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Editorial: TAPPI Journal 2024 Best Research Paper focuses on realistic potential for using nonwood residues in sustainable packaging, TAPPI Journal April 2025

ABSTRACT: Each year, the TAPPI Journal Editorial Board honors outstanding content by nominating and voting for the Best Research Paper published the previous year based on scientific merit, innovation, creativity, and clarity. TAPPI and the TAPPI Journal Editorial Board would like to congratulate the authors of the 2024 TAPPI Journal Best Research Paper: Antonio Suarez, Ashok Ghosh, Fritz Paulsen, and Peter W. Hart of Smurfit Westrock (formerly WestRock). The winning paper, “Life cycle carbon analysis of packaging products containing nonwood residues: A case study on linerboard and corrugating medium,” was published in the March 2024 issue.

Optimizing OCC refining with defloccing, TAPPI Journal April 2025

ABSTRACT: Subjecting pulp to a high shear zone immediately after refining results in more efficient refining. This phenomenon was originally observed to benefit softwood pulp refining. It was attributed to floc reduction based on floc measurements in mill refiners and the observation of reduced headbox plugging. Hence, this phenomenon has been termed “defloccing.” The present work shows this technology also benefits refining of North American old corrugated containers (OCC). The combined results of several mill trials with OCC defloccing demonstrate the interactions between OCC refining intensity, defloccing technology, and other state-of-the-art refining improvements. At the same refining intensity, defloccing OCC on 100% recycled machines increases OCC refining efficiency by 15%, with greater efficiency improvement on machines that use softwood as well as OCC. Furthermore, it is shown that the benefits of defloccing are additive to refining improvements made in the refining zone of a refiner plate. Most OCC refiner plate designs can therefore benefit from the addition of a defloccing feature.

Dynamic compression characteristics of fiber-reinforced shoe press belts, TAPPI Journal April 2025

ABSTRACT: Shoe press belts contribute significantly to the overall dewatering performance in the press section of a paper machine. Within the shoe press nip, the press belt faces a dynamic and multidimensional load that mainly leads to a compression of the structure. As this will cause a loss in void volume, knowledge of the dynamic compression characteristics of shoe press belts is crucial for optimized dewatering. A novel method was developed to examine the dynamic compression characteristics of grooved polyurethane press belts. Therefore, an experimental setup allowing realistic boundary conditions to test specimens was placed in a servo-hydraulic testing machine. Press belt specimens with different matrix material formulations and groove patterns were tested under varying load rates equivalent to different paper machine operational speeds. The results showed an evident sensitivity of the dynamic compression stiffness to the operational speed of the paper machine. This behavior was seen to be more sensitive to changes in the matrix material formulation than to adaptions of the groove pattern. As a result, the compression of the press belt within a shoe press nip is not only influenced by the peak pressure within the shoe press nip but also depends on the operational speed of the paper machine.

Study on the effect of aluminum diethyl phosphinate in synergy with ammonium polyphosphate on the flame retardancy of cellulose paper, TAPPI Journal April 2025

ABSTRACT: This paper involved the synergistic incorporation of ammonium polyphosphate (APP) and diethyl aluminum phosphinate (AlPi) as flame-retardant fillers for producing flame-retardant paper. The research revealed that APPs were square particles with a smooth surface, and their solubility was 0.29 g/100 mL at 20°C, which increased to 4.12 g/100 mL at 60°C. The surfaces of AlPis were rough and irregular. The solubility of AlPi was 0.023 g/100 mL at 20°C, and the solubility remained stable when the temperature increased. The addition of AlPi had a minor influence on the pulp beating degree. The tensile strength of kraft/APP/AlPi decreased with the increase of the AlPi addition. For a paper with 20 wt% APP and 0 wt% AlPi, the limiting oxygen index (LOI) value was 27.2%, and it burned completely at the eighth second during vertical combustion. When the AlPi additive content increased to 20 wt%, its LOI value increased to 32.2%, and the vertical combustion self-extinguished as soon as the flame was removed. Scanning electron microscopy (SEM) showed that the char residue of the kraft/APP/AlPi had a more complete fiber network structure than that of kraft/APP. The Raman spectroscopy indicated that the area ratio of the D (amorphous phase; disordered graphite vibration) band to the G (crystal phase; graphite carbon vibration) band (ID/ IG) ratio of kraft/APP/AlPi was lower than that of kraft/APP, meaning that the graphitization degree of the char residue of kraft/APP/AlPi was higher than that of kraft/APP, which indicated the kraft/APP/AlPi had better flame retardancy.

Formability and load-bearing capacity of multilayered paperboard in three-dimensional forming, TAPPI Journal August 2025

ABSTRACT: The forming of paper-based products presents significant challenges, including maintaining geometric integrity, managing springback, and overcoming instability limits. These arise from the material properties of paper, with its high anisotropy, inhomogeneity, and limited strain. Multilayered paperboard, formed without adhesives, offers a promising solution. By customizing layer composition and orientation, this approach leverages mutual fiber support to enhance forming properties. Experimental and numerical analyses reveal that adhesive-free bonding during deep drawing enhances the material’s formability and load-bearing capacity and reduces anisotropic springback. These innovations enable superior product protection compared to conventional industrial single-layered paperboard of similar thickness. This study demonstrates the advantages of tailored layer configurations for improved geometric precision and stability, providing a pathway for sustainable, high-performance packaging solutions.

In-situ process monitoring in deep-drawing of paper using partially transparent tools, TAPPI Journal August 2025

ABSTRACT: The production of three-dimensionally formed packaging from paper by deep drawing usually leads to the occurrence of wrinkles, which result from the high tangential compressive stresses in the flange area and the limited flowability of the material. Wrinkles, although mostly tolerated in industry, end in both a reduced visual appearance and a reduction in usability for packaging, as with, for example, when gas-tightness is required. Previous research efforts have been limited to determining the wrinkle distribution after completion of forming and removal of the formed part. Consequently, the possibility of understanding the sequence of formation of individual wrinkles in the inhomogeneous material is lost. To remedy this situation, a method for local in-situ process monitoring is presented. Using a transparent die and an industrial camera, the flange area can be observed during the forming process. An image processing algorithm is applied to analyze the local development of the deep drawing process from the continuously recorded image data. The method described can be used to analyze the draw-in behavior and wrinkle formation locally and continuously over the drawing depth. The blank holder force influences the draw-in and the wrinkle pattern both locally and throughout the drawing process. A more precise understanding of the wrinkle formation will allow for more efficient process control in the future.

Editorial: TAPPI’s ongoing efforts in standards development for the pulp, paper, and related industries, TAPPI Journal February 2025

ABSTRACT: TAPPI has been involved in developing standards for the pulp and paper industry since the 1920s, and those efforts are still going on today with the help of volunteers who propose new standards and review existing ones. Just last year, 30 standards were either reviewed or reaffirmed, and one new standard was developed. There are currently 235 TAPPI Standard Test Methods and nearly 400 volunteers who work on them. These standards are used around the world in laboratories and production situations. Many are used by TAPPI Journal authors to support research efforts and assess results from their experiments, playing an important role in advancing science.

Controllable conversion of cellulose nanocrystals to cellulose microspheres: Insight on the effect of parameters during spray drying, TAPPI Journal February 2025

ABSTRACT: Cellulose microspheres, which have mainly been produced via the sol-gel method up until now, exhibit a promising potential for broad applications due to their regular microstructure and renewability. However, some issues with production of cellulose microspheres, such as the recycling of involved organic solvents and the removal of the residual solvents, should be solved. In this study, a cellulose nanocrystals (CNCs) suspension was used to produce cellulose microspheres via spray drying in order to avoid the use of organic solvents. The effects of CNCs particle size, CNCs concentration, and inlet temperature of spray drying on microstructure and particle size of cellulose microspheres were investigated. The results indicated that the optimal average particle size and concentration of CNCs used for obtaining cellulose microspheres were 106 nm and 0.1 wt%, respectively. Under the optimal conditions, cellulose microspheres with a regular spherical morphology and an average particle size of ca. 3 ìm were obtained. The sulfuric acid hydrolysis and spray drying process barely affected the crystalline structure of cellulose. However, the introduced sulfhydryl groups, which were confirmed by Fourier transform infrared spectroscopy results, degraded the thermostability of cellulose. Generally speaking, converting CNCs to cellulose microspheres via spray drying is beneficial for promoting the controllable and continuous production of cellulose microspheres.

Effects of different parameters on the morphology of electrospun cellulose acetate/polyaniline nanocomposite, TAPPI Journal February 2025

ABSTRACT: Cellulose is the most abundant naturally occurring polysaccharide. Its inherent mechanical stability, biocompatibility, biodegradability, and abundant hydroxyl groups available for derivatization provide benefits in the production of fiber-based materials such as conductive fibers. Cellulose derivatives, including cellulose esters such as cellulose acetate (CA), are readily generated in the fiber form following dissolution using a variety of solvents. Electrospinning is one of the emerging technologies with an outstanding ability to regenerate fibers in the nanoscale range. Polyaniline (PANI) is a conductive polymer that is popular for its high chemical stability, nontoxicity, good processability, and stable intrinsic redox state. This study explored the fabrication of a conductive PANI/CA nanocomposite through electrospinning. Working conditions, electrospinning variables, and solution parameters were established to produce coherent PANI/CA nanofibers. The effects of varying CA concentration, amount of PANI, molecular weight of CA, and feed flowrate on the morphology of the nanofibers were investigated.

A study of softness standard samples using a tissue softness analyzer and hand-felt panels, TAPPI Journal February 2025