It was not long, however, before the use of flexography in the sector began to gain momentum, particularly in the USA and in mainland Europe.
Press manufacturers were producing well engineered equipment, but developments in inks, anilox rollers and origination were unable to keep pace.
Initially solvent based ink systems led the way, but it was the evolution in water-based and water-soluble inks and the use of photopolymer plates that enabled flexo to improve its quality and increase its share of the market. Towards the later part of the 20th century flexo had become the dominant process for new press installations.
Much of the early part of the 21st century has seen UV flexo rapidly rise to become the dominant technology for new press sales.
Today screen, litho and gravure printing continue to have specific niche roles to play in the label sector and their distinct advantages are often used in conjunction with the more mainstream flexo and letterpress processes on combination printing equipment. Offset litho continues to be the dominant process used in the manufacture of sheet and web-fed wet-glue labels, although gravure still plays a key role in web-fed production in some parts of Europe.
It is the recent growth in digital printing however, that has brought about the most dramatic changes to the label printing landscape and it is this process that is set to challenge conventional analog printing in developing economies. (See Figure 1.1).
Figure 1.1 - Trend in key european label press installations 1980-2012 (Source- Labels & Labeling)
KEY DEVELOPMENTS IN THE PRINTING SECTOR
A number of significant developments have influenced the changing fortunes of print processes used in the label sector.
Developments in die-cutting.
The die-cutting of the label laminate to size and shape is a fundamental process involved in the manufacture of self-adhesive labels.
Most letterpress equipment originally relied on expensive flatbed die-cutting units as the chosen method of conversion. It was the flexo sector however, that took another leap forward with the introduction of cheaper and faster running rotary cutting units. Further progression was made in the 1990’s with the development of flexible magnetic cutting dies manufactured using laser technology.
Flexible dies worked in conjunction with rotary magnetic cylinders to enable quick changeovers and Trend in key European label press installations by technology (1980 to 2012).
Figure 1.2 - Typical flexible die-cutting shim Source- Wink
In the near future laser die-cutting developments (already widely used with the latest UV inkjet presses) are set to foster further advances in label printing.
Developments in digital repro
Rapid developments in digital reproduction and artwork have resulted in a quantum leap in the quality and speed of repro and plate making, which had positive impacts on all printing processes.
Digital image processing equipment made it possible for converters to produce their own artwork and stepped film efficiently in-house, which has resulted in improved control and output of jobs.
Developments in inks
A key development in the evolution of printing processes was the introduction of UV inks. Water-based inks proved unsuitable for keying to synthetic materials and it was the introduction of reliable UV curable inks that propelled flexo ahead of letterpress as the dominant process for self-adhesive label production.
The latest developments in LED curing however, offer interesting competition to other UV systems.
Figure 1.3 - HP Indigo 30000 Digital Printing Press Source- L&L Sep 2013
GROWTH IN DIGITAL PRINT
Digital ink jet evolved in the 1970s and 1980s and was originally seen as a simple process for overprinting sequential numbering and simple variable data.
Figure 1.4 - How digital is impacting on the label industry Source- Labels & Labeling
In 1993 however the E-Print 1000, the world’s first digital color press was launched. In the mid-1990s reel-fed digital presses were introduced, with the Xeikon press launched in 1993. With the cost of entry falling, digital printing began to take off with three types of digital technology … dry toner, liquid toner and inkjet at the fore.
A number of factors boosted the attractiveness of the digital process including;
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Variable imaging and data
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Multi-versions and label variations produced economically
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Potential for personalisation
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Reduction in set up and running waste
More than 2,200 digital label presses have now been installed worldwide (end 2013), since the first launches of this new technology in the mid-1990s. Close to 350 new digital presses are now being installed each year into label printing companies in Europe, North and South America and Australasia. Today installations of new digital presses annually now make up some 24% of all narrow web label presses installed worldwide (See Figure 1.4).
Over the next five years annual installations are forecast to rise to at least 35% of all worldwide narrow web press installations.
Market share of new digital presses installed worldwide as a percentage of total new presses installed are stimated to be in excess of 35% in the UK and Europe by 2018.
Advances in ink-jet technology will undoubtedly see the digital process grow in stature and the launch of the nanographic* offset inkjet printing process is creating great interest in the sector.
Nanographic offset inkjet utilises nano-sized pigments to absorb much more light than other pigments, and thus permits images with ultra-sharp dots of extremely high uniformity and broad CMYK color gamut.
INTRODUCTION OF SERVO DRIVE MOTORS
The introduction of servo drive motors into conventional press engineering has resulted in higher quality, shorter set-up times and less waste. This has given conventional analog printing processes a timely boost against the rising tide of digital.
Servo drive technology for hybrid and single driven label presses may be axle driven with several gear ratios, axle driven by mechanical transmission elements or direct axle driven by assembled motor with no mechanical elements.
Figure 1.5 - A modern combination press (Nilpeter)
Servo drive technology enables manufacturers to produce presses with:
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No gears or bearer rings.
Such presses offer fast set-up by recalling press data out of the job file, including length and cross cutting, register pre-setting, web tension pre-setting, web thickness setting, as well flying imprinting - that is text or image change without stopping the machine.
COMBINATION PRINTING
Combination printing is at the heart of innovation in the narrow web label sector, with the focus on adding-value to the label rather than cutting costs. It is particularly found in the wines and spirits, cosmetics and luxury goods market sectors.
Using a system of interchangeable cassettes, combination printing is the method of grouping a number of different printing and converting processes on one platform, in order to optimise the graphics and embellishments that can be produced in one pass (see Figure 1.5).
For example, the solid color coverage of screen with the halftone printing quality of letterpress, flexo or offset.
Combination printing focuses on the strengths and advantages of each printing method and converting process in order to maximise the visual appeal of the label and to enhance its graphic content. This factor alone reinforces the need for end-users, designers and converters to really understand the attributes of each printing process and how they can effectively be combined to deliver optimum results.
Today, hybrid combinations of different technologies within a single company are no longer the exception, but have become the norm.
LABEL PRINTING - THE FUTURE
A recent survey conducted by Labelexpo (2014) provided an interesting snapshot of those printing press technologies that were of greatest interest to visitors to their global exhibitions.
The survey highlighted flexo as the most sought after technology. (See Figure 1.6).
Figure 1.6 - Interest in printing technologies
