• Flexible film - compared to offset and gravure, flexo offers the possibility of printing on pressure-sensitive substrates;
• Label printing, where flexography is the dominant printing method and demand has continued to rise;
• Folding cartons - flexo does not dominate in this area, but its usage is growing rapidly.

Figure 1 gives an indication of how flexo has grown historically to 2002 with a projection to 2007. The trend shows that although gravure will grow during the period 1998-2007, flexo will perform better in terms of percentage growth, albeit from a more advantageous starting point in 1998. While gravure grew from 12,000 million square metres in 1998 to 12,500 million square metres in 2002 (and is expected to grow from some 12,500 million square metres in 2002 to around 13,500 million square metres), flexo grew from 18,000 million square metres to 22,000 million square metres and is set to grow from around 22,000 million square metres to some 24,250 million square metres over the same time period.

Figure 2 gives an indication of the various company activities in Europe in the area of flexography and gravure. The figure shows that virtually all companies in Europe, with the exception of Huhtamäki, offer both flexo and gravure print processes. In a number of them, such as Frantschach, Constantia, Hueck Folien, Clondalkin and Wipak, there is a fairly even split between the two processes. Amcor and Alcan/Pechiney (merged in 2004) have the largest overall capacity but here there is a bias towards gravure. Meanwhile, Sealed Air, Autobar, Parkside and Schurpack are biased towards flexo.

Technological developments

Recently, a surge in new products and technical developments has provided the impetus for the growth seen today in flexographic printing. In prepress, new types of plate have been developed that have had a significant impact within the market - particularly digitally-imaged plates using computer-to-plate (CTP) technology. Plates have also been developed that are imaged directly into the polymer without the use of film or the black layer currently used.

Other developments include sleeve-type applications for both plates and anilox rolls. Together with the development of gearless printing presses, these will facilitate make-ready off press, saving time and cost, and allow infinitely variable printing lengths.

Doctor blades

Two distinctly different types of doctor blade systems are used by the flexo industry. The first is the reverse-angle blade system, but the most common system in use is the enclosed doctor blade system. End seals are responsible for some of the biggest problems faced by printers, and it is necessary to ensure that the correct size for the chamber is used.

A recent innovation is the new-style doctor blade, which allows both blade and end seal change without the use of tools. Figure 3 shows a reverse blade and enclosed blade system.

Gearless technology

The introduction of gearless direct-drive press technology in the late 1990s, which allows any intermediate repeat length to be attained, is widely acknowledged as one of the most innovative advances in flexo presses over the last 30 years. Sleeve systems that can be incorporated into flexo presses were key to the development of gearless flexo presses, allowing plates to be made up off-press, on the sleeve. This can be done individually and placed on the sleeve, or the photopolymer sleeve in the round can be processed. By this method, all the processing along with washout and drying, is done in the round, although it does involve significant cost.

Mid-web printing presses

The introduction of mid-web printing presses has given printers the ability to produce at higher quality and shorter lead-times. The cost of going to press with any chosen design is also significantly less. Cost is a significant factor, and flexo is now able to offer lower costs and quicker turnaround times compared with gravure and offset. Flexo has an additional advantage in that offset cannot print on flexible film/flexible packaging.

UV inks

While yet to be widely accepted throughout flexography, UV inks have made significant gains in narrow web and label markets where water-based conventional inks still dominate the narrow web industry. Many improvements in print quality have been made to UV inks, which has further encouraged the switch to UV in addition - alongside the traditional environmental concerns that have also contributed towards uptake.

Prepress

Another area, which has seen considerable development within flexographic technology is prepress. Digital workflow gives flexo printers the ability to get to press in greatly reduced time frames. Compared to gravure printers, flexo printers can get to press in significantly less time. The advantage here for flexo printers is high turnaround time and improving quality with reduced cost, compared to gravure.

'Combination presses', coupling flexography with other printing technologies, are also coming to the fore. These combination presses can print more than one type of process, such as gravure and flexo, and are used as a laboratory tool to evaluate new substrates and investigate new technology.

New anilox rollers

The industry is changing from line to process printing and from two-roll to anilox systems. Faster speeds are now possible in the printing processes and anilox rollers are able to provide increasingly fine, higher-quality production. New anilox rollers demand thinner ink films, placing a burden on ink manufacturers to develop stronger inks.

A problem also facing ink manufacturers as a result of the development of these anilox rollers is drying times. This is resulting in improved interaction between manufacturers, suppliers and printers as a matter of necessity in order for flexography to maintain its current market share.

Plate-making systems

Remote digital origination from camera, proofing and transmission of data for plate-making has allowed flexo to be originated from anywhere in the world. At Drupa 1995, the first plate processor was put on show. Today, 400-plus systems are in place worldwide. However, one drawback has been the fact that the onward processing, washing, drying, detacking etc. takes a couple of hours.

Recently, two new plate-making systems have come on to the market: a thermal imaging plate, and a photopolymer plate engraved directly into the photopolymer. As of 2004, the latter plate was available only for narrow web UV printing. However, it is thought that it will be available for all processes and all types of ink in the near future, leading to a revolution in the flexo industry as costs are driven out of flexo plating. BASF and DuPont, two of the largest suppliers of plate-making development in Germany, in association with digital imaging systems makers, are bringing these new types of plates on to the market.

Inline production

Inline production for cartonboard is a significant development in flexo where as many colours as are required by the customer can be printed in a single pass. In addition, varnishing, hot foil stamping and other finishing processes, along with die-cutting (either flatbed or rotary) can be achieved all in one pass. Cartonboard is viewed as a potential boom market for flexo in the coming years.

Company developments

A number of products came on to the market in 2003, which look set to consolidate the technological trends for flexo that were set in place at the beginning of the decade. These include new gearless machines, printing presses, multicoaters, automated quality control systems and cleaning products. As mentioned earlier, gearless technology also represents a key area of innovation for the flexo industry, with Uteco among those companies at the forefront of moves in this area with the launch of a new machine featuring gearless technology in 2003.

Uteco launches gearless machine

In 2003, the Verona-based Uteco company, in response to the need for high-quality and quick turnaround jobs, launched the new Amethyst 8C-CI. The machine, sold in the UK by the Byfleet-based Eurograv Ltd, is said to offer predictable, consistent quality output with speed-to-market and optimum processing uptime. The machine offers quick changeover and ease of use with its simple on-board sleeve change system, for both printing plate cylinders and ceramic anilox rolls.

The Amethyst machine comes from the Emerald CI range and many of its patented features and gearless 'know-how' (such as the Uteco direct drive system and print deck positioning system) were adopted for this press. Other innovations include a new style doctor blade allowing both blade and end seal change without the use of tools.

The Amethyst 8C-CI is available in web widths of 1,050, 1,250, 1,450 and 1,650mm and speeds of 300 metres per minute. It can also accommodate reel diameters of 800, 1,000 and 2,000mm, and can be supplied with different types of semi-automatic/fully automatic unwinders and rewinders.

Uteco 11-colour flexographic UV printing press

In 2003, special shrink sleeves from Labelmakers, one of Australia's largest label printers and converters, were employed for the first time in five different Kraft products. These sleeves, with similar graphics, are being applied to a jar, a tall bottle, a small carton and other containers. The sleeves are printed by Labelmakers on the new Uteco Emerald 828, 11-colour Flexographic UV printing press. This press, installed at the company's Somerton plant in 2003, is a combination flexo press with eight colours around the Central Impression (CI), plus three satellite stations, the last of which has in-line lamination.

Among the other flexographic press models in the Uteco range, suitable for narrow web applications, are the 500mm web width Coral C.I. with UV. This is Uteco's entry-level central impression press, supplied in four and six colours, operating at speeds of up to 820 feet per minute.

High-quality flexo printing of aluminium foil

There is enormous potential for the decorative printing of aluminium foil, using either flexo or gravure. Because of its bright or matt surface, aluminium foil provides designers with the scope to create image-enhancing packs with visual impact. Pouches for the drinks industry, usually made from a multi-layer composite in which aluminium foil is often used as the barrier layer, can have their visual appeal enhanced by flexo printing.

In Austria, the Teich Group installed its second Emerald SIL for printing aluminium foil in 2003. This gearless machine also uses UV inks, although Uteco's Emerald 8C or 10C (ten-colour) is also available in gearless versions. The central drum has a diameter of 2,700mm and reaches a maximum printing repeat of 800mm and press speeds in excess of 600m per minute.

RK Print Coat Instruments - new FlexiProof 100, K303 Multicoater

Many ink manufacturing facilities, printing and converting plants around the world are installing RK Print Coat Instruments' sample preparation systems to ensure accurate ink colour, consistent ink density, and type and quality of coatings. The demands placed upon ink producers require the ink formulator to develop and produce inks that work with higher densities, with finer screens at faster press speeds.

Among the RK systems available are the new FlexiProof 100 launched in 2003. This is a multi-tasking tool that enables users to produce proofs using water, solvent or UV flexographic inks. The system is a scaled-down version of a full-sized flexo press that can be used to undertake accurate quality control and printability testing, computer colour matching etc.

The K303 Multicoater is another new export earner for the company. This bench top unit, described as ideal for the production of samples for quality control and R&D, has a coating area of 350 x440mm. It is supplied with interchangeable gravure and flexographic printing heads that provide for highly accurate surface coatings and laminations.

The K303 Multicoater can be supplied with standard gravure plates - either eight wedges or three wedges.

The maximum printing area is 275x285mm. Anilox flexo plates are used, from which the ink is transferred via the stereo roller onto the substrate.

Futec Europe - quality inspection

Quality inspection is of crucial importance to users of flexo, and the development of strobe-based video web inspection systems and more recently 100 per cent automated defect detection systems with line scan technology, capable of inspecting the entire web in real-time, have had a profound impact on printing techniques - most notably in flexo printing.

Futec Europe describes itself as a pioneer of automated in-line defect detection systems, using colour line scan technology. These 100 per cent-automated defect detection systems are growing in popularity at the expense of batch sampling systems. Futec's EasyMax, an automated defect detection system, provides for faster identification of potential high-impact defects, resulting in a more immediate corrective action.

With a 4,000-bit x 40 MHz colour line scan camera, the EasyMax automatically detects and identifies a wide range of both persistent and random flaws including colour variations, discolouration, doctor blade defects, fish eyes, fogging etc.

Label press control

The availability of improved filmic substrates, led by polyethylene and polypropylene, has aided self-adhesive growth at the expense of glue-applied paper labels. However, the consequences of inadequate tension controls while running these filmic materials may result in excessive waste and a gamut of web handling problems.

New web control devices have been introduced recently from US-based Montalvo to address the processing variables that arise in modern day production. One such example is the X-3100ce tension controller, which is being marketed in the UK and Ireland by Arrowhive Equipment. The equipment is an analogue tension controller with digital parameter handling for closed loop control. It incorporates the latest 'embedded' electronic technology and offers on-board industry-standard PC/PLC communication and features progressive PID regulation.

The company's package of control products for the narrow web sector also includes the C-Series range of brakes/ clutches and Montalvo Simplex web guides.

Plastotype introduce new products for anilox rolls Plastotype, the flexographic printing specialist, launched a range of new products in 2003 for the cleaning of anilox rollers and other components. The range includes the company's own brand of Aquasonic flexographic cleaning materials, developed as a method for the rapid removal of contaminants from anilox rollers, and for flushing debris from circulation systems.

Aquasonic products are designed to work on-press to shift dried and deeply engrained inks, lacquers and coatings, or clogged dust and dirt. Key lines include Quick'clean, able to clean effectively clogged chrome or ceramic anilox rollers.

Other products include the Vegra Special Cleaner VP 9735, said to be ideal for anilox rolls/screen rollers and gravure cylinders. Among recent introductions is the General Pressroom Cleaner, an all-purpose, powerful cleaner/degreaser formulated for all sectors of the print industry.

Uniclean is available for all types of photopolymer plates and inks. It has been formulated for optimum cleaning, and was developed after consultation with printers/converters.