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‘Straight Line’ Pallet Repair System Lets Builders Make the Decisions
The ‘straight line’ system is one of the two main ways of automating pallet repairs and recycling.
By Clarence Leising
Date Posted: 8/1/2003
There are five things you want to accomplish went putting in a system for repairing and recycling pallets. Briefly, here they are:
!Get the pallets to the builder as easy as possible.
!Get the pallets away from the builder as soon as he completes repairs.
!Get the scrap away from the builder.
!Use equipment to remove damaged lead boards as needed.
!Ensure the builder never has to take more than one step to reach any supplies or tools (repair stock, fasteners, nailing tool, pry bar, etc.)
The ‘straight line’ system is one of the two main ways of automating pallet repairs and recycling. In the straight line system, incoming pallet cores are not sorted in advance. Stacks are moved by forklift directly to the repair tables or work benches, which are aligned on both sides of a conveyor. The builder pulls a pallet from stack onto the table and decides if it is ‘ready-to-go,’ needs repairs, is scrap or an odd size pallet that can be dismantled to recycle lumber. He performs any necessary repairs and puts the finished pallet on the conveyor. ‘Ready-to-go,’ scrap and odd pallets also go on the conveyor. This system gets pallets to the repair station quickly and delegates to the builders the decision as to how the pallet will be processed.
This system uses a slider bed conveyor with a completely flat top -- a 42-inch belt and a 48-inch bed. Both pallets and scrap wood go down the same conveyor.
This system has several advantages. First, you are not limited to the size of pallets you can process. If any square pallets (36-inch, 40-inch, 42-inch, 44-inch or 48-inch) are in the mix along with your GMAs, you can repair them at the same time without handling them again.
You put the scrap on the conveyor first and then the pallets. At the end of the conveyor, leave an 18-inch gap between dead rollers. Directly beneath the gap is the scrap or waste conveyor. The scrap falls through the gap onto the waste conveyor -- and is taken to a dumpster or directly to a grinder -- and the pallets continue on to more dead rollers.
A pallet that needs plating is turned over by the builders, and pallets that are plated are returned to the line to be sorted and stacked. When a pallet reaches the sorting station, the sorter picks it up, decides if it is an A or a B pallet, then puts it into the appropriate stacker. This method will prevent plated pallets from being segregated and collected into full stacks. Customers do not want to look at an order of pallets they bought and find stacks of plated pallets. Using a plater as part of the line will prevent this from occurring.
The second advantage of this system is that 100% of the scrap wood goes straight to the conveyor. Scrap wood does not get lost along the way, and it cannot jam the belt as is possible with an overhead conveyor. Other systems may require the builders to throw scrap into boxes, which gets mixed up and must be straightened out from time to time. When builders are straightening scrap material, they are not building pallets.
There is another advantage to slider bed conveyors. When boards that are 40 inches long and can be recycled are removed, they will be visible coming down the conveyor. No one can hide their scrap. This can result in big savings in wood costs.
I once stood in a pallet recycling shop in Salt Lake City, Utah, and we picked out a lift of usable wood from the conveyor belt in 20 minutes. A board costs about 15 cents to produce, so it is possible to save between $30 and $50 per day -- or about $10,000 per year!
Do you need one person to pull out the reusable boards from the scrap conveyor? No. Instead, tell your builders to stop sending good boards down the line and use them. Why do the builders send good boards down the line? Simple: the good boards contain nails. They don't want to take the time to bend down the nails, so they send them to scrap.
In addition to grading pallets, the sorter keeps an eye on the scrap coming down the line to ensure that no good boards go to the waste conveyor. The last thing this worker does is to sort all the scrap and odd size pallets as they come down the line. Scrap pallets normally should be sorted as to whether they are under or over 40 inches and also by thickness.
Another advantage of this system is that you can make the height of the conveyor equal to the height of the pallet repair tables. This will eliminate more lifting of pallets. Workers can slide the first 10-12 pallets off a stack. Other systems may require more lifting.
Should a conveyor fail, you could have a worker carry the pallets down the line until it is fixed. The odds are against all your stackers breaking down at the same time, but even if that were to happen, you could still stack the pallets by hand.
Repair tables should have a good size working area; they also should have a crown in the middle so the repair worker can spin the pallet for easy access to all sides. There should be room beside and behind the builder to hold tools and fasteners, and a rack above to hold repair stock. Everything should be close and organized.
What about maintenance costs? With a slider conveyor and dead rollers, maintenance costs are minimal. The slider conveyor has a motor, gear box and four bearings. You also need safety cables, and I highly recommend speed control. I recommend the speed control be set so the conveyor moves pallets and scrap at a rate of 25 to 35 feet per minute. Speeds faster than that will reduce the sorter’s time for properly grading pallets while speeds slower than that will be less productive.
This is the superior system, in my opinion, for three important reasons. First, it does not limit the size of pallets with which you can work. Second, by sending all the scrap down the conveyor, you should save from $30 to $50 per day. Finally, the builders never have to move from their repair station. This allows them to become comfortable with their work station.
This system should produce between 300 to 400 pallets per builder, and I have seen it in operation and producing from 500 to 600 pallets per builder. Production levels will depend on the quality of pallet cores.
(Editor’s Note: Clarence Leising is a representative of Eagle Metal Products. He previously held management positions in pallet recycling companies in the Northeast for 25 years. He may be contacted at (800) 521-3245.)Page 1 Page 2