| 摘要 |
1,219,337. Seaming non-metallic sheet material. INTERNATIONAL PAPER CO. 14 June, 1968 [11 Oct., 1967], No. 28415/68. Heading B5K. [Also in Divisions B2 and B8] A method of closing a container formed from card coated with plastics material, comprises applying a wetting material to selected portions of selected panels and then heat-sealing the selected panels together before there is substantial loss of the wetting material from the selected portions. The resultant seal is inhibited in the region of the selected portion to facilitate the opening of the container. As shown, a gable top container has wetting material applied to the edges 90, 91 of panels 60, 61 before heatsealing. The wetting material penetrates the exposed, non-coated edge of the card. Dried, sealing-resistant coatings 83-88 may also be applied to both sides of panels 60, 61 and to the insides of panels 45, 46. After closure of the container with conventional heat-sealing equipment, the formation of the pouring spout shown is thus facilitated. The wetting material may be water containing a wetting agent to facilitate penetration of the card fibres along edges 90, 91. Alternatively, a thickening agent may be added to the water. Examples of suitable agents are given. |
