Browsing by Author "Kim, Saewhan"
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- Investigation of the Effect of Pallet Top-Deck Stiffness on Corrugated Box Compression Strength as a Function of Multiple Unit Load Design VariablesKim, Saewhan; Horvath, Laszlo; Russell, Jennifer D.; Park, Jonghun (MDPI, 2021-11-03)Unit loads consisting of a pallet, packages, and a product securement system are the dominant way of shipping products across the United States. The most common packaging types used in unit loads are corrugated boxes. Due to the great stresses created during unit load stacking, accurately predicting the compression strength of corrugated boxes is critical to preventing unit load failure. Although many variables affect the compression strength of corrugated boxes, recently, it was found that changing the pallet’s top deck stiffness can significantly affect compression strength. However, there is still a lack of understanding of how these different factors influence this phenomenon. This study investigated the effect of pallet’s top-deck stiffness on corrugated box compression strength as a function of initial top deck thickness, pallet wood species, box size, and board grade. The amount of increase in top deck thickness needed to lower the board grade of corrugated boxes by one level from the initial unit load scenario was determined using PDS™. The benefits of increasing top deck thickness diminish as the initial top deck thickness increases due to less severe pallet deflection from the start. The benefits were more pronounced as higher board grade boxes were initially used, and as smaller-sized boxes were used due to the heavier weights of these unit loads. Therefore, supposing that a company uses lower stiffness pallets or heavy corrugated boxes for their unit loads, this study suggests that they will find more opportunities to optimize their unit loads by increasing their pallet’s top deck thickness.
- Investigation of the Environmental Effect of Unit Load Design Optimization Using Physical Interaction Between Pallets and Corrugated BoxesKim, Saewhan (Virginia Tech, 2022-08-12)Packaging sustainability has become one of the most notable issues of this era. Many researchers have endeavored to characterize or compare the environmental burdens of a single level of packaging, such as primary, secondary, or tertiary packaging. However, goods are often handled, stored, and transported through the supply chain system in unit load form consisting of pallets, corrugated boxes, and load stabilizers. Hence, it is important to holistically understand the environmental impact of not only individual packaging levels, but also the unit load form. We can use the interactions between the unit load components to reduce the environmental burdens generated in the supply chain system. Past studies discovered that pallet top deck thickness has a huge effect on corrugated box compression strength. Using this knowledge, researchers were able to optimize the cost of unit loads by increasing pallet top deck thickness and reducing the board grade of corrugated boxes. This study (1) further discovered how different unit load design factors, such as initial top deck thickness, pallet wood species, box size, and board grade, affect the performance of the previously proposed unit load design optimization method, and (2) we investigated if the unit load optimization method could also enhance unit load sustainability. The study's first phase identified that the benefits of increasing top deck thickness were more pronounced as the initial top deck thickness decreased, higher board grade boxes were initially utilized, and smaller-sized boxes were used. The second phase of this study showed that increasing top deck thickness and reducing the board grade of corrugated boxes could offset environmental impacts by as much as 23%. Environmental benefits were mostly achieved by reducing the amount of relatively more-processed materials in the corrugated boards. This phase also provided preliminary unit load conditions as guidance for unit load professionals to estimate the possibility of optimizing their unit load design in an environmentally beneficial way.
- Measurement and Analysis of Last-Mile Parcel Delivery Truck Vibration Levels in KoreaKim, Saewhan; Horvath, Laszlo; Lee, Soohyung; Lee, Sangwook (MDPI, 2024-04-12)South Korea has one of the largest e-commerce markets in the world. The last-mile delivery segment of e-commerce often causes critical damage to products in protective packages. Despite the rapid growth of the e-commerce market in Korea, the last-mile distribution environment has not yet been thoroughly investigated. The main aim of this study was to provide an understanding of the vibration levels that were measured from various parcel delivery routes within Seoul, Korea, using common types of parcel delivery trucks. Vibration levels of ten delivery trucks were measured and analyzed in terms of power spectral densities (PSDs) and presented as PSD spectra. The last-mile delivery vehicle vibration levels in Korea were found to be consistently lower (in the 1 to 200 Hz frequency range) than those recommended by international standards and lower than the vibration levels of parcel delivery vehicles in the U.S. and Hungary. The results also revealed that the highest intensity peak of the PSD spectrum for Korea was located in the lower frequency range (1.5 to 2 Hz) compared to the ISTA 3A pickup and delivery test profile (3 to 4 Hz) and the test profile recommended for Hungary (13 to 16 Hz). A smoothed composite spectrum was also provided to support Korean packaging engineers in optimizing their packages by simulating proper last-mile truck delivery vibration levels in lab conditions.
- Measurement and Analysis of the Shock and Drop Levels Experienced by Small and Medium Packages in the Korean Parcel Delivery SystemKim, Saewhan; Horvath, Laszlo; Lee, Sangwook (MDPI, 2024-05-08)South Korea is one of the leading markets for the e-commerce industry. In line with the rapid growth of the e-commerce industry, the parcel delivery volume in Korea has also proliferated. Despite the developments in the Korean e-commerce and courier industries, consumers still experience a high package damage rate. In response, many packaging engineers in Korea have raised the need for new parcel shipping environment tests that reflect the Korean ground shipping environment in order to properly optimize packages. However, only limited information on the Korean parcel shipping environment is currently available. Therefore, this study focused on measuring and analyzing the shock and drop levels that parcels experience during ground shipping in Korea. Shock data were collected from a total of sixty one-way shipments for small, lightweight packages and medium, mid-weight packages. The findings revealed that the two types of boxes do not experience significantly different numbers of shock events or drop heights in the Korean parcel delivery environment. Furthermore, the number of shock events that occur in Korea is substantially less than the international testing standard and less than in previous studies conducted in both Europe and the USA. In contrast, however, the drop heights are higher than those in the international testing standard and previous studies. Shock events were found to occur most frequently on the edges and to be concentrated around the bottoms of the packages. Most shock events happen while packages are loaded and unloaded at hub terminals and sub terminals.
- Predicting the Effect of Pallet Overhang on the Box Compression StrengthKim, Saewhan; Horvath, Laszlo; Molina, Eduardo; Frank, Benjamin; Johnson, Steven; Johnson, Alonda (2023)Unit loads, consisting of pallets and corrugated boxes, are one of the primary forms of storage and distribution of packaged products. The corrugated box’s compression strength can easily be affected by environmental parameters, such as pallet overhang, which reduce a box’s effective compression strength. The effects of overhang on box compression strength have been investigated by multiple researchers, but each previous study used its own unique set of different sizes of boxes made from different materials, limiting the broad comparability of the results and challenging strong statistical analysis. The current study, performed on behalf of the Fibre Box Association and ICPF, aimed to investigate the effects of pallet overhang on box compression strength using four different sizes of corrugated boxes, made from two different board combinations, in order to compare existing values in the Fibre Box Handbook, and potentially explore the possibility of developing a more universal model for predicting the effects of pallet overhang. The four sizes of boxes, for each nominal 32 ECT C-flute and nominal 48 ECT BC-flute corrugated materials, were examined in over a dozen single-side overhang configurations and five adjacent-side overhang scenarios. Compression tests were conducted in compliance with the TAPPI 804 standard. A range of multiple linear and nonlinear regression models based on these test results were developed for this study. These models provide the estimated change in a box’s compression strength due to any overhang, compared to a no-overhang scenario, by percentage. As expected from earlier work, effective box compression strength decreases as the magnitude of overhang increases. Significant differences were found when the same overhang was investigated on the width versus the length side of the boxes. It was also observed that the magnitude of the adjacent-side overhang effect on box compression strength is not simply related to the combination of short and long sides’ overhang effects, but it has a unique effect that is most likely related to the loss of additional box corner support as compared to single side box overhang. The box size relative to the amount of overhang was also a statistically significant factor affecting effective box compression strength in the tested overhang scenarios. This work also indicated the need for further research refining the first-order model and extending it to other materials, box sizes, and box aspect ratios.
- Sustainable and Secure Transport: Achieving Environmental Impact Reductions by Optimizing Pallet-Package Strength Interactions during TransportKim, Saewhan; Horvath, Laszlo; Russell, Jennifer D.; Park, Jonghun (MDPI, 2023-08-22)Increasing quantities of products are being transported across widely distributed supply networks; the sustainability of the packaging used to transport these goods, or unit loads, presents an area of potential concern. The most common type of unit load in the U.S. is wooden pallets supporting various configurations of stacked corrugated boxes. Research into unit load cost optimization revealed that increasing the stiffness of a pallet’s top deck can significantly affect the strength of the assembled, stacked corrugated boxes and provides opportunities to reduce the board grade required for accompanying corrugated boxes. However, there remains a knowledge gap regarding the environmental implications of this type of unit load optimization method. To address this, we conducted a life cycle analysis (LCA) to investigate the environmental implications of optimizing a unit load using this method. The environmental impacts of paired (pallet and box) unit load design scenarios (n = 108) were investigated using varied wood species, pallet top deck thicknesses, corrugated boxes sizes, corrugated flutes, and board grades. Initial and optimized unit load scenarios ensured that the unit loads offered equivalent performance. LCA results indicate that optimizing the unit load can reduce environmental impacts by up to 23%, with benefits accruing across most impact categories primarily due to the reduction in corrugated material used. Ozone depletion, the exception, was mainly affected by the increase in the amount of required pallet materials. This study provides minimum required conditions as preliminary guidance for determining the usefulness of unit load specific analysis, and a sensitivity analysis confirmed these values remain unchanged even with different transportation distances. Through the unit load optimization method, this study demonstrates that an effective way to reduce the overall environmental impact and cost of transported unit loads involves increasing the stiffness of the top decks and reducing the corrugated board grade.