Unbreakable

For the end user, adhesives play a 'seen but not heard' role in product consumption, but for the packaging industry, innovative adhesives that are reliable – and, increasingly, sustainable – are taking centre stage. Converting Today reached out to leading brand owners, retailers and converters to learn more.

With the vast majority of products housed in some sort of packaging, the reliability of the packaging is as important to the manufacturer as its desirability to the consumer. Adhesives see a wide variety of applications in the packaging world, from converting to paper bonding to box construction, and the demands of the industry are just as varied.

FEICA, the Association of the European Adhesive and Sealant Industry, represents national and multinational manufacturers across Europe. The voice of the industry, FEICA actively supports and promotes the industry's interests by constructively influencing EU legislation. It also works to connect key players in the industry, promote the use of adhesives and sealants to targeted audiences, and continues to build strong relations between comparable international organisations.

The association's aim to promote adhesives and sealants is constantly underpinned by its sustainability awareness, reports FEICA communication officer Isabelle Alenus. "Packaging is one of the largest markets for adhesives, with applications including bags, corrugated board, foil laminates, non-wovens and flexible packaging," she says. "There are so many applications in the packaging industry that rely on adhesives, due to stability requirements for storage and transport, or for aesthetic reasons. Many normal packaging products such as envelopes and paper bags consist of just a single layer of material, but most packaging nowadays is actually different materials laminated together."

 A changing field

It is clear that adhesives have a hugely important role in the constantly changing world of packaging. "By laminating cardboard with paper – high-gloss paper, in particular – it is possible to put product information on the cardboard and give the product a commercially attractive appearance," Alenus goes on to explain. "Adhesives based on starch, dextrin and gluten, as well as polyvinyl acetate dispersions, are used for this purpose. We have also recently seen some interesting developments in the use of solvent-free systems, so-called 'high-solid' products and adhesives based on aqueous polyurethane dispersions. For automatic packaging machinery applications, we are also seeing higher demand for viscosity stability, with dispersion adhesives and hot melts being used to seal machinery."

On the increasingly important role of sustainability in packaging adhesives, FEICA is appropriately vocal. The association is involved in such projects as the Downstream Users of Chemicals Coordination group (DUCC) – part of the exposure scenario communications package (ESCom) – which helps companies to communicate consistent and harmonised messages throughout the supply chain.

Alena notes, "We have a toolbox approach to helping our members improve sustainability. We take into account the numerous applications, technologies and raw materials across the diverse industry, and adapt our support to suit members' needs. This allows every company, big or small, the opportunity to pick the tool that best suits them – it needs to be understood that doing nothing is not an option."

 Progressive adhesives

As one of the UK and Ireland's major food industry exporters, Nestlé produces some of the worlds' most recognisable brands, from KitKat to Nescafé to Shreddies. Nestlé demonstrates a demanding approach to its packaging, with regular developments relating to issues such as substance migration in food products listed high up on its requirements for suppliers.

At the Packaging Innovations trade show held in Birmingham in 2015, Nestlé announced that the company was keen to develop its guidance notes regarding packaging adhesives for its suppliers, highlighting the importance of packaging safety and compliance in the food industry. Nestlé's group packaging manager Alison Ingle explained how this upgraded approach to the company's packaging adhesives is part of its good manufacturing practice rules.

"It's very important that we have a multilateral approach to managing safety and compliance," said Ingle. "We need to have a good relationship between suppliers and manufacturers in sharing information on the development side and at factory level. No packaging material is inert – there are chemicals within our packaging that we need to consider, and it needs to be safe for our consumers. Without technical partnerships, we need to ensure that we are assessing new technology and putting its safety into consideration."

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. Paper labels were replaced with metallic PSL labels for the core range and have helped premiumise the brand and give it a more modern look.”

Clearly the choice of adhesive is a 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.

John Whitely, converting manager, Diamond Packaging explained: “Choosing the right adhesive is extremely important. One huge factor that plays a role is environmental expectations (for example, 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% fibre tear, and an optimum 100%, 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.”

 Smart packaging

For the UK's fourth largest supermarket chain, WM Morrison Supermarkets, the issues of adhesives in packaging is driven by its ongoing aim to “utilise smart packaging to keep our food fresh for as long as possible.” With a customer base that is simultaneously value and quality-conscious, Morrison’s has increased its use of recycled and recyclable materials, and reduced the overall weight of its packaging.

In terms of adhesives, the supermarket's recent development has seen the launch of new packaging for Morrison’s own-brand snacks. Morrison’s now features Macfarlane’s Esterpeel lidding film with ‘Reseal-it’ technology, which offers tamper-evident benefits and weight reduction alongside its desirable resealable quality.

Sean Hancock, lead print manager of packaging for Morrison’s, says, "We are always looking for new formats and keeping up with changing demands, particularly with regards to vertical integration through our manufacturing business. This new packaging for our own-brand snacks is certainly an innovation that meets the growing trend for resealable products, while achieving the highest standards for food safety across the manufacturing process."

For the converter’s perspective, Converting Today reached out to flexible packaging innovator Parkside Flexibles and their managing director, Nick Smith. When asked what the most important adhesive technologies of the moment are, he responded: “Current packaging trends are highlighting a need for reclosable features to be integrated into existing packaging formats. Consumers and brand owners alike are looking for solutions to address this and other trends, such as sustainability, portion control, and frustration-free openings.”

Choosing the right adhesive is therefore vital, as he continues: “The adhesive cannot affect the packing line in terms of speed of sealing or be inconsistent in its sealing performance. Leaking packs are expensive for the entire supply chain, and with the current media focus on product contamination and hygiene, the adhesive becomes an increasingly integral part of pack design. In particular, adhesives used to manufacture reclosable packs must easily peel and reseal but also have the initial lock seal performance of standard non-reclosable solutions.”

On the subject of the future of adhesives, he concluded: “Feedback from packaging manufacturers and brand owners alike suggests that there will be further take-up of reseal technologies in the future. With our laser scribing technology, we can reduce the pack manufacturers’ costs, increase line speeds and ultimately reduce the carbon footprint of packs. Our designs also give shoppers better flexibility for when and how much they eat, reducing food waste through improved storage and portion control. Although reseal technology is something that consumers like to have, the signs are that it could become the must-have for the future.”

As experiences, time management and enjoyment continue to drive convenience for consumers, adhesives’ role in providing performance enhancing packaging will continue to support innovation and growth. With the addition of sustainable and flexible resealing solutions in the future, it is a bond that will only get stronger.