Web Workflow Systems' Efficient Workflow

The latest Goss Omni Makeready workflow and control tools are claimed to be enhancing efficiency on job change-overs to make web offset even more competitive.

The latest Goss Omni Makeready workflow and control tools are claimed to be enhancing efficiency on job change-overs to make web offset even more competitive.

In conjunction with the Goss Web Center workflow system and Omnicon controls, the latest Omni Makeready package allows faster make-readies with lower waste, claimed Goss.

Antoine Chevalier, Goss International's director of commercial web product management, commented: "Several recent advances in digital workflow and control system technology are complementing features like automated plate changing and the Goss Automatic Transfer technology, making it faster and easier for operators to achieve low waste and faster start-ups.

These advancements are rapidly expanding the range of web offset applications and they have made web printers competitive at run lengths well below 10,000 copies." The latest version of the Goss Omni Makeready system, available for company's Sunday and M-600 presses, includes optimised ink key movement.

It has Ethernet ink key control boards mounted on each printing unit, which can now be integrated with closed-loop color systems, added the company.

As a result, real-time information is relayed quicker and the movement of the ink keys is faster and more accurate.

Goss said that improved self-learning algorithms within the Omni Makeready system augment pre-press data, whilst systems can read coverage values from the pre-press interface and automatically adjust those values based on stored data from previous jobs, as well as input data on paper stock and ink.

High ink coverage, or low-coverage jobs can require that ink keys be set in extreme open or closed positions, added the company.

That makes it difficult to maintain a constant ink film and avoid misting, starvation and excessive waste.

By automatically calculating the print coverage and then presetting the ink roller speed accordingly, the Omni Makeready system is said to avoid the requirement for extreme open and closed key positions.

Moving leftover ink from the prior job through the ink train before establishing correct levels for the next job is another cause of wasted copies.

A solution with the Omni Makeready feature is to partially remove ink in advance during the deceleration phase for job 'A'.

Again, using preset data and adjustment of the roller speed, the systems can then assess ink coverage needed for job 'B', calculate the variation between the ink remaining in the train from job 'A' and pre-charge the ink train as job 'B' is ramping up.

The pre-charging feature can also be used for faster start-ups after a press has been shut down, added Goss.

After ink keys are adjusted, the time taken to reach the correct, steady density can be long, resulting in wasted copies.

Temporarily exaggerating, or boosting the ink key opening beyond the required level can accelerate the response time of the inker.

The Omni Makeready boosting technique has been proven to cut response times in half, it is claimed.

Chevalier explained: "When run lengths averaged 100,000 or more, start-up or make-ready waste of 5-10,000 copies may have been acceptable.

Today, web offset run lengths themselves of 10,000 or lower are becoming routine.

The pressure to streamline job change-overs is intensifying and the latest Omni Makeready features are part of a comprehensive Goss effort across the production process to meet this challenge, bringing the inherent advantage of the web offset process to much lower run-length thresholds.".

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