Basics of cleanroom technology

The step from a cleanroom to a qualified cleanroom in accordance with EN ISO 14644-1 can be very fluid, depending on the existing influences from the free environment at the installation site or adjacent production and storage areas, as well as the materials used and the clothing worn by cleanroom-trained employees. A cleanroom is a room in which the concentration of airborne particles is kept as low as possible. In order to create and maintain the desired cleanroom atmosphere, it is necessary to create a closed room in a pressure-tight design, the nature of which enables constant temperature, humidity and pressure conditions.

As people generally represent the greatest risk of contamination, the implementation of personnel airlocks is essential. It is important that the clothing of the people working in a cleanroom is selected in accordance with the cleanroom class and activity or product. The entry and exit of materials must also be controlled via suitable airlock and pass-through systems in order to ensure trouble-free, process-safe operation of the cleanroom (alternating door interlocks, etc.).

As a rule, several differently classified cleanrooms are combined, which are then often entered via multi-level (different) airlocks. Here too, the right concept for disposable and reusable clothing and consumables plays an important role. Room overpressure, air exchange rate and flow velocity (turbulent, laminar) depend on the cleanroom class to be realized. Rooms of different classifications therefore have different room pressures (pressure cascades), the proportional control of which (e.g. room 2 - room 1 - airlock) can be realized via differentiated control and regulation modules. Continuous testing and documentation of the desired or implemented cleanroom class can be carried out either using portable particle measuring devices or by installing a permanent monitoring system.