| 摘要 |
Packaging containers of single-use disposable type which are manufactured from flexible paper/plastic laminate normally display sealing fins (3) which extend over one or more of the walls (2) of the packaging container (1). In parallelepipedic packaging containers, triangular corner flaps (4) moreover occur over which extend the sealing fins (3). The corner flaps are folded down and secured on the final formation of the packaging container against its side wall. This however entails that the material with many times thickness must be double-folded, which entails deformations and stretching which damages the packaging material so that this no longer remains completely liquid-tight and gas-tight. According to the invention, the above-outlined drawbacks may be obviated in that the fibre layer included in the material is heated to a temperature of between 80 and 250° C. in the fold region, whereby the material softens so that the downward folding of the corner flaps together with subjacent parts of the sealing fin (3) may take place without the material being damaged. The liquid-tightness and gas-tightness of the finished packaging container will hereby be considerably improved, which is crucially important in the packaging of, for example, liquid foods. |
