| 摘要 |
<p>PURPOSE: To perform hermetic sealing with reliability even when a melt state after a heating treatment cannot be held. CONSTITUTION: A liquid paper container is produced by hermetically sealing sealing areas of a square tube-form sleeve for the liquid paper container comprising a square tube-form side wall part A, a square tube-form top seal part T on the side wall part A, and a square tube-form bottom seal part B under the side wall part A In a method for hermetically sealing the liquid paper container, the sending areas are previously heated and melted in a first thermal treatment. While being overlapped with each other and contact bonded by a pair of pressurizing block plates 21, 22, the sealing areas are high-frequency heated in a second heating treatment by a high-frequency generating means incorporated in the pressurizing block plates 21, 22, thereby being hermetically sealed.</p> |
