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Baumer hhs Gmbh Group press release – Krefeld, July 4th 2024
“Adhesives are indispensable in packaging production: they reduce material requirements and enable lighter packaging, which is in line with the objectives of the new Packaging and Packaging Waste Regulation (PPWR). Although adhesives only make up a small proportion of total packaging, they have a significant impact on recycling processes, paper production and the CO2 footprint. The Sugra (“Sustainable Gluing with Renewable Adhesives”) project is dedicated to this topic: it is developing adhesives based on renewable raw materials that protect the recycling process and reduce the CO2 footprint. These adhesives meet the requirements of modern production techniques and promote sustainable production without compromising performance.
The basis of adhesives is starch: this natural raw material is already used intensively in natural and modified form. Starch plays a particularly important role in paper production and processing, as it increases the strength of paper and refines its surfaces. In corrugated cardboard production, starch is used to bond the layers together.
Starch-based adhesives are not new: they are already used in flexible paper packaging to bond layers. However, the starch adhesives currently available have clear limitations when it comes to bonding folding cartons and corrugated cardboard boxes, due to long setting times and low initial tack. After the pressing process, these packages often open again, as their higher bending stiffness compared to paper increases the tendency for the adhesive gap to crack. This can only be remedied by longer storage under pressure or greatly reduced production speed – both of which are uneconomical.
The Sugra project aims to develop starch adhesives that are suitable for folding cartons and corrugated boxes without compromising performance. Traditionally, adhesive manufacturers develop their products for existing adhesive application equipment – which is why many of them use Baumer hhs nozzle application technology in their laboratories. Sugra, however, is taking a new approach: the development of the adhesive and the adaptation of the application equipment go hand in hand. Initial results show that even minor adjustments to Baumer hhs application technology can significantly improve the performance of starch adhesives.
Another approach is the use of this adhesive in the lamination of layers in substrate and packaging production. The desired good washability in the recycling process promotes the separation of the layers and thus reduces the introduction of foreign substances into the pulp.
The use of starch as a raw material is not without controversy: food competition and land and water use in the cultivation of plants containing starch are key issues. It would make more sense to obtain adhesives from plant production waste or previously unused plants. Baumer hhs is involved in many of these research approaches. However, the critical point is that many of these approaches are still at an early stage of research. Starch as a raw material, on the other hand, is already available in large quantities today, enabling a rapid switch to more sustainable production. The choice of starch source is also important: Sugra relies on the potato as a “climate champion”. According to the IFEU Institute and the German Federal Environment Agency, potatoes have a 15 times lower carbon footprint than rice and are grown locally in most countries, which reduces the transportation burden.
Other aspects speak in favor of starch as a packaging adhesive: Starch is an important component of paper, so recycling companies are very familiar with the handling of starch in the recycling process. The small amount of adhesives does not increase the wastewater load or the oxygen requirement. Starch adhesives can also be easily washed out in the recycling process. Another advantage is the color: Starch adhesives are milky and form a light white to slightly transparent layer when set – an advantage over other bio-based adhesive raw materials such as lignin, which often have an intense color.
The expertise in adhesive development comes from the Fraunhofer Institute IAP in Potsdam, which has many years of experience in the modification of starches. The Fraunhofer IAP develops the basis of the starch adhesive and improves it iteratively in close cooperation with the project partners. The food conformity of the adhesives is guaranteed by careful selection of raw materials.
The Research Foundation for the Paper Industry (Papiertechnische Stiftung) provides proof of the suitability of the adhesives developed. The adhesive strength and recyclability are evaluated according to recognized standards. Within this framework, measurement methods are being further developed, in particular to be able to simulate the conditions of high-speed production machines. The benchmark is established synthetic dispersion adhesives.
As consortium leader of the Sugra project, Baumer hhs is conducting application tests in its Solution Center. The focus is on the processability and application quality of the adhesives. The tests are carried out at production-related speeds. Another approach of the project is the targeted further development of the application equipment in order to meet the special requirements of starch adhesives.
To give you an idea of the research effort to date: To date, 111 variants of the starch adhesive have been developed. This development has gone through 10 iteration loops, with further adjustments being made based on feedback from the Baumer hhs Solution Center. The application tests are carried out at speeds of up to 300 m/min. At the same time, the Research Foundation for the Paper Industry (Papiertechnische Stiftung) is carrying out tack measurements and bonding tests with the most promising variants. The research is progressing and the learning progress is remarkable. This level of effort would be almost inconceivable without public funding.
The practical testing in real production environments is carried out by the industry partners in real production environments. Baumer hhs initiated this project in order to actively support the transition to more sustainable packaging. Baumer hhs is open to further cooperation and actively promotes other partnerships.
The project was first presented to the public at drupa 2024 and met with great interest, particularly from brand owners who support the development of more sustainable packaging. The project is at the halfway stage and continues to develop and verify the results.
Special thanks go to the Agency for Renewable Resources (FNR), the project management agency of the Federal Ministry of Food and Agriculture, which is funding the Sugra project under the funding code 2220NR168A.”
For any questions about this press release contact marketing@baumerhhs.com
