TRAPEZOIDAL PACKAGING BOX AND SEALING DEVICE

PROBLEM TO BE SOLVED: To pack articles of various sizes in packaging boxes of the same sizes while fixing the articles to the boxes, and to easily seal the boxes using a machine.SOLUTION: There is provided a packaging box configured in such a manner that: a pair of end plates 1 and a pair of side plates 2 are provided so as to be continuous with each other via corner ridge lines 3, and a bottom surface is closed; inner flaps 7 and outer flaps 8 continuous with upper ends of the end plates 1 and upper ends of the side plates 2 are sequentially stacked; and outer flaps 8 are abutted on each other and sealed. In at least one end plate 1, oblique folded lines 9 separated from the corner ridge lines 3 upward from both lower sides are formed, an intermediate part disposed between the oblique folded lines 9 of end plates 1 is pushed inward by front and rear pressing implements of a sealing device, the end plates 1 are valley-folded so that the surface side thereof is recessed along the oblique folded lines 9, the end plates 1 are inclined inward toward upside, a tape T is stuck to the packaging box while a sectional shape between both the end plates 1 is upward trapezoidal, and thereby the box is sealed.