Improve Palletizing Safety Through Automation
PALLETS MEAN BUSINESS
Ever since the standardization of the simple pallet-and-stack method of transporting goods, there has been a constant evolution in the palletizing ecosystem. The objective has always remained to safely and quickly move goods from place to place whether it was on to a truck, into a warehouse or in to a container. Pallets have become such an integral part of logistics that the U.S. market size for pallets is expected to be $13.4 Billion in 2023, which happens to be a bit larger than the GDP of Lithuania for comparison. Pallets have become the universal tool for stacking and storing products in warehouses and trucks. Part of what makes pallets such a good solution to so many links in the logistics chain is that they can easily be handled by fork trucks or pallet jacks. This is such a common combination that even experienced fork truck operators think nothing of picking up a loaded pallet without inspecting it and taking it to a warehouse location without making sure that the location is ready to receive the pallet load (right size, weight rating, and no obstructions, for example). OHSA Safety data from 2011 through 2017 indicate that an average of 8,500 forklift injuries occurred annually and a total of 614 deaths happened during that time period. Most injuries are caused by fork truck rollovers and many of those are related to what shape the pallet was in and if it was properly stacked and secured before being moved.
BEFORE THE PALLET MOVES
Loading up a pallet for transport is more than just stacking finished product on the deck of the pallet then having it carried away by a fork truck. There are usually height limitations due to a variety of reasons. Certain combinations of height and weight make the fork truck more prone to tipping. When you have a mixed load, be sure the heavier portion of the load goes on the bottom. This will help keep the center of gravity low and will keep the load more stable. Inspect pallets regularly for wood splits, and loose nails. These can be weak areas that fall apart under load causing a spill or tip-over. Damaged pallets should be replaced. Be sure to stack pallets evenly to create a stable load. Stay within the weight limits for the pallet being used. Just as stacking too high can lead to instability, too much weight can have a similar effect making it harder for the fork truck driver to maintain control. Stack and store pallets according to their design. Most are designed to be stacked on directly on top of each other, all with the same alignment. Others may be designed to be rotated 90˚ for each successive pallet layer. Regardless of type it will have a maximum height limit rating which should be followed.
BUILDING UP A LOADED PALLET
The palletizing system, working from the bottom up has to have a way to safely handle the pallets and stack them properly and ready to be moved to the end of the production line for loading. It is important to know the size of pallets that are being used. In the US, the three most common sizes are 48” X 40”, 42” X 42” and 48” X 48”. There are other standard sizes as well, so it is important to know exactly which pallet will be used as the base. For example, there is a standard “Euro pallet” size that is 47.5” X 39.4”, which is close to the common US standard, but not identical. The finished goods are usually put into a box that is sized to nest exactly on top of the pallet being used, with no gaps. As an example, a 10” X 12” rectangular box can be loaded on to a 48” X 40” pallet in a 4 X 4 pattern. Where it is possible, box sizes should be chosen so that each row can be collated to overlap with the edge of the box below it and at the same time, nest properly in their row with no gaps. This results in a more secure stacking arrangement. This is not always possible, so some additional steps are usually recommended. Using tier sheets or slip sheets between layers helps reduce the relative movement between layers of boxes. In some cases, it makes sense to strap the load in place and most pallet loads are finished off with stretch wrap to enclose the boxes and help secure them to the pallet.
Typical limitations for height are to stack the pallet no more than 48” high and with a total weight of about 3000 pounds. These are just rough numbers, so you will want to use the guidance of the pallet manufacturer. Pallet dimensions of 48” are designed to fit nicely in the back of an enclosed freight truck which has a 96” (8 foot) wide interior. The whole palletizing system has evolved so that, if done right, finished goods can move quickly and securely from the end of a manufacturing line to a freight truck and on to the customer’s loading dock. Manual palletizing is hard work, and prone to errors and can be risky since it involves working close to moving machinery. For these reasons, plus the ability to have a predictable output, this is one area that is typically a high priority for automation. CRG Automation has experience at all levels of palletizing. They have designed, built and installed equipment as listed below.
- Robot arm with custom EOAT (end of arm tooling) with full perimeter safety guard package and production alarm systems
- Case and pallet conveyor; product collators
- Pallet dispensers, tier and/or slip-sheet dispensers
- Automatic stretch wrappers and strapping machines
- Labeling systems, bar code readers and weighing systems
- Integration into warehouse management systems
For safety, security, and reliability, CRG automation specializes in the custom engineering of automated solutions for the packaging, material handling and manufacturing industries. Reach out today and see what we can do for you.