From conveying items in production, to palletizing them on the way to the dock door, manufacturers are searching for automated material handling systems to boost their bottom line. Where speeds are low, depalletizing and palletizing operations can be done manually. But, as speeds increase or the product becomes difficult to handle, automating these operations becomes a necessity. Long a standard, automated depalletizing and palletizing are designed to alternately remove empty containers, feed them back into a filling line, and stack finished product.
Until recently, a conventional palletizer could adequately perform this task. As product is conveyed, the palletizer arranges it in a pattern on a stripper plate, and then layers it onto the pallet. Low-speed palletizers stack 1-10 cases per minute; high-speed palletizers stack over 150 cases per minute. Either can have a floor-level infeed, fixed at 3 ft. or a high-level infeed, fixed at 10 ft.
Today, robotic technology poses a challenge to the traditional high-speed palletizer. A robotic palletizer uses an end effector (or gripper) to pick-up the product that is coming down the conveyor and places it onto the pallet. Robotic palletizing solutions come in four basic designs: Cartesian, scara, articulating arm and gantry. The most prevalent palletizing robot is the articulating arm: it is the fastest and most flexible.
Manufacturing operations and supply chain managers should carefully consider their options when deciding on the type of system they need to automate a palletizing operation. Both robotic and conventional palletizing and depalletizing solutions can be configured for any pattern. The trick is determining which solution is the best fit to meet the other parameters in an application.
Though not a rigid rule, conventional palletizers are more commonly used for applications requiring higher speeds or involving products with reduced packaging. Reduced packaging is particularly common for high-volume environments, and is due in part to the high cost of corrugate.
Robotic solutions generally fit lower-speed lines and situations where the palletizer needs to handle multiple lines simultaneously. Because of their typically smaller footprint, robotic solutions are also an option where floor space is at a premium.
Carefully constructed ROI projections should be the ultimate consideration in deciding whether to go with a conventional or robotic solution, or whether to choose an automated solution at all. For example, automating full-load handling may dilute the ROI for a multi-line robotic palletizing system.
If robotics appears to be the answer, an additional facet of the decision-making process will ultimately be what types of robots and components will go into the solution. Most current robotic palletizers or depalletizers use either gantry robots, known as “square” robots, or jointed-arm robots, known as “round” robots, both nicknamed for their types of motion.
Gantry robots are linear-motion robots, meaning they move up, down and across in a work envelope that can be more than 80 feet long. They are typically built to the dimensions of a specific project and offer more flexibility, including the capacity to work with a large number of pick-and-place locations.
Jointed-arm robots are more limited in the size of their work envelope but are typically economic and fast. In a typical palletizing application, a jointed-arm robot can build four pallet loads within its work cell. Another important decision in a robotics application is which end-of-arm tool (EOAT), or “end-effector,” will be used. Vacuum-type end-effectors have many uses in general manufacturing, but they are not suited for palletizing and depalletizing operations, particularly for items that are packaged for product display, such as open-top cases and shrink-wrapped trays. In these types of situations, a side-clamp or fork-and-clamp tool is a better choice.
When considering a robotic palletizing solution, use the following guidelines. 1. Don’t be taken in by the “flexibility” hype propogated by robotics companies. Conventional solutions can be more flexible than robotic solutions, depending on the given application. Do a thorough technical evaluation of the alternatives for your particular application before making a final decision.
2. Get a firm guarantee on robotic rates, including consequences if those rates are not met.
3. Don’t be too quick to use vacuum tooling; clamping may offer better performance and flexibility.
4. Ensure that your personnel receive adequate training. No robotics system is as easy to operate and troubleshoot as the salesperson will report.
5. Find a robotics integrator that specializes in the task you are trying to accomplish. Experience in robotic welding systems does not guarantee success in robotic case palletizing.
As choosing the right type of robot or end-effector to use for a palletizing or depalletizing project is key, so too is choosing the right partner to build the solution. Since core knowledge of palletizing or depalletizing engineering is required to adequately spec this kind of solution, it is important to choose a business partner who has experience with these types of operations.
Many companies looking for a robotic solution often head to a general robotics company, but this can be a mistake. Palletizing and depalletizing projects, particularly in manufacturing, require proven material handling integration experience to determine whether a robotics solution is appropriate, or even whether a mix of robotics and other technologies is required. In a robotic depalletizing solution, for example, a vision system might be needed to determine the position of product that has shifted during transit.
Another mistake can be turning to a robotics company that outsources the components of a robotics solution rather than using a single-source provider that designs, manufactures, and supports their solution. A solution from a single-source provider frequently offers better project control, better quality of the components, and an efficient commissioning schedule. Single-source providers also bring lower risk to the process and a higher level of sales, service and maintenance support. Whatever the solution robotic or conventional a trusted partner who can identify and recommend a solution to a complex production requirement is an invaluable resource, especially for integrating a palletizing or depalletizing system into a manufacturing company’s wider material handling system. FKI Logistex North America __________________________________________________________________ In general, robotic solutions are the most flexible palletizing solutions. For sales and marketing information, contact Jill Raab, marketing communications coordinator, FKI Logistex North America, by phone at (314) 993-4700 or by e-mail at [email protected]. For media information, contact David Abels, senior account executive, Koroberi, Inc. (www.koroberi.com), by phone at (919) 960-9794 ext. 22 or by e-mail at [email protected]. David Abels Senior Account Executive Koroberi Inc. P: 919-960-9794 x22 F: 919-960-8570 E: [email protected] ?? ?? ?? ?? www.fkilogistex.com
