PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 8, Number 1, 2022
starches and microfibrillated cellulose and it has also been demonstrated in the project how the strength properties (such as z-strength) could be restored at a higher bulk. TESTING “ Novel method for the evaluation of mechanical property of pigment coating layer and its application: Influence of spreading of latex binder on final properties of coating layer ”, Jee-Hong Lee & Hak Lae Lee, Progress in Organic Coatings, Vol.163, February 2022, 106652. The mechanical properties of paper coating layers are important in various processes and applications. Proper evaluation of the coating layers is essential for improving coating layer design. In this study, a novel method for the evaluation of the mechanical properties of coating layers was developed using a surface and interfacial characterizing analysis system (SAICAS) instrument, which has an important advantage of not requiring any special sample preparation process. Failure analysis results showed that the SAICAS method provided uniform and reproducible sectioning of the coating layer regardless of the layer's mechanical strength, indicating this is suitable for measuring the mechanical properties of coating layers. The influence of the spreading of latex binder on the final properties of the coating layer was examined and its correlations with structural properties were quantitatively analyzed. This was applied to analyze the mechanical, topographical, and optical properties of coating layers. The results showed that the peel strength and gloss were highly correlated with the spreading of latex. The chemical composition of S/B latex also influenced the peel strength of the coating layer. The transitions observed in the length distribution of pigment – binder interfaces greatly influenced the properties of the coating layer, including peel strength, gloss, and light- scattering efficiency. “ Novel Dynamic Test Methods for Paperboard Composite Structures ”, Abolhasan Nazarinezhad Giashi, T. Gereke, T. Mbarek & C. Cherif. Experimental Techniques , (2021) online. Paperboard-based composites, typically in the form of carton plies, polyethylene, and aluminum foil, are widely used for food packaging applications. The main goal of packaging converting procedures is to create robust and well-shaped commercial packages. This high speed process is very dynamic, resulting in enormous deformation rates within a few milliseconds. In contrast to previous quasi-static investigations, the envisaged dynamic material characterization for soft and thin paperboard plies will help understand and predict the material response during this high speed packaging process. Even though several experimental standards are already available for paperboard tensile tests, these standards are limited to conventional quasi- static test procedures. Specific cylindrical clamps made of aluminum were designed to prevent samples with a thickness of 100 m from slipping. By means of accurate measuring techniques, a maximum strain rate of 80 s -1 was achieved, which effectively corresponded to actual strain rates that occur in paperboard converting procedures. It was shown that paperboard plies exhibited anisotropic properties and rate-dependent characteristics. Compared to quasi-static properties, the dynamic experiments revealed stiffer hardening properties at higher strain rates. A rate-dependent material model based on Cowper- Symonds and Johnson-Cook analytical laws was generated to formulate a paperboard dynamic constitutive model. Experimental investigations towards analytical material formulations were successfully conducted to predict and determine the rate dependent material characteristics of paperboards plies at high strain rates. “Experimental quantification of differences in damage due to in -plane tensile test and bending of paperboard”, Gustav Marin, Mikael Nygårds & Sören Östlund, Packaging Technology & Science , (2021) online. Creasing is an essential process to
Technical Abstracts
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