Adhesive Matters

As an essential component of packaging design and production, converters are continuing to transform with the adhesives they implement across their ranges says Dave Howell

The converting sector continues to increase its consumption of adhesives. According to current research from ReportsnReports.com, the global packaging adhesive market will see growth of GAGR of 6.6 per cent by 2019, with US alone demand for sealants and adhesives forecast to rise by 2.8 per cent with a market value of $12.8 billion.

Emulsion and dispersion adhesives and sealants will remain the leading product type through 2019. The on-going displacement of solvent-based products is forecast to support increases as end users strive to meet emissions regulations through the adoption of water-based and higher solids formulations. Despite loss of market share, solvent-based products are expected to see above average demand increases, boosted by a rebounding construction sector and product reformulation efforts to improve their environmental profiles.

For converters choosing the right components to meet their client needs is a critical part of their business proposition. Brand owners are constantly looking for packaging innovation to enable brand differentiation in the marketplace. Often, this will mean new form factors, which in turn require a different approach to their construction. Choosing the right adhesive - regulation notwithstanding - is a crucial decision to get right.

Indeed, brand owners are now taking the initiative when developing their packaging requirements. Nestlé for instance recently announced at the Packaging and Innovations tradeshow at the NEC Birmingham that they would be extending their existing GMP (Good Manufacturing Practice) guidelines to include more clarity for adhesive usage and application.

Alison Ingle, group packaging manager at Nestlé UK and Ireland explained: "We will be releasing guidance notes to our suppliers this year because adhesives aren't covered fully in terms of current regulations. It's very important we have a multilateral approach to managing safety and compliance. We need to have good relationships between suppliers and manufacturers in sharing information in the development side and at the factory level." This comes after the implementation of new hazard label requirements under UN GHS (Globally Harmonized System of classification and labelling of chemicals), which includes the use of Borax commonly used with bottle label adhesives.

The Carlsberg Group has also been innovating with their new Farris PET bottles. Christine Nygaard-Andersen, Carlsberg Group brand manager, said: 'The introduction of a one-way PET bottle (superseding the returnable plastic bottles) was the perfect opportunity to reinvigorate the brand. New designs build on the incredibly strong and recognizable Farris diamond equity and are carried across all brand extensions. Paper labels were replaced with metallic PSL labels for the core range and have helped premiumize the brand and give it a more modern look."

Clearly the choice of adhesive is crucial one for converters. A balance has to be struck between an adhesive that is robust enough to seal the packaging and remain intact throughout the supply chain, yet can be easily opened by the consumer.

Pierce Covert, president of Glue Machinery Corp told Packaging Digest: "Adhesive suppliers need to provide the correct adhesive to bond, but another important factor is the equipment that's used to apply (the adhesive) and compress it. It's a combination of efforts between the brand owners, converters, box manufacturers, adhesive suppliers, adhesive machinery suppliers and equipment used to do the actual packaging."

In addition, John Whitely, converting manager, Diamond Packaging told Converting Today: "Choosing the right adhesive is extremely important. One huge factor that plays a role is environmental expectations (e.g., freezer grade adhesives). The packaging structure, substrate, and performance are part of the analysis that allows us to pick the right adhesive for a particular packaging application."

Whitely continued: "From a manufacturing perspective we are always looking for a robust seal with a minimum of 90 per cent fibre tear, and an optimum 100 per cent, as we are gluing the manufacturer's joint. From our customers' standpoint when adhesives are being chosen for their lines it is typically in the form of a hot melt adhesive. This could be chosen for many different reasons such as structure, substrate, performance expectations, etc."

Innovation and development

How packaging is sealed is an important consideration for all converting service providers. The application of adhesive is one area where innovation is taking place. Traditional hot melt systems can be prone to nozzle clogging, contamination and usually have long set-up times. Using tank systems can alleviate some of these issues, as tank sizes can be large and heat-up times shorted as well as temperature being easily maintained, but they are still far from an ideal system.

Tank-free adhesive systems have been developed that resolve many of the issues that tank systems have suffered from, as no tank is actually needed. Adhesive pellets are drawn up by vacuum into the heating chamber where it is immediate dispensed from. Systems such as the Graco InvisiPac offer heat up times of only ten minutes.

UAE's Al Buheira Lacnor Dairies in association with Pak have been developing their own hot melt adhesives aimed at secondary packaging applications. Al Buheira Lacnor's production manager Alfred Fernandes said: "The new adhesives delivered marked improvements in operational performance. During the two-month trial, we saw a 49 per cent reduction in maintenance costs and our total consumption of hot melt adhesive dropped by 37 per cent. These results would translate into annual saving of more than $100,000 across all our packaging lines, significantly offsetting the additional cost of the new adhesive."

Understanding the lifecycle of packaging is also important from an adhesives perspective. With recycling an important component that brands are paying close attention to, how packaging can be handled at the end of the consumer cycle is a key focus. Returned bottles are a good example here. Labels and their adhesive need to be easily removed to ensure the bottle can go back into the production system with ease. Innovations such as H.B. Fuller's water-based pressure sensitive adhesive Fulltak SE 8301 is a good example. Under typical conditions, Fulltak SE 8301 delivers two hours ice-water resistance, thus maintaining brand integrity during use. Brands such as Pernod Ricard and Heineken are clear brands that can leverage this technology.

Another example that illustrates how adhesives have advanced comes from DuPont that has developed a system for improved recloseable and resealable packaging solution that can reduce food waste - something that all brands are actively pursuing with increased pressure from consumers. The solution was developed by Bemis Co. using DuPont adhesive technologies including Selar PA and DuPont Bynel. Bemis' SmartTack EZ Peel Reseal allows freshness to be preserved. "BelGioioso Club Store package with Bemis SmartTack EZ Peel Reseal technology is a real breakthrough in terms of packaging science and innovation," said Jane Skelton, head of Print and Packaging, Sainsbury.

Offering alternative closure mechanism to brand owners is one of the key areas of development for converters. Battelle and Mondelez are working together to create a new adhesive that could replace some traditional closures for foodstuffs and other packaging applications.

"Unlike traditional Pressure Sensitive Adhesives, the new Low Tack Adhesive (LTA) is not messy, tacky or expensive. For example, it won't pick up crumbs from crackers or cookies, that make traditional adhesives ineffective," said Cindy Conner, senior market manager in Consumer, Industrial and Medical Products at Battelle. "All consumers need to do is press it together to create an effective and consistent seal that stands the test of repeated cycles of opening and reclosing," Conner added.

The adhesive can be pre-applied to packaging film using conventional printing and coating technologies, followed by curing with ultra-violet energy. It is cost effective to manufacture and apply, and can be easily introduced into existing packaging operations. The developers of the technology believe LTA can be customized for a variety of applications needing higher strength as a cost-effective alternative to traditional hook and loop closures.

Innovation continues with adhesive technology as brand owners and their design partners continue to push what is possible with packaging solutions. Whether it is an adhesive for primary or secondary packaging, converters have a wide range of adhesive choice. Future development though continues with new adhesives offering the flexible packing converters in particular new options across their ranges.