Fraunhofer Institute for Process Engineering and Packaging IVV
100 percent paper — 100 percent recycling
When it comes to replacing plastic-based packaging materials with recyclable materials made from natural fibers, the fact that the alternative materials have different processing and quality properties is a major challenge. Until now, creating joins and seals in paper packaging that meet high quality standards has required the addition of extraneous materials such as adhesives and plastic. This reduces the recyclability of the packaging and results in complex, costly recycling processes.
In the joint research project “Papure,” researchers from four Fraunhofer institutes are combining their research expertise to develop a complex joining process. This process enables the production of paper packaging without this material contamination, while also ensuring quality and reliability.
In addition to increasing sustainability, the process also improves the quality of the recycled material and allows more paper to stay in the recycling loop.
Meltable cleavage products to replace foreign materials
The new approach being developed in this project involves exposing paper to a CO laser, which creates re-meltable glycosidic cleavage products on the surface of the paper. Heat contact processes that are already established in industry can then be used to join the paper, instead of the extraneous materials that would otherwise be required.
Application-specific joining process
As part of this research project, a joining process is being developed at Fraunhofer IVV. This process involves the application of a specific amount of heat and mechanical pressure, which causes optimal fusing of the cleavage products produced using the CO laser, resulting in high-quality joins.
The quality of a join is mainly determined by both the strength and the visual appearance of the seam. A tensile test is used to assess the strength of the seams in accordance with DIN 55529:2005-09. In principle, the goal is tensile strength of 8 N/15 mm or 80 percent of the strength of the paper material. These sealing seams may only have some slight warping and must be free from discoloration. These criteria are being used a basis for developing suitable procedures, tools and requirement profiles so that the joining process can be implemented in packaging plants.
Projektinformationen PAPURE
| Program: | Prepare |
| Project term: | 04, 2023 to 03, 2026 |
| Funding: | Fraunhofer-Gesellschaft |
| Project partner: | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Dresden (Projektseite des IWS); Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik IWU, Chemnitz; Fraunhofer-Institut für Angewandte Polymerforschung IAP, Potsdam |