ISO 8573-1 is an international standard for measuring the quality of compressed air. This is important for robotic palletizing because the vacuum grippers often used in these systems are pneumatic.
When you use vacuum grippers for palletizing, air quality can mean the difference between successfully picking a box and dropping it.
But what effect does the air quality in your robot work environment have?
How do you compare vacuum gripper models and their air quality ratings?
And how can you tell which vacuum gripper is best for your particular palletizing task?
Let’s take a look at the ISO 8563-1 standard to understand how you can use it to make better decisions about your palletizing robot.
What is ISO 8573-1?
ISO8573-1 is an international standard for compressed air purity classes developed by the International Organization for Standardization (ISO). It defines a set of criteria for assessing and classifying the purity of compressed air and is essential for tasks where clean air is required.
The standard consists of 8 parts that provide classes and test methods. It classifies air quality by type and size of contaminant or particles in the compressed air.
The standard sections are:
Purity classes for particles, water, and oil.
Test methods for oil aerosol, humidity, solid particles, and oil/solvents.
Test methods for solid particle content and microbiological contaminants.
Solid particle test methods.
Liquid water testing methods.
From these tests and procedures, an air supply is given a rating that indicates air purity.
For robotic vacuum grippers, the type of contaminant may vary depending on the specific environment in which you are using the robot. However, the most common type is particles, such as ambient dust in a warehouse environment.
Why air quality is important for reliable robot palletizing
Air quality is a property that people often forget to consider when they are buying a palletizing robot. However, the air quality rating of a robotic vacuum gripper can significantly affect the performance of the robot in a palletizing task.
Contaminants affect the vacuum gripper’s suction force. As a result, air quality influences the weight of objects that the gripper can lift.
Most vacuum grippers have some type of air filtration system. However, they have different ratings in accordance with ISO 8573-1. If your gripper’s filtration system can’t filter out the type of contaminants that are in the air, it may fail to pick up the boxes reliably.
If your robot works in a clean room, you probably don’t need to worry about air quality. For all other environments, you must consider air quality.
How vacuum grippers use air when palletizing
Vacuum grippers often used in palletizing robots work by producing a vacuum force, usually with a vacuum pump connected to the gripper.
Vacuum grippers work by using the venturi effect, a principle that relies on the suction created when a liquid is forced through a narrow passage. When compressed air is pushed through a venturi tube, it creates a vacuum with a lower pressure than the atmosphere.
Vacuum grippers typically have two main operating components: suction cups and an air supply (which includes a pressure regulator with an air filtration system).
During operation, the suction cups begin to fill with air. This air is quickly sucked out, creating a negative air pressure in the cup that sticks the cup to the top of the box.
If there are contaminants in the air supply, it creates a weaker lift force by reducing the quality of the vacuum.
Air rating comparison of 2 reliable vacuum grippers
You can see the effect of air rating on the performance of vacuum grippers by looking at different models.
At Robotiq, we have three sets of vacuum grippers: EPick, AirPick, and PowerPick. The EPick includes its own mini vacuum pump inside the gripper itself – rather than using an external air supply – so it’s a bit different from the two.
Let’s compare AirPick and PowerPick to see the impact of the air quality rating:
Example 1: AirPick
AirPick is the ideal choice for a large number of palletizing tasks. It is capable of accurately lifting boxes and objects for many pick and place tasks. It has a compact design for cobots and, in the right environments, offers powerful vacuum flow.
The AirPick filtration system is rated to ISO 8573-1 Class 2-4-2. This means it provides a particle size separation of <0.1µm — which is equivalent to the grain size of corn starch.
The air filter is 5 microns, the mist separator is 0.3 micron, and the micro mist separator is 0.01 micron.
Example 2: PowerPick
PowerPick is a stronger vacuum gripper designed to increase reliability and force for lifting heavier objects. It also offers many more configuration options to suit more palletizing tasks.
The PowerPick filtration system is rated to ISO 8573-1 Class 7-4-4. This means it provides particle size separation of <40µm — equivalent to plant pollen grains. The air filter is also 5 microns.
This rating means that the PowerPick can handle air with particle sizes 400 times larger than the AirPick.
The improved vacuum system has a maximum load capacity of 11.5 kg (25 lbs) and provides a strong suction force to ensure that boxes are firmly held even in dustier environments.
What air quality does your palletizing task require?
How can you use this information to decide which palletizing system is right for you?
When looking at a vacuum gripper system, determine if the vacuum’s air quality rating matches the environment in which it will operate.
You can check the air quality of your environment with measuring equipment. Or you can run a test application with a vacuum gripper and determine that the performance meets your needs.
By understanding what type of air purity is required for your specific application, you can ensure that your palletizing task is running at peak performance.
What questions do you have about air quality ratings? Tell us in the comments below or join the discussion at LinkedIn, Twitter, Facebookor the DoF professional robotics community.