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
Corrugated medium strength assessments in different flute structures, TAPPI Journal April 2026
ABSTRACT: Recent advancements in our ability to evaluate papers and our understanding of the mechanics of box failure have brought a renewed focus on measuring the performance of corrugated medium and an associated evolution of paper measurement approaches. This study evaluates the load curves, Hardness (where the fluted structure’s loading shifts away from an elastic response), and Concora medium crush test (CMT) values for a range of corrugated mediums in different common flute geometries. The shape of the load curve is a function of the geometry of the fluting profile and the relative stiffness of the paper, with smaller flutes and heavier papers reaching both the Hardness value and the ultimate load at lower deformation. Nonetheless, while the specific dynamics during the loading process vary, Hardness and CMT values correlate linearly between flute structures, even when testing specimens after different equilibration periods post-fluting. These correlations confirm the applicability of the standard A-flute CMT test to a broad range of papers and potential combined board flute structures, supporting quality assurance processes for medium production and optimization in corrugated board manufacturing.
Journal articles
Permeability simulation for filled paper based on three-dimensional structural model developed by X-ray computed tomography scanning, TAPPI Journal March 2026
ABSTRACT: In this study, an in-depth exploration of filled paper was conducted to understand its structural and permeability characteristics. Cotton linter pulp and precipitated calcium carbonate (PCC) filler were utilized to prepare pure fiber paper, and PCC1 and PCC2 filled papers with different filler particle sizes. Then, the pore structure parameters of paper samples were characterized by mercury intrusion porosimetry, and the X-ray computed tomography (X-CT) scanning was carried out. Subsequently, the 3D microstructures were established based on the X-CT slice images, and the filler characteristic parameters and filler 3D distribution were quantitatively analyzed. Finally, permeation simulations in the thickness and horizontal directions were performed. The findings indicate that filling changes the paper porosity, and the pore tortuosity varies with direction. The estimated pore•throat radius distribution shows specific patterns for different papers. The fillers have different distribution characteristics in the paper samples. Moreover, the paper permeability differs with direction, with smallsized filler having a significant impact on fluid penetration in the thickness direction. Overall, this study provides an effective method for investigating internal paper filler and its distribution, which contributes to the understanding of paper structure•performance relationships.
Journal articles
Effects of in-plane straining on the out-of-plane delamination properties of paperboard, TAPPI Journal March 2026
ABSTRACT: Delamination strength is an essential property for the creasing and folding operations of paperboard into boxes. Due to fixation during creasing, the paperboard suffers in-plane straining. In the present study, we aim to increase our understanding of how in-plane straining affects the delamination properties of paperboard. Samples of paperboard were first strained in in-plane tensile loading, both in the machine-direction and in the cross-direction. Afterward, the paperboard is loaded in the out-of-plane (ZD) direction. Three different grades of commercial paperboard from two major manufacturers were tested in a climate-controlled lab. The results showed similar results for all grades of paperboard, with the delamination strength and the out-of-plane stiffness decreasing virtually linearly with pre-straining. With about 5% plastic in-plane straining, the strength was reduced by about 20% and the stiffness decreased by more than 50% for all grades of paperboard. Normalizing the strength and the stiffness with their values without pre-straining reveals virtually the same relation for all grades of paperboard. If proven to be a general result, this will prove valuable in reducing the demand for experiments.
Journal articles
Magazine articles
Recycling performance of softwood and hardwood unbleached kraft pulps for packaging papers, TAPPI Journal February 2023
ABSTRACT: The scope of this work is to evaluate the recyclability potential of hardwood and softwood unbleached kraft pulps, leading to a sound basis for comparison and even to support a decision about fibers accord-ing to the performance achieved. The influence of successive recycling cycles (up to 10 cycles) on the fiber morphol-ogy, pulp suspension drainability, water retention capacity, and handsheet mechanical properties were studied for Eucalyptus globulus and Pinus sylvestris unbleached kraft pulps. The performance of these pulps as linerboard and corrugating medium for packaging was also evaluated. The requirements for brown kraftliner and for high perfor-mance recycled fluting grades is preserved for E. globulus pulp during all 10 recycling cycles, evidenced by the mod-erate decrease of burst index and crush resistance index and by the short-span compression index, whereas the P. sylvestris pulp loses this rating after the second cycle. These results strongly support the higher performance of E. globulus pulp for recycling as compared with softwood kraft pulp from the perspective of packaging papers.
Journal articles
Magazine articles
A fast and non-destructive alternative to the burnout method for paperboard quality inspections using phase-contrast X-ray imaging, TAPPI Journal February 2023
ABSTRACT: An X-ray based quality inspection method for paperboard was implemented and tested as a fast and non-destructive alternative to the burnout method. An argument against X-ray imaging for inspection of paper and paperboard has been that X-ray absorption is low in paper. To overcome this limitation, we used phase-contrast X-ray imaging (PCXI), which gives higher contrast than conventional attenuation-based imaging for low-absorbing materials such as paper. The suggested PCXI method was applied to previously prepared and quality rated samples using the burnout method. A strong similarity between the burnout images and the PCXI images was observed. In conclusion, further development of the phase-contrast X-ray method would provide an interesting option for replacing or complementing the standard burnout method.
Journal articles
Magazine articles
Chemical addition to wet webs using foam application, TAPPI Journal January 2023
ABSTRACT: In papermaking, the conventional way to add chemicals to the web is to dose them into the fiber stock and form the paper afterwards. However, in many cases, adding chemicals directly to the stock is challenging. For example, strength aids tend to increase flocculation in the stock, which limits the addition amounts of those aids. The need for better performance of paper (and paperboard) products has given rise to the need for functionalization of paper. Adding such functional chemicals to the stock is usually rather inefficient. Hence, novel methods are needed to add chemicals to the paper bulk. One such method is dosing chemicals to the wet web via foam application. In this study, we built a laboratory-scale sheetfed dynamic foam application device and utilized it to study addition of starch to wet bleached chemithermomechanical pulp (BCTMP) paper handsheets. The impact of parameters such as vacuum level, the amount of added chemical, and the viscosity of the foaming liquid on the penetration of starch into the wet web was explored. Starch penetration into wet webs was measured via iodine-potassium iodide staining, followed by image analysis. According to our results, controlling the viscosity of the foaming liquid gives the best possibility to control the penetration.
Journal articles
Magazine articles
Z-direction chemical analysis for new application methods, TAPPI Journal January 2023
ABSTRACT: In conventional wet-end chemical addition during paper production, chemical distribution through the z-direction of the sheet is usually not considered an important characteristic. With a nontraditional chemical dosing approach, such as foam-assisted additive addition, the chemistry can appear at different concentrations throughout the sheet, typically in a z-direction gradient. To fully understand the strength properties of the sheet, it is helpful to view or quantify the chemical distribution through the sheet in the z-direction. One qualitative method uses a dye technique along with confocal laser scanning microscopy to generate an image where the relative chemical concentration can be observed. A quantitative method involves compiling nitrogen analyses of layered subsections of the sheet into a composite graph of relative chemical concentration vs. the z-direction of the sheet. Chemical distribution analysis can be paired with traditional z-direction strength tests, such as Scott bond and z-direction tensile, to help one understand and improve the chemical addition process and its effects.
Journal articles
Magazine articles
Editorial: Critical literature reviews in open source journals, TAPPI Journal June 2023
ABSTRACT: We stand on the shoulders of giants” is a famous metaphor used by Sir Isaac Newton. This testifies to the fact that new information or discoveries are built on understanding and analyzing earlier information. Particularly in science, technology, engineering, and math (STEM) fields, it is important to have thorough analysis of earlier research activities in a particular field to propose a new direction of research, to evolve new ideas, and to develop new test methods and standards. It is a mandatory and required aspect of every original research paper to have a Literature Review section in the introductory part of the paper.
Journal articles
Magazine articles
Co-pulping of Trewia nudiflora and Trema orientalis, TAPPI Journal June 2023
ABSTRACT: Trewia nudiflora, a fast-growing species, was evaluated as a pulpwood. The a-cellulose content of this species was 40.4% with a Klason lignin of 21.5%. It was characterized by shorter fibers with a thin cell wall. The pulp yield was 40% with a kappa number of 16 at the conditions of 18% active alkali charge and 30% sulfidity for 2 h cooking at 170°C. T. nudiflora was similar to Trema orientalis in anatomical, morphological, and chemical composition; therefore, mixed chips at a 50:50 mixture ratio were cooked under optimum conditions. The pulp yield of mixed chip cooking was 45.4% with a kappa number of 19.4. The tensile and tear index of T. nudiflora pulps were 64.8 Nœm/g and 11.5 kPaœm2/g at 35 °SR, respectively. The mixed chips, T. nudiflora, and T. orientalis pulps showed above 81% brightness when bleached by D0(EP)D1 sequence using 20 kg chlorine dioxide (ClO2)/ton of pulp.
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.