FIELD: packing. SUBSTANCE: carton with gable top has gable upper part, gable bottom part and bottom rib projecting from gable bottom part. Pack has outer edge, distal seam on bottom rib passing in line with length of bottom rib on section between gable bottom part and outer edge, proximal seam on bottom rib passing in line with length of bottom rib on section between gable bottom part and distal seam, and relieved area on central section of proximal seam. Subject of invention is also device for sealing pack bottom rib and method of sealing bottom rib of pack with gable top and gable bottom. EFFECT: increased strength of pack bottom rib preventing leakage of contact through bottom. 17 cl, 4 dwg
