The Tape2Grape project, carried out at the Fraunhofer Institute for Surface and Bioprocess Engineering (IGB) in Straubing, aimed to create a new, fully biobased and biodegradable grafting tape for fruit and horticulture. The initiative was launched in October 2021 as part of the “New Products for the Bioeconomy” competition (IBÖ) and concluded in September 2022 under the grant number IBÖ08‑031B1184. The research focused on developing a tape that could replace conventional petroleum‑derived grafting films, thereby reducing environmental impact while maintaining the mechanical and biological performance required for successful grafting.
The technical work was organized into five work packages. First, a comprehensive patent and literature review identified that most existing grafting tapes are petrochemical in origin, with only one patent (CN102617890A) describing a biodegradable tape that still contains non‑biobased components. The search was broadened to include biodegradable films and foils, revealing several patents for packaging, mulch, and cling films but none specifically for horticultural grafting. This review guided the selection of candidate materials.
In the second work package, the team sourced a range of biobased polymers and additives. Base polymers included thermoplastic starch, polylactide (PLA), and polyhydroxyalkanoate (PHA). Plasticizers such as glycerin, sorbitol, PEG 1000, and citrate salts were chosen to improve flexibility, while natural additives—propolis and chitosan—were added to explore potential antimicrobial and mechanical benefits. These materials were procured in sufficient quantities for laboratory experimentation.
The third package involved laboratory‑scale compounding and prototype production. The selected polymers and additives were mixed in an extruder at varying ratios, then processed into thin films using a hydraulic laboratory press. These prototypes represented the first tangible forms of the proposed grafting tape.
The fourth work package evaluated the material properties against the requirements set by the IGB. The prototypes were subjected to water‑stability tests that mimicked real‑world conditions: hazelnut sticks were wrapped in the tape and exposed to alternating wet and dry cycles. The tests assessed dimensional stability, adhesion, and resistance to moisture. Several formulations demonstrated promising performance, maintaining integrity and flexibility throughout the cycles, indicating suitability for grafting applications.
Finally, the fifth package assessed the results and assembled a consortium for the feasibility phase. Four partners were identified: F. Schacht GmbH & Co. KG, an online retailer of nursery products who also provided economic expertise; Baumschule Schmitt, a local nursery; the Landesanstalt für Wein‑und Gartenbau Veitshöchheim, which would conduct field trials under realistic conditions; and Jura‑Plast GmbH, a film manufacturer capable of scaling up production. The consortium was formed toward the end of the scouting phase, and a strategy for the feasibility phase was developed in collaboration with these partners.
Throughout the project, the focus remained on creating a tape that meets horticultural standards while being fully biodegradable. The laboratory tests confirmed that certain biobased polymer blends, enhanced with natural additives, can achieve the necessary water stability and mechanical properties. The collaboration framework established during the scouting phase positions the project to advance from laboratory prototypes to pilot production and real‑world testing, with the ultimate goal of delivering a sustainable grafting tape to the market.