Currently, pallets are designed assuming that the load is distributed evenly on the top of the pallet. When pallets are loaded with packages such as corrugated boxes or returnable plastic containers, due to their physical shape, packages, are not capable of deforming freely with the pallet and a bridging phenomenon occurs. During this load bridging phenomenon, a portion of the vertical forces are redistributed as horizontal forces which causes the redistribution of the vertical compression stresses on the pallet towards the support. As a result, the deflection of the pallet can decrease and the load capacity of the pallet can increase significantly. The second chapter of this paper investigates the effect of package content on pallet deflection. The study concluded that package content did not have a significant effect on pallet deflection within the boundary conditions of the experiment. The third part of this paper considers how a specific pallet characteristic could affect the way a corrugated box performs. Standard box design procedures include adjustments of estimated compression strength for relative humidity, overhang on pallets, vibration, and alignment of boxes. However, there is no adjustment factor for pallet stiffness. The objective of the study described in this thesis is to find an answer for how the compression strength of a box is affected by pallet stiffness and top deckboard twist. The study concluded that the pallet stiffness and top deckboard twist do not have an effect on the compression strength of the box until less than 12% of the area box is supported. / Master of Science

<p>It is well known that transportation means high and varying loads for products as well as packages. To develop corrugated boxes with optimal design and efficient use of raw materials is crucial. Vibrations and shocks acting on pallets during transportation are transferred to the corrugated boxes and considerably reduce the integrity and life time of the boxes. The development of experimental and analytical tools for measurement and prediction of the influence of dynamic loads on the box performance, such as stacking strength and conservation of stacking pattern would therefore be of large practical importance. In order to develop such tools, it is important to know the load distribution between different boxes. This master thesis presents a technique for investigating these stresses based on a pressure sensitive film, which gives many data points. A series of tests using random and sinusoidal vibration testing have been done utilising this technique and results are presented for different positions on the pallet and for different box filling methods. Investigations performed on the vibrations of the boxes also demonstrate a pitch type of motion. A level-crossing study on the forces existing between the boxes shows a Rayleigh force distribution. A mathematical model is also proposed for simulation of a stacking system. Advantages and disadvantages with this technique and with the model are described. Comparison between the experimental and numerical results shows a proper correlation. Using the pressure sensitive film as a quantitative sensor and applying the recorded data for the statistical study of the contact forces existing in a stack of boxes gives useful and important results for further analysis of the fatigue life and vulnerable positions of boxes.</p><p> </p>

It is well known that transportation means high and varying loads for products as well as packages. To develop corrugated boxes with optimal design and efficient use of raw materials is crucial. Vibrations and shocks acting on pallets during transportation are transferred to the corrugated boxes and considerably reduce the integrity and life time of the boxes. The development of experimental and analytical tools for measurement and prediction of the influence of dynamic loads on the box performance, such as stacking strength and conservation of stacking pattern would therefore be of large practical importance. In order to develop such tools, it is important to know the load distribution between different boxes. This master thesis presents a technique for investigating these stresses based on a pressure sensitive film, which gives many data points. A series of tests using random and sinusoidal vibration testing have been done utilising this technique and results are presented for different positions on the pallet and for different box filling methods. Investigations performed on the vibrations of the boxes also demonstrate a pitch type of motion. A level-crossing study on the forces existing between the boxes shows a Rayleigh force distribution. A mathematical model is also proposed for simulation of a stacking system. Advantages and disadvantages with this technique and with the model are described. Comparison between the experimental and numerical results shows a proper correlation. Using the pressure sensitive film as a quantitative sensor and applying the recorded data for the statistical study of the contact forces existing in a stack of boxes gives useful and important results for further analysis of the fatigue life and vulnerable positions of boxes.

Growing pressure on the packaging design to enhance the environmental and logistics performance of a packaging system stresses the packaging designers to search new design strategies that not only fulfill logistics requirements in the supply chain, but also reduce the CO 2emissions during the packaging life cycle. This thesis focuses on the packaging design process and suggests some improvements by considering its logistics performance and CO 2emissions. A Green packaging development model was proposed for corrugated box design to explore the inter-dependencies that exist among compressive strength, waste and CO2emissions. The verification of the proposed model unveils the significance of a holistic view of the packaging system in the packaging design process and reveals the importance of packaging design decisions on the logistics performance and CO 2 emissions. The thesis finally concluded that the packaging logistics performance should be considered in a packaging design process to explore the Green packaging design solution.

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. / Master of Science / Sustainability-minded individuals, industries, and policymakers recently recognized the environmental burdens associated with packaging as a critical concern to society. Many initiatives and studies have been conducted to prevent and reduce the environmental impacts of individual packaging systems, such as corrugated boxes, plastic bottles, and pallets. However, not many efforts have been made to enhance the environmental performance of a whole unit load, which is the most common distribution packaging form used to transport and store goods. It is essential to understand the physical interactions between unit load components, such as corrugated boxes and pallets, in order to improve a unit load's environmental performance effectively. The unit load optimization concept introduced in the past study, which showed that increasing top deck thickness can reduce the needed board grade of corrugated boxes, was further investigated and utilized in this study to offset the environmental burdens of a unit load by substituting different materials used. To assess the environmental performance of that unit load design optimization method, this study first endeavored to understand further how various unit load design factors could affect the result of unit load optimization, and second, we analyzed many different scenarios using a life cycle analysis method. The study found that the unit load design method that uses deck board thickness to change the amount of corrugated board needed had more potential for lighter pallets with thinner deck boards carrying heavier loads. The results also showed that increasing top deck board thickness and reducing the board grade of the corrugated board could improve the environmental performance of a unit load when the corrugated material is sufficiently substituted with a reasonable amount of pallet material.

During unitized shipment, the components of unit loads are interacting with each other. During floor stacking of unit loads, the load on the top of the pallet causes the top deck of the pallet to bend which creates an uneven top deck surface resulting in uneven, or asymmetrical support of the corrugated boxes. This asymmetrical support could significantly affect the strength of the corrugated boxes, and it depends on the top deck stiffness of the pallet. This study is aimed at investigating how the variations of pallet top deck stiffness and the resulting asymmetric support, affects corrugated box compression strength. Pallet top deck stiffness was determined to have a significant effect on box compression strength. There was a 27-37% increase in box compression strength for boxes supported by high stiffness pallets in comparison to low stiffness pallets. The fact that boxes were weaker on low stiffness pallets could be explained by the uneven pressure distribution between the pallet deck and bottom layer of boxes. Pressure data showed that a higher percentage of total pressure was located under the box sidewalls that were supported on the outside stringers of low stiffness pallets in comparison to high stiffness pallets. This was disproportionately loading one side of the box. Utilizing the effects of pallet top deck stiffness on box compression performance, a unit load cost analysis is presented showing that a stiffer pallet can be used to carry boxes with less board material; hence, it can reduce the total unit load packaging cost. / Master of Science / Packaged products are primarily shipped as unit loads that consist of packaged products restrained to a platform, commonly a pallet. Paying particular attention to the design of the unit loads' components is necessary to safely ship products while still maintaining low packaging costs and sustainability initiatives. Stacking unit loads is a common practice to effectively use warehouse space, but warehouse stacking causes large amounts of weight for packaging to support. Pallets are not completely rigid and will deform because of this weight. The purpose of the study was to investigate the effect of pallet stiffness on the compression strength of corrugated boxes. Compression tests were completed on boxes supported by pallet designs having different deck stiffnesses. The top deck stiffness of a pallet was determined to have up to a 37% effect on the strength of corrugated boxes. Pressure data recorded between the bottom layer of boxes and the top deck of the pallet showed a larger percentage of pressure was located towards the outside edges of the unit load for boxes carried by a flexible pallet. Effectively, one side of the box was stressed more than the other causing package failure. Utilizing the effects of pallet top deck stiffness on box compression performance, a unit load cost analysis is presented showing that a stiffer pallet can be used to carry boxes with less board material; hence, it can reduce the total unit load packaging cost.

This report investigates whether a FEM model can be used to assess the risk of crack growth in corrugated board. A set of box geometries with cracks at different locations were loaded and then compared using the evaluated J-integral within the FEM software. To validate the results, comparisons have been made between the FEM liner material and real liner material. It is described how the material model that is used in FEM is constructed as well as how the simulated box is built. The box is loaded in two load cases, and a simplification by using a linear elastic material model has been made. The answer seems positive that it may be possible to assess cracks in a corrugated box using FEM, but the model developed in this report needs further testing and improvements. / Den här rapporten undersöker om en FEM modell kan användas för att bedöma risken för spricktillväxt i wellpapp. Olika lådgeometrier med sprickor belastades och jämfördes med hjälp av FEM-program genom uppmätt J-integral. För validering av resultat så jämfördes resultat från linermaterial modellerad i FEM med materialtest av verkligt linermaterial. I rapporten beskrivs det också hur materialmodellen som används i FEM är konstruerad samt hur lådmodellen är byggd. För jämförelsen av J-integral är lådmodellen belastad med två olika lastfall, därutöver är materialmodellen förenklad så att en linjärelastisk modell används.Svaret till inledande frågan verkar vara att det är möjligt att bedöma sprickor i wellpapp genom användning av FEM. Dock behöver metoden som används i denna rapport fler tester för valideringar samt andra förbättringar.