Test procedures for cleanroom products

Festo products for cleanrooms

FAQ and practical tips

In the past, very few industries ran production in cleanrooms. Today, however, cleanroom production has extended beyond electronics and photovoltaic manufacturing, medical technology and the semiconductor industry. Numerous other industry sectors also require components that are suitable for use in cleanrooms. The most important information can be found here.

Which products does Festo offer for use in the cleanroom?

You can use all cylinders, pneumatic valves, pneumatic grippers and actuators, all industrial robots, vacuum and compressed air systems, sensors, compressed air filters, compressed air regulators and pneumatic fittings from more than 80 product ranges from Festo in ISO class 7 cleanroom environments. Most are suitable for use in classes 6 and 5, and many can even be used in class 4 environments. We can provide matching special solutions as well.

All of our cleanroom products are assigned to cleanroom classes in accordance with ISO 14664. It’s best to work through the exact requirements with our specialists, because particle emission depends on the actual application. That’s the fastest way to find a feasible solution.

Valuable knowledge concerning cleanrooms

Are there only std. cleanroom products?

Not at all. We frequently come across applications where standard solutions are inadequate. For example, when the cleanliness requirements are so strict that only a special solution can be used. A simple modification is often enough. It’s best to contact our experts directly in cases like this.

Adapted special solutions

We have more than 20 years of cleanroom experience and our engineers continuously adapt series components in order to make them suitable for use in class 4 or stricter environments in accordance with ISO 14664.

We use a two-stage consultation concept: we listen to you and we approach the problem together. Highly sensitive zones can often be isolated, outside of which an ISO class 5 or 6 component is sufficient. Our engineers put everything together and submit a solution to you, along with a quote.

How are cleanroom products qualified?

Cleanroom: test for cleanroom products

Our products are tested and qualified by certified institutes in accordance with ISO-14644. You can read how the measurements are carried out in the test reports. Here you can find out, for instance, what the operating conditions during the test were and which test equipment was used.

How does the test work?

We clean the products with isopropanol and ultrapure air, carry out visual checks and then have them tested. Our test samples originate directly from Festo stock, so pre-selection as with other suppliers does not take place.

How are cleanroom products classified?

You can rest assured that cleanroom solutions from Festo are tested and classified in accordance with ISO 14644-1. ISO 14644 divides cleanrooms into nine classes according to the number and size of airborne particles.

Please note: our classification only provides an indication of how you can use our products in cleanrooms. In there is any doubt, we recommend performing the tests under real conditions.

How do I find fit cleanroom products?

To ensure that you quickly arrive at a functioning cleanroom application, we’ve compiled all tested components from more than 80 of Festo’s product ranges in our cleanroom catalog including all types of pneumatic actuators, pneumatic valves and valve manifolds, compressed air treatment and accessories, as well as electric actuator technology. This is entirely adequate as a rule.

Cleanroom catalogue plus X

If you’re interested in a product that we haven’t yet tested for cleanroom compatibility, we’d be happy to test it for you upon request. Our specialists are open to any other questions you might have as well, and are capable of retrofitting any desired components for ISO class 4.

What’s important for cleanroom products?

The most important criterion is that the utilized products comply with the specified cleanroom class during operation. That’s what counts. All of Festo’s cleanroom products are qualified in accordance with the VDI standard and classified per ISO 14644-14. However, the cleanroom class depends on where the product is used within the application. This sounds complicated but it’s good news.

Cleanroom class according to location of use

The fact that the cleanroom-compatibility of a piece of operating equipment always depends on where it’s used means that you don’t have to ensure stricter cleanliness everywhere. Cleanrooms are not homogenous zones. Maybe you need ISO-14644-14 class 5 directly above the workpiece, while class 7 is enough for the rest of the workflow. Festo’s standard products fulfill the requirements in most cases.
This applies to packaging as well. Technically correct cleanroom packaging is possible with Festo, but it’s seldom really necessary and you can often do away with this cost factor. Our experience shows that most components can be assembled and prepared for shipping in a normal environment. Final cleaning takes place directly on-site.
Don’t hesitate to get in touch with us if you have any doubts - for example, if the component needs to fulfill a safety function or if your ambient conditions deviate from the values listed in the data sheet.

Tips for cleanroom design

End-position switch

Double-acting cylinder with cables for proximity sensors

When wiring the end-position switches of double-acting cylinders, you need to make sure that the cables cannot be moved and that they do not rub against each other or any other equipment.

Cylinder cushioning

PPV and PPS cushioning in the compact air cylinder

Avoid impacts with high force in the end position. Cylinder cushioning is available for this purpose. Adjustable and self-adjusting PPV and PPS variants significantly reduce particle emission.

Single-acting cylinder

Double-acting cylinders versus single-acting cylinders

It is better not to use any single-acting cylinders because particles are discharged into the atmosphere via the exhaust. The piston rod seal is also considerably thicker in double-acting cylinders.

Bellows actuators

 Electromechanical bellows actuator

When correctly assembled, cylinder fittings are leak-free [1]. In contrast, the piston rod seal is a source of particle contamination due to its design. A bellows or vacuum exhaust can be helpful in this respect [2].

Mechanical abrasion

Double-acting cylinder

You should avoid the use of rod eyes [1], rod clevises, flexible couplings and clevis flanges [2] due to the abraded particles they cause. Make sure that tubing doesn’t move or rub against anything.

Vacuum applications

Rotary actuator

In the case of vacuum applications it is advisable to make use of our rotary actuators. This is due to the fact that rotary motion is easier to seal than linear motion, and is thus more suitable.

Compressed air treatment

Compressed air treatment with filters

Fine particulates and contamination should be filtered out in several stages during compressed air treatment. We recommend the use of a filter cascade with 40 µm [1], 5 µm [2] and 1 µm [3] stages in cleanrooms.

Exhaust air

Valve manifold

Pneumatic valve pilot air is rarely of significance [1]. In contrast, exhaust air must always be ducted and may not be discharged into the cleanroom via pneumatic mufflers [3]. Fittings are leak-free when correctly mounted [2].

Ball screw linear actuators

Ball screw linear actuators for cleanrooms

Ball screw linear actuators are better suited for cleanrooms than belt driven linear actuators: they result in less abrasion and discharge fewer particles. Furthermore, the spindles are greased and bind abraded particles as a result.

Energy chains

Energy chains for cleanrooms

Standard energy chains are critical in cleanrooms. Although special cleanroom energy chains are available, it is better to position the industrial robots underneath the workpiece already during the design engineering phase if at all possible.

And last but not least: when it comes to cleanroom compatibility at Festo, we always assume that closed, monitored compressed air systems are being used, without leakages and without particles being discharged into the environment by the exhaust air.

It's important to note that our components are not suitable for conveying (with tubing and fittings) or switching (with pneumatic valves) purified air! Our fine filters and micro-filters are the only exception to this rule, which generate highly purified air depending on the grade of filtration.

Who else needs to know this?

Cleanroom engineering is a collaborative art and as early as the planning phase, you should provide all involved parties with the necessary information. The quickest way is to use this link.