| 摘要 |
PROBLEM TO BE SOLVED: To enhance the hermetical sealing strength and adhesion uniformity of a hermetically sealed surface part by forming a continuous band to four-side container end part closing pieces by supplying a high temp. fluid toward the narrow strip-shaped part of a thermoplastic inside surface. SOLUTION: A carton C is formed from cardboard of which both surfaces are coated with a thermoplastic resin and has four top part closing piece forming hermetical sealing panels 41-44. These panels 41-44 form hermetical sealing fins and, in such a state that top part closing pieces are preliminarily bent a heating head is allowed to fall until received in the opened top part closing pieces. Thereafter, high temp. air is supplied toward the inside surfaces of the hermetical sealing panels to form patterns of sticking matter partially shown by head shadow. A horizontal sticking strip length part 9a and a vertical sticking strip length part 9b' are formed to the inside of the panels 43 and a horizontal sticking strips 12' are further formed to the inside surface of the panels 44. By this constitution, airtight hermetical sealing becomes possible by a continuous strip shape. |
