Packing, especially for edible fats and method and device for its production

In a method for producing thermoplastics packing parts, especially for an edible fats packing, a plastics film 1 is fed into a thermoforming device 2, 3. During the forming by means of the forming tool parts 2, 3, a material-weakening, which serves as a rupture indication, is achieved by a ridge projecting from either tool part 3 being pressed into the film 1 and forming in this a circumferential groove of essentially V-shaped cross section in a circumferential flange on the packing part. The forming of the rupture indication is effected under proportional spring load, the pressing force at the ridge, according to the particular film material, being regulated such that minimum material thickness in the groove constitutes ca. 2-15% of the original film thickness. A device for realizing the method comprises, apart from the abovenamed components, a gas spring 9 for achievement of the said proportional spring load. By virtue of the method and by means of the device, a packing intended especially for edible fats is produced, which is constituted by two fit-together thermoplastics parts formed each in one piece, which firstly allow rational original sealing with no need for metal foil and secondly allow resealing.