Inline or CI? The flexo debate

Omet VaryFlex, flexo+offset+gravure inline printing platform

With the pandemic wreaking havoc with public health and fundamentally changing consumer behaviour in the retail trade, Nick Coombes speaks exclusively with Paolo Grasso, Head of Sales for the Label Business Unit at Omet about what is driving the market, and how this innovative manufacturer is responding to the pandemic

Nick Coombes: Inline vs CI is not a new discussion – how do you see the flexo scene today?

Paolo Grasso: The industry has spent years debating this, and there is no simple answer because it depends what you are trying to achieve. They both use the flexo technique, but that’s where the similarity ends in real terms.

 

NC: Is it more about application than technique?

PG: Yes, because the two different ways of using the flexo process largely dictate the end product.

 

NC: How do you see the current situation with CI?

PG: Its recent growth has been partially stimulated by the decline in run lengths of products that traditionally have been printed on rotogravure. Quality-wise, solvent-based CI flexo is a sufficient match for solvent-based gravure, but the investment and running costs are significantly lower if you consider pre-press, storage, set-up and so on. CI also has a smaller footprint and is easier to operate and maintain. The competing technologies serve principally the same market, but the trend is shorter runs on narrower presses.

 

NC: How does that compare with inline?

PG: The inline process has developed from the narrow web technology that began life as a means of producing self-adhesive or pressure-sensitive labels. Over the past decade or so, this sector has enjoyed high growth as demand for smaller single-pack portions and product differentiation has increased. This market is highly accustomed to the use of UV inks and lacquers, with the latest trend towards LED/ UV curing on grounds of greater efficiency and lower costs.

 

NC: Where has this growth in narrow web come from?

PG: Labels have grown in size, form and application. For instance, the beer industry that was once dominated by glue applied labels has recently turned to a self-adhesive filmic no-label look that enhances the appearance and allows for a longer lifecycle of the brand on the bottle. Other areas of significant growth include the use of unsupported film for shrink sleeves and in-mould labels that typically use PVC, PETG, and OPP substrates. If you imagine the size of a shrink sleeve with its 360-degree decoration and compare it with a traditional label, you will see why demand has grown for inline presses with wider web widths. In this market sector, 430mm (17”) is normal, but 530mm (21”) and 670mm (26”) are both growing.

 

 

NC: Are we reaching a crossover point between CI and inline?

PG: We have a situation where overall volumes are going up, but so are the number of SKUs, which means shorter runs but greater variety. I’d say the crossover point is 670-850mm (26-33”) – you can tell this by the number of inline and CI manufacturers who have developed new technology in those sizes. It’s the point where quick and easy makeready facilitates the handling of shorter runs at a viable cost. The inline approach is based on LED/UV, while CI is still mostly solvent-based. LED/UV is much closer to gravure in quality, while solvent-based is cheaper. Look at the food packaging industry for example; there is no appetite for LED/UV in primary packaging, and this is where inline manufacturers are fighting their toughest battles. Some progress has been made with low-migration inks and lacquers, but it is still far from being an industrial process. This is where CI is strong and likely to remain the reference technology for the foreseeable future. The only change might be a greater uptake of EB curing, but I can see this happening only if investment and running costs fall significantly.

 

NC: Are there any other considerations when deciding between inline and CI?

PG: Most modern CI presses run at 450m/min or faster on web widths of 1.3m or wider, so are set up for high volumes – the inline process has come from a self-adhesive label background where 200m/min is seriously quick on web widths of typically 430m. CI converters measure production in tonnes, inline measures in pieces which are then converted to linear metres. A short CI run might be one tonne, whereas on an inline press 300kg would be more normal – but it’s not one size fits all.

 

NC: Do you have any examples of converters using a mix? PG: Yes, a large printing company acquired a smaller one that had four Omet LED flexo lines in operation running specialised short-run work. The jobs were 90% related to direct-food primary packaging, where the absence of odour taint is critical. The parent company operates exclusively with solvent-based rotogravure presses supplying the same brand owners. The only difference is run lengths – the Omet lines are economical to 1,200 linear metres, using typically 300kg of laminated film and as low as 100kg for special orders. There is no way these could be produced as economically on a CI press. But there is a need for a business model agile enough to react quickly to changes in market demand. This makes a very strong case for inline. Shorter runs, more SKUs, faster delivery and more added value are all factors the narrow web sector has addressed in recent years, so the knowhow and technology is well established. Where CI still scores is in larger volumes and primary food packaging, where the very best print quality is not essential.

 

NC: How do you see digital print affecting this market sector?

PG: Demand for digital print is growing fast, but cost is still an overriding factor and until that changes I see digital as a complementary rather than a replacement technology. Our platform design allows us to adapt to supplying a variety of hybrid print solutions in different configurations. For example, we have supplied customers with hybrid presses that combine offset/flexo/gravure print units, all inline narrow web, and using a mix of solvent and UV or EB curing systems. This blend of technology allows converters to achieve unbeatable quality at the lowest possible cost.

 

NC: What does a hybrid line offer?

PG: I’ll give you an example. To minimise the cost of laying an overall white while maintaining proper densities, we integrate a rotogravure station on the press line. Solvent white ink is very inexpensive while the coverage is the best you can get, and the changeover time is reduced to one unit on the entire press. For complete food compatibility we print wet-on-wet offset and then use an EB oven to cure all colours, varnish and additional effects in one shot. EB curing does not require photo initiators, so there is zero risk of migration and contamination.

 

Omrt XJet, hybrid flexo+digital inline printing press

 

NC: What other hybrids are commercially attractive?

PG: The flexo/digital combination optimises cost without sacrificing quality. Since 2017 we have cooperated with Durst to integrate their RSC print engines into a machine we call the Omet XJET. This press is targeted at the pressure-sensitive label market as well as shrink sleeves with its 1200 x 1200dpi inkjet with 2pico-litre drops.

 

NC: What’s a typical use of this hybrid technology?

PG: If a converter needs to do a trial print run for a brand owner’s test marketing campaign, he can economically print the job entirely digitally but with a flexo plate for the white base. This offers big savings while still allowing a print run of 100 different images. As brand owners and converters look for greater differentiation, it’s those with the greatest imagination that will benefit most.

 

NC: How do you see the market shaping up in the years ahead?

PG: Digital will definitely take a larger share of the market over the next five years. This doesn’t mean existing print methods will disappear. On the contrary, they will complement each other. Hybridisation will become the new standard.