We often put the tasks of palletizing and depalletizing together when we talk about automation. But, there are some key differences between these two logistical tasks.
Do you need to treat palletizing and palletizing tasks differently?
Is one task harder to achieve with a robot than the other?
Could the same robot perform both tasks?
When you understand the specific requirements of palletizing and depalletizing, you can make better decisions about adding automation to your production workflow. It will help you to prepare your facility for robotic palletizing and get the most from your new investment.
Let’s look at the similarities and differences between these two robotic tasks…
The meaning of palletizing
Palletizing means placing or stacking items onto a wooden, plastic, or metal pallet for shipping or storage. It is a vital task for logistics as it helps to avoid damage or loss of products during transportation. Billions of pallets are used worldwide every day.
The traditional way to perform palletizing is to do it manually. A worker takes boxes or other forms of packaged products from the production line and stacks them onto the empty pallet.
More recently, collaborative robots have become a popular way to achieve palletizing. Robots are more consistent than human workers and help to reduce the number of injuries that are common for palletizing workers.
The meaning of depalletizing
Depalletizing means systematically removing boxes, bags, or other packaged items from a loaded pallet. It is often the first stage in a manufacturing process, where raw materials have arrived into a facility loaded onto a pallet.
Compared to palletizing, depalletizing is often a more complex task. However, robotic systems can still perform depalletizing with the right setup.
A related task is “repalletizing.” Here, items are removed from one loaded pallet and placed onto a second pallet for further shipment.
The similarities between palletizing and depalletizing
Before we look at the differences between these two tasks, it’s worth reminding ourselves of the similarities. Palletizing and depalletizing are clearly very similar tasks.
Some clear similarities between the two tasks are:
- They are often achievable with the same robot. The Robotiq Palletizing Solution, for example, works equally well for either task.
- They both involve moving boxes, bags, or other items between a fixed point (e.g. the end of a conveyor) and a regularly arranged pattern on a pallet.
- They are both repetitive, dull jobs that people don’t like to perform manually.
- They are often a bottleneck to production in facilities, especially when palletizing operators perform multiple roles.
These similarities are important when you are deploying a robot. They mean that you can often treat palletizing and depalletizing together. The deployment and integration work that you do for, say, palletizing will apply directly to the deployment of a depalletizing task, and vice versa.
5 Key differences between palletizing and depalletizing
There are also some important differences between palletizing and depalletizing. Even though the tasks look similar, you will likely encounter unique challenges with one that might not arise — or would arise in a different form — with the other.
Some key differences between the two tasks are:
1. Unloading challenges
With a palletizing task, you control everything about the items on the pallet. The robot picks up the box from a conveyor, for example, and places it in a precise location on the pallet.
With depalletizing, you are unloading items from a pallet that somebody else loaded. There is always a possibility that items will be in unexpected positions on the pallet or the distribution of items is inconsistent.
2. Items moved in transit
Pallets move a lot during transit. Securing the load with inadequate shrinkwrap is one of the most common mistakes in palletizing.
When you are depalletizing, it is not uncommon for items to have moved in transit. Your depalletizing robot must be able to account for such movement or it will make mistakes.
3. Robot vision
A common way to handle the uncertainty of unloading pallets is to add robot vision to depalletizing applications.
Vision sensing adds to the complexity of your robotic application, but it improves the system’s flexibility to changes. With palletizing, you can often get away without adding any vision sensing to your robot.
4. Different upstream and downstream processes
A clear difference between palletizing and depalletizing is that they interact with different processes in your production workflow.
Palletizing tasks usually come after upstream packaging tasks, such as sealing, labeling, and case erecting.
Depalletizing tasks usually come at the start of your workflow and will interact with tasks like picking, sorting, and unpacking.
5. Location in your facility
Likely, a palletizing and depalletizing robot will sit in different locations in your facility. You will want to locate the robot close to whichever upstream or downstream processes come before or after it in your workflow.
If your production quantities are low, you might be able to use the same robot for both palletizing and depalletizing. If so, you will need to take this into account when you design your robot cell and decide how it will fit into the layout of your facility.
How to decide if you need a palletizing or depalletizing robot
Do you need a palletizing or depalletizing robot in your own facility? Maybe you need both?
There are some questions you can ask yourself to help you find the best palletizing solution for your unique situation.
Ask yourself questions like:
- Do we have most bottlenecks at the beginning or at the end of our workflow?
- Where in the facility do we want to place the robot?
- Do we want to try to perform both tasks with the same robot or have multiple robots?
- What would be our throughput of product for either of the tasks?
Have a look at our solutions page to see case studies of companies that have succeeded with robotic palletizing.
Would palletizing or depalletizing make the most sense for you right now? Tell us in the comments below or join the discussion on LinkedIn, Twitter, Facebook, or the DoF professional robotics community.
Read more about this on: Workfloor: Robotics News for the Factory
