Manufacture of cap for container

A method for producing a cap for a container, comprising:

• forming the cap so that the cap has a top plate and a circular sidewall, wherein two opposite sides of the circular sidewall circularly connect to each other, one periphery of the circular sidewall connecting to one surface of the top plate forming a closed end, and another periphery of the circular sidewall at an opposite side of the closed end forms an opened end;
• and,
• cutting incision lines in the circular sidewall, the incision lines forming a ring member located at the opened end of the cap separated from a main body of the cap by a first incision line in between the opened end of the main body and the ring member, the ring member being connected to the main body by a plurality of connecting portions;
• wherein a plurality of connecting pins are located along the first incision line so that the plurality of connecting pins connect the main body and the ring member at the two sides of the first incision line;
• wherein a plurality of second incision lines are located on the main body or the ring member and located at one side of the plurality of connecting portions so that at least one of the plurality of second incision lines is connected with the first incision line and so that a first of the plurality of second incision lines does not connect with any other incision line;
• wherein a first connecting portion from the plurality of connecting portions is in between the first of the plurality of second incision lines and the first incision line;
• wherein a second connecting portion from the plurality of connecting portions is formed in between the first of the plurality of second incision lines and another of the plurality of second incision lines;
• and
• wherein the main body remains connected to the ring member by the first connecting portion and remains connected to the ring member by the second connecting portion even when the plurality of connecting pins are broken.