Staying ahead with short run gravure printing
In general, package printing jobs are becoming shorter and shorter. Hence many printers struggle to produce in an economic way. Sebastian Reisig, former editor of Flexo & Gravure Global, visited Drukerij Zwart to find out how a printer became a producer of economic short run rotogravure printing jobs.
This interview with Harry Sieljes, Managing Director for Drukkerij Zwart BV, was conducted by Sebastian Reisig
Before printing short run gravure jobs on the narrow web presses supplied by Bobst Italia, what process did the company use?
Harry Sieljes: We used rotogravure printing all the time. In “ancient” times, we had an old Windmöller & Hölscher press with a 700 mm web (27.6“) width and an older Chambon with a 350 mm (13.8“) web width. The main reason why we had narrow web printing presses was that in those days the only packaging products we were making were tea tags and heat seal top labels for coffee packs. That means that the required dimensions of the printing units in terms of repeat length and width was quite small and also meant that you could make quite some volume in terms of pieces without the need of making a lot of square meters.
When we started to re-invent the company we thought it was a good idea to stick to that narrow web concept. We developed this concept for other product/market combinations and other material groups with a certain philosophy in mind, for meeting new and future market demands in the food packaging industries. Our experience and the fact that we have always used narrow web presses is surely our big advantage over our competitors. Because they probably thought about switching to narrow web, but if you have to start from scratch while your whole organizational set up is for wide web, it’s not that easy.
How many rotogravure presses do you have right now?
Harry Sieljes: We currently own four gravure presses all the MW type from Bobst Italia. We can move with people, orders, change over parts, gravure cylinders and substrates in a random way to each machine. This provides great flexibility and parallel capacity. Three presses are running, one is on order and will be installed in the autumn of 2015. The existing machines were installed in 2007, 2009, and 2013 respectively.
Over the years we have made lots of changes to be as flexible, standardised and lean as possible. When we made the decision in 2007 to buy a new narrow web press, there were only DCM and some exotic manufacturers offering such technology. Back in 2007, the technology in the DCM was still based on a central driveshaft with gearboxes for each print unit, web eating length register arrangements and conventional design of drying units and not very effective ink volume control. To make a long story short, it was not really what we wanted. We intended to improve the internal efficiency, and adapt the organisation to it.
So I had a meeting with Renzo Melotti, the head of R&D of Bobst Italia. I explained some starting points from my view about a modern gravure printing press and organization, and they designed a machine from this information and, of course, we were buying it from them. For example, I asked him what is the point of pouring a bucket of ink in a ink tray? Why not insert the bucket directly into the press? Saving steps, this is lean thinking. What is the point of having a fast-drying classic dryer, when you do not need to run the press at a high speed of 500 m/min (1640.4 fpm) because of your job structure? That is how we saved material during the set up.
Our old nine colour DCM had a web path of 120 metres (393.7 ft), our first 12 colour Bobst Italia has only 55 metres (180.4 ft) web path. So, today we have four MW machines from Bobst Italia, comprising 44 gravure print units. It’s not that we often need 12 printing units for a job. This has organisational reasons. When an eight colour job is running, we can prepare the four other printing units with the new job, hence we save a lot of time when setting up the next job. The average print run time today is 40 minutes.
We try to use this time in the most efficient manner. State-of-the-art printing presses do not need much supervision as there is so much control technology on board. This has enabled us to change the focus from run-on to change-over on a running press.
Labour costs in Europe are very high. So why should we pay big money for labour that is looking to a process that basically is running well. You’d better point your efforts to change over and set up.
If you compare an old machine with the new ones, how much faster are they ready for printing?
Harry Sieljes: A lot faster! We save about 15–20 min per colour and when you talk about settings etc., the process is also dramatically faster thanks to modern registering/systems.
But, being productive is not only a matter of technology. Machines are just a tool. That maybe counts for 40%, an organization that is fit for purpose really brings the success and counts for 60% at least. For example, if you are printing short runs, you are faced with massive a traffic of ink press returns, not because of individual ink volumes, they are very low in MW technology, but because of the large number of jobs you print. If you can’t handle that number of press returns, a short run printing philosophy can economically kill you.
You staff each press with two printers?
Harry Sieljes: Yes. There are a lot of tasks to do besides the print job, i.e. trouble shooting, preparing the next job, etc. That is where we can save time, we do not have to focus on many metres, we focus on high performance setup for 24h. Furthermore we have for each shift one guy in the cylinder department, one from the washing department, and one from materials handling. If required, they can support the team on the printing press. In short run printing, in-line activities do not really fit.