Gravure looks East

5 July 2011



Nick Coombes looks at how far gravure has moved on as a printing technique for packaging.


There are three major drivers in today’s market for printed packaging, and at first sight they appear to be contradictory. How can the demand for highest quality print be matched with that for ever declining run lengths, when keen pricing is taken for granted? It’s the puzzle that printers continue to battle with, as brand owners drive harder bargains. In the end, only the manufacturers can solve the problem with advances in technology that bring gravure into line with market demands.

A brief overview of the market shows a marked contrast between the USA and Asia in terms of gravure usage. In the former, where flexo is a well accepted process, and in general, quality demands have not been so high, gravure has a lowly market share – probably only one fifth that of flexo. In Asia, where quality demands are more exacting, particularly in terms of special substrates and decorated finishes, gravure has the majority share. The situation in Europe is less clearly defined.

Much of this boils down to cost and simplicity of process. The law of supply and demand, as well as narrower web widths, mean that cylinder engraving costs, always cited as the drawback of gravure, are lower in Asia. There, supply is plentiful and cheap because of lower labour costs, and demand is high because there is not the pressure on ‘green’ technology that exists in the western markets. Gravure presses are essentially simple, and well suited to the high volumes required by the tobacco and pharma markets in Asia. Typically, engraving a new cylinder in Asia will cost around 25% of what it would cost in the USA, with Europe halfway in between.

These are significant market forces, and would appear in the light of the trend towards shorter run lengths to mitigate against gravure. But interestingly, a survey carried out in 2009 showed that in the previous three years, average run lengths on gravure presses had actually risen! While gravure has always been perceived as a high quality print process, with superior ink coverage, brilliance and vignettes, it is now more closely challenged by UV-flexo in these areas, so there has to be a quantitative as well as a qualitative reason behind this. The answer lies in the pre-press costs. While gravure has its problems: cylinder manufacturing and storage; make ready times and the knock-on effect of delivery times in today’s JIT market; waste; cleaning; and solvent issues, flexo, for all its advances in quality has seen costs rise too, and as a more complex process, it is more expensive as an overall investment package if the whole production sequence is considered.

The cylinder problem revolves less around engraving costs than the logistical problem of handling and storing, as well as the proportion of unused investment capital tied up at any one time. Various manufacturers have experimented with materials to replace steel. These include a hollow nickel/copper hybrid that requires an air mandrel, and a steel/PU foam sandwich construction that needs an expanding shaft. Both styles have been developed with a number of the leading gravure press manufacturers, and unlike traditional cylinders, offer a far higher adaptation quotient to different makes of press. Both are lighter to handle and store, and quicker to change over. Saueressig and Janoschka are two companies that have been successful in this field.

Part of the improved set-up times and lower makeready costs relate to the improvements made in colour control and press set-up automation. By bringing gravure into line with register technology long established in offset printing, and more recently UV-flexo, customers whose work is printed gravure can now enjoy a much faster approval process and shortening of delivery times. Ink management technology that brings commercial product in line more quickly with the authorised colour proof, means gravure is relevant to shorter runs too. And the knock-on effect of this is reduced substrate wastage.

One of the technical developments to have made a difference is the new type of doctor blade. Designed initially to cope with the abrasive nature of certain inks, which led to inconsistent tonal values, the new blade was designed to present a more consistent profile throughout the print run. Initially chemically etched, the blades are now produced using automated grinding machines, but the secret is the coating that is applied, which significantly increases the service life and improves ink coverage for high definition. The Swiss company Daetwyler has been successful in pioneering this technology.

Inks & coatings

Available and popular in litho printing for more than two decades, and more recently adopted by flexo printers in the quest for high quality, UV and EB inks and coatings have so far been excluded from the gravure sector. But recent developments in the chemical make-up of the ink in relation to its curing capacity has allowed EB to be viable in the gravure process. Key to its success was coping with the essential, it was important to eliminate some of the volatiles, in this case ammonia, to improve ink performance. By combining drying with EB curing, the quality of the printed product remains consistent with that expected of gravure printing. The problem came when the water-based inks were overprinted with an EB coating, which offered poor adhesive qualities. This can be solved by using acrylate functional inks, which under EB irradiation reduce the amount of unwanted residuals and offer better adhesion.

All this leaves the press manufacturers with a dilemma. The sophisticated technology required by converters in the developed markets involves a heavy commitment to R&D and with it the associated higher sales price of the new press. Without these advances, no converter is going to be able to compete in the world of international brands where quality has to be the highest, and price, if not the lowest, then very near. At the opposite end of the scale are the requirements of the converters in Asia and other emerging markets, where costs overall are lower (especially labour), and technical know-how and support more thinly spread. For these companies, a simpler and cheaper press is needed.

One answer is to meet the demands of the low cost markets by actually manufacturing locally, and The Bobst Group, which includes the rationalised Rotomec and Schiavi gravure ranges, and has experience of overseas production, is looking closely at this option. The risk of ‘technology pirating’ is still present of course, but it is now considered a risk worth taking to establish a better market share in the region. With cost bases typically twothirds lower than in Europe, and with very different buying criteria for gravure presses, in terms of automation, performance and durability, several western manufacturers are already well ahead with plans for developing manufacturing facilities in locations from India across to China.

The number of converters from Asia who attended the Rotomec Open House last year was significant as it highlights, perhaps, the main territory where gravure has its greatest future potential. Run lengths will continue to be longer in these markets, especially in tobacco package printing, because the ‘health lobby’ has yet to become empowered there, and also because of the sheer numbers of population. The ‘green lobby’ also is less well established, so the use of solvent based inks and coatings is less of a problem. The company’s 888 gravure press, which is built in Shanghai typifies the situation. Quality built, but to a price, it fits the market well, but is unsaleable elsewhere owing to its simplicity and manual operation.

Europe’s other leading gravure manufacturer, Cerutti, also reports high interest levels from the Asian markets, especially China, and also from the Middle East, from where the company took orders for four large presses in 2010. Reporting a dormant European market and even less demand from North America, Cerutti is looking at North African countries as well as Latin America, particularly Brazil, for its future growth. Key to its success in selling 40 presses in 2010, was its adoption of lean manufacturing techniques, which have not only reduced costs, but also significantly cut build times by up to 25%.

What seems certain is that Asia holds one of the big keys to the future success of the gravure printing process. But the area that keeps demand for the technology high also poses the biggest threat to western gravure press manufacturers. The speed with which simple and cheap Asian technology can quickly become sophisticated and competitive with its western counterparts cannot be ignored. There are significant precedents in other industries!

Business steps up

Eurograv, a leading supplier to the gravure industry, reports a significant increase in new customers using CBG doctor blades, especially for gift-wrap, high-end security, and pharmaceutical printers, who are choosing the newly patented Wing Lamella profile.

Trials proved that this doctor blade can reduce the pressure by between 20% and 50%. Colour strength is improved and scumming with aggressive whites and metallics is reduced, while users also report less wear to cylinders. Eurograv’s Mike Attard commented: “Clients no longer have to bed in the blade, which allows faster set-up times and increased blade life. This is partly the result of the high quality ESR (electro slag refined) steel used, and the unique Wing lamella profile.”

Eurograv also reports renewed interest in the Uteco range of presses, especially the Q-Press, which is a dedicated sleeve change machine that caters for a wide range of print repeats, without having to manually feed a shaft into the sleeves offline. The Q-Press uses a mandrel that is directly attached to the electronic line shaft for quick online sleeve changes, and also gives direct registration control. This means less waste and better colour to colour registration during acceleration and deceleration via the Uteco SyncroWeb platform.

In 2010, Uteco entered a partnership with Kholi Industries to manufacture the V-Press in India. This guarantees a competitive price with optimised performance, and the ELS is now considered an entry-level press for those joining the gravure printing market with limited investment capital.


The Rotomec 400X HS is designed for high speed, high volume work. Rotomec 400X HS The Rotomec MW 80 is designed for short run work with a medium web width. Rotomec MW 80 Saueressig’s new Gelenium range of gravure sleeves. Saueressig

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Cerutti
Daetwyler
Saueressig

Rotomec 400X HS Rotomec 400X HS
Saueressig Saueressig
Rotomec MW 80 Rotomec MW 80


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