It’s been said taking something apart is easier than putting it together. If you’re in business to dismantle and recycle wood pallets, you might say otherwise. Taking apart (or dismantling) wooden pallets is dangerous, deafening and draining for employees. The work in pallet recycling plants is largely manual labor, and it’s always challenging to recruit and retain staff for a job that has people in constant contact with band saws, debris and vibration. Yet, the job is critical because the pallet, literally and figuratively, supports the nation’s supply chain.
There are nearly two billion pallets in service in the United States every day. Ninety-three percent of all pallets in service are wooden, and seventy percent of these are recycled by a network of regional companies that collect used pallets by the trailer load from local retailers to begin their recycling process.1
The process typically goes like this:
- Recyclers collect trailer loads of pallets from local area retailers
- Unload pallets from the trailers at their facility and begin the sortation process
- Sort by type (red & blue “loop” or block pallets; whitewood or “stringer” pallets; and plastic pallets)
- Loop pallets are picked up by the respective owner-company and sent to their own authorized repair center to selectively remove boards (average of two components) for repair and paint
- Repair or complete dismantling of stringer pallets for lumber reclamation
- Complete dismantling is done manually by literally dragging the pallet thru a horizontal band saw to cut the nails or screws
- Reclaimed lumber will be cut to size or scrapped and ground for mulch
- Build new pallets with recycled or new wood or a combination of new and used
Of the three main labor areas (sort, dismantle and assembly), clearly dismantling is the worst job in the plant and difficult for owners to find or retain labor willing to do this dangerous job.
A little over a year ago, PalletCentral magazine, which the National Wooden Pallet & Container Association (NWPCA) publishes, asked owners of pallet recycling firms what they were focused on to more efficiently build a better pallet. One CEO said he thinks about how his company can find and retain workers, ramp up new employees faster and redesign jobs to create positions requiring greater skill. I would suggest any owner, or in this case CEO, first consider implementing robotic automation for their pallet dismantling process, the worst job in the plant, to help realize his goals. I would seek to automate this process prior to looking at sortation and assembly since non-robotic automation is available for those processes and in place at many facilities I have visited. Once dismantling is tackled, robotic sortation would be next on my list and then, robotic assembly.
Robotic dismantling is not new to us. Seven years ago our Swedish division began developing a specialized selective component robotic removal system for a large loop pallet manufacturer. The system was designed to work with Euro pallets and used hydraulic blades to cleave thru the joints and shear the nails. More than twenty-five systems are now installed. Because of the closed top and bottom design of U.S. block pallets, a different approach was needed. Once again, Yaskawa went to work and developed a new board and block removal process which employs an underwater specially designed circular saw. The water is used to cool the blade, arrest sparks and float the debris and boards to an angular belt conveyor and into a dumpster. Production rates for both systems is sixty pallets per hour, 24/7, if needed.
Let’s move back to stringer pallets and the task of dismantling for lumber reclamation. This requires yet a different process since the circular saw or hydraulic blades can only reach the perimeter of the pallet and is used only for block pallet selective component removal. In partnership with Alliance Automation (Van Wert, Ohio), we have developed a robotic solution that imitates what a person does; namely picking up a pallet and pushing (instead of pulling) it through a horizontal band saw. With a patented gripper and a proprietary real time feedback control loop between the saw motor load and robot movement, we have a robust solution for this tough job. Cycle times for this system is a pallet every 25-30 seconds, producing up to 110 pallets per hour in real-world working conditions.
Dismantling pallets isn’t the only part of recycling that a robot can shoulder. Robots can assemble custom, stringer and block pallets ranging in size from 20 inches (50.8 cm) to 120 inches (304.8 cm). In contrast to a dedicated pallet nailer machine, which might take several hours to adjust for each pallet size, an operator can adjust a robot nailing cell to assemble a new pallet size in five minutes. Plus, the robot’s precision and efficiency, combined with the use of a bulk nail feeding option, can significantly reduce the expense of nails.
For the pallet recycling plant owner who wants to consider robots, it’s essential to have trained staff to maintain the equipment. Training is an investment that pays off, and here’s why. The CEO mentioned in PalletCentral wanted new ways to retain workers and create positions that require greater skill. What better way to do this than having some of the plant’s workers learn how to operate and maintain their robot “co-workers”? Training is important for keeping robots running smoothly and recovering from routine situations that occur during normal operations.
In addition to improved working conditions and higher value opportunities for the operators, robotics automation can reduce the burden of finding and retaining labor, increase productivity, reduce injuries and provide consistent quality.
Roger Christian is a Division Leader, New Business Development at Yaskawa America, Inc.– Motoman Robotics Division