The paper and packaging industry is at a significant turning point. Traditional resources, such as wood, face availability and cost challenges, pushing researchers to explore viable alternatives. Among them, peatland plants are emerging as promising candidates for sustainable packaging solutions. But how can these plants, often associated with specific habitats, compete with wood in terms of performance and durability?
Paludicultures, including plants such as peat moss, reed and phalaris, are already being assigned diverse roles. They are used as building materials, livestock feed and foodstuffs. However, their low lignin content also makes them attractive as sources of raw materials for the manufacture of sustainable paper packaging. Researchers at the Fraunhofer Institute for Process Engineering and Packaging IVV demonstrated their potential through feasibility tests. They made folding boxes, trays and other similar items, proving that bog plants could become a key resource in the paper industry.
Wood Dependence and the Search for Alternatives
Wood constitutes the primary raw material for the production of paper. In Germany, with an import rate of around 80% for wood raw materials, the market is under increasing pressure. This situation prompted researchers at Fraunhofer IVV in Freising and Dresden to explore the potential of bog plants such as reed, sedge or phalaris for sustainable packaging. The PALUDI project, which is part of the Fraunhofer initiative on biogenic value creation and smart agriculture, benefits from the support of the German Federal Ministry of Education and Research (BMBF), the Bavarian Ministry of Economy, Regional Development and Energy, as well as the Ministry of Science, Culture, Federal and European Affairs of Mecklenburg-Vorpommern.
The plants studied by the project are intentionally grown in rehydrated peatlands. This practice, known as paludiculture, aims to meet the requirements of the European Nature Restoration Act of February 2024, which requires that 30 percent of forest, grassland and wetland areas be rehydrated and renatured. “This involves agriculture in wet peatlands with locally adapted plant species. Paludicultures help maintain peatlands and contribute to climate protection by minimizing carbon emissions,” explained Fabian Kayatz, project manager at Fraunhofer IVV.
Technical Advantages of Peatland Plants
Compared to wood, reeds and similar plants have a lower lignin content, which allows a reduction in the use of chemicals during the transformation of plant fibers into paper pulp. According to chemical analyzes of paludicultures in the Freisinger Moos region, the lignin content varies between 20 and 23 percent, much lower than that of soft or hard wood. “The less lignin, i.e. the natural adhesive in the cell walls of plants, the fewer resources such as acids or alkalis are required during chemical processing, and the more stable the network of fibers that is formed,” specified Fabian Kayatz. In addition, the pulp obtained from these plant fibers has better mechanical properties than that of other straw pulps, such as corn or bamboo.
Lignin from non-woody plants can be released or separated from fibers with less energy. The fiber processing methods developed within the project make it possible to work at temperatures below 100°C, well below those of conventional wood fiber processing methods, thereby reducing energy consumption. The results showed that, depending on the parameters, up to 83% of lignin could be released by the Fraunhofer IVV method. “After harvesting the peatland plants, the resulting biomass could be processed on an industrial scale in a pulp mill,” added Fabian Kayatz, although the project work was carried out on a laboratory scale.
-Towards Innovative Packaging
The following experiments demonstrated that flat and molded papers made from these fibers had good processability. The tensile strength of the laboratory samples was significantly higher than that of the reference samples. By adding additives such as starch and sizing agents, the tensile strength and elasticity as well as the water-repellent properties of the papers could be further improved. Additionally, these papers have proven suitable for processing methods such as folding, gluing and printing.
Using fiber molding and thermoforming processes, researchers were able to produce sturdy paper pots and trays from reed fibers without additives. A specific laboratory has been developed for the production of these packaging demonstrators. “Peatland plants have great potential for manufacturing innovative, bio-based packaging, as we have demonstrated with our resource-friendly pulp production processes,” resumed Fabian Kayatz.
However, optimization steps remain to be taken to move to industrial production and to design packaging acceptable to consumers, particularly in terms of sensory perception or material coating. Initial plans include manufacturing packaging for the non-food sector such as cosmetics, logistics and office supplies.
Illustration caption: Compared to wood, reed canary grass is characterized by its low lignin content. © Fraunhofer IVV
Source : Fraunhofer
