Zeal for sealing

3 April 2017

Zeal for sealing

Zeal for sealing

Getting the right finish is vital in today’s aesthetically driven packaging market. Running inks, loss of brand quality or perceived value and reduced shelf life or food safety are just some of the problems that can arise when companies don’t take care of their finish.

One of the most basic and common finishing processes is laminating, which involves covering the print with a clear plastic film. Laminating output helps protect the print from the elements – light, water, dirt, inadvertent folding or crushing, and graffiti, for example. It can also help make the colours in the print appear more vibrant. Lamination, especially using thick laminates, also helps add rigidity to prints in those cases where mounting or printing on a rigid substrate is impractical or not feasible.

Laminates come in a variety of finishes such as gloss, matte and lustre. While gloss laminates can make colours pop, they can cause glare, depending upon the ambient lighting conditions. A matte finish may cause less glare, but can make the colours appear dull. Some users find semi-gloss laminates to represent a happy medium between the two. On the downside, bear in mind that lamination will make a graphic unrecyclable.

Often, a good alternative to lamination is aqueous coating, which, as its name indicates, is water-based. UV coating – which is cured by exposure to ultraviolet light – is another alternative to lamination, and can also be used to add a variety of special effects.

According to a new study from The Freedonia Group, solvent-based coatings historically have maintained the largest share of protective and speciality coatings. However, solvent-based coatings are projected to be surpassed by water-based coatings by 2020 as regulatory concerns continue to impact the protective and speciality market. Solvents will continue to lose share to other formulations, with trends favouring the use of water-based, high-solids, and other coatings that have lower or no VOC emissions. These and other trends are presented in the study, titled ‘Protective & Specialty Coatings Market in the US’.

Demand for water-based coatings in the protective and speciality segment is predicted to expand at an annual rate of 2.5% to 85 million gallons in 2020, supplanting solvent-borne coatings as the market leader. The trend toward water-borne coatings in the automotive refinish market, which historically has widely used solvent-borne coatings in an array of applications, is of particular importance for this formulation, says the study.

Water-based coatings are also gaining a foothold in protective marine coatings as several worldwide treaties and US regulations have put stringent limits on harmful emissions produced by marine coatings.


 Keeping up with trends

As a leading company in the supply of coating and laminating systems, Bobst is in a strong position to provide insight into recent developments in the market. Bobst sales manager Carlo Rosso speaks to Converting Today, addressing what’s new in lamination as well as particular developments from Bobst.

 “Lamination is a must for the majority of modern packaging for many reasons, [with applications] such as a barrier to light, barrier to the migration of fat, barrier to humidity, sealability of packaging, structure of packaging (standup punching), pasteurisation, and many more. Over the past ten years, Bobst has focused on three key aspects of lamination: the optical aspects of the laminated structure (such as brilliancy and maximum transparency), increasingly lower levels of solvent residue at the end of the process and reduction in the consumption of adhesives and solvents.”

“Laminating as a market seems to be moving towards more compact machines; the two most recent machines we have launched have been created for higher production volumes. Nowadays, the production of many flexo converters comprises very short runs, and considering that the US print market is 80% flexo, we engineered the compact laminators to fulfil this requirement.”

With regard to solventless adhesives, Rosso says: “Solventless adhesive is especially suited for laminates that do not require high mechanical or barrier properties. However, this is not enough for high-performance packaging. Considering the strong growth of retortable pouches, pet food and other products that require sterilisation, the use of solvent-based adhesive is necessary due to its high bonding characteristics. We’ve even seen instances of migration from solventless to solvent-based adhesives. Our machines’ production speed and optical quality are definitely better.”

Rosso concludes on a very important point, namely, that the lamination process uses costly materials, such as printed film, adhesives and occasionally aluminium foil, which is why such great care must be taken to reduce any waste and to constantly improve consistency and repeatability of the process. This has been a core focus for Bobst and other lamination and coating companies. For many high-volume applications and packaging applications, such as snack food, Bobst has perfected the extrusion laminating process on its equipment, as it is a more economical and environmentally-friendly process. The process enables the production of strong structures by extruding a film between the two substrates to be laminated together without using adhesives. All of this ensures the volume and quality are not affected but the costs of manufacture are more manageable.


 A cure for curing

Another company well versed in the ways of coating and lamination is Nordmeccanica, which launched a potentially revolutionary technology at drupa last year. Converting Today catches up with commercial director Giancarlo Caimmi, a 19 year veteran of the company, for his thoughts on these new developments and what they mean for the market.

“At drupa 2016, Nordmeccanica released an industry-changing technology. I am intentionally mentioning a ‘technology’ and not a ‘new machine’. [It is] an adhesive formulated to run on a laminator that targets one of the few inconveniences in solventless lamination. Solventless lamination is the most environmentally and energy friendly technology in the converting industry. Nevertheless, the adhesive curing stage requires converters to sit laminated rolls for hours and days in the curing room, waiting for the adhesive to be fully cured and ready for the next steps. With our innovation, we allow converters to go to slitter in 90 minutes and get the compound ready for food contact in a day. That’s unprecedented.”

“The technology is based on a simple idea. Instead of mixing the two components before the coating head in a meter-mixing pump, we use a twin coating head machine design and the two components are coated separately on the two webs, one component on each web. The Dow adhesive formulated for this application is named Symbiex and the Nordmeccanica laminator is Duplex SL One Shot. Each component of the adhesive sits in stable chemical conditions in the two coating heads, reacting once the two coated webs are joined at the lamination nip. At that time, polymerisation starts and develops very quickly to allow for the shortest curing time ever reached.”

“Our technology guarantees the accuracy of the coating heads, and the superior web handling reliability required by the process. The rest is in the advantages offered by the innovation. No mixing units are required, there’s a low rate of washing thanks to hours and hours of pot life, and there’s quicker setup of the station thanks to the patent-pending innovation in the motorisation of the dosing rollers setup”

From a commercial perspective, Converting Today asks what some of the most popular machines in coating and laminating are. Caimmi responds that this is not the correct way to look at the market, but rather “there is the right product for the right use from the company that brought to the industry every single remarkable innovation in coating and lamination technology: the 5 roller coating head, the compact line of laminators, the Triplex (in each available version), the Dry bond line of products featuring industry hits such as Linear.” In addition, there are technical solutions, such as the flat drying oven that provides further advantages once configured to OEM specifications. It is not one-size-fits-all, but rather the right tool for the task.

There is also the question of consolidation and its impact on packaging, with a view to understanding how this impacts coating and laminating machines and the converting sector. Caimmi is clear that everything needs to be done in the interest of converters, and as a laminator can serve multiple presses in a print line, it is more about efficiency in quality and production than consolidation of systems.

As for the overall market, converters continue to see benefits in coating and laminating. “Coating and lamination is a core cash cow in our industry. ROI on coaters and laminators is much faster than for any other piece of converting equipment. Increasingly, converters are going into coating and lamination because that accounts for a great portion of their profits, allowing them to not only effectively serve their customers with quality products in the time frames necessary but to be more efficient and reduce their margins. “

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