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The paper composite sandwich structure with corrugation and honeycomb cores has been widely used in civil and national defense industries, and the cushioning energy absorption characteristic is a key indicator to evaluate the performance of this composite structure. Therefore, this paper is focused on the influences of honeycomb thickness on the shock acceleration response and deformation characteristics to analyze cushioning energy absorption performance of the composite structure by various experimental tests. The experimental result shows that the paper corrugation layer firstly comes into crushed, and then the paper honeycomb layer is crushed. Additionally, the large honeycomb thickness may cause the secondary collapse of paper honeycomb layer. Under the same impact energy or impact mass, the cushioning energy absorption of the single-sided composite sandwich structure is better than that of the double-sided structure with the same honeycomb thickness. However, the impact resistance of the double-sided composite structure is better than that of the single-sided structure. For the paper composite sandwich structures with the honeycomb thicknesses 10, 15, 20, and 25 mm, the increase of honeycomb thickness would decrease the cushioning energy absorption of the whole structure under the drop impact with low energy. However, under the drop impact with high energy, the influence of honeycomb thickness on cushioning energy absorption is contrary. For the paper composite sandwich structure, the specific energy absorption, unit volume energy absorption, and stroke efficiency for the honeycomb thicknesses 10, 15, 20, and 25 mm are higher than those for the honeycomb thickness 70 mm. Therefore, the low honeycomb thickness is more advantageous for the cushioning energy absorption of paper composite sandwich structure.

This study introduces the opinion of the corrugation hierarchy to develop the second-order corrugation paperboard, and explore the deformation characteristics, yield strength, and energy absorbing capacity under out-of-plane static evenly compression loading by experimental and analytical approaches. On the basis of the inclined-straight strut elements of corrugation unit and plastic hinge lines, the yield and crushing strengths of corrugation unit were analyzed. This study shows that as the compressive stress increases, the second-order corrugation core layer is firstly crushed, and the first-order corrugation structures gradually compacted until the failure of entire structure. The corrugation type has an obvious influence on the yield strength of the corrugation sandwich panel, and the yield strength of B-flute corrugation sandwich panel is wholly higher than that of the C-flute structure. At the same compression rate, the flute type has a significant impact on energy absorption, and the C-flute second-order corrugation sandwich panel has better bearing capacity than the B-flute structure. The second-order corrugation sandwich panel has a better bearing capacity than the first-order structure. The static compression rate has little effect on the yield strength and deformation mode. However, with the increase of the static compression rate, the corrugation sandwich panel has a better cushioning energy absorption and material utilization rate.

In view of cushioning energy absorption of paper composite sandwich structures with sinusoidal corrugation and hexagonal honeycomb cores, the static yield strength and compression deformation were firstly analyzed by experiments, then the unit volume energy absorption, unit area energy absorption, and specific energy absorption were evaluated. Further, the influences of static compression rate, corrugation types, and honeycomb thickness on the cushioning energy absorption were respectively studied. The experimental observations show that the paper composite sandwich structures are crushed layer by layer due to the difference in the yield strength of sandwiches, and the honeycomb core is crushed after the collapsing of corrugation core. The three evaluation indices of cushioning energy absorption have similar change rule with the compression rate, corrugation types, and honeycomb thickness. The influence of static compression rate on the yield strength and cushioning energy absorption of the paper composite sandwich structure is not obvious. The composite sandwich structures consisting of paper corrugation sandwich with large inertia moment and honeycomb sandwich with large thickness have more excellent cushioning energy absorption, the B-corrugation can increase the unit volume energy absorption of paper composite sandwich structures by up to 18% than C-corrugation, and the 3-honeycomb can increase the unit volume energy absorption of paper composite sandwich structures by up to 32% than 2-honeycomb.

The composite layered structures including paper corrugation, paper honeycomb and expandable polyethylene are innovative structures of cushioning energy absorption, and the compression and impact resistances of the expandable polyethylene can be enhanced by laminating the corrugated paperboard or honeycomb paperboard. This article evaluated the compression performance and cushioning energy absorption of the composite layered structures by the static compression and drop impact compression tests. On one hand, the static compression properties showed that the total energy absorption, energy absorption per unit volume and stroke efficiency of the composite layered structures were all higher than those of expandable polyethylene. The specific energy absorption was enhanced with the increase in compression strain but almost not affected by the compression rate. The specific energy absorption of the composite layered structures including the expandable polyethylene and honeycomb paperboard was greater than those of the expandable polyethylene and corrugated paperboard. The energy absorption efficiency of the composite layered structures including the expandable polyethylene and corrugated paperboard was large for the low compression stress level, yet that of the composite layered structures including the expandable polyethylene and honeycomb paperboard was large for the high compression stress level. On the other hand, the dynamic compression characteristics showed that the peak stress, energy absorption per unit area, energy absorption per unit volume and specific energy absorption of the composite layered structures embodying paper sandwich cores and expandable polyethylene had linear increasing trends with the increase of drop shock energy. At the same drop impact condition, the composite layered structures including the honeycomb paperboard and expandable polyethylene had better cushioning energy absorption, the peak stress decreased by 23.6% on average, the energy absorption efficiency raised by 8.85% on average and the specific energy absorption increased by 18.1% on average than those including the corrugated paperboard and expandable polyethylene. Therefore, the corrugated paperboard and honeycomb paperboard can helpfully improve the cushioning energy absorption of the expandable polyethylene, and the composite layered structures embodying the expandable polyethylene, corrugated paperboard and honeycomb paperboard may hold excellent packaging protection.

X-PLY corrugated paperboard is a new-type corrugated paperboard with three layers of orthotropic corrugated sandwiches structure, and may be employed to protect products from shock or vibration damage during distribution. This article deals with the characterization of properties of X-PLY corrugated paperboard relevant to its application for protective packaging in distribution, such as dynamic cushioning curves, vibration transmissibility and frequency curves. The main feature of article is the evaluation on the dynamic shock cushioning characteristics and vibration transmissibility of X-PLY corrugated paperboards by a series of experimental studies on the drop shock tester and vibration tester, the establishment of experimental formulas of dynamic cushioning curves, and the analysis of peak frequencies, vibration transmissibility and damping ratios. By using the fitting polynomial of curve and method of the least mean square, the experimental formulas and characteristic coefficients of dynamic cushioning curves have been obtained. From the vibration tests with slow sine sweep, the peak frequencies and vibration transmissibility are measured and used to estimate the damping ratios. These works provide basic data and curves relevant to its application for protective packaging in distribution.