The role of adhesives in optimising packaging processes

Without packaging, the food industry stands still. Packaging ensures that the products can be transported safely to retailers and consumers and often extends the shelf life of food. At the same time, packaging without adhesives is unthinkable, as adhesives are essential for the cohesion and functionality of packaging.

“The food industry can’t work without packaging, and packaging can’t work without adhesives”, as Bert Gausepohl and Jan Hunke, Managing Directors of Bühnen GmbH & Co. KG in Bremen, point out. “In the food industry, there’s a growing trend towards more paper packaging. This also means a greater demand for adhesives.”

Adhesives are the backbone of many packaging solutions. They hold together cardboard, films and other packaging materials and ensure that food is packaged hygienically and protected against microorganisms and damage during transport.

Nowadays, sustainability is far more than a buzzword in the packaging industry and in adhesive production. The desire for greater ecological compatibility focuses on the product itself on the one hand and on the manufacturing process on the other.

“We continue to highlight the importance of taking a comprehensive view of the bonding process and the major role that the optimisation of production processes plays”, Gausepohl emphasises. “In our field, sustainability ultimately means reducing the use of adhesives. That can only happen if we accurately fine-tune machines and processes. We’ve actually seen production lines where nozzles were set in such a way that the adhesive shot right past the cardboard packaging to be glued.”

Process optimisation in packaging production – what does that mean, exactly? The goal is to precisely control the exact amount of adhesive needed to bond the packaging, to evenly distribute the adhesive and to prevent overdosages and uneven application. If companies succeed in this goal, the quality of the packaging improves and the process generates less waste, meaning that costs can be saved and resources conserved.

However, other factors also play a role when it comes to the quality and sustainability of the final packaging product, environmental conditions, for example. If cardboard packaging is stored in moist or cold environments, it may reduce the available warmth in the bonding process and affect the end result. “Customers are experts when it comes to their products. We are experts for processes, we analyse them to reduce production errors”, the Managing Directors explain. “Ultimately, our goal is to always put out cleanly bonded products, using the ideal adhesive with increasingly “green” components.”

It may be an unusual idea, but adhesives can also play a decisive role in preventing food waste. In industrial processing, machine downtime can also occur due to faulty bonding. Maybe the packaging machines apply the adhesive incorrectly, which can lead to inadequate sealing of packages. This can cause unwanted stoppage in the production chain as machines have to be serviced or repaired. This kind of downtime not only results in a loss of time and efficiency, but can also interrupt the required cooling chains, impacting the quality of sensitive frozen products, for example. The consequence of hours of downtime is that the food ultimately has to be thrown away.

“In these cases, each extra hour incurs considerable costs. This shows how important efficient and smooth production is for preventing food waste”, says Gausepohl. “Although the adhesive often only accounts for a small percentage of total product cost, choosing the right adhesive can be crucial.”

Adhesives consist of a variety of components such as binders and solvents, plasticisers or crosslinkers, fillers and additives. The hot melt adhesives sold by Bühnen generally contain resins, waxes, polymers and similar components. “Adhesives are petrochemical products, you can’t change that”, Hunke explains. “They are neither biodegradable nor compostable. However, the industry is on the path to sustainability and is working on new solutions.”

Today, Bühnen offers several nature products that are more sustainable and incorporate more “green” components. These are obtained from sustainable sources. In the future, they will include a higher proportion of bio-based raw materials, and the use of recycled materials is already increasing in research applications.

Alternative adhesives often cost only a few cents more than conventional adhesives, but the market is still reluctant to switch to new products. “There is a need for more education in this area. Alternatively, the EU might also create subsidies or guidelines to support a change in the market”, state the adhesive experts.

Incidentally, Bühnen’s easy4you service package offers customers support for the complete bonding process from a single source. It includes the analysis of processes, optimisation, maintenance and training as well as the provision of application equipment – everything included in the price of the adhesive, as it were.