Reduce Gravure Waste

Rotomec Demonstrates TAPS System at Open House in Technology Center.

Rotomec held an open house at its Technology Center Nov. 16–18, 2009, that was attended by more than 150 converters from 15 countries. Visitors saw a demonstration of the TAPS (Total-Automatic-Pre-register-Setting) system, which is said to reduce waste to unprecedented levels at press makeready and changeovers, whether it’s a new or repeat job.

To highlight the TAPS performance, as well as the efficiency of the inking and drying systems of the RS 4003 MP press, Rotomec devised for the demonstration a job with different design complexities to be printed on 25 micron polyethylene (PE) film. PE film is reputedly the most difficult substrate to print in gravure because it is a very extensible material that also requires drying at low temperature.

At the touch of a dedicated pushbutton on the main console, TAPS starts the press, moves all the cylinders into register position, and switches the register control into automatic mode by reading a dedicated pattern printed on the web. The process is completed in just a few minutes.

The demonstration started with the ten-color press set up to print a six-color job. As the TAPS enables any type of printing cylinders (integral, hollow or sleeve) to be inserted in the press in any angular position, a member of the audience was invited to move some of the gravure cylinders ready on the trolleys to show that indeed their random position does not affect the speed of the pre-register setting.

One of the advantages of the TAPS system is that it is unaffected by conventional pre-register issues: it does not require any pre-register devices such as laser pointer, pre-register rings, adhesive tapes, or reading sensors for cylinder marks, and as such it avoid any mistakes that might occur in the setting phase of those devices. 

TAPS is also unaffected by the web path configuration because it works even in case of mistakes occurring during web threading, or by the sequence of printing units. It also works with reverse printing. 

Quick Acceleration
After the trolley insertion and the push of the TAPS button to start the automatic pre-register setting, visitors could follow the fast sequence of the cylinder phasing and register setting on the six printing units in operation, which took only few minutes before the machine started accelerating to quickly achieve the speed of 350 m/min.

The excellent tenure of the register during acceleration and printing reportedly is due to the HDI (High-Dynamic-Interface) function, which is fitted on all Rotomec presses.  The integration between the electronic shaft (ES) and the Registron register control enables the fastest corrections time, even at the critical times of speed variations.

On a second screen fitted on the machine fairing, visitors could see the amount of waste generated by the demonstration. On the three days of demonstration, which started with a web length of 64 m in the press, the substrate waste did not exceed 86 m.

At the end of the printing demonstration, visitors gathered around the rewinder to collect print samples and check the quality of printing on the PE substrate, which was said to be excellent.

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