| 摘要 |
A first technical problem of this invention is to create a process for forming one or more air intake holes in the neck of an easy-to-delaminate bottle, while keeping the inner layer intact without leaving in it any vestige of' cut caused by the blade edge of a punch-cutter A second technical problem is to create a shape of the air intake holes so that the peeling of the inner layer from the outer layer would go on smoothly and reliably around an inside opening of the hole on the inner-surface side of an outer layer. A principle means of this invention to solve these technical problems is a process for forming one or more air intake holes wherein
the punch-cutter to be used has a cylindrical blade at the tip, and also has a hooking portion or portions, which is/are disposed on an inner peripheral surface of the cylindrical blade and which performs a function of hooking into a portion of the outer layer that has come inside the cylindrical blade so as to prevent the cylindrical blade from slipping out of that portion of the outer layer at a time when the cylindrical blade is moved backward,
the cylindrical blade is pressed forward until the blade edge comes to a position quite close to the inner surface of the outer layer, and at this position, the outer layer is not yet cut out completely, but there still remains a circular uncut portion ahead of the blade edge,
then, the cylindrical blade is moved backward, and a the cut piece inside the cylindrical blade is also moved backward along with the uncut portion because of the function of a hooking portion or portions that can hook into a portion of the outer layer that has come inside the cylindrical blade so as to prevent the cylindrical blade from slipping out of that portion of the outer layer, and
the uncut portion is broken due to this backward movement, and the cut piece is taken out in a completely cut shape so that the air intake hole is cut out as a through-hole. |
