PROBLEM TO BE SOLVED: To form, near a seal line, rupture lines in a specific shape having a part of the seal line as its one side, which zones a specific area, therefore, unseal without a tool such as a cutter and facilitate an unsealing job, and to eliminate the use of other unsealing material and, therefore, facilitate recycling. SOLUTION: An unsealing mechanism A comprises a seal line 2 for it, two straight perforation lines 3 and 4 provided in the shape of a triangle having a part of the seal line 2 as its bottom, and a perforation line 5 in the shape of a circular arc provided in the apex part of the perforation lines 3 and 4. It is preferable that the angle between the two straight perforation line 3 and 4 (apex angle) be 50-70 deg. and the radius R of the circular-arc perforation line 5 in the apex part be about 10-15 mm. In order to unseal the package body, a part inside the apex part of the triangle 7 is pushed with a thumb to rupture the circular-arc perforation line 5 and, further, the straight perforation lines 3 and 4 on both the sides as well. By this constitution the need for a cutter is eliminated the unsealing is facilitated.
展开▼
