For decades inkjet has been used for the labelling and coding of boxes, but this represents the tip of the iceberg of packaging applications and many inkjet printers are being designed to tackle much broader but more challenging applications. The corrugated packaging market, widely acknowledged as being rather slow-moving and margin-depressed, continues to hold lots of potential for inkjet technology because it is such a large market for package printing. Corrugated is also moving away from traditional long runs as brand owners and other users look to reduce inventories and deliver products just in time. The overall printed and unprinted packaging production market can be broken down into eight segments. Paperboard containers and boxes is the largest, followed by corrugated, which in 2003 was valued at US$117 million. The projected value for corrugated in 2008 is estimated to reach $140 million.

Corrugated packaging is made from combining two sheets of paper called the liner, which is glued to a corrugated inner medium called fluting. There are several types of corrugated, each with different flute sizes and profiles, which offer many combinations designed to create packaging with different characteristics and performances. The top liner can be brown made from virgin fibre called Kraft liner, or from recycled fibre called Test liner. Other liners are bleached but the highest quality is clay-coated to obtain a high level of whiteness.

The combined corrugated market for the US and Europe is about 80 billion square metres, of which 90 per cent is printed. Around 94 per cent of the corrugated production goes into transport packaging and about 6 per cent to point-of-purchase (PoP) displays. The market has an annual growth rate in produced square metreage of 2–3 per cent, with the food and beverage segments being the highest end users. Print designs vary from one- and two-colour line work, mostly packaging for industry use with a company logo and a box article number, up to highly sophisticated images printed in 4–6 colours for boxes with display character at the PoP. The most common print technology used for corrugated is flexography, with water-born inks. Offset is also used and in some rare cases screen printing is employed.

In most instances corrugated is post-printed, meaning printed on the finished corrugated sheet. In some cases however, it is preferred to print the liner before it is glued to the corrugated substrate. This pre-print process, sometimes done in flexo, more often in offset, is selected for three different reasons. The first is higher print quality because printing directly on the corrugated board generates an uneven colour lay-down due to the uneven substrate (the so-called washboard effect). The second reason is that with offset, higher print qualities can be printed than with flexo but a direct offset print on corrugated board is not possible because the high pressure between the rolls would flatten the substrate.

The third reason is cost: because a set of offset plates is much cheaper than a set of flexo plates it is sometimes more economic to choose a pre-print offset process than a post-print flexo route. The additional operation necessary to laminate the printed paper to the corrugated substrate makes this procedure economic only for short runs and also stretches the delivery time. The corrugated industry is typically divided into integrated manufacturers with their own corrugator and sheet plants buying pre-cut sheets from a corrugator.

Sheet plants often print only one- or two-colour line work with an integrated printer-cutter-folder. Their competitive advantage is delivery speed. It is common that they deliver within 24 hours or even the same day. Their weakness is that they are restricted to simple designs. They overcome it sometimes by tolling sophisticated images to offset printers but this is a costly and time-consuming alternative. The alternative to purchase a multi-colour flexo machine, however, would fix them into the high-end/high-cost market with a significant payback risk. High-end printings also need longer delivery times due to the more difficult print set-up and the separate cutting-folding operation so that the sheet plants would lose their strategic strength, which is speed.

Corrugated box manufacturers who already serve the high-end market suffer from the high production cost and their lack of speed. High-end markets are much more volatile because of their orientation to the end consumer.

Shorter and shorter product lifecycles, increased sale through campaigns and the fragmentation of consumer markets into different ethnic groups and their languages have led to a fragmentation of the consumer groups and a consequent personalisation of packaging. These factors have reduced the average print run to below 5,000 sheets for many companies. For them the total annual set-up time is longer than the annual net production time.

The buyers of corrugated boxes are manufacturing industries and marketing companies or brand owners. Both are under pressure to reduce their inventories to a minimum and deliver their products just in time. Lean manufacturing and continuous replenishment dominate their cost management and they both are linked to a situation in which calls are not based any more on estimations but on real sale. The target to keep capital employed to a minimum is in opposition to the need to continuously update the product range through innovation, relaunches and campaign selling. In the meantime it is widely acknowledged that 80 per cent of the purchasing decisions are made at the PoP. This makes packaging decoration a much more important tool of product marketing and of retailer marketing because they want to see ever more often their name being printed next to the product brand. On top of the stress factor, the heavy consolidation of the retailer market (e.g. in Europe, eight retailer groups cover 80 per cent of the total market) has given the retailers a tremendous purchasing power with a direct influence on price and consequently on the upstream margin.

The fragmentation of the demand side and restrictive stock management throughout the entire supply chain have reduced the average print run to below 5,000 sheets with few repeat orders for many corrugated companies. For them the total set-up time is much longer than the total net production time.

It is for them that high-speed digital printing from machines such as the FastJet will offer an economic solution for short production runs up to 3,000m2. But it will not only be more cost-effective than analogue printing procedures, it will at the same time radically shorten the production cycle from design to printed box at no obsolescent stock.

Is the situation different in other packaging markets? No. However, compared with the flexible packaging market with its large variation in substrates and specifications for further processing (pasteurisation, sterilisation etc.) the demands on print for corrugated packaging are relatively simple. The printed ink must be rub-resistant and show certain slip characteristics for the subsequent conversion. Furthermore large segments of this market only show a medium print quality. This makes corrugated the right segment to enter the packaging market with a new printing technology.

FastJet has been designed to inkjet print corrugated sheets at high speeds. The technology has been jointly developed by Sun Chemical, the world’s largest ink producer and Inca Digital, Cambridge, UK, a leading manufacturer of high-speed digital flatbed printers.

It has been designed to print digital high-speed inkjet technology for printing corrugated sheets.

Unlike standard scanning inkjet systems, where the print head shuttles back and forth, the print heads in a single-pass system are fixed and do not move at all. Rather, the media passes beneath the stationary print heads and the entire image is printed in a single pass.
Other digital print solutions also aimed at the packaging market include Dotrix’s the.factory and the CORjet from Israel-based Scitex Vision. Belgium-based Dotrix, now an Agfa subsidiary, demonstrated at drupa 2004 the.factory. It is the first single pass printer meant as a production machine. It is capable of printing 907m2 per hour at widths up to 63cm. The roll-to-roll (R2R) printer can be equipped with an unwinder and sheet cutter. Dotrix is using drop-on-demand (DoD) print heads from Toshiba TEC with greyscale capability, meaning that the original print resolution of 300dpi tuned through variation of the droplet size appears as being 900dpi. The inks used are UV-curable. The target markets according to Dotrix are folding cartons and flexible packaging.

Scitex Vision’s CORjet printer can handle corrugated formats of up to 160x320cm and print in four (CMYK) or six (CMYK+ LC+ LM) colours. The technology is not single pass and its maximum throughput rate of 150m2/h is sufficient for prototyping and test marketing but make it too slow for regular industrial production. CORjet has a print resolution of up to 600pi and prints with proprietary water-based inks.

At this stage of development FastJet only aims at the market of corrugated transport boxes. For the sake of speed it sacrifices print quality and it has developed the maximum print width to a format where it can cover about 80 per cent of the targeted market. Sun Chemical’s own market research has shown that a print resolution of 300dpi can cover a wide enough market potential in the corrugated sector. Sun Chemical Digital does not believe that it is realistic to develop a solution for all quality demands. Speed is crucial in the packaging market; the whole industry’s culture is based on speed. Corrugated printers regularly deliver within 24 hours already with analogue print systems albeit only for repeat orders. A digital printer needs to fit into the conversion process otherwise it becomes a process constraint.

FastJet technology, with its value mix of operational flexibility, total cost of print and print quality, addresses a segment that accounts for 10 per cent of the total corrugated market with the understanding that this segment is growing at a rate of more than 10 per cent per year.
The FastJet printer was demonstrated for the first time at drupa 2004 as a concept machine. Visitors to the stand were shown that single pass printing in CMYK at 520mm width is possible at a speed of 1.6m/second or 100m/min.

Since then Inca has continued the development: the print arrays have been doubled in width and the nozzle redundancy that further increased the technology is now ready to enter the verification stage in the corrugated market with an alpha machine in an industrial environment. It will help the two developers understand and improve FastJet’s reliability in a sheet plant where it has to cope with dust, humidity and heat. The alpha testing will answer questions about the operating tolerances of FastJet, its exact performance specifications, for example the drop size and ink lay-down, and about the necessary sheet and liner qualities to produce a desired image quality and the further conversion of the printed sheets.

The alpha machine testing will also provide important data about the performance of the technology in an industrial environment and the operating cost of the system. But the most important unknown quantity is the lifetime of the print heads. Will they last for 500kg of ink as they do in the special graphics industry? Will they last for a shorter time because dust will clog the nozzles? Or will they last longer because the UV lamps are so remote from the print heads that no stray light can dry the ink on the nozzle plate? Bill Baxter, Managing Director of Inca, is confident though, as the company has been running the concept machine for nearly a year without a single nozzle failure.

Sun Chemical and Inca are already designing the beta printer and the prototype of the first series machine will be installed at the end of the year. In addition to the alpha machine, the beta will provide an in-line pre-coater to ensure that print quality is optimised, independent of the liner specification. Although the beta partner is not yet decided the preference goes to a customer on continental Europe.

Sun Chemical wants to develop a service and support network that can help FastJet customers within hours if the machine fails. Packaging buyers will expect their orders to be delivered within 24 hours once they have chosen a supplier who prints digitally. The expectations will be very high and the success of FastJet will very much depend on the reliability of the technology and support to the printer customer. This is why Sun Chemical and Inca intend to spend a lot of energy in training customer staff to maintain the machine and do small repairs themselves but will also elaborate with each customer a realistic intervention scheme. Every printer will have different products, customers and staff skills. Sun Chemical wants to offer customers not only a digital printing solution but to help them develop an individual digital value proposition for their clients. This will include training sales staff and developing efficient communication routes with pre-press agencies. The beta project will be the learning case for this extended value proposition. With a successful alpha and beta experience FastJet will be officially launched to the global market at the Corrugated Show in Paris in May 2006.

Despite the interest that FastJet has generated since its debut at drupa in 2004, Sun Chemical and Inca are anxious not to call FastJet a disruptive print technology. Bill Baxter says that much of what happens the very moment the drop is fired is unpredictable and based on trial and error: “We only know as much as has been proven by experience without really scientifically understanding it. The alpha and beta verification process is designed to show that the technology is robust enough for industrial production.” Therefore Sun Chemical is reluctant to communicate how many machines it plans to sell in the years to come. But if the alpha and beta testing go well the belief is that in 2009 about
1 per cent of all corrugated prints in Europe and the US will be printed with FastJet.

And then Sun Chemical will also start to think about other application areas. A natural development would be FastJet for corrugated sheets. For the folding carton market, however, they believe that the print quality is not there yet. Print heads with greyscale technology could be a solution to achieve a higher apparent print resolution but to date they do not yet print at the required speed. But with a higher print quality also the flexible packaging market could be targeted with a roll-to-roll solution. The company’s strength is its high penetration of the global packaging market with inks. It can benefit from know-how in UV flexo inks for the flexible packaging market with proprietary chemistry.