Products are palletized in just about every industrial manufacturing setting around the world.  This repetitive, and many times dangerous task of stacking boxes, bags, parts, or assemblies on to a pallet leads many organizations to implement automated means to accomplish this task.  Here are ten important aspects of robotic palletizing systems.  

10. Main Criteria: Reach/Payload/Speed/Axes

After a potential robotic palletizing application is identified, it is important to select the proper robot for the job.  All robot manufacturers provide a wide variety of robot specifications to meet the desired performance.  A few of the main points of criteria include:

• Reach: The “reach” of the robot is commonly presented as the distance from the center of the robot to the furthest extension of the arm. This typically resembles a spherical shape which is important to consider when palletizing products from a low to high elevation.  You can find palletizing robots with reaches anywhere from 70 to 125 inches.
• Payload: Various factors go into selecting the proper payload robot. Note that the payload must include both the weight of the End of Arm Tool as well as the product it is handling.  It is also important to understand that the robot’s stated payload is only valid for loads with the center of mass at the center of the faceplate of the arm.  Any offsets in the End of Arm Tool or product will diminish this overall payload.
• Speed: Speed is harder to classify and compare due to speeds typically being stated in terms of rotational speeds of each axis/joint (i.e. degrees/sec). Many times a simulation is required to validate speed requirements.
• Axes: In most cases, a 4-axis robot is used because products tend to be parallel with the floor when picked and placed in palletizing applications. In other cases where products need to be rotated or tilted, 5- or 6-axis robots can be utilized.

 

9. Palletizing Robot Bells & Whistles

A simple YouTube search will undoubtedly yield thousands of examples of various palletizing applications used in industry.  Each application, however, has its own unique distinguishing aspects that sets it apart.  There are several “bells and whistles” that can be applied to robotic palletizing systems.  Some of these may include:

• Integrated or 3^rd party robot vision
• Force feedback to measure cases or parts as they are picked
• Foundry grade options
• Enhanced safety software
• Mobile robot / Robot-on-Rail systems
• Mixed load palletizing software

 

8. Flexibility & Re-Purposing

“We don’t know what we don’t know,” is often a statement made by packaging engineers or plant managers regarding what the future holds for their packaging needs down the road.  Because of the ever-changing, custom nature of consumer goods, what is palletized today might not be palletized the same way tomorrow.  Robots allow for a great deal of flexibility in handling various products and patterns with the same robot. 

If future product specifications are known up-front, the proper robot can be selected and End of Arm Tooling can be designed such that the change can be handled with minimal effort.  But in those cases where a completely unique requirement is introduced, robotics can many times still allow for minimal implementation requirements by simply changing out tooling or ancillary equipment while re-using the same robot.  

7. Reduced Maintenance Cost

Prior to robots becoming common in the palletizing space, conventional palletizers ruled the industry.  These systems use conveyor, turning mechanisms, pushers, accumulation tables, stripper plates, and lifts to form layers of product to palletize.  While effective, these systems typically involve a great deal of moving parts and preventative maintenance components.  Robots, which are inherently a group of cast iron arms and servo motors, require very little maintenance and will easily prove to be one of the most reliable pieces of equipment in a facility.  

6. End of Arm Tool Design

End of arm tools are the heart of any robot system.  In many cases, the end of arm tool is the last thing to touch a customer’s product before the customer receives it.  That being said, gentle, reliable, and effective handling of cases, bags, or parts is vital in a successful robotic palletizing system.  Robotic palletizing end of arm tools can take the form of:

• Zoned vacuum cups
• Compression plates with or without bottom support
• Universal vacuum pads
• Clam-shell, claw grippers

 

5. Multiple Lines

Robots can have a wide-reaching envelope in which to pick and place product when palletizing.  Due to this, robots are typically tasked with handling multiple, simultaneous production lines with multiple load build locations.  Most common configurations are 1-in/1-out, 2-in/2-out, 3-in/3-out, and 4-in/4-out systems.  The economics for justifying a robotic palletizing system tend to increase as you handle multiple product lines (versus a single 1-in/1-out system).  Furthermore, if rate and space really start to become a concern, Bastian Solutions' robotics division has developed a full-layer robotic palletizing system which can be another alternative to evaluate.  This system uses conveyorized case manipulation, preliminary layer-forming, and a full-layer end of arm tool to palletize cases.  

4. Collaboration

The latest hot trend in the robotics realm is collaborative robots (or “cobots”).  While the majority of uses for collaborative robots are in machine tending or part handling roles, cobots such as Fanuc’s CR-35iA model are made specifically with palletizing/de-palletizing in mind.  Being one of the largest co-bots on the market, this robot has the ability to reach to the far end of a pallet to place cases.  However, with only a 35 kg payload, one must consider the weight of the product and a relatively simple, light-weight end of arm tool.    

3. Economics

Robotic palletizing system implementation has never been more affordable and justifiable.  With robot and ancillary component prices dropping, and the robotic knowledge base growing steadily, achieving typical one to two year return-on-investment thresholds is very realistic.  A single-robot palletizing system could run anywhere from $250,000 - $500,000 depending on the scope of the equipment needed.  With rising costs of labor, need for safe working environments, and keeping operations on the cutting edge of technology, this cost is often easy to justify.  

2. It’s All About the Utilization

While robots can certainly do a lot without breaking a sweat, there is a point in which they cannot take on additional rate or complexity in pallet patterns.  With every application, it is a prudent practice to evaluate the utilization of the robot with respect to the tasks it needs to accomplish.  One should complete a time study which would account for all the time it takes to pick and place product, pick and place sheets and/or pallets, conveyance time, and any additional ancillary tasks required.  This utilization calculation will tell the integrator or end-user if only a single robot is needed or if multiple robots will be required.  

1. Proper Integration is the Key to Project Success

While much of the “low hanging fruit” in the palletizing automation realm has been addressed across the industry, applications are becoming increasingly complex.  Proper initial development, engineering, integration, and after-market service are invaluable for the overall success of a project throughout its life cycle.  One must pay close attention to the specifications of every piece of ancillary equipment in a robotic palletizing cell as well to ensure overall system effectiveness:

• Pallet Conveyor
• Pallet Dispenser & Stackers
• Stretch Wrappers
• Pop-Up Transfers
• Transfer & Shuttle Cars
• Among others

Bastian Solutions robotics' division would be more than happy to look over your latest palletizing needs and determine if a robotic palletizing system would help you meet your business goals. Contact us today. 

Author: Matt Kohler