摘要 |
There is disclosed a heat-sealing method including: feeding a fusible fiber sheet (12) into the clearance between a pair of rolls (1, 5), at least one of which has sealing ridges (2, 6) of a predetermined pattern on its outer circumference; and heating and pressing the fiber sheet (12) with the sealing ridges (2, 6), to form fused portions corresponding to the pattern of the sealing ridges (2, 6), in the fiber sheet (12). An insulator (4) is disposed to cover the outer circumference of the rolls (1, 5), as lacking the sealing ridges. The insulator (4) is made of a material which has a lower thermal conductivity than that of the sealing ridges and which can be elastically contracted by the pressure of the rolls (1, 5). The fiber sheet (12) to be fed into the clearance between the rolls (1, 5) rotating is compressed by the insulator (4) to discharge its internal air and is then heated and pressed by the sealing ridges (2, 6) so that it is heat-sealed. |