Ink jet comes of age

Three decades ago flexo based print rollers put simple codes on cases. Today, flexo printing vies with gravure to print some of the highest quality packages.

Like flexo, the simple ink jet coders of two decades ago have been replaced with networked equipment, with the latest of the piezoelectric, digital models launched having added graphics to the range.

And, as the edges of coding and graphics once again blur, it is ink jet equipment – with its greyscale tech-nology – that would appear to offer some of the most exciting prospects on the packaging digital printing front.

Mention digital printing presses to some packaging producers and they would shake their heads and mutter something about speeds, quality and cost of inks.

But at the international print show – Ipex 2002 – recently you would have had to have been an ostrich with its head firmly in the sand not to have seen the potential value of digital print to the brand owner and user of converted flexible packaging and labels. Certainly, its versatility offers practical yet creative options for the packaging user and designer.

Behind every good ink jet printer is a print head. Xaar develops ink jet technology, targeting the packaging market through its manufacturing arm Xaarjet. Its heads are to be found in many ink jet machines (dotrix and Willett, to name but two) and its technology is licensed to other producers such as Toshiba TEC with whom it has recently collaborated.

Ian Macgregor, Xaar director of marketing said: "One of the key things today, where hundreds of new products come to market, is the importance placed by an fmcg manufacturer on finding out as early as possible if a product will succeed or fail. Digital print can provide that with its ability to print sample packs and test them in supermarkets.

"In addition, in many local markets such as Asia, Africa and smaller European countries, it allows information – sometimes regulatory – to be printed on the packs in the local language. It brings sensitivity and creativity to a localised market."

Greyscale could be offering blue skies ahead on short run packaging. "Apart from being able to offer variable or personal print, the new greyscale head we have developed with Toshiba TEC gives an enhanced image without any loss in speed," he explained.

Believed to be the first full production greyscale ink jet printhead, it is said to be capable of producing "photographic quality" onto plastics such as for CD decoration and has other packaging applications including carton and label printing.

Just what makes for the huge difference in quality? "The natural resolution is 300dpi but what this technology does is to fire multiple droplets from the same nozzle in rapid succession. These merge to form pixels of variable size. Because of this you get an image with curves rather than the digital 'blob or no blob'.

"The user gets something that looks more like 1000dpi rather than the 300 it actually is – near photographic quality at relatively low print resolution." And the printhead, which is currently on beta test with customers, is designed for the rigours of industrial printing, he reports.

What does the future hold? "We do not see Xaar coming in and replacing flexo," he stressed. "We have one element of the total solution."

But managing director of dotrix Rob Haak, the Belgian-based manage-ment buyout company formed from the former industrial printing business of Barco Graphics last December, says his equipment is "a cost effective alternative to flexo and gravure printing.

"We have to meet the challenge of our customers and their customers. Those challenges are shorter run lengths, shorter lead times, minimal inventories, more product variety, more differentiation and mass customisation."

Its .factory's [pronounced dot fact-ory] industrial digital press uses Toshiba drop on demand greyscale heads with UV ink jet inks.

"The benefit of that to the end user is light fast, scratch fast and heat resistant print," he explained.

On the label front he has confirmed that label press manufacturer Mark Andy has ordered two of the company's SPICE (single pass ink jet colour engine) units to prove the point. The move comes as a result of increasing demands by label users for shorter run lengths and faster turnaround.

The integration of the base unit of the .fact-ory into the 2200 label press was announced at LabelExpo when Mark Andy president John Eulich described prototype equipment.

Mark Andy will use one press as a demon-stration machine in its Missouri headquarters and the other has gone recently for beta test-ing at label converter Stralfors, Gothenborg. The 330mm wide flexo/digital ink jet press is designed to print fully variable data up to six colours.

In case and carton coding, which some would say was a far more mundane yet a far more commercial application for ink jet printing and coding, the issues of the day are the ability to print bar codes consistently, the need to 'keep clean' and the move towards networking of equipment.

At Interpack, in a move set to take the costs out of premier case coding, Willett launched an ultra high-resolution digital printer.

The 610 "features technology that will take impulse jet a lot further", says chief executive officer Robert Willett. Quality and consistency of print are said to be achieved by the printer's self priming ink system and innovative head cleaning technology claimed to ensure mess, rejects and downtime can be eliminated.

"It sets the benchmark in high quality digital printing technology, which can consistently print combinations of bar codes, text and graphics directly onto secondary packaging. And it provides a real and cost effective alternative to labels and pre-printed cartons."

Group marketing director David Jenkins told Packaging Today International: "We have exclusive global rights to the acquired patented technology that keeps the heads clean. Like many good ideas it is simple. A pulse of ink dribbles through each head and is then recycled."

The head is cleaned in milliseconds between each print so that each code is "always as good as the last with no more expensive production re-runs".

Fluid replenishment is also claimed to be clean, simple and straightforward. Its system has been designed to pierce pre-loaded, foil-sealed inkbottles automatically.

Since the e.centre's report on recommendations for best practice for ink jet printing bar codes onto fibreboard cases, published last February, much emphasis has been placed on the use of correct equipment and liquid or phase change inks.

Bar codes from the 610 can be consistently and reliably scanned ensuring acceptance by the customer says Willett. "Costly product returns can therefore be eliminated."

Chris Simpson of Interactive Coding Equipment welcomes the e.centre recommendations but points out that the onus is still on ink jet manufacturers to provide the right equipment to ensure that the guidelines can be met consistently and cost-effectively.

"The procedures and recommendations in the report are very useful and help to give a legitimacy to ink jet coding that we previously lacked," he comments. "In many ways, they are common sense and draw together in an official document many of the points manufacturers were making individually to customers.

"Nevertheless, the bottom line is that consistency and quality codes are still best achieved by using quality equipment. Factory production lines are harsh environments with dust and vibration causing particular problems to ink jet printers, requiring frequent operator intervention to maintain the standards demanded by the e.centre recommendations."

In particular, he believes that fully automatic self-cleaning printhead technology is a major breakthrough. "To achieve consistent high quality printing throughout a production shift, ink jet printers need to have their heads regularly cleaned to clear any blocked nozzles. There is no other way round this," he explains.

"Before self-cleaning heads, this meant regular monitoring and stopping of the line to carry this out manually. This obviously had a knock-on affect on production throughput as well as wasting ink, creating mess and involving unnecessary manual labour."

His company's contribution is the Infineon, described as a fully self-maintaining case coder.

With its arrival, high-resolution on-line printing has finally become a realistic alternative to printed labels and pre-printed outer cases, offering users significant cost savings while guaranteeing high print quality, says ICE.

The self-cleaning system also operates every time the machine is asked to print, ensuring that the print-heads remain immune to dust and debris and guaranteeing high quality print time after time without operator intervention.

The equipment "produces a high quality indelible print finish, unlike hot melt wax ink jet printers where the essential printed information can be scratched or rubbed off in transit," adds the company.

The 180dpi printheads have 500 addressable jets allowing clear and accurate reproduction of bar codes, company logos, time and date fields to be printed directly onto outer case packaging. Print area is 70x400mm for each of up to four printheads at a maximum print speed of 33m/min.

Typical print costs are 10% that of an equivalent printed label, giving a typical return on investment of under 12 months, stresses ICE.

The Infineon is fully Internet ready and an on-board Ethernet facility is fitted as standard to allow simple integration into factory networks. Other standard features include full network capabilities, allowing image requirements to be produced and controlled remotely from the machine to help reduce coding and operator errors.

Willett also sees networks as the way forward. At interpack it showed the second generation of its Connector software for the networking and management of CIJ coders.

It allows up to 99 Series 400 printers to be connected to one PC, which is able to monitor and control each printer, and download and select the designs to be printed. Connections may be made over networks or incorporated into existing Ethernet networks using TCP/IP connections. Linx Printing Technologies chose the Düsseldorf show to unveil its 6800 Spectrum pigmented ink jet printer.

"Designed to offer users greater all-round flexibility, the user-friendly operation and low maintenance de-sign offers improved print consistency, reliability and opacity while also significantly reducing the cost of ownership," said the company.

Key features include an innovative ink circulation system and ink tank design claimed to provide consistent pigment dispersal and print opacity. The Linx 6800 Spectrum does not rely on mechanical stirrers or factory air.

Intelligent printer software auto-matically adjusts the ink circulation routines at start up, according to the shutdown duration. It offers an intelligent start-up routine that can be preset to eliminate delays. An IP65-rated enclosure protects the printer from dust and wash downs.

"Acceptable for all coding on cases is our 5000 series," says general manager of Markem UK, Simon Chidgey. With up to four printheads from one control, the 5000 series combines a high-resolution print head with the firm's touch dry ink jet tech-nology to "reliably print 100% scann-able bar codes and detailed logos".

Basically, the solid wax is melted in the reservoir, delivered in hot liquid form to the piezoelectric head and fired from 256 jets on each head. "Unlike traditional inks this does not bleed into the carton," explained Simon Chidgey. "So it keeps the integrity of the coding and is accepted by all major supermarkets for warehouse barcoding.

"The equipment can code the traded units as the cases come past from several lines. Scanning will verify the product from typically a code on the tape on the base of the case and then the ink jet coder will automatically print the variable data on each case as it goes past at up to 45 cases/min," added Simon Chidgey.

Introduced by the company at Interpack was SmartTouch, a common user interface claimed to provide a faster and easier way to talk to the coder. Using a common operating system with touch screen controls, it allows users to programme, design and back up images. Whether used off or on line, the user can view the results of changes through a colour (WYSIWYG) display.

The German produced Wolke m600 printer uses digital thermal ink jet technology featuring the universal Hewlett-Packard cartridge in an industrial environment. Says Sue Brocklehurst of exclusive UK and Ireland distributor Sunala: "It is clean and simple to use with environmentally friendly water-based ink.

"The entire printing technology is located in the exchangeable cartridge, eliminating expenditure on mainten-ance, service visits, solvents and cleaning materials."

Claimed to be ideal for printing high-resolution bar codes, logos and alpha numerics up to 600dpi onto absorbent surfaces such as cartons, cases, labels and blister cards, the equipment is currently being used in the pharmaceutical, healthcare and food industries, she reports.

Menu-based, it works in real time and drives up to four printheads with a print height of up to 12.7mm. Printing speeds range from 300m/min at 60dpi up to 30m/min at 600dpi.

Domino featured its advanced performance A-series ink jet solutions at Interpack. The range of advanced fluids is claimed to stick strongly to difficult to code substrates such as LDPE and HDPE, confectionery products and chilled foods. The firm also has a range of inks for producing reliable quality print for flexible pouches and plastics used by the food industry, it says.