Summary

From Manfred Werfel's foreword to this World Printers Forum Report:

What is the best time to replace a defective part of a printing press? It is best to replace a faulty or damaged machine part exactly one day before it finally fails.

But how can this time be determined? Because this seems almost impossible, many users replace critical parts on a fixed schedule. But that can be too early and cause unnecessary costs. Others replace faulty modules only after they have caused damage already. This is usually too late and increases the damage unnecessarily or even leads to a complete breakdown of the machine.

There should therefore be a way to establish a proactive maintenance system that avoids the disadvantages of a too early or too late replacement. But many parts of a complex production line are not accessible or cannot be viewed without dismantling the machine. So is it better to replace them regularly according to a maintenance schedule?

Fortunately, there are technical possibilities for using modern analysis methods and sensors to actually look into the machine (and listen inside of it) without disassembling it. We present the most important methods in this report: vibration analysis, ultrasonic analysis and thermographic image analysis.

The availability of such analysis methods and their costs today are in an area that also enables their use in small and medium-sized newspaper printing plants. In addition, printers do not necessarily have to purchase those tools themselves, as they can be used by external experts as part of a consulting project.

My Indian colleagues have gained a great deal of practical experience in dealing with such analysis systems in recent years and I am pleased that they are sharing their experience with all other newspaper printers in this report.

Condition monitoring of production equipment helps publishers and printers operate their systems more efficiently and minimise costs and effort. Ultimately, it extends the life of presses and mailroom equipment.

From the Executive Summary:

Modern newspaper companies around the world use various ways to ensure high efficiency of their printing machines. Condition monitoring, a widely practiced method, helps to achieve this with relatively less effort. The two major ongoing changes in the newspaper printing business – narrowing profit margins and downsizing of the engineering workforce – are likely to create a great demand for condition monitoring in the near future.

WAN-IFRA embarked on a Mechanical Audit of Printing Presses project in 2016, and publishers and printers in India and South Asia took an overwhelming interest in it. The project aimed to analyse the critical parts of a printing press for their condition, the nature and severity of any existing anomalies and possible root causes of faults, and also to make recommendations either to avoid failure or improve the condition of the machine by acting proactively. Such analyses are possible by employing three basic condition monitoring techniques, namely, Vibration Analysis, Ultrasound Analysis and Thermography Analysis.

Vibration Analysis gives a frequency spectrum wherein different fault frequencies are identifiable, and this helps to determine various fault sources. It also indicates the severity of the problem.

Ultrasound Analysis helps to identify problems such as inadequate greasing, contaminants in grease, raceway problems in a bearing, compressed air leaks and vacuum leaks, to name a few.

The thermographic Image analysis helps to identify anomalies in electrical parts, cabinets, connectors etc. Also, this could help identify the problems in small motor drives, problems in ink roller nip contacts and reel stand brakes. Generally, an infrared picture has very wide applications, but the depth of analysis is limited.

Based on the data and findings in these projects, this report throws some light on the common anomalies noticed in printing presses – the kind of anomalies and possible reasons for deterioration, the parts that are prone to damage, electrical issues associated with these anomalies, and other issues in the maintenance of printing presses.