| 摘要 |
A conversion unit converting a first continuous web substrate (2) into a second substrate in the form of converted blanks of predetermined length (3). On account of cutting tool rotation speed, the web (2) moves at various speeds for cutting the web cut lengths and other aspects of cutting and transport process having a constant input speed. The unit includes a first motorized arrangement (4) for producing a first run driving (F) of the web (2), a sheeter (12) having rotary tools (13, 14) for cutting the web into blanks (3), a second motorized arrangement (17) for producing a second run driving of the substrate (2, 3), the second arrangement being positioned in the immediate proximity of the sheeter (12), and at least one station (21, 22, 23) having rotary tools (26, 27, 28, 29, 32, 33) for converting the blanks (3). A speed of rotation (38, 41) of the second arrangement (17) varies during a cycle of rotation of the tools (13, 14) of the sheeter (12), comprising a phase at constant tangential speed (46), substantially equal to the speed of rotation of the tools (13, 14) of the sheeter (12), during which the cut is made, a speed reduction phase (43), during which a length of the web (2), dependent on the difference between the length of the blank (3) and an extension of the periphery of the tools (26, 27, 28, 29, 32, 33), is kept upstream of the second arrangement (17), and a speed increase phase (44), during which the substrate (2, 3) is discharged downstream of the second arrangement (17). |
