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Eduardo Molina's Research

Development of a Finite Element Model to Predict the Deflection of a Stacked Unit Load of Corrugated Boxes

Eduardo Molina


Eduardo Molina

Ph.D. Student.

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Eduardo Molina grew up in Costa Rica. He now leaves in Blacksburg with his wife Diana, and in his free time, he enjoys cooking, photography and camping. He completed his BS degree in Costa Rica in Industrial Production Engineering, and then completed his Master’s in Packaging focused in packaging for distribution here at Virginia Tech. Eduardo decided to stay at VT and complete his PhD. The strong link between sustainability and packaging was one of the elements that first caught his attention about our packaging program and research goals. The opportunity offered to gain experience in managing a laboratory, as well as learning and gaining real-world experience in package testing made the decision easy for him.

Through his current research project, Eduardo hopes to create the knowledge necessary to provide packaging engineers the possibility of optimizing pallet performance by taking into consideration the interactions between pallets and different package characteristics such as box size and unit load aspect ratio. 

Eduardo is currently working as an Instructor in the Packaging Systems and Design program. He teaches classes in Packaging Machinery and Production Systems; Distribution for Packaging Systems, Packaging Supply Chain; and Computer-Aided Design in Packaging. His ultimate goal is to pursue a career in academia, helping to tackle issues that affect packaging and its sustainability on a global scale.

Eduardo views grad school like a fully immersive experience in Project Management. It meant having to manage resources, plan ahead of time, having to learn new skills, deal with unexpected events or results, and many other factors that come into play to deliver a final product (such as writing a dissertation for his degree completion) within a specific timeline and under many constraints. His graduate education has given him the experience and confidence to face almost anything in the future.

Right now, through his research, Eduardo has discovered interesting interactions between how a unit load of stacked boxes is built and how the pallet performs. For example, if there are two unit loads of the same weight and with similar products but one has tall boxes/packages and the other has short ones, the pallet supporting the unit load with the tall packages will present deflection that is almost 60% less. The taller boxes help with what is called the “load bridging effect”, redistributing the weight of the load towards the supports under the pallets and away from the center of the pallet, where it is weaker. Knowledge like this, provided in a systematic and easy to utilize manner, has the potential to help the industry improve the overall design of unit loads. There are many other interesting factors that are being analyzed as well that significantly influence how a pallet performs.

Eduardo is currently working on developing a computer simulation model to use when you have a pallet and boxes stacked on it, which will study how they interact. It’s been proven that a pallet bends differently when carrying different loads. If the load is very rigid, the pallet will not bend as much, and hence have a better performance in the field, than a pallet that is carrying a very flexible load. But there are many types of loads, and studying each different one in the lab is time consuming and expensive. What his computer simulation software will do, is build a modelling system that will help understand the changes that occur under different loads, without having to study the actual load in a lab. Such as, if you increase the size of the box, or if you add another layer of product, or if you increase the friction of the pallet - how those changes affect the performance of the pallet will be able to be modelled by the computer quickly and efficiently instead of having to physically create each type of load and study it in the lab. And, having this knowledge ahead of time will help in the pallet development and design process, making them stronger from the start, making the process more efficient, reducing the overall resources that are required, and hopefully making the whole industry more sustainable.

Research Summary:

Different types of unit loads can cause load bridging on pallets, which means that the weight is not distributed evenly across the pallet. Various factors including box size, aspect ratio, coefficient friction, number of layers, containment force, etc. influences the amount of load bridging. The investigation of the load bridging effect using physical testing is complex, expensive, and time consuming. Using finite element modeling would significantly increase the effectiveness of load bridging research. The proposed project will validate experimentally, in 2D and 3D, a finite modeling system for testing the interactions of packages causing load bridging. And, once validated it will be used to develop an adjustment factor to help apply the testing results of a pallet loaded using a uniform flexible load to a pallet loaded with corrugated boxes where load bridging occurs.


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