Packaging manufacturer reduces waste in gravure printing
Data acquisition for troubleshooting and process improvement
Gravure printing is used for print jobs with a high edition of usually more than 300,000 copies. With the increasing competition on the market, the packaging manufacturers are constantly striving to enhance the efficiency of their plants, especially to reduce the set-up times and the waste. For this purpose, it is important to know and analyze exactly the processes running on the machine.
A critical point in the printing process are the changes of the rolls that are done as flying roll changes at full production speed - appr. 50 times a day. On the reel at the end of the printing line, an empty winding tube is accelerated on a second rewinder, until the circumferential speed of the tube matches the speed of the chilling line. The empty tube is stuck to the chilling paper web. Simultaneously, the printed roll is cut and ejected.
When changing the rolls, the web tension is of special importance. The timing of acceleration of the shell, pressing and cutting must fit exactly. Fluctuations in web tension inevitably lead to a defective print image and hence waste that has been up to now always at 40 meters.
of the machine status
Overall data acquisition
and analysis of different control circuits
of tolerance variations
Using the iba system, procedures and interactions, especially in the field of roll changes could be made visible and traceable. Optimizations in the hydraulics of the reel winding resulted in a considerable stabilization of the tension of the paper web. As a result, the waste is only 5 meters now.
"The waste could finally be reduced by 90%."