What is palletizing?
Palletizing is one of the most promising collaborative robot applications but before going too deep into details, let's start with simple definitions.
Palletizing or palletization refers to the action of placing products on a pallet for shipment or storage in logistics supply chains. Ideally, products are stacked in a pattern that maximizes the amount of product in the load by weight and volume while being stable enough to prevent products from shifting, toppling, or crushing each other. Currently, most palletizing applications are accomplished by manual labor. However, since workers are becoming harder to find and once we find them, don't talk about stacking boxes all day because they'll leave. Today's manufacturers are introducing robots into their workshops to make up for the lack of employees that can and want to do the job.
An automated palletizing process can be repeated endlessly, assuming the flow of boxes and pallets is constant. Some industries use robots for a single step of production, like emptying injection-molding machines or CNC machines. When production is running around the clock, robots let you minimize cycle time and run the process continuously by removing parts from the machine’s working area. Others will use in-line systems that were designed and created to accommodate massive amounts of products an hour. Their downside: no flexibility.
Palletizing with a cobot
In our vocabulary, a cobot is a slang or contracted term for collaborative robot. Here is what we think is the best definition for a cobot: "Collaborative robots are complex machines which work hand in hand with human beings. In a shared work process, they support and relieve the human operator.'' source: IFA. So basically it is a device that helps you accomplish your day-to-day job!"
On the more technical side of things what makes a robot "collaborative" is the fact that it can detect abnormal activity in their environment through force limitation or vision monitoring. These sensors allow for cooperation between humans and robots without any physical separation. Most importantly, a cobot answers to the 4th criteria of safe collaboration which is force and power limitation. In fact, all collaborative robots have force sensors in their joints that stop their motion in case of an impact. This allows you to run the robot at full speed and not worry about the potential danger of the kinetic energy being carried by this robot arm.
There are various cobot models on the market, but, no matter which brand your are choosing, a risk assessment should always be performed during the cell implementation to make sure the environment around the cobot and the cobot itself is safe.
Going back to palletizing and the mesmerizing number of choices on the market, choosing a robot to stack boxes, as simple as it seems, can be a complicated thing. You need to account for payload capacity, speed, reach, programming etc.
Anatomy of a palletizing cell
A palletizing cell can be pretty complex sometimes. However, there are recurrent items that represent the core of a robotic palletizing cell. The anatomy is broken down in the following terminology.
- Pallet: There are now many different kinds of pallets on the market like wood, plastic, paper/cardboard, metal and aluminum just to name a few. Size is also a big topic, standards may be different depending on where you are in the world.
- Conveyors: Used to route boxes to the robot. We could say that there is an infinite amount of conveyor configurations on the market. They are now adapted and optimized for specific industries. Make sure you chose the appropriate model for your business.
- Controller: Coordinates the machine’s motions. It is also where you can plug other components like safety scanner or light curtains.
- Operator: Operates the robot (in a robotic cell).
- Gripper: Grasps the box from the conveyor and places it on the pallet. Usually a vacuum gripper is the best option to pick the boxes. Make sure the suction cup configuration is adapted to your box and payload otherwise you might have issues with the pick reliability and repeatability.
- Teach pendant: Handheld device used to program the robot. We suggest always getting a protective case for you teach pendant, it's like your phone, you don't want to drop it.
- Status lights: lndicates the different status of the machine ie: pallet ready, pallet full, error, emergency stop etc.
- Cable management system: Used to protect cables that connect the robot to the other components. It also prevents cable pinching and breaking.
- Robot: Performs the actions of palletizing boxes for the operator.
- Sefeguarding: Not always required, but always has to be considered with a risk assessment analysis. They are usually found in three forms: fences, light curtains and area scanners.
You may want to look at the following blog posts to get a better idea of the different steps necessary to accomplish automated palletizing with a Cobot Palletizing Solution.
Like any industrial machine, a palletizing cell requires a risk assessment and risk reduction before being put into production. The purpose of the risk assessment is to identify the potential safety risks, their probability of occurring and their impact. The risk reduction identifies the mitigation measures that can be used to reduce them. A machine should only be put into production once the risks have been identified and reduced to an acceptable level.
For a robot palletizing cell specifically, many items need to be taken into account, for example:
- Weight of the payload and the robot
- Speed of the load
- Type of product (size, material, etc.)
- Shape of all the moving parts (presence of sharp edges, etc.)
- Presence of a linear axis, which most of the time cannot be power/force limited
Once the risks have been identified, some safety measures can be applied. For example, using a cobot instead of a traditional robot can help to reduce risk as they can operate using a power/force limitation mode. However, depending on the application (even with cobots), it can be required to use safeguarding of the cell, for example with area scanners or light curtains.
Companies are using cobots (collaborative robots) to accomplish three things: expand production, redirect human workers to higher-value tasks, and ensure everyone's safety. In this section, we'll look at several examples of how they're making it happen.
Alliora: When automation brings scaling
At Alliora, a French packaging company, collaborative robots are being used as smaller, safer alternatives to traditional manual works. Each cobot execute repetitive task and physical task. As Antoine Bruno, the company's general manager, says, "It is a very physical job. The boxes are between 5 kg and 12 kg. It is very repetitive, it is very heavy, and it is very physical. People don't like doing the palletizing task. Sometimes we have a high level of orders. In this case, we can't have any people on the line." Cobot Palletizing Solution is a completely valid approach, and it is clearly very effective for Alliora's purposes.
Manual workers in the company are able to program the robots at a basic level, but that seems to be all the robotics training they have at this stage. The operators' jobs have remained pretty similar to conventional manual palletizing they did previously. The main difference is one of scale. Before, each worker would carry each box to the pallet; now, they let boxes palletize by themselves.
Crum Manufacturing: 20h saved each week for a single task
Integrator CRUM Manufacturing sees many companies struggle to manually palletize efficiently.
Whether it is palletizing or creating new check fixtures, if a company wants something automated, they come to integrators like Crum Manufacturing and they design, build, and integrate those systems.
One customer came to them with a problem. They wanted to automate the palletizing of their product boxes. Like most companies, their customer doesn't have a dedicated palletizer or person to palletize. They're running one line and when they have a little downtime they try to hurry up and load 5-10 boxes. Then they go back and run their other system. It's not efficient. They still have to integrate some sort of manual or hydraulic turn/lift table themselves for ergonomic reasons. It's a problem people are still trying to work out.
Additional ressources on palletizing
eBook: Automate a Palletizing Cell
Start Production Faster wit Robotic Palletizing. Check out how to automate a palletizing cell.
The True Cost of Robotic Palletizing
How much does it really cost to deploy a palletizing robot? Is the price tag really the true amount that you'll pay? Or are there extras you need to know
7 Signs Your Business Is Ready for Cobot Palletizing
Is your business ready for cobot palletizing? How can you tell if a palletizing cobot will suit you? Here are 7 signs to help you make a good decision.