Pull-off closure for containers

A pull-off closure for containers having an opening whose end portion defines an annular collar projecting externally;

• the closure comprising:
• an upper portion shaped as a shell having an upper face from which extends a collar, which can be turned over to abut on the annular collar of the container, during capping of the container, the upper face and the collar forming, at a connection thereof, an annular edge;
• lines of weakness formed inside on the upper face and on the collar forming an opening strip which extends in a tab extending beyond the collar;
• a gripping element associated with the tab, wherein the lines of weakness extend on the collar outside the annular edge;
• wherein a ratio between:
• a distance between two median end points, proximal to the tab, measured parallel to a first axis passing through a center of the upper face and being parallel to the upper face, and
• a diameter of the upper face,
• is between 0.5 and 0.7;
• wherein a ratio between:
• a distance between two transversal end points, distal from the tab and the first axis, measured parallel to a second axis at right angles to the first axis, the second axis passing through the center and being parallel to the upper face, and
• the diameter of the upper face,
• is between 0.1 and 0.2;
• wherein the lines of weakness terminate at a height, measured as a projection on the first axis, of between 0.5 mm and 4 mm;
• wherein each line of weakness is curved and has a first radius which is between 4 mm and 8 mm;
• wherein each line of weakness has a second radius which is between 3 mm and 5 mm.