This paper presents a comprehensive review of optimization practices in the corrugated board industry, which has recently experienced significant interest in using optimization methodologies driven by sustainable demands and increasing computational capabilities. The authors cover different review perspectives, including historical context, manufacturing applications, design optimization, and numerical optimization algorithms used. The main findings of this study indicate that the corrugated board industry has experienced a shift from trial-and-error and expert-driven approaches to data-centric strategies, particularly since the beginning of the 21st century. Interestingly, the industry has also adopted Multi-Disciplinary Optimization techniques from other fields, which demonstrates the importance of knowledge convergence across sectors. However, due to the complex nature of corrugated boards—including materials, design, and manufacturing processes—there is still much research to be done in this area. This work provides guidance for future research directions and encourages innovation and improvement in corrugated board optimization practices. In particular, the strong developments of material models for paper in recent years will boost the use of optimization tools in this field.

Composites are pivotal in Europe's evolving packaging sector, which is undergoing changes due to circular and bioeconomy initiatives, which prioritize eco‐friendly packaging. Despite paper's high recycling rates, dynamic markets challenge recycling and circularity. Innovative paper‐based composites demand flexible recyclability assessments, which impacts product development. Recyclability methods are evolving as they struggle to match the dynamic changes occurring in the packaging sector. This article outlines paper recycling and compares global lab recyclability evaluation methods.

The aim of this work is to investigate the influence of fiber fibrillation and fines on the pore structure of well-defined regenerated fiber sheets as well as the water flow through the sheet. For this purpose, sheets were produced with refined, fibrillated fibers only, with unfibrillated fibers and fines, as well as with fibrillated fibers and fines. Next, the samples were analyzed by brightfield and fluorescence microscopy, mercury porosimetry, and an ascending test. Both the fibrils and the added fines reach into the pores between the fibers or are deposited there. As a result, pore size decreases and capillary flow slows down. The two effects overlap when the fiber surface is fibrillated and fines are present. Sheets with thicker fibers form a pore structure with larger pores in between the fibers. However, such a change in pore size has no significant influence on the flow of water through the sheet in the performed ascending tests. It is shown that a statistical model with the parameters fibrillation and fines content can be used to describe the ascending rate nearly as well as the Lucas–Washburn equation. Consequently, the equation could be improved by the addition of further fiber and sheet properties.

This paper proposes a novel approach to represent the geometry of the corrugated board profile during compression using graphs. Graphs are lighter than images, and the computational time of compression analysis is then significantly reduced compared to using the original image data for the same analysis. The main goal of using such graphs is to gain more knowledge about the mechanical behavior of corrugated boards under compression compared to the current load–deformation curve approach. A node tracking algorithm is applied to characterize the different phases occurring during the compression test in order to predict physical phenomena, including buckling and contact. The main results show that analyzing the nodes provides significant insights into the compression phases, which has not been achieved in the current state of the art. The authors believe that the objective of this research is crucial to better understanding the physics of corrugated boards under compression, and it can also be extended to other engineering structures.

This paper deals with the modelling of the heat transfer process in a thin porous fibrous material such as a paper sheet when it is subjected to an incident heat flux introduced by a laser beam. A mathematical model based on the control volume principle is developed for numerical estimation of radial temperature distribution which is validated experimentally by infrared thermography. Here the heat flux is introduced by a CO2 laser beam of 10.6 μm wavelength and an infrared image sequence is recorded as a function of time with a high resolution infrared camera. The preliminary validation results indicate that the simulation model can predict the transient development of sheet temperature very accurately under the specified heating conditions. The model can enhance our understanding and insights of the heat transfer process in such media, which is of great interest for many drying and thermal applications. Though the application shown here is on a 0.1 mm thick paper sheet, the model can be extended to any thin porous fibrous media such as textiles and nonwovens.

Research into paper-based devices and ionic liquids has increased considerably in the past few years. Thus, the combination of paper-based devices with ionic liquids is also becoming an increasingly frequent research subject. However, the influence of the ionic liquid on the paper properties has been hardly considered. In this paper, the influence of a hydrophobic ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide) on the mechanical properties of laboratory paper, isotropic and oriented, made from eucalyptus sulfate and cotton linters, is investigated. The tensile strength, elastic modulus, and breaking strain of papers saturated with ionic liquid were about 60 to 90% of the dry paper characteristics. In contrast to water, the breaking strain did not increase in the presence of the ionic liquid. This is because the ionic liquid only slightly swelled the fibers.