Pallets and corrugated boxes are ubiquitous in the global supply chain. However, the interactions that exist between the boxes and pallet are ignored during the pallet design process resulting in an over design of pallet performance and the waste of raw materials. The goal of this research is to understand how pallet performance is affected by headspace, box size, and base design across multiple support conditions using block class wooden pallets.
Headspace and base design had no effect on pallet deflection for the experimental weights used throughout testing. The effect of box size was significant on pallet deflection across multiple support conditions. The effect was greatest for lower stiffness pallets and low stiffness support conditions (RAW) with up to a 50% reduction in pallet deflection observed by switching from small to large boxes on a very low stiffness pallet.
Evaluation of pressure mat data showed an increase in the redistribution of pressure away from the center of the pallet and towards the supports as box size increased. The redistribution of pressure towards the supports is known as load bridging and validates the observed reduction in pallet deflection as a function of box size. The results indicate that incorporating the effect of packages into current pallet design practices could result more effective and cheaper pallet designs. / Master of Science / Transportation and storage of material goods at a national and international level is an integral part of our economy with pallets and corrugated boxes making up the majority of packaging materials. Currently, the interactions that exist between the boxes and pallet are ignored during pallet design resulting in an over design of pallet performance and a waste of raw materials. Understanding the interactions that exist in a unit load is important in optimizing pallet performance, reducing the amount of raw materials used, and ultimately reducing cost.
This research project is specifically focused on the interactions between corrugated boxes and block class wooden pallets. The effect of headspace (the gap between the products and the top of the box) and box size was investigated as a function of pallet stiffness, support condition, and bottom deck design. Both pallet deflection and the pressure distribution on the top surface of the pallet were examined to evaluate pallet performance.
It was found that headspace does not have an effect on pallet deflection unless the weight of the unit load exceeds 3,500 lbs. for small boxes and 1,750 lbs. for large boxes. Base design showed no significant effect on pallet deflection for all of the support conditions evaluated. The effect of box size had a major effect on the deflection of the pallet. Large boxes showed the greatest change especially when lower stiffness pallets were used. Increasing the box size can reduce the deflection of the pallet as much as 50% which means that pallets supporting larger boxes could support much more weight than currently estimated.
Evaluation of pressure mat data showed that when the size of the boxes increased, more pressure is distributed towards the supports. More pressure is applied to the pallet section on the top of the supports; therefore, less pressure is available to cause pallet bending. This finding validates the observed reduction in pallet deflection as a function of box size. The obtained results help pallet designers to incorporate the interactions between the packages and the pallet into their design process which will allow them to reduce the amount material used for pallet.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/101680 |
| Date | 08 July 2019 |
| Creators | Morrissette, Steven Michael |
| Contributors | Forest Resources and Environmental Conservation, Horvath, Laszlo, Hindman, Daniel P., Kline, David E. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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