# Impact of Temperature and Humidity on Key Mechanical Properties of Corrugated Board
###### Abstract  
This research explores how temperature and relative humidity impact the mechanical properties of corrugated cardboard. Samples were treated under a range of controlled climate conditions in a climate chamber to simulate varying environmental exposures. Following this conditioning, we performed a series of mechanical tests: the Edge Crush Test (ECT) to assess compressive strength, four-point Bending Tests (BNTs) in both the Machine (MD) and Cross Directions (CD) to evaluate bending stiffness, Sample Torsion Tests (SSTs) for shear stiffness, and Transverse Shear Tests (TSIs) to measure torsional rigidity. By comparing results across these tests, we aim to determine which mechanical property shows the highest sensitivity to changes in humidity levels. Findings from this study are expected to offer valuable insights into the environmental adaptability of corrugated board, particularly for applications in packaging and storage, where climate variability can affect material performance and durability. Such insights will support the development of more robust and adaptable packaging solutions optimised for specific climate conditions. corrugated board; temperature effects; humidity effects; mechanical properties; edge crush test; bending stiffness test; shear stiffness test; torsional stiffness test +
Footnote †: journal: Applied sciences  
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[PERSON], [PERSON], [PERSON], A.  
by [PERSON] et al. [8]. Furthermore, [PERSON] et al. investigated failure mechanisms during cold chain transportation [9], and [PERSON] et al. checked the dimensional stability of press-formed paperboard trays during heating and cooling [10]. Many solutions have also been proposed to increase the water resistance of paperboard, including adding a hydrolysis-resistant polyester-based thermo-plastic polyurethane [11] or spraying with coatings such as polymeric, mineral-filled polymeric and hybrid silica sol-gel products [12]. In addition to humidity and temperature, many factors affect the strength parameters of cardboard and packaging. One of them is cardboard imperfections. Two types of imperfections can be distinguished, namely global and local. Systematic, large-scale deviation from the ideal flat shape of cardboard, modelled as based on the Kirchhoff plate theory, was proposed by [PERSON] and [PERSON] [13]. The topic of local imperfections was dealt with by [PERSON], who investigated the effect of the size of imperfections on the load-bearing capacity of packaging [14], and later extended the nonlinear buckling analysis of [PERSON] and Harvey orthotropic plates by geometric imperfections [15]. [PERSON] et al. presented numerical analyses of three- and five-layer cardboard, with local imperfections, and their effect on effective stiffnesses [16; 17]. In 2022, [PERSON] and [PERSON] conducted an experimental study and numerical analysis of in-plane compression of corrugated paperboard panels considering local and global imperfections [18]. Despite the different origin, other factors influencing the strength parameters of cardboard and packaging are the presence and size of holes or perforations. [PERSON] et al. analysed the effect of hand and ventilation holes on box compressive strength using an artificial neural network [19]. [PERSON] et al. also investigated the effect of ventilation holes on the load-bearing capacity of corrugated cardboard packaging, by comparing experimental data with numerical analysis results [20]. In 2011, [PERSON] et al. proposed a constitutive model for the mechanical response of the folding of creased paperboard [21], while, in 2009, [PERSON] and [PERSON] formulated a mechanical model based on delamination [22]. [PERSON] et al. carried out, using homogenisation, numerical analyses of cardboard with creasing or perforation to determine the influence of such factors on the mechanical properties of cardboard materials [23].