| 摘要 |
<p>PURPOSE:To ensure sufficient heat-bonding strength for the bottom of a paper container without generating pin holes or scorching of the paper layer by a method wherein after a cylindrical body is formed by a blank sheet, corona discharge treatment is applied on the outer surface resin layer at a part to be heat-bonded on the blank sheet. CONSTITUTION:A laminate sheet 6 consists of a outer surface resin layer 3 of a polyolefin resin, a core layer 4 which contains paper, and an inner surface resin layer 5 of a non-crystalline/low-crystalline saturated polyester of which the glass transition temperature of 40 deg.C or higher. After forming a cylindrical body by bonding right and left side edges of a blank sheet 7 which is cut into a rectangular shape, corona discharge treatment is applied on the outer surface resin layer at a part to be heat- bonded which is formed between the outer surface resin layer 3 and inner surface resin layer 5 of the laminate sheet 6, and wet tension of the treated surface if made to be 46-52 dyne. By this method, heating by a sealing temperature of approximate 300 deg.C for the heat-bonding part can be used when the bottom part of the paper container is formed, and a heat-bonded part with sufficient bonding strength can be formed without generating pin holes or scorching of paper, etc.</p> |
