaining individual assemblies of said bottom and top sections;
• and
• f. downwardly bending said peripheral portions along the heat-sealed elongated sides by lowering a bending member against said peripheral portions.