||It has been suggested that this article be merged into pallet. (Discuss) Proposed since October 2012.|
Plastic pallets are pallets made of a variety of plastics.
Plastic pallets are produced and used widely in the U.S. and Europe, spurred by the adoption of the ISPM 15. Regulatory standards for wood packaging material (WPM) in international trade require it to be either heat treated or fumigated in accordance to ISPM 15 guidelines. The European Pallet Association, established in 1991, monitors the standards set for Euro pallets, which pallets used to export product from America must meet. Both European and American companies have embraced plastic as an attractive alternative to the original wooden material in packaging and shipping pallets.
The benefits of plastic pallets over wood pallets include the ability to be easily sanitized, resistance to odor, fire retardancy, longer service life span, durability and better product protection, non-splintering, and lighter weight, thus saving on transportation and labor costs and making them safer and more environmentally friendly. Wood pallets can pose serious bio-hazard risks as they are susceptible to bacterial and chemical contamination, such as E. coli problems in food and produce transportation, and even insect infestation, and thus the need for ISPM 15. Plastic pallets are re-usable and recyclable, while used wood pallets have disposal issues. A full comparison of wood vs plastic can be made by a life cycle analysis.
Plastic pallets can cost 10 times as much as hardwood pallets and even more expensive compared to cheap expendable softwood pallets. Some plastic pallets can collapse from plastic creep if used to store heavy loads for long periods.
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There are six main types of plastic processes that are used to make pallets:
- High pressure injection molding
- Structural foam molding
- Compression molding
- Rotational molding
- Profile extrusion
Plastic pallets are available in a wide variety. You need to know how much weight you are putting on a pallet and how it will be used and handled to select the proper type of pallet for your application. When looking at what you are putting on the pallet, capacities are based on evenly distributed loads. If you are putting coils or bags of product, the weight is not evenly distributed. The following should help a bit in explaining the different plastic pallet designs available.
Plastic pallets from compression molding tend to have more rigid structure due to compression, allowing plastic density to reach 0.95-0.97 for PP and HDPE. PP has more advantage than HDPE in room temperature where its stiffness plays role in racking, stacking, and dynamic system. Whereas HDPE has lower brittleness temperature than PP allowing better application in cold storage -20 Celsius. Further tests showed that PP products that have wall thickness above 3,5 mm have similar brittleness as HDPE in less than -20 Celsius environment.
Rackable – These are the strongest plastic pallets available. They are built to withstand their weight capacities on an open rack system that does not have decking. In other words, the rack has just a front and back beam with nothing between. Options vary from light duty to heavy duty. Steel, composite and galvanized reinforcement bars are available in some models. If your racks have decking you can use a stackable pallet.
Stackable – These pallets are designed with a bottom deck that allows you to stack pallets on top of other loaded pallets without damaging the load. Stackable pallets have a variety of bottoms. The picture frame bottom is a full perimeter frame with the middle clear. The cruciform base has the full perimeter frame with a cross through the middle. The three rail pallet has three rails in one direction. Post and rail have two rails with three posts through the middle. When I mention rails I am speaking of what touches the floor.
Nestable – These are a very popular distribution pallet due to their space saving advantage. The legs of these pallets nest inside each other to maximize your floor space when not in use. Most nestable pallets ship 30 - 75 to an 8' stack. These pallets are suited for distribution systems, warehouse w. i. p. pallets, storage, raising floor levels, or any general applications.
Export pallet – Available in both stackable and nestable versions. Inexpensive plastic pallets designed for one-way shipments or general light warehouse and storage use. The most cost effective pallets are manufactured in a 40 x 48 size to “cube out” shipping containers. They vary greatly in weight capacities and life expectancy.
Drum pallets – These plastic pallets are specifically designed to handle four fifty-gallon drums. Drum pallets are available in a variety of qualities from export to spill containment.
Solid deck pallets – They are just that, the deck or top of the pallet is solid plastic. These are available in a variety of configurations. Options also include reinforcement bars to handle the heavy loads, anti skid surfaces, and perimeter lips to keep your load in place.
Plastic pallets are available in two different qualities. Export pallets are manufactured with materials that are not meant to last. Export pallets are not uniform in color, nor plastic content. Warehouse use pallets are generally manufactured with PE and or PP content, from post industrial waste. If you see a pallet in a color other than black and gray, there is a very high probability that the pallet is manufactured with virgin plastics making it a very expensive pallet. Plastic pallets are a green alternative to wood as most are not only recycled content but recyclable as well.
There is no clear documented time at which plastic pallets first appeared, but the consensus in the pallet industry is that they most likely appeared in the United States after World War II. Credit is given to retired B-29 captain Leo Nathans for creating plastic pallets for the auto industry to ship car parts when plastic pallets were a precious commodity due to war effort.
Modern Material Handling Magazine earliest mention of plastic pallets is in 1964 for a fiberglass reinforced plastic pallet.
In the early 1970s, the rotational molding process was used to produce polyethylene pallets in Oklahoma for the food, pharmaceutical and food industries only as returnable units, whereas the producer of products would ship to their customer and the customer would return the pallet to the supplier for reuse. The process was also used to produce pallets for in process applications at Food and Pharmaceutical facilities, where a high degree of cleanliness was required. Robert Lux with Thermodynamics in Oklahoma has been cited by many sources as the father of the rotationally molded pallet with over 300 designs to his credit in his 35 years of material handling product design.
Having not been innovated sense its inception in 1964. One of the first innovations can be credited to Fast Lock Pallet. Creating the first interlocking plastic pallet. Allowing users to create custom size pallets on the spot in seconds.
- "Resources: WHAT IS ISPM-15?". Buckeye Diamond Logistics, Inc. Retrieved 8 February 2015.
- "What are Plastic Pallets?". Winston Containers. 11 January 2015. Retrieved 8 February 2015.
- "Don’t reuse wood pallets". Cheap Like Me Blog. 3 June 2010. Retrieved 8 February 2015.
- Lee, S. G. (March 2004), "A simplified life cycle assessment of re-usable and single-use bulk transit packaging", Packaging Technology and Science: 67–83, doi:10.1002/pts.643, retrieved 15 October 2012
- Raballand, ibid., pg11
- Swedberg, C (March 2012), "Asset-Tracking Technology Helps iGPS Rescue Its Pallets", RFID journal: 49–60, retrieved 15 October 2012
- Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6