This means that the air pressure through the airlock into the cleanroom is gradually higher. This prevents particles or microorganisms from the ambient air from entering the cleanroom. However, this requires that only one door of the airlock can be opened at a time (mutual interlocking). As in the cleanroom itself, the air quality in the airlock is also monitored to prevent contamination of products, processes or the cleanroom itself. Purging with filtered air can either be active with its own filter systems or passive as an overflow from the higher-pressure room into the airlock. Unfortunately, the importance of airlocks is often underestimated, although they are the key to the safe operation of a cleanroom. This applies not only to the entry of personnel, but also to the materials used.
The products that are processed, measured, packaged or assembled in the cleanroom must enter the cleanroom “risk-free”. The airlocks used for this purpose are very diverse. From small material pass-throughs (also a type of material pass-trhough) for manual materials to large rooms for heavy machines, components or large handling volumes. The requirements are as individual as our customers’ products. Material pass-trhoughs, which are designed as independent walk-in rooms, usually have one thing in common: they have automatically opening doors or roller shutters to keep the process flow and handling simple.
What cleanliness class must a material pass-trhough have?
Once the airlock has been loaded, the rinsing process begins in order to raise the cleanliness level to that of the cleanroom. During this time, both doors are locked. It is therefore important that the material pass-trhough has the same cleanroom class as the cleanroom itself when rinsed.
Rinsing is carried out using filtered air. As a rule, material pass-trhoughs are not air-conditioned – only in special cases if this is necessary for risk-based process reasons.
How are materials airlocked into the cleanroom?
The outer packaging that generates contamination, such as wood, cardboard or paper, must be removed outside the airlock. The outer plastic packaging is then wiped down with a suitable cleaning agent. In this condition, the material is brought into the airlock from the outside and the airlock is exited again. The employee in cleanroom clothing enters the airlock from the clean side and removes the first plastic packaging and takes the material into the cleanroom. The last packaging should only be removed when the material is ready for use. Please note that all transport equipment entering the cleanroom must also be cleaned in the airlock.
Bringing large machines into the cleanroom?
What if you occasionally need to replace a machine in the cleanroom or an additional machine is to be integrated later?
Well, that depends on the frequency. In most cases, it does not make sense to equip the (material) airlock for this case, as this involves enormous costs and space requirements or a later future size cannot even be determined at the time of installation. In this case, we usually install some openable wall elements. The cleanroom must then be taken out of operation for the time of opening and installation and then re-qualified. However, this effort is usually disproportionate to the cost of a very large material pass-trhough that would have to be provided for this purpose.
Store material in the material pass-trhough?
It is also important to note at this point: The airlock is not a storage area!
A material pass-trhough is a very expensive storage area and is not intended as such. An airlock is basically just a transit area, the material can wait outside. ?
