How is Baumer HHS addressing the subject of sustainability?

Percy Dengler: At Baumer HHS, in its role as a packaging industry partner for industrial gluing applications, we ask ourselves the following questions, among others: How do we, our customers and our industry partners define the term “sustainability”? What impact does gluing have on the sustainability of packaging? Gluing is a core step of packaging production, but just one link in the value chain. From our perspective, the UN Sustainable Development Goal of “partnership” is among the most important, because working in partnership is the only way to establish the basic conditions for real sustainability. And that goes for packaging production, too. For this reason, we closely coordinate research activities with industry partners and customers to identify potentials for improving sustainability in packaging production. There’s no question about it: Sustainable gluing is the future.

Who do you collaborate with?

Thomas Walther: The Europe-wide 4evergreen initiative, for example, aims to ensure that fibre-based packaging makes a greater contribution to a circular, sustainable economy, while minimising impacts on the climate and environment. As a founding member, we are actively involved in achieving this goal. Other members of 4evergreen include Nestlé, Danone, Procter & Gamble, Westrock, AR Packaging, as well as numerous paper and paperboard manufacturers and recycling businesses. In other words, this alliance brings together organisations along the entire value chain. Baumer is also active worldwide in bilateral collaboration projects with adhesive manufactures and customers. Our company is open to any partner interested in advancing sustainability.

Percy Dengler: We pursue the “rethink” approach, which means first deciding what is the right thing to do, and then doing it right. We want to rethink adhesive application. We are examining the subject comprehensively, and right now are in intense discussion on different levels with customers, industry partners and research institutions. As this shows, we are not “greenwashing” the issue by any means.

What are the most important aspects of your comprehensive approach?

Percy Dengler: The answer to the question of how industrial gluing can support the efforts of the packaging industry to increase sustainability is highly complex. A lot of things that appear to be sustainable at first glance, prove to be critical in the overall balance. You can only evaluate the sustainability of packaging if you take its entire life cycle into account. Unfortunately, the public debate often is dominated by isolated aspects that narrow the focus down to isolated sustainability criteria, which serve only the interests of isolated suppliers. Changing the course of industrial gluing starts with developing bio-based, sustainable adhesives, developing a functioning circular economy, and further optimising and/or minimising glue consumption. Beyond that, we want to give our customers even more targeted support, helping them achieve maximum energy efficiency and avoid waste in their gluing processes. We have a long tradition of designing our equipment and solutions for optimised glue consumption, maximum energy efficiency and waste reduction. But we still see potential for further improvement. Conversely, bio-based adhesives and the development of a functioning circular economy are comparatively new issues for us. With this in mind, our aim is to scrutinise the entire value chain and critically question our own actions time and again.

What exactly are bio-based adhesives?

Thomas Walther: Today’s adhesives generally contain additives made of non-renewable fossil raw materials. One example is polymers, which are made from petroleum. In view of the growing global population and the worldwide rise in the demand for packaging, the packaging sector is called upon to resolve the conflict between growth and resource scarcity and to significantly improve the environmental footprint of its products and processes. Bio-based adhesives made from renewable raw materials can help.

What renewable raw materials are you referring to?

Thomas Walther: Examples include starch-based raw materials, natural resins, natural rubber and natural latex. From Baumer’s point of view, however, it would be better to focus at least to some extent on biomass, meaning waste products from other processes or farming.

For example?

Thomas Walther: We see interesting potential in crop residues from grain production and other farming sectors, as well as in lignin, which is generated in large quantities in the paper and wood industries, ultimately as a waste product. Lignin is a carbon compound. Because of its specific properties, it has the potential to replace synthetic additives used in adhesives manufacturing.

What criteria determine whether a type of biomass is suitable for industrial adhesives?

Thomas Walther: There are many factors involved. For instance, adhesives made from biomass have to display the same application properties as conventional adhesives, so they don’t adversely affect packaging production by causing reduced output or higher reject rates, and thus more waste. Otherwise, sustainability would only exist on paper. Researchers therefore have to include the application properties in their analysis of bio-based adhesives from the outset. Baumer does use starch-based adhesives in selected industrial segments. But they are not yet suitable for the high-speed machines used in packaging production. In a lot of cases, some of their properties simply are inadequate, for example they display low application quality, long setting times and insufficient gap filling. We conduct in-house research into the application and bonding properties of bio-based adhesives, and we are an active partner in research alliances.

Doesn’t starch come under the category of food?

Thomas Walther: Yes, it does. So even when using sustainable raw materials, we have to weigh conflicting goals. Rising demand for starch could force up the price of specific food products. Rising demand for natural rubber could lead to clearing of the rainforest to make way for rubber plantations. Not only that, the cost of harvesting and transport, including the associated CO2 emissions, would have to be taken into account for adhesives based on natural rubber. Social issues would have to be another part of the analysis. Does a plantation economy threaten the supply of agricultural products to the local population? Does a plantation economy benefit the local population or just a few large landowners?

Percy Dengler: The basic conditions required to produce biomass are one factor that determines their sustainability. Working with our partners in industry, we base our evaluation of these raw materials on the economic, social and ecological criteria defined in the UN’s 2030 Agenda for Sustainable Development. We draw up a life cycle assessment (LCA) to assess their entire impact, including potential for goals that conflict with other areas. In other words, we take an in-depth look at this complex issue in order to achieve real sustainability in automated adhesive application.

Why is Baumer, a manufacturer of industrial gluing solutions, working so intensively on sustainable adhesives?

Percy Dengler: Vigorous knowledge transfer between Baumer and its partners in industry and research is a fundamental prerequisite for developing solutions that support industrial gluing with bio-based adhesives. Sustainability must go hand-in-hand with the demanding requirements the packaging industry and other sectors have when it comes to productivity, quality, reliability, flexibility and cost-efficiency. To ensure that it does, Baumer works closely with adhesive manufacturers and research partners to develop adhesives. Our extensive know-how in industrial gluing is used to develop sustainable adhesives, and we in turn use the expertise of adhesive manufacturers to develop our gluing solutions. We adapt our equipment wherever necessary to achieve the necessary levels of productivity, quality, reliability, flexibility and cost-efficiency for our customers’ processes. The entire process must be geared towards sustainability if it is to earn the label “green gluing”.

What is your opinion of regulatory measures such as the EU’s Plastics Strategy which, in line with the “polluter pays” principle, introduces extended producer responsibility for the environmental impact of packaging?

Percy Dengler: Baumer welcomes such measures because they spur on progress. The market is putting pressure on the packaging industry to improve the reputation of its products. The industry has to make the manufacturing process for these products as eco-friendly as possible. And the packaging itself has to be as eco-friendly as possible. With our sustainability strategy, we want to support our customers as effectively as we can in their efforts to produce eco-friendly packaging. Eco-friendly packaging secures jobs in the packaging industry and in supplier companies. And regulatory measures promote innovation. For example, in a very short time, we have received a surprising number of inquiries for machines capable of applying glue to produce paper-based straws and cups, which increasingly are replacing their single-use counterparts made of plastic.

How does biomass rate when it comes to cost-efficiency?

Percy Dengler: Adhesives made from biomass have to achieve a price/performance ratio comparable to that of conventional adhesives. In other words, adhesive manufacturing needs biomass that can be produced and made available in sufficient quantities. The petroleum-based raw materials used in the production of conventional adhesives are subject to price fluctuations, which would be largely eliminated in the case of sustainable adhesives. That would be another advantage of bio-based adhesives.

Do adhesives made from biomass offer advantages in terms of recycling?

Thomas Walther: Some manufacturers even advertise their bio-adhesives as being compostable. From Baumer’s standpoint, however, the goal must not be to compost paper-based packaging, return it to the environment. Our goal is to recycle it, to establish a functioning circular economy in which packaging materials are automatically recycled, and in this way to minimise the impact of packaging on the environment. Conventional adhesives can have a negative influence on the recycling of paper-based packaging. This is particularly true of hot melt adhesives. End-of-line packaging specialists, for example, try to replace them with cold glues, which are easier to recycle.

Today, more and more hot melt adhesives based on biomass are appearing on the market. In view of sustainable gluing, it basically is a welcome trend. But here too, it’s important to analyse their impact on the recycling process. Regardless of what they are made from, hot melt adhesives have one thing in common: In waste paper processing and recycled paper manufacturing, they have a tendency to form sticky impurities, which can impair the quality of recycled paper grades and lead to costly disruptions in papermaking machines. Baumer has already had some good experience with hot melt adhesives made at least in part from biomass. But there are still some unresolved issues. The easier it is to recycle packaging, the less it costs to recycle it. Put another way, good recyclability improves the cost-efficiency of the packaging. What is more, good recyclability increases the rate of recovery of valuable fibre and helps meet the recovery targets of the EU’s Circular Economy Action Plan.