This aricle was originally published in the Print Monthly September 2016 issue
Sometimes the best technology takes some of the old with some of the new. Brian Sims discovers how the traditionally built Kluge EHG Press is tackling modern production requirements.
The world is moving on at such a rapid speed with new products coming at us at all angles. New technology, new processes, and mind blowing changes to the print world we all know and love. Due to my background with a Japanese company, I have always tried not to get carried away looking solely forward for solutions to engineering problems, but also be mindful to look around and behind. The development of the ideas of others in Japanese culture is considered a great sign of respect and admiration. This month, I chose to dig under the covers of the Kluge EHG Press. It is a very traditional machine but is finding increasingly new markets now that run lengths are dropping and the long established processes of embossing, foiling, and die-cutting are finding a renaissance.
With reference to my opening statement on broader thinking, Kluge has a number of presses that can add significant value to modern printed products. The EHD, EHF, and EHG presses are of traditional platen design, clearly benefiting from four generations of organic development of a classic construction spanning from the beginning of the last century to the present day.
A number of finishing effects may be deemed impractical for today’s modern production, but this could not be further from the truth. These effects may suit shorter run lengths, but that is exactly where old and new technology has synergy. What is wrong with hook- ing up a digital printer with a platen style finishing device when they both thrive on short-run lengths?
So, before we delve into the technical aspects of the machine itself, maybe a review of what post-press processes are possible on it would be useful—what can the Kluge EHG do?
Foiling or foil stamping is the application of a coloured layer from a carrier by the process of pressure and heat. The shape required is determined by the die having the desired finished profile. Pressure and heat is applied once the substrate has been sandwiched between the die, foil, and counter or platen.
It is a misconception that foiling is limited to gold and silver metallic finishing. You can have a wide range of colours and finishing including wood grain, leather, pearl, marble, and snake skin patterns. Foiling will only produce a flat profile; it can be raised but this will require a combination work, which includes the use of embossing.
Embossing uses similar processes to foiling in as much as the substrate is sandwiched between a die and platen. The difference in this case, is the platen or counter has a relief of the profile required on it that fits specifically into the mating profile on the die. The pressure applied in the process forms the relief in the substrate itself. Profiles can be raised (embossed) or indented (debossed).
Die-cutting uses the same pressure and platen combination but by using an outline of a desired profile, the pressure applied actually breaks through the substrate leaving an outline required and waste known as trim.
Finally, holograms. They are thought of as modern effects but they have history back as far as the 1940s. In the 1980s they became more commercially available and now they can be bonded to any material that can sustain the pressure and heat of the stamping process.
So, how does the Kluge EHG manage to complete all of these processes in such a small package? Well firstly, at its heart is the platen and pressure ‘sandwich’ system. What is extremely noticeable about the Kluge EHG is the robustness of the retro-designed press. As I said in my opening, some of the best ideas do not have ‘sell by dates’ and this machine is testament to the adage, ‘if it ain’t broke, don’t fix it’.
The toggle base is the ‘top’ part of the sandwich and holds the die. The design of the toggle base on the Kluge EHG gives a secure mounting of any die on an infinite number of positions. Added to this is the toggle base with a two section heating plate to allow for flexibility when planning work.
Moving on through the machine, the traditional, effective, and timeless design features continue to shine through. The feeder is of a simple construction of what Kluge call their ‘straight in, straight out’ feeding motion limiting any misfeeds. This system also allows for a great variation of stock thickness and shape, which is vitally important when working in niche markets.
As we have discussed, you are not only feeding substrate but also foil and to accomplish this to within 0.1mm of registration, the Kluge EHG has two foil infeed units each on their own drive shaft in turn driven by an independent stepper motor. Kluge calls this the Electronic Foil Control System (EFCS) and it can memorise up to 25 different foil lengths in each unit.
Due to the paper handling system, ‘straight in, straight out’, the delivery system works on much the same process in as much there is a four finger lift and delivery framework that allows the embossed or foiled sheet to be delicately lifted onto an auto- mated pile system.
The Kluge EHG has a number of unique features ensuring a seamless production run. There is an easily reversible cam system to move the register mechanism from left hand to the right hand side of the machine. The machine comes with a missing sheet detector to avoid costly double sheet mistakes, and finally in the standard package there is a variable frequency drive allowing for a range of speeds to be selected.
If you are looking for additional features and applications such as holo- gram application, the Kluge EHG has a hologram registration unit which enables accurate registration of a holo- gram which can be vitally important for security printing.
In summing up this machine, it clearly confluences modern production requirements and traditional build. Declining run lengths and the demands for added value by clients means that the Kluge EHG happily manages to knit together what at first glance looks like quite different wants or needs, but manages to skilfully pull it off.
Brian Sims is the founder of Metis, a specialised business, legal, and technology consultancy for the print industry. To find out more on the issues in this article or his services go to www.metis-uk.eu or e-mail [email protected]