TAPPI Journal Archive

About TAPPI Journal

As of March 2022, TAPPI Journal’s (TJ) publishing model is 100% Open Access (OA) to improve the accessibility of its published articles, increase researcher engagement and make research more visible. This new format helps researchers meet their funding and grant application requirements and potentially increase the number of citations. As in the past, the copyright remains with the author, and unlike other technical journals, TJ does not require a publication fee. Read more.

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Editorial: Design considerations for developing high-quality flexible packaging laminates, TAPPI Journal July 2025

ABSTRACT: The global flexible packaging industry has constantly evolved by developing new materials, film design, polymer processing techniques, and machinery to overcome challenges posed by consumer demands, regulation, and societal pressure. While achieving superior quality and improved mechanical film attributes has always been the cornerstone for new technical developments in this industry, the end-of life shortcoming for most plastic films has driven the value chain to strive harder to design and develop sustainable packaging structures.

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.

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.

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.

Adhesion with purpose: The value of primers in sustainable flexible packaging, TAPPI Journal July 2025

ABSTRACT: Primers play a crucial role in flexible packaging by providing adhesion, enhancing performance, and improving the overall quality of packaging structures. As the packaging industry shifts towards more sustainable solutions, it brings new challenges for meeting adhesion requirements. Different types of sustainable materials, with their complicated physical and chemical properties, usually result in poor adhesion in extrusion coating or extrusion lamination, whether this is due to fast crystallization, secondary crystallization, low processing temperature, lack of functional groups, or a combination thereof. Water-based primers ensure that these innovations meet both functional and environmental standards for the packaging of tomorrow. Conventional water-based primers, including polyethyleneimine (PEI) and ethylene acrylic acid (EAA), offer significant advantages in sustainable packaging design by chemically modifying the surface of the substrate to enhance adhesion. In this study, we will discuss adhesion issues in three case studies involving sustainable packaging materials: (1) extrusion coating of polyvinyl alcohol (PVOH) on paper; (2) extrusion lamination of paper and metallized film with starch biopolymer; and (3) extrusion coating of polyhydroxyalkanoates (PHA) on paper. These cases represent three adhesion challenges related to sustainable materials, namely fast crystallization rate, low processing temperature, and secondary crystallization. A three-step adhesion improvement procedure was employed to identify the proper primer in each case study. This procedure included a wetting-out test with primer, an adhesion test, and an extrusion test with priming. In our results, strong fiber tearing or destructive bonds were achieved in each case with the help of water-based primers. These results demonstrate the value of water-based primers in enabling the transition to more sustainable packaging structures without compromising performance.