Crack the pack code

Increasing amounts of variable coding for on-shelf packaging have served to focus attention on types and specifications of coding that are reliable and effective for given products on a given line.

So, for instance, Linx Printing Technologies believes that its latest generation of laser coders, combining 9.3 wavelength tubes with full-washdown IP65-rated design, is having a substantial impact in beverage plants filling polyethylene terephthalate (PET).

"They are seeing real benefits with a very clear, readable, whiter code on the PET, with the additional advantage of a shallower scribe into the plastic," laser product manager David Martin says. "This is becoming more important as beverage firms use ever-thinner PET bottles."

There have been other key improvements, says Linx, in thermal management to cool the laser tube. "This means that IP65 lasers can run without the need for expensive factory compressed air or water-plant systems," says Martin. Instead, blower units or self-contained water-cooling systems are used.

In the view of Linx, the earlier generation of dot-matrix laser coders has largely been surpassed by more sophisticated full scribing laser, with its higher code quality. But for other suppliers, such as the recently-integrated Markem and Imaje businesses, the older technology still has a role to play.

According to UK sales manager Steve Ellison, the firm's 10W-output Smartlase 110-I pulsed dot-matrix coder has the benefit of a small footprint, and a lower price.

Markem-Imaje also offers high-speed, high-quality scribing or vector lasers, from the 7011 low-power system to the higher-power 7031S, typically used on PET lines. Versions of its Lightjet vector coder are available in outputs of 100W and higher, says Ellison, and have been installed to code packs such as Absolut Vodka's frosted glass bottles at speeds of up to 15,000 an hour. In this case, says the firm, dot-matrix was inadequate.

A 'reactive technology'​

But overall, Ellison provides a telling insight into the laser market when he describes it as a "reactive technology". By this, he means that despite the relatively high capital cost of these systems, they are not a sales priority, largely because they require no consumables. "None of my sales team is tasked with meeting particular targets with laser sales," he says.

At the same time, Domino reports that the return on investment (ROI) with laser systems is making them more attractive to food industry users. "Increased efficiencies are driving down the cost of manufacture, while reliability and quality are also improving," claims UK business development manager Simon Smith.

Laser can also be used for coding on to board sleeves and cartons. Domino has coders applying variable data on lines running at speeds of around 40m a minute, he says.

Smith explains that Domino's chief interest is in online coding applications, and argues that in most operations, offline coding would bring "efficiency flaws". But some smaller firms might not be able to consider on line options.

Allen Coding recently introduced its ACF 400 offline, intermittent carton coder, which uses thermal technology to print onto cartons, sleeves, blister cards, leaflets or cut labels.

This is not to say that Allen is ignoring the laser coding market. In fact, its variable power laser range, including the 10W-output Lasersystem K-1010 model, has seen something of a "growth spurt" recently, says md Adrian Shepherd. Here, some growth has come from food sectors such as dairy, partly explained by concerns over solvent-based inks.

Not all suppliers see dairy as a target for laser. Says Smith at Domino: "Continuous inkjet (CIJ) remains the choice for dairies. It's about speed and the operating environment. Laser needs a fairly dry and stable environment."

One growth market for Allen has been clients upgrading from hot-foil coding to thermal transfer. As Shepherd says: "It is far easier to change the data. This can be done digitally, whereas with hot-foil it's quite laborious."

Here, Allen's secret weapon (or not-so-secret, given that some 500 were installed by the end of 2008) is the 53LTi intermittent coder. "This is a volume product, brought in de-featured for people wanting a good quality image, without the high-level functionality," says Shepherd.

For the higher reaches of the market, Allen has its high-speed 55ssT thermal transfer printer, which will switch between continuous and intermittent operation. The first generation is going through a de-bugging process. Or as Shepherd puts it: "Our Chicago technical centre has been through customer feedback to enhance features such as the web tension and the programmable friction feed roller."

Latest-generation SmartDate thermal transfer coders from Markem-Imaje are typically used either in print-and-apply labelling or in online direct coding for form-fill-seal lines. Ellison admits: "We lost our leading position to some extent in this market. But with SmartDate 5, a lot of work has gone into leapfrogging the competition." The full-colour touchscreen puts it on a par with others in the industry, and the ribbon-saving is "very efficient", he says.

Others have been seeking to strengthen their base in the thermal transfer market, with Domino having acquired the technology behind its V-series coders under a year and a half ago. This has now been standardised in the Domino range, says Smith. At 1,400m, Domino claims to have the longest ribbon capacity on the market. And if that were not enough, like Markem-Imaje, it can complement this with a ribbon-saving feature for greater longevity.

This move is indicative of the long-term trend among the consolidated international base of coding suppliers to offer a one-stop-shop across the different technologies. So, for instance, Allen Coding has reciprocated Domino's push into thermal transfer by announcing that it will introduce its own non-contact inkjet product during 2009.

Continuous inkjet mainstay​

Of course, CIJ remains the mainstay of most coding firms' ranges, accounting for some 70% of the primary coding market, Markem-Imaje estimates. As a consequence, there is continual eye-catching innovation in delivery systems, complemented by ever-evolving ink offerings.

As line speeds have increased, so has the pressure on CIJ suppliers to match those speeds, while not restricting the amount of data. Domino has met this challenge by introducing the A series Duo: a single-head, twin-jet system typically used on high-speed canning and beverage lines.

At Markem-Imaje, the emphasis has been on optimising ROI and reducing operator input. "When you have self-flushing, self-cleaning heads, there's a big knock-on effect in terms of maintenance and operator intervention," says Ellison. "Our 9000 series reduces it hugely."

Also reduced is the requirement for the "expensive on-cost" of filters, says Ellison, with just two of these in each 9000 coder. When it comes to fluids, Markem-Imaje says the move has been to more condensed forms in closed, cartridge-style formats.

Reducing the volume and consumption of solvents and additives is a key concern. Linx has added the Solver variant to its 6900 CIJ range. This is said to cut solvent usage by up to 40%, using software control to limit evaporation rather than, as in some systems, recirculating the solvent.

As ever, ink development has focused on formulations which offer high adhesion and quick drying while minimising (or eliminating) the use of volatile solvents. Most suppliers offer the range of options from 'standard' methyl ethyl ketone (MEK) to alcohol-based and water-based alternatives.

Although applications of direct online variable print on to flexible packaging are growing, print-and-apply labelling is of vital importance in many fresh food categories.

For top and bottom labelling of its cakes, Avana Bakeries has installed some 20 systems from Harland Machine Systems over the past decade. The latest installation combines Harland's Proteus label heads above and below the split-belt conveyor with thermal transfer coding from Markem-Imaje.

Sales manager at Harland Des Dunleavy confirms: "The move to variable data has seen the increased use of thermal coders, which are much more flexible than hot-foil coders." In this area, the firm has worked with a number of suppliers on food-industry projects. "The Harland label head, fitted with the latest coders, can match increased speed requirements."

Pressure-sensitive labelling equipment supplier Pago has seen particularly strong growth in the importance of variable data and sequential number printing in the drinks industry. Md Craig Peachey also underlines the need for high placement accuracy at high line speeds, considerations which he says influenced food manufacturer Atkins & Potts' purchase of a Pagosystem 80 labeller.

Other areas where Pago has seen increased demand include on-shelf merchandising. Peachey summarises brand-owners' beliefs: "Sales can be influenced by in-store and on-pack promotions, brand loyalty can be changed, and financial considerations can be overturned by innovative promotions."

Innovations include bottleneck hangers for Bacardi and Bottle Green and on-cap 'wobblers' for Wells and Young's and Walders.

In the current climate the benefits of such labelling will no doubt be scrutinised closely.

KEY CONTACTS Allen Coding 01707 379500 Domino 01954 782551 Harland 0161 848 4800 Linx 01480 302100 Markem-Imaje 0161 333 8400 Pago 01206 755206