## 2 Experimental Design
### Experimental Apparatus and Methods  
In the uniaxial compression test for the shipping container, the loading rate of the universal testing machine was set to 10 \(\pm\) 3 mm/min, and on the load-deformation curve obtained, the starting point of deformation was from the point at which a preload of 222 N was applied [16]. The uniaxial compression creep test equipment for the shipping containers was composed of a hardware system consisting of a load-adding device, linear displacement-measuring device (linear variable differential transformer, LVDT), specimen compression device, load-measuring device, and software system to continuously measure and analyze the deformation of the specimen with time (Figure 2). In order to automatically measure the creep amount of the container continuously for a long-time by the LVDT installed in one place, the moving plate equipped with dead weight must perform accurate linear translation movement along the guide axis. For this purpose, a guide poster equipped with a ball bearing guide with a width of 10 cm was used in the creep test equipment manufactured. After applying a 222 N preload to set the reference point for measuring the deformation [16], three levels of constant load, selected from the ASTM D642 CS for each relative humidity scenario (23 \({}^{\circ}\)C; rh 50%, 70%, and 90%), were applied to the test specimen using a load-adding device; then, the 12 h creep test was performed [9]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Division** & \multicolumn{2}{c}{**Container A**} & \multicolumn{2}{c}{**Container B**} & \multicolumn{2}{c}{**Container C**} \\ \hline \multirow{3}{*}{Outer size} & - & (prototype) L968\(\times\) W994 \(\times\) H1870 mm & - & (prototype) L690\(\times\) W664 \(\times\) H990 mm & \multirow{3}{*}{-} & (prototype) L892\(\times\) W881 \(\times\) H289 mm \\  & - & (model) L484\(\times\) W497 \(\times\) H935 mm(\({}^{0}\)) & - & (model) L345\(\times\) W332 \(\times\) H445 mm(\({}^{0}\)) & & \\ \multirow{3}{*}{Container type} & - & RSC, single-winged & - & RSC, single-winged & - & RSC, double-winged \\  & - & (extremely) vertical long (H/L = 1.88; & - & (slightly) vertical long (H/L = 1.29; & - & (extremely) horizontal long \\  & & L/W = 1.03) & & L/W = 1.04) & & (H/L = 0.28; L/W = 2.34) \\ \multirow{3}{*}{
\begin{tabular}{c} Paper combination\({}^{(1,2)}\) \\ \end{tabular} } & - & BB/F-DW & - & A/F-SW & - & A/F-SW \\  & - & KLB175/S120/CK180/S120/K180 & - & KLB225/CK180/K180 & - & KLB175/CK180/K180 \\ \hline \multirow{6}{*}{Container type} & \multicolumn{4}{c}{Note: (1) KLB225: (BS, bursting strength) 726 kPa, (RC, ring crush) 332 N, (t) 0.30 mm; KLB175: (BS) 569 kPa, (RC) 258 N, (t) 0.27 mm; K180: (BS) 353 kPa, (RC) 194 N, (t) 0.28 mm; CK180: (BS) 392 kPa, (RC) 270 N, (t) 0.27 mm; S120: (BS) 125 kPa, (RC) 82 N, (t) 0.17 mm. (2) KBLB25 and KBL9175: 40% UKP + 30% AOCC + 30% KOCC, KOCC = Korean old corrugated container, UKP = unbleached kraft pulp, AOCC = American old corrugated container; K180 and S120: 100% KOCC; CK180: 20% AOCC + 80% KOCC. (3) BB and FD-DW (BB blue-double wall), A/F-SW (A blue-single wall), RSC (regular slotted container). (4) Geometric similarity, \(\lambda=W_{m}/W_{p}=D_{m}/D_{p}=H_{m}/H_{p}=1/2\) (\(m\) = model, \(p\) = prototype).} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Specifications of the shipping containers used for the target packages [14].