Corrugated paper boxes are the predominant packaging and shipping material and account for the majority of packaging refuse by weight. Wooden pallets are equally predominant in shipping, transportation and warehousing logistics. The interaction between these two components is complex and unexplored leaving industry to compensate with outdated component specific safety factors. Providing a focused exploration of the box and pallet interaction will open the door for holistic design practices that will reduce cost, weight, damage, and safety incidents. This study was separated into four chapters exploring different aspects of the corrugated box to pallet interaction. The first chapter evaluates the support surface provided by a pallet consists of deckboards spaced perpendicular to the length of the pallet. The resulting gaps between deckboards reduce the support to the box. Gaps were limited to 55% of box sidewall length for practical reasons. The effect of gaps was significant and produced a nonlinear reduction in box strength. Small boxes were more susceptible to gaps than larger boxes. Moving the gap closer to the corner increased its effect while increasing the number of gaps did not increase the effect. A modification to the McKee equation was produced that was capable of predicting the loss in strength due to gaps. The equation is novel in that is modifies a widely used equation and is the first such equation capable of handling multiple box sizes. This study also has practical implications for packaging designers who must contend with pallet gap. Chapter 2 explores the relationship between deckboard deflection and box compression strength. Testing found that reducing the stiffness of the deckboard decreases the compression strength of the box by 26.4%. The location of the box relative to the stringer also had varying effects on the box strength. A combination of deckboard stiffness and gaps produced mixed with results with gaps reducing the effect of stiffness. It was observed that lower stiffness deckboards not only deflect but also twist during compression. The torsion is suspected to have a significant influence on compression but further exploration is needed. The third chapter tests the effect of box flap length on box compression strength under various support conditions. Variables included four flap lengths, gaps between deckboards, low stiffness deckboards, column stacking and misaligned stacking. The results show that the box flaps can be reduced by 25% with no significant effect of box strength under any support condition tested. Furthermore, the box flap can be reduced by 50% with less than 10% loss in compression strength under all scenarios. These results have significant sustainability implication as 25% and 50% reduction in box flap reduce material usage by approximately 12% and 24%, respectively. In the fourth and final chapter, the theory of beam-on-elastic foundation is applied to deckboard bending and corrugated boxes. In this model the corrugated box acts and the foundation and the deckboard is the beam. Rotational stiffness, load bridging, and foundation stiffness changes required the development of novel testing solution and model development. The model was capable of predicting the distribution of force along the length sidewall but was not capable of predicting the ultimate strength of the box. The model developed in the study will be applicable in determining potential weakness in the unit load in addition to optimizing those that are over designed. These four chapters represent a considerable contribution of applicable research to a field that relied on outdated safety factors over thirty years. These safety factors often lead to costly over design in an industry where corrugated box and pallets volumes make event the smallest improvements highly beneficial. Furthermore, this research has opened the door for significant additional research that will undoubtedly provided even greater economic and sustainability benefits. / Ph. D.

Pallets play a crucial role in the supply chain with approximately 2.6 billion in circulation in the United States alone. Although often overlooked, pallets can become costly for a company if not designed correctly for their specific supply chain. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. Forklifts are the dominant mode of material handling for palletized products, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic nature of forklifts in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert during material handling. Forklifts in multiple facilities were instrumented with Lansmont SAVER 3X90 and 3D15 data loggers to measure the acceleration peak, g of shock impacts, duration of impacts, random vibration intensity and RMS (g) values during forklift handling in the field. The highest vibration levels were observed for distribution facilities with an average acceleration (peak, g) of 0.353 g. Based on the results of the vibration data collection, the vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that LTL facilities recorded the highest average shock impact of all the facilities investigated, with an average acceleration value of 4.74 g with an average shock duration of 7.42 msec. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains. / Master of Science / With 2.6 billion pallets in circulation within the United States alone, pallets play a significant role in the supply chain. Pallets can become costly for a company if not designed correctly for their specific supply chain, so it is important not to overlook a pallet. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. The forklift is the most common mode of material handling for the transportation of palletized products within a warehousing system, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic shock and vibration characteristics that forklifts experience in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert on pallets during material handling. Forklifts in multiple facilities were instrumented with Lansmont data loggers to measure the dynamic characteristics of both shock and vibration in the field. The highest vibration levels were observed for distribution facilities. Based on the results of the vibration data collection, a vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that Less-than-Truckload (LTL) facilities recorded the highest average shock impact of all the facilities investigated. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains.

The most common fastening technique that is used to connect the components of wooden pallets together are helically or annularly threaded pallet nails. Pallet nails create a strong durable connection and increase manufacturing efficiency for a low cost. However, nails can also cause iron staining, wood splitting, and when exposed can cause product damage or personnel injury. Using adhesives could be a solution to these problems, but only if the adhesives' strength and durability is comparable or higher than nails. The objective of the study was to investigate the tensile and shear strength of pallet connections secured using commercially available wood adhesives and compare their performance to pallet connections secured using common pallet nails. The lowest pre-compression pressure resulted in the best tension and shear performance for a solvent based construction adhesive (SBCA). The pre-compression pressure did not have any practical effect on the performance of the two-part emulsion polymer isocyanate (EPI) adhesive. Samples made with the solvent based construction adhesive (SBCA) had greater strength and energy at failure than nailed samples. Meanwhile, the samples made with the two-part emulsion polymer isocyanate (EPI) adhesive had equal or greater strength than nailed samples, except for during the tension parallel to the grain tests in which they had equal or lower strength. / MS / The most common technique used to connect the components of wooden pallets together is nails. Pallet nails create a strong connection with high manufacturing efficiency for a low cost. However, nails can cause iron staining, wood splitting, and when exposed can cause product damage or personnel injury. Using adhesives could be a solution to these problems, but only if the adhesives’ strength and durability is comparable or higher than nails. The objective of this study was to investigate the tensile and shear strength of pallet connections when secured using commercially available wood adhesives and compare its performance to pallet connections secured by using common pallet nails. The lowest pre-compression pressure tested resulted in the best overall performance for a solvent based construction adhesive (SBCA); meanwhile, pre-compression pressure did not have any practical effect on the performance of the two-part emulsion polymer isocyanate (EPI) adhesive tested. Therefore, using a lower pre-compression pressure would provide adequate performance and could also improve the ease of manufacturing and potentially reduce overall costs. Based on the tests conducted it was found that the solvent based construction adhesive (SBCA) demonstrated the best performance of all connection methods and could be a potential replacement for nails. More tests, such as weathering and impact, should be conducted to determine the full limitations of the adhesive in use.

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 / Within the United States alone, there are more than 2 billion pallets in service daily. These pallets transport and store a wide variety of products. There are many factors that could effect the performance of a pallet, and it is still unknown which design factors and possible package interactions will or will not effect pallet performance. The first objective of this thesis is to investigate the effect of package content on pallet deflection. The study concludes that the package content does not have an effect on pallet deflection. With about 1300 manufacturing plants that produce corrugated in the Unites States and Canada, the industry alone provides $26 billion to economies. Corrugated paperboard boxes are used daily for distribution and packaging, allowing products to easily and safely travel the globe. A majority of the time, these boxes are transported and stored on wooden pallets. Currently, there is no safety factor for box design that takes pallet stiffness into consideration. The second objective of this thesis is to investigate the effect of top deckboard twist on box compression strength. The results from 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.

The physical supply chain relies on three components to transport products: the pallet, the package, and unit load stabilizers. The interactions between these three components can be investigated to understand the relationship between them to find potential optimization strategies. The relationship between corrugated boxes and pallets have been previously investigated and have found that the relationship can be used to reduce the quantity of material used in unit loads and can also reduce the cost per unit load if the package and pallet are designed using a systems approach. Although corrugated boxes are a common form of packaging, plastic pails are also used in packaging for liquids and powders, but they have not been previously investigated. To understand the interactions between the wooden pallet and plastic pails, physical tests were conducted and then used to create and validate a finite element model. The experiments were carried out in three phases. The first phase included physical testing of plastic pails where the deckboard gap and overhang support conditions would be isolated by using a rigid deckboard scenario. The second phase also used physical tests to investigate plastic pails but instead used flexible deckboards and used an overhang support condition and a 3.5 in. gap support condition. The third phase of experiments would develop and validate a finite element model to further understand the impact of deckboard gaps and overhang depending on the location of the gap. Previous physical experiments were used to create and validate the finite element model. Nonlinear eigen buckling analysis was used to model the plastic pail buckling failure that was seen in physical testing. The model based on the physical experiments was able to predict the behavior of the plastic pail within a range of 5-12% variation with higher variation being introduced when the flexible deckboard is introduced. The finite element model was then used to model a range of deckboard gap sizes and overhang sizes as well as different locations for deckboard gaps. The results of the experiments indicate that the percent of pail perimeter that is supported directly on the pallet impacts the compression strength of the plastic pail. Decreasing the quantity of support decreases the compression strength of the plastic pail in a linear pattern. The location of the deckboard gap also influenced the compression strength because of the quantity of pail being supported being altered. The results of the experiments can be used by industry members to provide guidelines on unit load design to prevent plastic pail failure. Industry members can also use the results as a baseline investigation and further the finite element model by incorporating their own plastic pail design. / Doctor of Philosophy / The physical movement of products relies on three main elements: pallets, packaging, and stabilizers for unit loads. Examining how these components interact helps uncover their relationships and potential strategies for optimization. Previous studies have explored the connection between corrugated boxes and pallets, revealing ways to reduce material usage and costs through a systems-based design approach. While corrugated boxes are commonly studied, plastic pails, used for liquids and powders, have not received similar attention. To understand the dynamics between wooden pallets and plastic pails, physical tests were conducted. The physical experiments illustrated the importance of investigating the relationship within unit loads but there are limitations that exist when doing physical experimentation such as time and materials. A finite element model is a mathematical model that can be used to simulate physical phenomenon to further understand physical interactions without having to conduct physical experiments. Using the results of the physical experiments that were conducted, a finite element model was developed to further investigate the system that exists between pails and pallets. The experiments occurred in three phases. The first phase focused on isolating deckboard gap and overhang support conditions using a rigid deckboard scenario in plastic pail testing. In the second phase, a pallet with flexible deckboards was used to explore overhang and a 3.5-in. gap support condition. The third phase involved creating and validating a finite element model to better grasp the impact of deckboard gaps and overhang, considering gap location. Previous physical experiments guided the model's development and validation. Nonlinear eigen buckling analysis simulated plastic pail buckling failure observed in physical tests. The model predicted plastic pail behavior within a 5-12% variation range, with greater variation when using flexible deckboards. This model explored various deckboard gap and overhang sizes, along with different gap location and found that the quantity of unsupported perimeter that the pail experiences affects the quantity of load that the pail can experience before achieving failure. These results are impactful to industry members because it quantifies the impact that pallets can have on their package. Understanding the interactions between the package and the pallet can also be used to create unit loads that are safer by quantifying the buckling load of plastic pails. Investigating plastic pails and the interactions between pallet components can lead to creating safer and better design unit loads in the industry.

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.

Pallet cant quality directly impacts pallet part processing and material costs. By knowing the quality of the cants being processed, pallet manufacturers can predict costs to attain better value from their raw materials and more accurately price their pallets. The study objectives were 1) to develop a procedure for accurately predicting hardwood pallet part yield as a function of raw material geometry and grade, processing equipment, and pallet part geometry, 2) to develop a model for accurately predicting raw material costs for hardwood pallet parts as a function of yield, 3) to examine current pallet industry methods of determining hardwood cant quality, and 4) to develop and evaluate hardwood cant grading rules for use in the pallet industry. Yield studies were necessary to accurately quantify the relationship between yield and cant quality. Thirty-one yield studies were conducted throughout the Eastern United States at pallet mills producing pallet parts from hardwood cants. 47, 258 board feet of hardwood cants were graded, and the usable pallet part yield and yield losses were determined for each grade. Yield losses were separated into three components: kerf loss, dimension loss, and defect loss. Kerf and dimension losses are a function of raw material and part geometry and were calculated without regard to cant quality. Defect loss is dependent on cant quality and was calculated for each cant grade as a function of total yield, kerf loss, and dimension loss. Mathematical models were developed from twenty-eight mill studies to predict each yield loss component as a function of cant dimensions, grade, and orientation, cutting bill parameters, pallet part dimensions, and kerf. Dimension and kerf losses were predicted geometrically. Regression analysis was used to predict defect loss. Results indicated that these models accurately predicted the total yield of usable pallet parts and pallet part material costs as a function of cant quality and price. Results also indicated that the pallet industry's current method of counting the number of "bad" ends per cant bundle to determine cant quality is not adequate. The effectiveness of the proposed cant grading rules was determined by grading cants and analyzing the cant grade distributions and corresponding pallet part yields. The grade rules produced statistically different quality divisions between grades. However, a more practical single cant grade based on the minimum quality for the proposed grade 2 rules is recommended. / Master of Science

No description available.

Pallets are a critical component of logistics infrastructure. Approximately 1.9 billion pallets are used each year in the United States for transportation of goods, from raw materials to finished products. Solid wood pallets represent 90% to 95% of the pallet market. To run their operations, wood pallet companies deal with suppliers, customers, and other supply chain components. Each of the steps is important to deliver the right products, with the required quality, and in a timely fashion. However, there is little research about the industry's supply chain practices. The objective of this research is to increase the understanding of the U.S. wood pallet manufacturing industry, its supply chain management practices, and factors affecting the supply chain management processes. To accomplish the research objectives, a nationwide mail survey of wood pallet manufacturers was carried out. In total 1,500 companies were sent questionnaires and the response rate was 14%. A model for supply chain success factors was developed based on previous research and was analyzed using the results from the survey. Results of the survey provide an up-to-date profile of the US wood pallet industry. It was found that pallet production per company was 727,229 units on average during 2009. Out of the 1500 respondents, 38.6% indicated they were medium-sized companies (20 to 99 employees) and 53.9% small companies (1 to 19 employees). Thirty five percentage of respondents indicated that their sales were less than one million dollars and 43% from one to five million dollars. Also, 45% of respondents were involved in pallet recycling or repair, and these companies indicated that, on average, 42% of the material in a recycled pallet is, in fact, new material. Regarding Supply Chain practices, close to three-quarters (73.1%) of respondents sold their products directly to customers and the order lead time for raw materials to shipment was 1 to 10 days for 81.9% of companies. The most important factors for purchasing decisions are availability, cost, and reliability of supplier (all rated 4.4 in an importance scale from 1 to 5, respectively). Respondents' answers suggest a preference to work with domestic materials (rated 4.3); however, respondents also indicated that there is currently a high level of competition for raw materials (rated 4.3). Results also indicated that information technology (IT) appears to receive little attention from wood pallet manufacturers, given that the importance of items in this area were rated relatively low, especially the use of internet for purchasing and training in IT (rated 2.2 and 2.1, respectively). Lastly, 86.0% of respondents did not believe that their customers would be willing to pay a premium for environmentally certified pallets, citing cost as the major barrier for a higher demand of these products. Also, a theoretical framework of supply chain management was designed, developed, and tested with factor analysis, allowing identification of seven factors in the wood pallet supply chain: (1) environmental uncertainty, (2) information technology, (3) supply chain relationships, (4) value-added process, (5) supply chain management performance, (6) business management, and (7) customer satisfaction. Relationships between factors were tested using multiple linear regression. Results show that value-added process positively affects supply chain relationships, and these in turn are positively correlated to supply chain management performance and customer satisfaction. Results from this research are useful for the industry to formulate a well-informed supply chain management strategy by understanding the connections between the different supply chain management practices and the business performance and customer satisfaction. The information presented is also useful for organizations supporting the wood pallet industry to design more effective assistance and educational programs. / Master of Science

Research on unit load stability aids manufacturing facilities in selecting the most efficient load stabilizer when shipping their products to market. This study's objective was to compare the performance a variety of different commonly used load stabilizers to stretch hooding. Stretch hooding is a method of load stabilization in which a tubular film is heat sealed at the top, stretched by four mechanical arms to a desired width, pulled down over the unit load. The film is slowly released as the arms descend, and is released under the pallet. 400ga stretch hooding, 80ga and 63ga stretch wrap and strapping were tested. Twenty unit loads for both vibration and impact testing were used, with 5 replications per load stabilizer. Container displacement and pallet-container displacement were measured, and the number of tares in the load stabilizer film, on the corners of the test units, after testing, was noted. Container displacement was significantly greater during impact testing than in vibration testing. Strapping was the most effective stabilizer during vibration testing because of its ability to restrict vertical displacement. The stretch hooding was the most effective stabilizer during impact testing because of its ability to restrict horizontal displacement. / Master of Science