Search
Use the search bar or filters below to find any TAPPI product or publication.
Filters
Content Type
Publications
Level of Knowledge
Committees
Collections
Journal articles
Editorial: Coating innovations for driving the next generation of sustainable packaging, TAPPI Journal November 2025
Welcome to the 2025 Special Coating Issue of TAPPI Journal. As we reflect on developments in 2025, the industry’s focus on sustainable packaging continues to sharpen, bringing several critical coating challenges and opportunities into view.
Journal articles
Designing paper and board barrier constructions for food contact applications, TAPPI Journal November 2025
ABSTRACT: This study examines the effect of multiple factors on barrier performance for purpose-built paper and paperboard constructions produced on an industrial pilot coater machine. Impacts from precoat latex chemistry, application method (flooded nip with bevel blade, jet with bevel blade, and pre-metered film coater, laboratory rod drawdown) and precoating calendering were studied in relation to resulting porosity, roughness, and barrier (liquid water, moisture, and oil). Results reveal a complex interaction between controllable and uncontrollable factors, offering insight for designing advanced barrier coatings on cellulosic substrates.
Journal articles
Editorial: TAPPI Journal eBook version offers easy content, TAPPI Journal September 2025
Many readers of TAPPI Journal are familiar with accessing the PDF version of our published research papers, but not all are familiar with the availability and functionality of our eBook version. As opposed to the traditional PDF format, which is a static digital replica of the paper, the eBook version offers a range of additional benefits that make the content more dynamic, accessible, and user-friendly. In addition, you can more easily review all papers in a particular issue much as you could in a print version, as opposed to opening multiple PDFs. Below are some highlights on accessing and making the most of the eBook version.
Journal articles
Magazine articles
Editorial: Shaping industry and career success with TAPPI Standards involvement, TAPPI Journal May 2023
ABSTRACT: Within TAPPI, there are many ways to help advance our industry and make sure it thrives for years to come. Writing a research paper for publication or acting as peer reviewer for TAPPI Journal, presenting at a conference or helping to organize one, and becoming involved in the many committees that are part of TAPPI Divisions are just some of the ways. One other very important way to contribute to our industry is through the standards development process.
Journal articles
Dynamic modeling, efficiency analysis, and hierarchical control of industrial airborne pulp dryers, TAPPI Journal October 2026
ABSTRACT: Industrial airborne pulp drying is governed by strongly coupled moisture transport, heat transfer, psychrometric behavior, airflow distribution, pressure dynamics, and fan operation. A nonlinear multi-zone dynamic model was formulated to represent these interactions through coupled mass and energy balances, pressure-driven deck-to-deck airflow, centrifugal-fan dynamics, and through-thickness moisture and temperature transport. Overall and thermal efficiencies, specific energy consumption, and specific moisture evaporation ratio (SMER) were incorporated for energetic assessment. A hierarchical direct synthesis methodology (DSM), comprising moisture–temperature and airflow–fan speed cascade loops with chamber-pressure regulation, was evaluated against proportionalintegral- derivative (PID) control and model predictive control (MPC) benchmarks. The MATLAB simulations of a six-zone dryer predicted progressive moisture reduction toward 0.120 kg H2O/kg dry pulp, overall efficiency near 0.60, thermal efficiency near 0.61, and SMER of approximately 0.95-0.96 kg H2O/kWh. The DSM provided the lowest accumulated moisture-tracking error and smooth control action, while PID control gave comparable fast loop regulation. The current MPC implementation exhibited poorer moisture–thermal tracking, indicating the need for further predictive model refinement and systematic tuning. The formulation provides a controloriented basis for subsequent parameter identification and industrial validation.
Journal articles
Copper-embedded polyvinyl alcohol (PVOH)-based antimicrobial and biodegradable coating for food packaging applications, TAPPI Journal October 2026
ABSTRACT: The food packaging industry increasingly seeks multifunctional, bio-based materials that ensure product safety while supporting strict municipal environmental sustainability goals. This research addresses functional limitations in compostable packaging by developing a polyvinyl alcohol (PVOH)-based antimicrobial and biodegradable coating through precise incorporation of active copper ions. Copper ions were incorporated into a 20% solids-content PVOH matrix at target concentrations of 100, 500, and 1,000 ppm, then applied to paper and polylactic acid (PLA) bioplastic substrates at a target coating weight of 6 g/m². Antimicrobial testing against Escherichia coli and Salmonella spp. using a bacterial overlay agar method demonstrated robust, localized microbial inhibition zones that increased with copper concentration. Biodegradability and industrial compostability were assessed under controlled conditions over 49 days in accordance with ASTM D5338 and ASTM D6400. Uncoated butcher paper controls exhibited 71.90% biodegradation, whereas copper-embedded PVOH-coated paper achieved 83.59%, conclusively demonstrating that integrated metallic ions did not hinder or delay natural macromolecular decomposition. Scanning electron microscopy and elemental analysis verified uniform coating distribution and stable copper dispersion across all treated surfaces. Differential scanning calorimetry revealed minor, predictable modifications to polymer crystallization kinetics without altering macrostructural film integrity. Barrier evaluations (ASTM F1249 and ASTM D3985) confirmed a substantial, highly significant reduction in oxygen transmission rates, whereas the reduction in water vapor transmission rates was not statistically significant due to PVOH’s inherently hydrophilic nature. These findings demonstrate that copper-embedded PVOH coatings provide a highly effective, active antimicrobial defense system while remaining completely compatible with commercial, sustainable industrial composting loops.
Journal articles
Nonlinear modeling of batch digester discharge dynamics with rheology-driven hydraulic transport and drainability coupling, TAPPI Journal September 2026
ABSTRACT: Batch digester blowdown constitutes a strongly nonlinear transient transport process governed by the coupled evolution of pulp consistency, slurry density, hydraulic resistance, liquid inventory, and discharge line dynamics. A control-oriented nonlinear formulation is developed by coupling dry fiber and free liquor mass balances with phase volume reconstruction, consistency-dependent hydraulic resistance, channeling and drainability effects, and a power law head flow relationship derived within a lumped hydraulic inertance framework. A fixed-gain PI con troller obtained from local linearization is employed as the conventional benchmark, whereas an integral sliding mode controller (SMC) explicitly compensates the nonlinear time-varying hydraulic structure and bounded disturbances. Both strategies are evaluated under identical actuator constraints and sequential perturbations involving oppos ing head, hydraulic resistance, channeling, drainability, and dilution. Numerical results demonstrate lower root mean-square error, integral absolute error, and peak flow-tracking error for the SMC, with rapid recovery toward the prescribed sliding boundary layer and improved robustness to variations in the nonlinear flow exponent n. Cumulative electrical energy and batch-specific specific energy consumption remain comparatively similar, indicat ing that the principal SMC benefit is enhanced hydraulic regulation rather than substantial batch energy reduction. Specific energy consumption is an established metric for energetic assessment of slurry transport. Model-based hydraulic demand, electrical power, and sliding manifold surfaces further characterize the nonlinear operating domain. The resulting framework provides a computational proof-of-concept for modeling and control of transient batch digester discharge systems.
Journal articles
Optimization of optical coverage of board surfaces with assessment of light scattering and absorption using mineral as a coating component, TAPPI Journal June 2026
ABSTRACT: One of the primary functions of mineral inclusion into paper or paperboard is to improve the optical performance of the substrate. A coating may be applied to a sheet in order to cover a dark base, to improve the sheet opacity, to give the correct smoothness and gloss, or to give a suitable surface on which to print. The brightness of a pigment has long been used as a guide for pigment choice in paper and board. However, the measured paper brightness is a function of color and light absorption (K) of the coating and base and the light scattering (S) within the sheet resulting from interfaces with different refractive index. The optical performance can be quantified by measuring the S&K coefficients as described by the Kubelka-Munk model/theory in a filled or coated paper sheet. In coating, this is often assessed as a function of coat weight, and the corresponding physical sheet properties are assessed at the same time; for example, the correct gloss, smoothness, point-to-point uniformity, and printability. The optical performance in the sheet is often not directly related to the pigment brightness, but is largely a function of the particle packing within the sheet and coating layer. In the first and second main sections of this work, respectively, we show how S&K calculations from the Kubelka- Munk equations can be used in coated sheets to determine the optical performance and how this can be used as a predictive tool for the final sheet performance. This is presented for base sheets with different starting brightness. The third section of this work focuses on how mineral combinations in coatings can be used to improve the light scattering and consequently the optical performance of the board. We include theoretical considerations and then finally share a case study for improvement on the optical properties of recycled board.
Journal articles
A systems approach for process debottlenecking towards a sustainable pulp and paper industry, TAPPI Journal April 2026
ABSTRACT: Increasing the competitiveness of the pulp and paper industry requires an effective optimization of its existing assets in line with a long-term vision for process transformation, production upgrade, and product diversification. Currently, pulp production increase is one of the main sources of additional revenue for the kraft industry. Likewise, energy efficiency is often employed as a cost-effective approach to reduce operating costs, enhancing the possibilities to lower fossil fuel consumption and contributing to a low-carbon economy. On the other hand, reaching higher production targets and facilitating process transformation, such as biorefinery implementation, heavily depend on the status and performance of a mill’s current infrastructure; therefore, a system analysis is needed to assess the new production requirements, the bottlenecks, and the interactions across departments. In order to obtain practical improvement solutions, direct and indirect impacts on process performance and resource utilization should be considered. This work provides an overview of the key challenges that need to be addressed for production increase and energy efficiency improvement. The methodology starts by a scope analysis for debottlenecking and screening capacity limitations vs. mill targets, followed by their ranking (bottleneck ranking diagram). Benchmarking, gap analysis, and root-cause techniques are applied to diagnose system inefficiencies. This mill-wide debottlenecking assessment is then used to guide the selection of a long-term sustainable operation and design a portfolio of improvement projects by avoiding cross effects of the short-term projects on the long term. A case study of a kraft pulp mill is used to illustrate the proposed methodology.
Journal articles
Pre-damping effects on water absorption and drying dynamics in flexographic printing, TAPPI Journal November 2025
ABSTRACT: Optimizing flexographic printability can involve the ink and the substrate, as well as the printing process. It has been widely reported in the literature that controlling topography of the substrate and its porosity are vital for good flexographic printability, especially when using water-based inks. This study focuses on how pre-damping a surface impacts liquid absorption and improves wet trapping (ink on ink with no intermediate drying) in flexographic printing. A Prüfbau universal print tester was adapted to analyze flexographic wet-on-wet ink printing and trapping using yellow and magenta inks for contrast. Slow drying of the first ink layer (yellow) leads to mottle when the second layer (magenta) is applied. The study explores the “wet sponge” hypothesis: a pre-damped surface should absorb liquid faster. The Lucas- Washburn equation describes long-term absorption, but it does not capture short-term uptake, which instead follows a linear dependence on time.