Pressure cascades with a cleanroom environment ensure that the flow of contamination is from clean to less clean. They are created by using airflow to create pressure differentials between any zones, which ensure that contamination flows from the cleanest zone down. Pressure management is critical to the effective performance of a cleanroom, keeping contamination from reaching the critical process environment.
In most cases where product protection is the end goal, a positive pressure cascade is applied from areas of critical importance to those of less critical importance. This positive pressure cascade ensures the flow of contamination is from clean to less clean once the pressure barrier is broken.
In cases where personnel protection is the end goal, a negative pressure cascade is maintained to ensure no contamination generated within the cleanroom is lost to the surrounding environment.
Read more about effective Cleanroom Design.