초록 ▼

A device for manufacturing packing bags from two packaging films, comprising two transport rollers, each of which pulls a film from a respective feed roll. The two films have marks printed on them at regular intervals. The transport rollers are pressed against corresponding idler rollers which betwe

A device for manufacturing packing bags from two packaging films, comprising two transport rollers, each of which pulls a film from a respective feed roll. The two films have marks printed on them at regular intervals. The transport rollers are pressed against corresponding idler rollers which between them preferably form a feed gap for the films. Downstream of the two transport rollers, there is at least one first buffer taking up slack in the assemblage of the two films or accommodating the lengths of the two films to match each other. The device can be used to synchronize two films that are printed with a regular pattern so that the patterns match.

대표청구항 ▼

The invention claimed is: 1. A device for manufacturing packaging bags, comprising: a first transport roller to pull a first film from a first feed roller, whereby the first film has first marks at a constant first interval (a), a second transport roller independent of said first transport roller t

The invention claimed is: 1. A device for manufacturing packaging bags, comprising: a first transport roller to pull a first film from a first feed roller, whereby the first film has first marks at a constant first interval (a), a second transport roller independent of said first transport roller to pull a second film from a second feed roller, whereby the second film has second marks at a constant second interval (a'), a first servomotor that is connected with the first transport roller and with a first angle-of-rotation sensor, a second servomotor that is connected with the second transport roller and with a second angle-of-rotation sensor, a first sensor that is located upstream of and next to the first transport roller and scans the first marks, a second sensor that is located upstream of and next to the second transport roller and scans the second marks, a control device which is connected with the first servomotor, the second servomotor, the first sensor, the second sensor, the first angle-of-rotation sensor and the second angle-of-rotation sensor, and which controls the first servomotor and the second servomotor so that a first mark and a second mark, having passed said first and second transport roller, come to coincide and at least one first buffer for at least one of said first and second film, the at least one first buffer being located downstream of said first and second transport roller, and wherein the device comprises: a first idle mechanism and a second idle mechanism that together form a narrow feed gap for the two films, said first and second idle mechanisms being located downstream of the first and second transport roller respectively and wherein the at least one first buffer is located downstream of said first and second idle mechanism. 2. The device according to claim 1, wherein the feed gap is wider than the sum of the thickness of the two films. 3. The device as claimed in claim 1, wherein the device comprises a second buffer located upstream of each of said first and second transport rollers, said second buffers being used for one of said films each. 4. The device as claimed in claim 3, wherein said two second buffers are coupled with each other. 5. The device as claimed in claim 1, wherein said at least one first buffer is a tensioning system. 6. The device as claimed in claim 1, wherein there is one single first buffer, said single first buffer being used for both of said films. 7. The device as claimed in claim 1, wherein there is at least one third sensor to measure the supply in said at least one first buffer. 8. The device as claimed in claim 1, wherein the absolute amount of the difference between the first interval (a) and the second interval (a') is greater than 0 but less than 0.1 times the first interval (a). 9. The device as claimed in claim 1, wherein the device comprises a third and fourth buffer located upstream of the first and second transport rollers. 10. The device as claimed in claim 9, wherein the first and second supply each have a drive mechanism which is controlled by a fourth sensor to measure the supply in the corresponding second buffer. 11. The device as claimed in claim 1, wherein it comprises a transverse sealing device downstream of the two idle mechanisms to form a transverse seal to connect the two films with each other. 12. The device as claimed in claim 10, wherein a second transverse sealing device is located next to a guide mechanism of the films that immediately follows the first transverse sealing device. 13. The device as claimed in claim 11, wherein the transverse sealing device is the first sealing device in a path passed by the two films from said feed rollers to said at least one first buffer, wherein said transverse sealing device is located downstream of said at least one first buffer. 14. The device as claimed in claim 1, wherein the distance between the first and second sensors and the first and second idle mechanisms is adjustable. 15. The device as claimed in claim 1, further comprising a blower nozzle to blow a stream of gas into the feed gap.