Palletizing refers to the operation of loading an object such as a corrugated carton on a pallet or a similar device in a defined pattern. Depalletizing refers to the operation of unloading the loaded object in the reverse pattern.
Many factories and plants today have automated their application with a palletizing robot solution of some kind. Robotic palletizing technology increases productivity and profitability while allowing for more flexibility to run products for longer periods of time.
A robot control system with a built-in palletizing function makes it possible to load and unload an object without spending a lot of time on teaching. Robotic work cells can be integrated towards any project. With current advancements in end of arm tooling (EOAT), robot palletizing work cells have been introduced to many factory floors.
In Order Fulfillment, there a few robotic solutions that are really revolutionizing the material handling world. These include Layer Forming and Inline Palletizing, Layer Depalletizing and Palletizing, and Mixed Case Palletizing, each have specific benefits that can truly improve a client’s operations with marked productivity, flexibility, and reliability.
In the past decade, the automated end of line palletizing of same package types has become proven technology. The economic justification of a palletizing system is mainly driven by the achievable throughput (cases per hour), the system availability, the required floor space and the utilization rate of the complete production line. Especially for high throughput demands, e.g. in the beverage industry, robots set new standards in Inline Palletizing. The use of articulated robot enables the implementation of new innovative robot based concepts for the high speed inline palletizing. With form fitting gripper systems, the incoming packages are moved actively and accurately into the correct target positions on a mesh belt conveyor. Hereby the robot motion is synchronized with the conveyor speed thus allowing a reliable layer forming process. Since the packages are gripped actively, the process does not depend on friction and packaging characteristics, which is often a challenge for shrink wrapped items.
During the layer forming process, a little gap between the packages is added in order to avoid potential collisions. Once a layer has been completed, a mechanical end stop is lowered and the layer is conveyed to the pick-up position of the layer picking robot. Immediately after the layer has passed the end stop, the end stop is raised again and the next layer can be assembled.
The layer picking robot can pull the whole layer with an integrated puller onto the gripper. Inside this gripper the layer is finally centered, thus a compact layer can be placed accurately onto the target pallet. As an option, the layer gripper can add a slip sheet. Depending on the production line speed, the robot-based inline palletizing system can be adapted to its required system performance. E.g., by adding another layer forming robot, the throughput can be doubled.
Economical automation can only be achieved if the installed equipment is optimally utilized. Transferred into layer picking systems, this implies that you are able to control the process and that the deployed technology can handle the highest percentage of your entire range of products and packaging types.
The variety of different product and packaging types (e.g. corrugated cardboard boxes, shrink wrapped items, open trays or boxes) in a distribution center have little in common, which makes automatic depalletizing and order picking difficult. However, as most package types have at least a flat bottom, universal gripping system has been designed to incorporate a roll-up principle. This enables you to handle layers of products where most other conventional technologies fail.
In this process, two servo driven rubber rollers are pushing against the pallet layer from opposite sides. The packages are thereby lifted up and rolled onto two symmetrical carrier plates. The gripper control software automatically adjusts the contact pressure and height position of the rubber rollers to suit the package weight and dimensions.
The roll-up principle supports a multiple layer pick cycle; thus, the overall picking performance can be significantly increased. The maximum layer number is limited by either the maximum payload weight or the maximum payload height.Seeing the Benefits
In the past decade, true mixed package type palletizing has become proven technology. The economic justification of a palletizing system is mainly driven by the achievable throughput (cases per hour), the system availability, the required floor space and the utilization rate of the complete production line. As SKU proliferation has escalated, this task has also become very labor intensive as well
The demands made on automated order picking in distribution centers grow by the day. Orders, articles, and a wide variety of containers must be picked and palletized, whether on pallets or pushcarts, right on schedule and with a minimum of errors
The range of articles and the dimensions and materials of the packaging units are virtually unlimited, be it open or closed trays or beverages wrapped in PET film. In response to these demands, an application module called Pallet-MIX for automated palletizing has been developed. The primary objective was the development of an application module using service, proven jointed-arm robots together with innovative software and gripper technology.
A conscious decision was made in favor of a jointed-arm robot with six degrees of freedom, in order to avoid the need for external turning of the packaging unit. This represents a significant advantage over gantry solutions. Performance and reliable palletizing of the packages were the prime criteria, with the aim of achieving high throughput rates.
During the past decades the proportion of deep frozen products in the food market has increased continuously in Europe and in the US. The main advantage for the customer is evident: a long storage life. These products have to be order-picked in a very cold distribution center. Up to now, this process has been done manually resulting in a high fluctuation of the work force.
At this temperature level (-30 °C; -22 °F), not only do the workers have to keep themselves warm, but the technical equipment is adversely affected: Lubricants lose their viscosity, plastics become hard and brittle, microelectronics (controller hardware) and sensors are usually not specified for such temperatures.
One or two companies have taken up these particular challenges and have developed a system for layer-wise order picking that can cope with these harsh environmental conditions. In this solution, source pallets are placed alternately on two in-feeding chain conveyors. The robot depalletizes the required number of layers from the source pallet and transfers them onto the target pallet, which is transported on a third conveyor. The picking sequence is specified by the customer’s order lines and the valid stacking rules; Thus the source pallets have to be supplied in the pre-defined order.
The gripper concept combines vacuum and clamping technology. The deployed components have been carefully selected to ensure a reliable operation in these extreme temperatures. Due to this approach, technology has proven that a wide range of deep frozen products can be handled successfully using standard packages. The servo-driven side clamps are used and moved to the optimum clamping position in relation to the product height. Sensors detect the current height of the top layer and the existence of slip sheets.
Slip sheets are picked with a reduced vacuum level and are transferred onto a slip sheet deposit position or onto the target pallet depending on the customer’s preference. If necessary, the side clamps can also pick up empty pallets. Thus the robot can remove empty pallets from the source conveyors or provide itself a new empty starter pallet onto the target conveyor.Seeing the Benefits