| 摘要 |
A one-piece blank (11) forms a liquid-tight carton having rectangular side walls (13, 15, 17 and 19) sealed or integral with one another at adjoining side edges (21) and flat end panels (25, 27) of polygonal shape, the end panels being sealed ultrasonically to the side walls through sealing tabs (29, 39). Ultrasonic heating and sealing of the upper end panel (27) is effected after the carton is filled with liquid, by compressing perimeter portions of the upper end panel and the sealing tabs (37, 39, 41) of the side walls between facing dies (67, 69), Fig. 6, which have diagonally inclined aligned surfaces (73, 75) in relationship to the side and end wall perimeter and application of an ultrasonic horn having an inclined surface identical to the surface (75). The carton formed by this blank facilitates nesting or multiple cartons, one above the other. <IMAGE> |
