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Journal articles
Data-efficient determination of machine-specific process windows in thermoforming using the example of PCR materials, TAPPI Journal July 2025
ABSTRACT: In an industrial context, process windows for thermoplastics in thermoforming processes are still often determined through time-consuming trial-and-error approaches. This results in increased effort when commissioning new machines, implementing new technologies, or substituting sheet materials. One key reason is the lack of methods that allow for efficient, process-related assessment of material behavior and a quantitative definition of a “target state” of the heated sheet in relation to geometry and process conditions. In this study, we present the In-Situ Thermoforming Characterization (ITC) method as an application-oriented approach that enables format-independent evaluation of material behavior directly within the forming station of a thermoforming system. The method was successfully applied to a material substitution case, replacing conventional virgin polypropylene (PP) with post-consumer recyclate (PCR) — in this case, recycled PP (rPP) — in the production of a defined cup geometry. The results enabled the transfer of existing process knowledge from the virgin material to the recyclate, thereby accelerating material qualification. Based on the collected data, material behavior under process conditions could be mapped within the design space, making it possible to identify machine settings that deliver equivalent forming results in our test setup. Overall, the method shows strong potential for efficient and precise determination of machine-specific process windows.
Journal articles
Local delamination in pharmaceutical blister packages • A thermomechanical theory on buckling of heat-sealed composite laminates in flexible packaging, TAPPI Journal July 2025
ABSTRACT: Pharmaceutical blister packages consist of cavities made from a thick polymeric form foil and a thin aluminum lid foil. Heat-sealing technology is usually used to bond the lid foil to the form foil. Occasionally, the sealed area shows buckling defects of the lid foil, which allow contamination to enter into the cavity. A contaminated product is a worst-case scenario for pharmaceutical production and must be avoided. We discuss a thermomechanical theory on buckling defects in blister packages and derive strategies to avoid these. The theory is based on the assumption that the seal of a blister packaging behaves like a laminate of thin composite layers under compressive load. Literature research on buckling of thin laminated films, thermal behavior of polymers, and seal strength of heat-sealed polymers provides the technical and physical background to elaborate the theory. The theory comprises three elements: an initial condition regarding thermal load and precedent defects; a buckling condition; and a crack propagation condition. The plausibility of the theory is verified using model calculations and heat-seal tests. The paper concludes with strategies against buckling of heat-sealed lid foils and an outlook on other applications in laminating and coating of polymer films.
Journal articles
19th European PLACE Conference highlights challenges of balancing sustainability with product protection, TAPPI Journal July 2025
ABSTRACT: The European PLACE (Polymers, Laminates, Adhesives, Coatings and Extrusion) Committee was founded in 2023 with the goal of continuing a biennial conference for the flexible packaging and converting industry, including converters, OEMs, raw materials suppliers, and academia. Previous iterations of the PLACE Conference were organized by TAPPI, but the new European Place Committee has now found a home within bdvi e.V. (Bund Deutscher Verpackungsingenieure), which is the Association of German Packaging Engineers, a registered nonprofit organization.
Journal articles
Nanotechnology Functionality in Flexible Packaging; New Methods of Manufacturing, The PLACE, December 2006
Nanotechnology Functionality in Flexible Packaging; New Methods of Manufacturing, The PLACE, December 2006
Journal articles
Enhanced Economics of 100% Solids Adhesives, The PLACE, December 2006
Enhanced Economics of 100% Solids Adhesives, The PLACE, December 2006
Journal articles
Clarifiers for Polypropylene Film, The PLACE, December 2006
Clarifiers for Polypropylene Film, The PLACE, December 2006
Journal articles
Coextruded HMW-HDPE Film Structures with Improved Bubble Stability, The PLACE, December 2006
Coextruded HMW-HDPE Film Structures with Improved Bubble Stability, The PLACE, December 2006
Journal articles
Don't Let Profits Go Up in Smoke: Modern Air Pollution Control Systems Reduce Energy Costs and Destroy Higher Levels of Air Pollutants
Don't Let Profits Go Up in Smoke: Modern Air Pollution Control Systems Reduce Energy Costs and Destroy Higher Levels of Air Pollutants
Journal articles
Non-Polar Process Aids Improve Extrusion Productivity, 2006 PLACE Conference
Non-Polar Process Aids Improve Extrusion Productivity, 2006 PLACE Conference
Journal articles
Toughening Clear Polypropylene With Styrenic Block Copolymers
Toughening Clear Polypropylene With Styrenic Block Copolymers