| 摘要 |
Accordingly to the invention, an apparatus is provided for heat sealing two superposed layers of plastic film (2), in which movable sealing bar means (6) is disposed opposite to fixed sealing bar means (4), the layers of plastic film (2) being passed between the movable (6) and fixed (4) sealing bar means. The plastic film layers (2) are intermittently fed for a length and temporarily stopped whenever intermittently fed. The movable sealing bar means (6) is reciprocatingly moved whenever the plastic film layers (2) are intermittently fed, between a first position in which the movable sealing bar means (6) is advanced toward the fixed sealing bar means (4) so that the layers of plastic film (2) are sandwiched between the movable (6) and fixed (4) sealing bar means, and a second position in which the movable sealing bar means (6) is retracted and spaced from the fixed sealing bar means (4) and the layers of plastic film (2). The layers of plastic film (2) are sandwiched between and heat sealed by the movable (6) and fixed (4) sealing bar means when temporarily stopped. The apparatus comprises a computer (36) connected to the plastic film intermittently feeding means (8) and the movable sealing bar drive means (28), the plastic film intermittently feeding means (8) and the movable sealing bar drive means (28) being controlled by the computer (36) in accordance with a predetermined program. The feeding speed V0 for the layers of plastic film (2), the feeding time T1 for the layers of plastic film (2), the driving speeds V1 and V2 of the movable sealing bar drive means (28) and the heat sealing time T2 for the layers of plastic film (2) are selected by the computer (36). In addition, the computer (36) is constructed so that a waiting time T4 can be inserted between the plastic film feeding time T1 and the plastic film heat sealing time T2 to thereby change the cycle time T3 of the apparatus. |
